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PG&E’s Emerging Technologies Program ET 14PGE1511
Biological Wastewater Treatment for Food
Processing Industry
ET Project Number: ET 14PGE1511
Project Manager: Sam Newman Pacific Gas and Electric Company Prepared By: Dr. Fayzul Pasha, P.E. Department of Civil and Geomatics Engineering California State University, Fresno 2320 E. San Ramon Ave, MS/EE94 Fresno, CA 93740
Dr. Dilruba Yeasmin Center for Irrigation Technology at Fresno State 5370 North Chestnut Avenue - M/S OF 18 Fresno, CA 93740
Dr. David Zoldoske Center for Irrigation Technology at Fresno State 5370 North Chestnut Avenue - M/S OF 18 Fresno, CA 93740
Issued: December 30, 2014
Copyright, 2014, Pacific Gas and Electric Company. All rights reserved.
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PG&E’s Emerging Technologies Program ET 14PGE1511
ACKNOWLEDGEMENTS
Pacific Gas and Electric Company’s Emerging Technologies Program is responsible for this project. It was developed as part of Pacific Gas and Electric Company’s Emerging Technology – Technology Evaluation program under internal project number ET14PGE1511. The Center for Irrigation Technology on the campus of California State University, Fresno conducted this technology evaluation for Pacific Gas and Electric Company with overall guidance and management from Sam Newman. For more information on this project, contact [email protected].
LEGAL NOTICE
This report was prepared for Pacific Gas and Electric Company for use by its employees and agents. Neither Pacific Gas and Electric Company nor any of its employees and agents:
(1) makes any written or oral warranty, expressed or implied, including, but not limited to those concerning merchantability or fitness for a particular purpose;
(2) assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, process, method, or policy contained herein; or
(3) represents that its use would not infringe any privately owned rights, including, but not limited to, patents, trademarks, or copyrights.
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PG&E’s Emerging Technologies Program ET 14PGE1511
ABBREVIATIONS AND ACRONYMS
B Boron
BIDA®
Dynamic Aerobic Biofilter
BOD Biochemical Oxygen Demand
Ca Calcium
CIT Center for Irrigation Technology at California State University, Fresno
COD Chemical Oxygen Demand
CSUF California State University, Fresno
CV Coefficient of Variation
EC Electrical Conductivity
GHG Green House Gas
gph Gallons per hour
gpd Gallons per day
K Potassium
kWh Kilowatt-hour
Mg Magnesium
MGD Million gallons per day
Na Sodium
NH4 Ammonium Nitrogen
NO3-N Nitrate Nitrogen
P Phosphorus
PG&E Pacific Gas and Electric Company
SALT-SOL Soluble Salts
TDS Total Dissolved Solids
TKN Total Kjeldahl Nitrogen
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PG&E’s Emerging Technologies Program ET 14PGE1511
TSS Total Suspended Solids
UAL University Agricultural Lab
U.S. DOE United States Department of Energy
U.S. EPA United States Environmental Protection Agency
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURES
Figure 1. Schematic of BIDA system (Source: BioFiltro 2014) ........... 2
Figure 2. Non-Exceedance probability curve for energy
requirement for the treatment of wastewater (by
Pump2) at CSUF dairy wastewater treatment plant ........... 5
Figure 3. CSUF wastewater treatment plant site ............................ 9
Figure 4. Process diagram of CSUF wastewater treatment plant ....... 9
Figure 5. System under construction: CSUF wastewater
treatment plant .......................................................... 10
Figure 6. Wastewater source: CSUF wastewater treatment plant ... 10
Figure 7. Top layer of the treatment plant: CSUF wastewater
treatment plant .......................................................... 11
Figure 8. Sprinker at the treatment plant: CSUF wastewater
treatment plant .......................................................... 11
Figure 9. A large tomato processor wastewater treatment plant
site ........................................................................... 12
Figure 10. Wastewater Treatment Plant: A large tomato processor
site ........................................................................... 12
Figure 11. Wastewater source: A large tomato processor site ......... 13
Figure 12. Top layer of the sastewater plant: A large tomato
processor site ............................................................ 13
Figure 13. Concentration with confidence limits before and after
the treatment at CSUF: Boron (B) ............................... 26
Figure 14. Concentration with confidence limits before and after
the treatment at CSUF: BOD5 ..................................... 26
Figure 15. Concentration with confidence limits before and after
the treatment at CSUF: Calcium (Ca) ........................... 27
Figure 16. Concentration with confidence limits before and after
the treatment at CSUF: COD ...................................... 27
Figure 17. Concentration with confidence limits before and after
the treatment at CSUF: EC ......................................... 28
Figure 18. Concentration with confidence limits before and after
the treatment at CSUF: Potassium (K) ......................... 28
Figure 19. Concentration with confidence limits before and after
the treatment at CSUF: Magnesium (Mg) ..................... 29
Figure 20. Concentration with confidence limits before and after
the treatment at CSUF: Sodium (Na) ........................... 29
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PG&E’s Emerging Technologies Program ET 14PGE1511
Figure 21. Concentration with confidence limits before and after the
treatment at CSUF: Ammonium Nitrogen (NH4) ............ 30
Figure 22. Concentration with confidence limits before and after
the treatment at CSUF: Nitrate Nitrogen (NO3-N) ......... 30
Figure 23. Concentration with confidence limits before and after the
treatment at CSUF: Phosphorus (P) ............................. 31
Figure 24. Concentration with confidence limits before and after the
treatment at CSUF: pH .............................................. 31
Figure 25. Concentration with confidence limits before and after
the treatment at CSUF: Soluble Salts (Salt-Sol) ............ 32
Figure 26. Concentration with confidence limits before and after
the treatment at CSUF: Total Dissolved Solids (TDS) ..... 32
Figure 27. Concentration with confidence limits before and after
the treatment at CSUF: Total Kjeldahl Nitrogen (TKN)... 33
Figure 28. Removal efficiency at CSUF: Boron (B) ........................ 35
Figure 29. Removal efficiency at CSUF: BOD5 .............................. 35
Figure 30. Removal efficiency at CSUF: Calcium (Ca) .................... 36
Figure 31. Removal efficiency at CSUF: COD ................................ 36
Figure 32. Removal efficiency at CSUF: EC .................................. 37
Figure 33. Removal efficiency at CSUF: Potassium (K) .................. 37
Figure 34. Removal efficiency at CSUF: Magnesium (Mg) ............... 38
Figure 35. Removal efficiency at CSUF: Sodium (Na) .................... 38
Figure 36. Removal efficiency at CSUF: Ammonium Nitrogen
(NH4) ....................................................................... 39
Figure 37. Removal efficiency at CSUF: Nitrate Nitrogen (NO3-N) ... 39
Figure 38. Removal efficiency at CSUF: Phosphorus (P) ................. 40
Figure 39. Removal efficiency at CSUF: pH .................................. 40
Figure 40. Removal efficiency at CSUF: Soluble Salts (Salt-Sol) ..... 41
Figure 41. Removal efficiency at CSUF: Total Dissolved Solids
(TDS) ....................................................................... 41
Figure 42. Removal efficiency at CSUF: Total Kjeldahl Nitrogen
(TKN) ....................................................................... 42
Figure 43. Energy requirement by Pump1 to pre-treat wastewater
at CSUF .................................................................... 43
Figure 44. Energy requirement by Pump2 to treat wastewater at
CSUF ........................................................................ 44
Figure 45. Energy requirement by Pump3 to distribute treated
water at CSUF ........................................................... 44
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PG&E’s Emerging Technologies Program ET 14PGE1511
Figure 46. Time series plot of energy requirement by each pump
and flow at CSUF dairy wastewater treatment plant
after discarding some data due to mechanical failure ...... 46
Figure 47. Sorted flow and energy at CSUF dairy wastewater
treatment plant after discarding some data due to
mechanical failure ...................................................... 47
Figure 48. Non-Exceedance probability curve for energy
requirement for the pre-treatment of wastewater (by
Pump1) at CSUF dairy wastewater treatment plant ......... 49
Figure 49. Non-Exceedance probability curve for energy
requirement for the treatment of wastewater (by
Pump2) at CSUF dairy wastewater treatment plant ......... 49
Figure 50. Non-Exceedance probability curve for energy
requirement for the distribution of treated water (by
Pump3) at CSUF dairy wastewater treatment plant ......... 50
Figure 51. Concentration with confidence limits before and after
the treatment at A large tomato processor: BOD5 ......... 52
Figure 52. Concentration with confidence limits before and after
the treatment at A large tomato processor: TSS ........... 52
Figure 53. Removal efficiency at A large tomato processor: BOD5 .. 53
Figure 54. Removal efficiency at A large tomato processor: TSS ..... 54
Figure 55. Energy requirement by Pump2 to treat wastewater at A
large tomato processor ............................................... 55
Figure 56. Energy requirement by Pump3 to distribute treated
water at A large tomato processor ................................ 55
Figure 57. Time series plot of energy requirement by each pump
and flow at A large tomato processor wastewater
treatment plant after discarding some data due to
mechanical failure ...................................................... 56
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PG&E’s Emerging Technologies Program ET 14PGE1511
TABLES
Table 1. Removal efficiency of water quality parameters at CSUF
dairy wastewater treatment plant ................................... 3
Table 2. Energy requirement to treat 1000 gallons of water at
CSUF dairy wastewater treatment plant .......................... 4
Table 3. Removal efficiency of water quality parameters at a
large tomato processor wastewater treatment plant ......... 5
Table 4. Energy requirement to treat 1000 gallons of water at a
large tomato processor wastewater treatment plant ......... 5
Table 5. Basic statistical parameters in CSUF water quality data
analysis .................................................................... 24
Table 6. Removal efficiency of water quality parameters at CSUF
dairy wastewater treatment plant ................................. 34
Table 7. Energy supply statistics for CSUF dairy wastewater
treatment plant .......................................................... 43
Table 8. Energy–water statistics at CSUF dairy wastewater
treatment plant after discarding some data due to
mechanical failure ...................................................... 45
Table 9. Energy requirement to treat 1000 gallons of water at
CSUF dairy wastewater treatment plant ........................ 48
Table 10. Basic statistical parameters in A large tomato processor
water quality data analysis .......................................... 51
Table 11. Removal efficiency of water quality parameters at A
large tomato processor wastewater treatment plant ....... 53
Table 12. Energy supply statistics for A large tomato processor
wastewater treatment plant ......................................... 54
Table 13. Energy–water statistics at A large tomato processor
wastewater treatment plant after discarding some data
due to mechanical failure ............................................ 56
Table 14. Energy requirement to treat 1000 gallons of water at A
large tomato processor wastewater treatment plant ....... 56
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PG&E’s Emerging Technologies Program ET 14PGE1511
EQUATIONS
Equation 1. Mean of data ............................................................. 21
Equation 2. Standard deviation of data .......................................... 21
Equation 3. Coefficient of variation (CV) of data .............................. 22
Equation 4. Confidence interval of data .......................................... 22
Equation 5. Removal efficiency ..................................................... 23
Equation 6. Energy requirement for 1000 gallons of water ................ 23
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PG&E’s Emerging Technologies Program ET 14PGE1511
CONTENTS
ABBREVIATIONS AND ACRONYMS __________________________________________________________ II
FIGURES _____________________________________________________________________________ IV
TABLES _______________________________________________________________________________ I
EQUATIONS ___________________________________________________________________________ I
CONTENTS ___________________________________________________________________________ 1
EXECUTIVE SUMMARY _____________________________________________________ 2
INTRODUCTION __________________________________________________________ 7
BACKGROUND __________________________________________________________ 8
Biofiltro .................................................................................. 8
Description of Sites ................................................................. 8
EMERGING TECHNOLOGY/PRODUCT ________________________________________ 14
Description of the Product ...................................................... 14
Advantages .......................................................................... 15
Risk and Chanlleges .............................................................. 15
ASSESSMENT OBJECTIVES _________________________________________________ 16
Objectives ............................................................................ 16
Technology Assessment ......................................................... 17
TECHNOLOGY EVALUATION _______________________________________________ 19
TECHNICAL APPROACH/TEST METHODOLOGY _________________________________ 20
Instrumentation Plan ............................................................. 20
DATA ANALYSIS - METHODS .................................................. 21
Water Quality Data Analysis Method ................................... 21 Energy Data Analysis Method ............................................. 23
RESULTS_______________________________________________________________ 24
DATA ANALYSIS - Results ...................................................... 24
Data Analysis – Result (CSUF Dairy) ................................... 24 Data Analysis – Result (A large tomato processor)................ 51
EVALUATIONS __________________________________________________________ 57
RECOMMENDATIONS ____________________________________________________ 58
APPENDICES ___________________________________________________________ 58
REFERENCES ___________________________________________________________ 59
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PG&E’s Emerging Technologies Program ET 14PGE1511
EXECUTIVE SUMMARY
PROJECT GOAL
The goal of this project is to test the performance of an earthworm-based wastewater
treatment system known as Dynamic Aerobic Biofilter (BIDA®) or BioFiltro for its ability to
reduce organic contaminants in agricultural waste and to measure the energy use to
achieve these reductions.
PROJECT DESCRIPTION
The BIDA® system consists of a few layers (listed from bottom to top) including an air
pocket, rocks/gravel, wood shavings/sawdust, with worms/castings within the upper layer of
the wood shavings (Figure 1). Sprinklers, which use most of the energy required in the
treatment process, are used to apply wastewater to the surface of the treatment system.
Once the wastewater is sprinkled on the surface of the system, wastewater infiltrates to the
bottom layer by gravity. During the infiltration process, the wastewater is filtered through
different layers as the earthworm-microbe interaction takes place. The entire process takes
around four hours.
FIGURE 1. SCHEMATIC OF BIDA SYSTEM (SOURCE: BIOFILTRO 2014)
This study evaluated the application of the BIDA® system to organic effluents from the
Fresno State dairy farm (Fresno, California) and a large tomato processor (Firebaugh,
California).
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PG&E’s Emerging Technologies Program ET 14PGE1511
PROJECT FINDINGS/RESULTS
Table 1 and Table 3 summarize the water quality analysis results for CSUF and a large tomato processor. Specifically, the tables present the removal efficiency in percent. The performance (in terms of
removal efficiency) of BioFiltro (or BIDA® technology) for treating wastewater at the CSUF dairy farm is found to be consistent and high (removal efficiency is above 90%) for the nitrogen-based water quality parameters such as NH4, NO3-N, and TKN. Removal efficiencies for other important water quality indicators such as BOD5 and COD are promising. The performance (in terms of removal efficiency) of BioFiltro at a large tomato processor site was found consistently high as well. Two water quality parameters, BOD5 and TSS were considered for this site (tomato processor) and the removal efficiency for each these parameters is 90% or above.
The energy requirements to treat a unit amount of water (kWh/1000 gallons) are summarized in Table 2, Table 4, and Figure 2. The calculated results have been compared to the baseline study (PG&E 2006) information. For the CSUF site, about 25 percent of the data (i.e., 25 percent of the total days) shows extraordinary performance compared to the baseline study (PG&E 2006) and the 50 percent energy requirement data are lower than the baseline requirement (2.5 kWh/1000 gallons for overall treatment) showing better performance than the baseline information. However, about 50 percent of the data did not perform as the plant was designed. Refer to Table 5 and Figure 37 in the Results section for detailed analysis. Mechanical failure is suspected to be one of the main reasons why about 50 percent of the data at both sites (CSUF and the tomato processor) did not outperform the baseline study. Mechanical failure included issues such as pipe and system leakage, plugged filters and pipe and pump clogging.
TABLE 1. REMOVAL EFFICIENCY OF WATER QUALITY PARAMETERS AT CSUF DAIRY WASTEWATER TREATMENT PLANT
Water Quality Parameter
Removal Efficiency
Mean Std. Dev CV
B (ppm) 7.4% 3.8% 0.52
BOD5 (mg/L) 23.5% 14.8% 0.63
Ca (ppm) 16.8% 9.5% 0.56
COD (mg/L) 46.9% 15.2% 0.32
EC (mmhos/cm) 12.1% 11.2% 0.92
K (ppm) -2.6% 4.4% -1.69
Mg (ppm) 2.7% 7.6% 2.84
Na (ppm) -2.9% 4.4% -1.52
NH4 (mg/L) 98.4% 3.8% 0.04
NO3-N 96.2% 4.3% 0.05
P (ppm) 8.9% 23.9% 2.69
pH 2.9% 1.9% 0.67
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PG&E’s Emerging Technologies Program ET 14PGE1511
Water Quality Parameter
Removal Efficiency
Mean Std. Dev CV
Salt-Sol (ppm) 12.1% 11.2% 0.92
TDS (mg/L) 10.1% 11.6% 1.15
TKN (ppm) 90.6% 18.0% 0.20
TABLE 2. ENERGY REQUIREMENT TO TREAT 1000 GALLONS OF WATER AT CSUF DAIRY WASTEWATER TREATMENT PLANT
Statistics Energy requirement (kWh) to treat 1000 gallons of waste water
Pre-treatment (Pump1)
Treatment (Pump2)
Distribution (Pump3)
Days in operation 104 104 104
Average 3.7 3.2 1.7
Max 12.2 14.4 8.4
Standard deviation 2.5 2.9 2.0
25 percentile 2.0 1.0 0.3
50 percentile (median) 3.1 1.8 0.4
75 percentile 4.8 5.0 2.8
90 percentile 7.1 6.7 4.1
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 2. NON-EXCEEDANCE PROBABILITY CURVE FOR ENERGY REQUIREMENT FOR THE TREATMENT OF WASTEWATER (BY
PUMP2) AT CSUF DAIRY WASTEWATER TREATMENT PLANT
TABLE 3. REMOVAL EFFICIENCY OF WATER QUALITY PARAMETERS AT A LARGE TOMATO PROCESSOR WASTEWATER
TREATMENT PLANT
Water Quality Parameter
Removal Efficiency Confidence Interval
Mean Std. Dev CV 99% LB 99% UB
BOD5 (mg/L) 96.4% 6.9% 0.07 83.9% 100.0%
TSS (mg/L) 89.7% 9.5% 0.11 69.3% 100.0%
TABLE 4. ENERGY REQUIREMENT TO TREAT 1000 GALLONS OF WATER AT A LARGE TOMATO PROCESSOR WASTEWATER
TREATMENT PLANT
Statistics
Energy requirement (kWh) to treat per 1000 gallons
Pre-treatment (Pump1)
Treatment (Pump2)
Distribution (Pump3)
Days in operation Not used
21 21
Average 6.7 8.0
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0
No
n-E
xce
ed
an
ce
Pro
bab
ilit
y (
%)
Energy Requirement (kWh/1000 gallons of wastewater)
Bas
elin
e Se
con
dar
y
Bas
elin
e O
vera
ll
Bas
elin
e Te
rtia
ry
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PG&E’s Emerging Technologies Program ET 14PGE1511
Statistics
Energy requirement (kWh) to treat per 1000 gallons
Pre-treatment (Pump1)
Treatment (Pump2)
Distribution (Pump3)
Max 11.3 10.3
Min 1.4 0.2
Standard deviation 2.6 2.4
25 percentile 5.6 7.7
50 percentile (median) 7.0 8.8
75 percentile 8.5 9.5
90 percentile 10.4 9.7
PROJECT RECOMMENDATIONS
Although the performance of the BioFiltro was found extraordinary for some water quality parameters (such as nitrogen-based parameters at the CSUF site and all the parameters at the large tomato processor site), the performance for some parameters was not found to be high or satisfactory. Please refer to the Analysis section under Results for details. Measurement errors and probable contaminations are suspected to be the reasons for this poor performance. Therefore, extra caution should be taken in future deployments, and the testing protocol for sampling, lab analysis, and data entry must be carefully maintained throughout the process.
In terms of energy requirement, while about 50% of the data (i.e., days) shows better performance indicating energy efficiency savings, the other 50% shows poor performance. Both the CSUF and large tomato processor sites are pilot studies. As such, some system parameters, such as the system’s required head and design flow need to be fine-tuned before starting the test. Lack of a fine-tuned system caused significant energy waste. Calibrating the system after remedying observed mechanical failures (such as pipe and system leakage, pipe and pump clogging, plugged filter etc.) was a challenge, particularly re-calibrating the system after replacing a broken pump.
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PG&E’s Emerging Technologies Program ET 14PGE1511
INTRODUCTION Like other industrial processes, energy consumption is not the main focus in wastewater
treatment processes, which must meet rigorous effectiveness and reliability requirements.
The treatment process itself - the use of chemicals in the process and the byproducts
resulting from the treatment process - are also of interest in the research community. The
discussion is centered on how to reduce the energy consumption in the wastewater
treatment process and how the treatment should be done.
As much as 10 percent of the total local government’s annual budget can be used for
energy use of which a significant amount is used for treating wastewater (U.S. DOE 2005).
This involves energy consumption for wastewater treatment and transport and energy
consumption for equipment and plant operation (U.S. EPA 2013). This energy consumption
makes wastewater treatment among the largest contributors to the community’s total
greenhouse gas (GHG) emissions (U.S. EPA 2013). One study reported that about 35
percent of the U.S. municipal energy budget is used for water and wastewater utilities
(NYSERDA, 2008). PG&E (Pacific Gas and Electric Company) and other utility companies are
exploring ways to reduce the total energy consumption in wastewater treatment process by
making the plant more efficient (PG&E 2009).
Reducing energy consumption in the wastewater treatment process, minimizing the adverse
effects of chemicals and byproducts on the natural ecology, increasing the treatment
efficiency, and identifying how the treatment should be conducted are the main research
topics in wastewater treatment technology. Researchers are not only considering ways to
increase the efficiency of the conventional wastewater treatment process but they are also
considering other types of wastewater treatment processes in which natural processes such
as earthworms can be used. Earthworms, which were called the friends of farmers by Sir
Charles Darwin, can tolerate toxicity and can routinely devour the microorganisms which
help the wastewater to be cleaned (Sinha et al 2010). Researchers are now testing the
potential use of earthworms for treating urban and agricultural wastewaters (Wang et al
2011, Tomar and Suthar 2011, Sinha et al 2007). They are conducting experiments to
understand the mechanisms of microorganism-earthworm interaction in depth (Liu et al
2012, Oh et al 2010, Zhao et al 2010). The performance and efficiency of earthworm-based
wastewater treatment is still under investigation (Xing et al 2011, Xing et al 2010, Yang et
al 2009, Sinha et al 2007). This research study can be added to this list.
The purpose of this study is to test the performance of an earthworm-based wastewater
treatment system known as Dynamic Aerobic Biofilter (BIDA®) or BioFiltro in reducing
organic contaminants in agricultural waste and to measure the amount of energy used to
achieve these reductions. The BIDA system utilizes red worms and microbes within a
biological filter to scrub wastewater organic contaminants.
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PG&E’s Emerging Technologies Program ET 14PGE1511
BACKGROUND BioFiltro is a Clean Tech Company based in Chile and the United States that provides a
solution for treating wastewater from communities and from the food processing and animal
husbandry industries (BioFiltro 2014). BioFiltro USA was launched by its mother company
BioFiltro Chile in Fresno, California in August of 2013, establishing its headquarters at the
Water, Energy and Technology (WET) Center located at California State University, Fresno
(CSUF). BioFiltro is a wastewater treatment company that builds, maintains and operates a
biological treatment technology known as the BIDA® System. This patented technology has
been used in five countries and 100 facilities since its inception in Santiago Chile in 1994.
The following section describes the process used in the BioFiltro.
BIOFILTRO The layers of the BIDA system consists of (listed from bottom to top) an air pocket,
rocks/gravel, wood shavings/sawdust, with worms/castings within the upper layer of
the wood shavings (see Figure 1) Specialized sprinklers are used to apply
wastewater to the surface of the treatment system. From the applied wastewater
larger solids/contaminants are trapped within the wood shavings where it is then
becomes accessible to the earthworms. The earthworms eat this material and
convert it to their manure/humus/castings which are teaming with billions of
microbes that eat away at the dissolved organic contaminants. The rest of the layer
is inhabited by microbial flora which assists in the treatment process before outflow.
The entire process from wastewater to treated water takes four hours, as gravity
pulls the wastewater through the different filter layers. Aeration and aerobic
conditions are maintained by perforated pipes throughout the filter media, and by
the burrowing of the earthworms in the upper layer (BioFiltro 2014).
DESCRIPTION OF SITES The California State University, Fresno wastewater treatment plant is located on the
1,000-acre University Agricultural Laboratory (UAL). Specifically the plant is near the
northwest corner of the intersection of Barstow and Chestnut Avenue. This plant was
aimed to treat the effluent from UAL dairy farm. This dairy farm was established in
1954. It maintains two different breeds of dairy cattle, Holstein and Jersey. There
are approximately 275 to 300 cows. About 150 of these cows are used in the milk
string, and each cow in the milk string is milked twice a day. The following figure
(Figure 3) shows the location and plant’s components. Figure 4 shows the process
diagram with the location of data loggers. Briefly the process is as follows.
The water is taken from the secondary accumulation lagoon situated in the northeast
at the dairy farm. The water from this lagoon is pumped to the accumulation tank
passing through the Parabolic Screen. Then the water is pumped to the pumping
tank passing through another final screen. The wastewater from the pumping tank
is moved through sprinklers and spread evenly across the sawdust/gravel bed. The
water goes into the sawdust/gravel bed and gravity takes four hours for final
treatment. The clean (treated water) is then returned to the lagoon.
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PG&E’s Emerging Technologies Program ET 14PGE1511
The second site is a large tomato processor located in Firebaugh, California that
produces diced tomatoes, whole peeled tomatoes, catsup, sauces, puree and paste.
The tomato processor is considering BioFiltro as an alternative wastewater treatment
to reduce the capital costs. Figure 9 shows the overall process diagram and the site
of the plan. A few pictures of the test set-up and equipment schematics are included
from Figure 3 to Figure 12.
FIGURE 3. CSUF WASTEWATER TREATMENT PLANT SITE
FIGURE 4. PROCESS DIAGRAM OF CSUF WASTEWATER TREATMENT PLANT
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 5. SYSTEM UNDER CONSTRUCTION: CSUF WASTEWATER TREATMENT PLANT
FIGURE 6. WASTEWATER SOURCE: CSUF WASTEWATER TREATMENT PLANT
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 7. TOP LAYER OF THE TREATMENT PLANT: CSUF WASTEWATER TREATMENT PLANT
FIGURE 8. SPRINKLER AT THE TREATMENT PLANT: CSUF WASTEWATER TREATMENT PLANT
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 9. A LARGE TOMATO PROCESSOR WASTEWATER TREATMENT PLANT SITE
FIGURE 10. WASTEWATER TREATMENT PLANT: A LARGE TOMATO PROCESSOR SITE
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 11. WASTEWATER SOURCE: A LARGE TOMATO PROCESSOR SITE
FIGURE 12. TOP LAYER OF THE WASTEWATER PLANT: A LARGE TOMATO PROCESSOR SITE
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PG&E’s Emerging Technologies Program ET 14PGE1511
EMERGING TECHNOLOGY/PRODUCT
DESCRIPTION OF THE PRODUCT The BIDA® System comes from biotechnology, which is technology based on biology.
It uses different natural, microbiological layers which are designed according to the
characteristics of the wastewater to be treated. Every source of wastewater has its
own specialized microbiological flora. This model filters the domestic and industrial
wastewater in order to return it to the environment as clean water where it can be
reused for irrigation, which is where 70 percent of the world's water resources are
consumed (Clarke Prize 2003, Crites and Tchobanoglous 1998, BioFiltro 2014).
This technology does not use chemicals and thus is expected to save energy when
compared to the conventional systems. It can be applied in an efficient and
sustainable manner in small and large volumes. This can make BioFiltro an
alternative for industry as well as rural and isolated communities. The BIDA® System
generates two byproducts which can be used in the agricultural and feeding
industries. Firstly an organic fertilizer and secondly worm protein which is a source of
nutrients with high protein and amino acid content (Clarke Prize 2003, Crites and
Tchobanoglous 1998, BioFiltro 2014).
The layers of the patented BIDA® system listed from bottom to top consist of an air
pocket, rocks/gravel, wood shavings/sawdust, and worms/castings within the upper
layer of the wood shavings. Specialized sprinklers are used to apply wastewater to
the surface of the treatment system. When the wastewater is applied, larger
solids/contaminants are trapped within the wood shavings where it is then accessible
to the earthworms. The earthworms then eat this material and convert it to their
manure/humus/castings which are teaming with billions of microbes which eat away
at the dissolved organic contaminants. The rest of the layer is inhabited by microbial
flora which assists in the treatment process before outflow. The entire process from
wastewater to treated water takes around four hours, as gravity pulls the
wastewater through the different filter layers. Aeration and aerobic conditions are
maintained by perforated pipes throughout the filter media, and by the burrowing of
the earthworms in the upper layer (Clarke Prize 2003, Crites and Tchobanoglous
1998, BioFiltro 2014).
It is expected that this product can be an alternative to the old technologies based
on mechanical aeration (activated sludge, aeration ponds, etc.)
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PG&E’s Emerging Technologies Program ET 14PGE1511
ADVANTAGES All the following advantages offer environmental benefits from biological
wastewater treatment approaches.
- Affordable CAPEX (capital expenditure) and OPEX (operational
expenditure) (today a lot dairies, food processing companies and
small/medium towns cannot install conventional technologies because it is
not viable from an economic perspective).
- Less energy consumption and thus improved sustainability.
- No sludge generation (traditional systems generate sludge which is a very
contaminated product that needs to be shipped and taken to special
landfills to dispose of).
- No chemical products are required in the process in comparison with
conventional technologies.
- The byproducts are organic fertilizer and worm protein, so the system can
generate valuable byproducts that have a market value and not pollutants
as traditional systems.
- Simple to operate compared to conventional system. Conventional
technologies are complicated and require qualified people to operate that
in rural areas especially may be difficult to find. On the other hand, the
BIDA® system does not required qualified people to operate.
RISK AND CHALLENGES There are some technologies for decentralized wastewater management such
as activated sludge, anaerobic digesters and aeration ponds. But the main
problems of those are:
- High CAPEX (capital expenditure) and OPEX (operational expenditure)
requirements.
- High energy consumption.
- Sludge generation (environmental pollutant).
- Chemical inputs
In general, all of these technologies do not provide sustainable solutions.
The BIDA® system is not a fuel switching technology. It is a technology that is
expected to consume about 85 percent less energy than conventional
technology to get the same quality effluent.
Upon successful completion of the pilot and full-scale tests, the system is
expected to have wider adoption with no risk and challenges.
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PG&E’s Emerging Technologies Program ET 14PGE1511
ASSESSMENT OBJECTIVES
OBJECTIVES There were four (4) major objectives identified in the Scope of Work for the project:
1. Installation of project monitoring equipment:
o Install the water- and energy-monitoring equipment at Fresno State dairy
by May 1st, 2014.
o Install the water- and energy-monitoring equipment at a large tomato
processor plant by June 1st, 2014.
2. Monitoring and data collection:
Collect data from project sites via installed power and water meters, as well
as submeters to be installed where appropriate. Conduct sampling on a
weekly basis (total of four events) with both the source water and treated
water being collected during each visit.
Collect grab samples of source and treated water weekly during the
evaluation period and analyze for key constituents listed below. The project
includes establishing an approved QC/QA procedure to assure samples are
collected, transported and analyzed appropriately.
o BOD (bio-chemical oxygen demand)
o COD (chemical oxygen demand)
o TSS (total suspended solids)
o TDS (total dissolved solids)
o Nitrogen/nitrates
o Salts/salinity
o Phosphorous
Energy and water use data will be collected using data monitors and water
samples will be collected weekly and analyzed by commercial laboratory.
3. Monitoring and data collection:
Analyze data weekly to determine data quality. The water quality, water flow,
and energy usage data will be used to support the following analysis
objectives:
(1) Energy analysis
o Energy usage for BioFiltro process
o Energy usage per gallon of water treated for BioFiltro process
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PG&E’s Emerging Technologies Program ET 14PGE1511
o Energy savings compared to conventional wastewater treatment
process (for both Fresno State dairy case and a large tomato processor
case). Baseline equipment standards and energy usage expectations
shall be identified in collaboration with PG&E’s wastewater treatment
baseline document and input from PG&E engineering team.
(2) Water quality verification
o Effectiveness of BioFiltro process at meeting water quality standards
o Volume of water recovered
(3) Business case assessment
o Land usage requirements for dairy and a large tomato processor
installation
o Clean water production per unit area
o System cost (up front)
o System cost (ongoing)
o System revenue streams
o Risk assessment: As bio-systems can be prone to fail when operating
conditions change (e.g., pH, temperature, organic levels), any
variations in water quality should be identified and ongoing
maintenance costs should be documented.
o Scalability assessment: To the extent possible, Fresno State will
provide recommendations for target customer types (industries,
locations, regulatory areas) and utility program needs.
4. Reporting:
o Interim Reports. CIT will provide the following interim reports to the
project team: Report of Site Selection and Operation Success/failure.
o Interim Report: Summarize project data to-date and analysis of
wastewater treatment effectiveness, energy and water usage comparison
to baseline treatment system, and business case evaluation. Report will
also discuss recommendations for future utility energy efficiency program
incorporation.
o Final Report. Summarize key findings and data using template provided by
PG&E Emerging Technologies Program, including the scope described
above.
TECHNOLOGY ASSESSMENT This would be a technology assessment as it is investigating the performance of the
new wastewater treatment technology that will provide opportunities to PG&E
customers for energy use improvement.
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PG&E’s Emerging Technologies Program ET 14PGE1511
Data is analyzed to determine the energy requirement to treat per 1000 gallons of
wastewater. It provides a basis to compare with the energy requirement found in the
wastewater treatment baseline document.
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PG&E’s Emerging Technologies Program ET 14PGE1511
TECHNOLOGY EVALUATION Technology will be implemented on the customer’s site, where the wastewater
is generated. Wastewater will be treated on-site and reused for irrigation or
other proposes in the same area. Otherwise, all the wastewater from a facility
needed to be tracked down and taken to a centralized wastewater treatment
plant which is very expensive primarily due to the trucking cost. The process
takes time and can generate additional pollutants and does not promote
reusing the water on-site what is very important to achieve sustainability in
the future.
Decentralized wastewater treatment management is the only way to achieve
sustainability in the future. Decentralized wastewater treatment i) allows the
reuse of wastewater that can help alleviate water shortages due to drought,
ii) reduces CAPEX intensive model like the centralized wastewater treatment
model where one needs to invest huge amounts of money to install sewage
lines, iii) reduces a significant amount of energy in comparison with the
centralized wastewater model where wastewater must be pumped from miles
away until it arrives at the centralized wastewater treatment plant, iv) there
is a big reduction in the carbon footprint emission of the decentralized
wastewater management model in comparison to the centralized wastewater
treatment model or with the trucking model. There may not be any risk to the
customers. Many industries today have implemented decentralized on-site
wastewater treatment (Clarke Prize 2003, Crites and Tchobanoglous 1998).
For each case, BioFiltro needs to know i) surface area available to install a
treatment plant, ii) volume of wastewater that will be treated, iii)
concentration of the contamination parameters of the wastewater that will be
treated, and iv) quality of the treated water that needs to be achieved.
The installation of the system is simple. BioFiltro needs contractors with
minimal experience in concrete, electrical, and piping work. BioFiltro does not
need PG&E to do this work. BioFiltro always uses small and local construction
companies to do the main job related to civil works. The media filters of
BIDA® system are implemented on-site through BioFiltro technical staff.
BioFiltro also does the start-up of the system and the O&M of the system.
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PG&E’s Emerging Technologies Program ET 14PGE1511
TECHNICAL APPROACH/TEST METHODOLOGY
INSTRUMENTATION PLAN The following instrumentations have been used in the data collection.
Variables that were used for measurement include:
- BattV for Battery Voltage in Volts
- Pulse for flow of water in gallons
- Pulse_T for total flow in gallons
- DiffVolt(3) for three current transformers
Sensors and devices used for measurement:
- CR1000 Datalogger for BattV and Pulse_T
- Seametrics M120 flow meter for Pulse
- YHDC-SCT-013 Current transformer for DiffVolt(3)
Location of each device and sensors are as follows:
- CR1000 Datalogger -> On an antenna pole next to Tank2 (refer to the
Results section for layout of the system)
- Seametrics M120 flow meter -> On pipe out from Pump3 (refer to
Results section for layout of the system)
- YHDC-SCT-013 Current transformer -> On power supply line of
Pump1, Pump2 and Pump3 (refer to Results section for layout of the
system)
Expected range of measurement for variables includes:
- BattV = 0 ~ 7,999 V
- Pulse = 0 ~ 7,999 Gallons
- Pulse_T = 0 ~7,999 Gallons
- DiffVolt(3) = -non-zero ~0~ non-zero/Integers
Data was scanned every second and data was stored every 30 seconds for
DiffVolt(3) and BattV and every minute for Pulse and Pulse_T
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PG&E’s Emerging Technologies Program ET 14PGE1511
DATA ANALYSIS - METHODS The following statistical methods have been used to analyze the water quality
and energy data. The methods are described below.
WATER QUALITY DATA ANALYSIS METHOD
The trend in the data has been observed by time series plot. This plot
provides an estimate of the quality of the data.
Basic statistical parameters such as mean, standard deviation, and
coefficient of variation have been calculated to quantify the uncertainty
associated with the data. Mean has been calculated by the following
equation:
EQUATION 1. MEAN OF DATA
�̅� = ∑ 𝑥𝑖
𝑛𝑖=1
𝑛
Where,
�̅� = mean
xi = any data i from a sample of n data
n = sample size
The standard deviation for sample has been calculated by the following
equation:
EQUATION 2. STANDARD DEVIATION OF DATA
𝜎 = ∑(𝑥𝑖 − �̅� )2
(𝑛−1)
Where,
𝜎 = standard deviation
�̅� = mean
xi = any data i from a sample of n data
n = sample size
The coefficient of variation (CV) which determines the extent of
variability is calculated by the ratio of standard deviation to the mean
as shown in the following equation:
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PG&E’s Emerging Technologies Program ET 14PGE1511
EQUATION 3. COEFFICIENT OF VARIATION (CV) OF DATA
𝐶𝑉 = 𝜎
�̅�
Where,
CV = coefficient of variation
𝜎 = standard deviation
�̅� = mean
Standard deviation and coefficient of variation provide estimates of
uncertainties associated with the data. However, to infer the
population parameter, confidence interval analysis can be made on the
sample data. Confidence interval provides a limit or a range in which
the population mean can be bounded for a level of confidence. The
following equation has been used to calculate the confidence interval
following the normal distribution:
EQUATION 4. CONFIDENCE INTERVAL OF DATA
𝐵𝐿 = �̅� − 𝑧 ∗𝜎
√𝑛
𝐵𝑈 = �̅� + 𝑧 ∗𝜎
√𝑛
Where,
BL, BU = lower and upper bounds of the confidence
interval respectively
𝜎= standard deviation
�̅� = mean
z = critical value of standard normal cumulative
distribution function for a confidence level such as for
confidence level 99%.
The efficiency of the wastewater treatment plant has been observed by
calculating the removal efficiency of each water quality parameter
separately. The following equation has been used to calculate the
removal efficiency:
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PG&E’s Emerging Technologies Program ET 14PGE1511
EQUATION 5. REMOVAL EFFICIENCY
Efficiency (%) =(𝐶𝑏𝑒𝑓𝑜𝑟𝑒− 𝐶𝑎𝑓𝑡𝑒𝑟)
𝐶𝑏𝑒𝑓𝑜𝑟𝑒∗ 100%
Where,
Cbefore, Cafter = parameter’s concentration before and
after the treatment.
Please note that three sets of efficiencies can be calculated for each
week for a particular parameter; (1) using the data directly collected
or observed, (2) using the upper bound of the confidence interval, and
(3) using the lower bound of the confidence interval. These three
efficiencies for a particular week have been calculated to observe the
range of the efficiency for that particular week. A common
denominator i.e., Cbefore in this case the observed value has been used
for all these three efficiency calculations.
Overall mean efficiency and standard deviation of the efficiency for a
particular parameter have also been calculated considering all the
efficiencies calculated for each week separately. This calculation
provides the general removal efficiency of that parameter and thus
helps to identify the robustness of the plant.
ENERGY DATA ANALYSIS METHOD
The trends in the energy consumption and water pumped have been
observed by time series plots. The mean of daily energy consumption
and water pumped have been calculated by Equation 1 and plotted in
the same time series plots to show the variabilities observed in these
two data sets.
Daily energy requirements to pretreat (mechanical separation), treat
(biological treatment), and to distribute (after treatment) unit amount
of water (in this case 1000 gallons of water) have been calculated by
the following equation:
EQUATION 6. ENERGY REQUIREMENT FOR 1000 GALLONS OF WATER
𝐸𝑟𝑒𝑞𝑢𝑖𝑟𝑒𝑑 =𝑇𝑜𝑡𝑎𝑙 𝑑𝑎𝑖𝑙𝑦 𝑒𝑛𝑒𝑟𝑔𝑦 𝑐𝑜𝑛𝑠𝑢𝑚𝑝𝑡𝑖𝑜𝑛
𝑇𝑜𝑡𝑎𝑙 𝑑𝑎𝑖𝑙𝑦 𝑤𝑎𝑡𝑒𝑟 𝑝𝑢𝑚𝑝𝑒𝑑∗ 1000
Where,
Erequired = Daily energy consumption in kWh/1000 gallons
of water
The basic statistical parameters such as mean, median, and some
percentile values of the unit energy requirements have been
calculated. These parameters would provide an estimate of the sample
data that is within the baseline energy requirement. In this regard, the
exceedance probability analysis on unit energy consumption has also
been completed to quantify the probability exceedance of a certain
unit energy requirement.
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PG&E’s Emerging Technologies Program ET 14PGE1511
RESULTS
DATA ANALYSIS - RESULTS The following sections analyze and present water quality and energy
requirement results.
DATA ANALYSIS – RESULT (CSUF DAIRY)
Sixteen water quality parameters have been considered for the CSUF dairy
site. These parameters include; B, BOD5, Ca, COD, EC, K, Mg, Na, NH4, NO3-
N, P, pH, Salt-Sol, TDS, TKN, and TSS. Water samples from the CSUF dairy
site have been collected from May 9th to October 15. Samples were collected
on a weekly basis i.e., once in a week. Due to mechanical failure, some
weeks’ samples were discarded, resulting in a maximum number of useful
data points seventeen (17) for some parameters. For some of the
parameters, the number of useful data points may be lower than 17. The
water samples were collected before and after the treatment hence the term
“Before” and “After” in the following sections of the report.
Table 5 shows the basic statistical parameters of the water quality data used
in this study. Although the standard procedure and protocols have been
followed during sample collection, transportation, and laboratory analysis,
some data still shows outliers. The outliers have been discarded during the
basic statistical parameters calculation. As seen from Table 5 the variability in
the data ranges from CV of 0.02 to CV of 0.42. The lowest variability is
observed for pH and the highest variability is observed for BOD5.
TABLE 5. BASIC STATISTICAL PARAMETERS IN CSUF WATER QUALITY DATA ANALYSIS
Water Quality Parameter
Before After
Mean Std. Dev CV Mean Std. Dev CV
B (ppm) 0.71 0.11 0.16 0.66 0.11 0.17
BOD5 (mg/L) 888.64 374.42 0.42 775.73 309.01 0.40
Ca (ppm) 91.62 10.19 0.13 75.94 9.83 0.13
COD (mg/L) 1478.57 86.11 0.06 775.73 309.01 0.40
EC (mmhos/cm) 4.49 0.74 0.16 3.92 0.63 0.16
K (ppm) 527.06 85.00 0.16 539.65 81.73 0.15
Mg (ppm) 83.59 11.25 0.13 81.38 13.00 0.16
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PG&E’s Emerging Technologies Program ET 14PGE1511
Water Quality Parameter
Before After
Mean Std. Dev CV Mean Std. Dev CV
Na (ppm) 208.59 28.07 0.13 214.18 26.89 0.13
NH4 (mg/L) 124.39 22.88 0.18 0.50 0.00 0.00
NO3-N 55.18 15.04 0.27 0.82 0.46 0.57
P (ppm) 43.21 6.26 0.14 36.95 4.12 0.11
pH 8.11 0.20 0.02 7.88 0.23 0.03
Salt-Sol (ppm) 2870.59 471.20 0.16 2507.29 403.12 0.16
TDS (mg/L) 3036.53 530.14 0.17 2714.41 494.51 0.18
TKN (ppm) 182.27 25.64 0.14 0.50 0.00 0.00
The trend in an entire data set for each of the parameters can be observed in
figures from Figure 13 to Figure 27. It is expected that the data would have
some measurement errors during the sampling and laboratory testing
processes. To account for this error, confidence limits have been calculated
considering the weekly recorded value as the mean. The confidence limits
would provide a range in which the true or population mean would fall. The
upper and lower limits of the confidence intervals for each week of the data
have been calculated for the 99% confidence level following a normal
distribution. The standard error of the sample (SES) has been calculated
using the statistical parameters listed in Table 5. As a result the time series
plots from Figure 13 to Figure 27 show three curves for each “Before” and
“After” water quality data. One curve is to show the mean (i.e., the recorded
data); one is to show the upper bound of 99% confidence limit; and the other
is to show the lower bound of 99% confidence limit.
Some figures show consistent trends in the data sets. These data sets either
have no spike or trough at all or have a single or minimum outliers. These
data sets include; B, BOD5, Ca, COD, NH4, NO3-N. Some data sets show an
upward trend as the weeks increase. The other data sets may have more than
one spike, trough or inconsistency in the trend. The local conditions such as
the weather pattern and the farming processes can contribute to the
inconsistencies in the trends.
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 13. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: BORON (B)
FIGURE 14. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: BOD5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Co
ncen
trati
on
(p
pm
)
Week
After - Mean Before - Mean
Before - LB 99% Before - UB 99%
After - LB 99% After - UB 99%
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
Co
ncen
trati
on
(m
g/L
)
Week
After - Mean Before - Mean
After - LB99% After - UB99%
Before - LB99% Before - UB99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 15. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: CALCIUM (CA)
FIGURE 16. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: COD
0
20
40
60
80
100
120
140
Co
ncen
trati
on
(p
pm
)
Week
Before - Mean After - Mean
After - LB99% After - UB99%
Before - LB99% Before - UB99%
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Week1 Week2 Week3 Week4 Week5 Week6 Week7 Week8
Co
ncen
trati
on
(mg
/L)
Week
After - Mean Before - Mean
After - LB99% After - UB99%
Before - LB99% Before - UB99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 17. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: EC
FIGURE 18. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: POTASSIUM (K)
0
1
2
3
4
5
6
7
8
Co
ncen
trati
on
(mm
ho
s/c
m)
Week
Before - Mean After - Mean
After - LB99% After - UB99%
Before - LB99% Before - UB99%
0
100
200
300
400
500
600
700
800
Co
ncen
trati
on
(pp
m)
Week
Concentration Before and After Treatment: K
After - Mean Before - Mean
After - LB99% After - UB99%
Before - LB99% Before - UB99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 19. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: MAGNESIUM (MG)
FIGURE 20. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: SODIUM (NA)
0
20
40
60
80
100
120
Co
ncen
trati
on
(pp
m)
Week
Before - Mean After - Mean
After - LB99% After - UB99%
Before - LB99% Before - UB99%
0
50
100
150
200
250
300
Co
ncen
trati
on
(pp
m)
Week
Before - Mean After - Mean
After - LB99% After - UB99%
Before - LB99% Before - UB99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 21. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: AMMONIUM
NITROGEN (NH4)
FIGURE 22. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: NITRATE
NITROGEN (NO3-N)
0
20
40
60
80
100
120
140
160
180
200
Co
ncen
trati
on
(mg
/L)
Week
After
Before
0
100
200
300
400
500
600
700
800
900
1000
Co
ncen
trati
on
(mg
/L)
Week
Before - Mean After - Mean
After - LB 99% After - UB 99%
Before - LB 99% Before - UB 99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 23. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: PHOSPHORUS (P)
FIGURE 24. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: PH
0
10
20
30
40
50
60
70
80
Co
ncen
trati
on
(pp
m)
Week
After - Mean Before - Mean
After - LB 99% After - UB 99%
Before - LB 99% Before - UB 99%
6.6
6.8
7.0
7.2
7.4
7.6
7.8
8.0
8.2
8.4
8.6
8.8
pH
Week
Before - Mean After - Mean
After - LB 99% After - UB 99%
Before - LB 99% Before - UB 99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 25. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: SOLUBLE SALTS
(SALT-SOL)
FIGURE 26. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: TOTAL DISSOLVED
SOLIDS (TDS)
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Co
ncen
trati
on
(p
pm
)
Week
Before - Mean After - Mean
After - LB 99% After - UB 99%
Before - LB 99% Before - UB 99%
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
Co
ncen
trati
on
(m
g/L
)
Week
Before - Mean After - Mean
After - LB 99% After - UB 99%
Before - LB 99% Before - UB 99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 27. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT CSUF: TOTAL KJELDAHL
NITROGEN (TKN)
The removal efficiency has been calculated separately for each of the water
quality parameters. For each water quality parameter weekly efficiency has
been calculated first and then the overall mean and standard deviation in the
removal efficiency was also calculated. The upper and lower bounds of the
removal efficiencies were also calculated. While Table 6 shows the overall
mean and standard deviation of the removal efficiencies, the figures from
Figure 28 to Figure 42 show the upper and lower limits of the removal
efficiency for each week. Any negative (i.e., concentration was higher in
“After” than “Before”) and outlier efficiencies have been discarded in the
overall efficiency calculation and also discarded in the plot.
The overall mean efficiency for all the water quality parameters ranges from
2.7% to 98.4%. While NH4 has the highest overall efficiency, Mg has the
lowest overall efficiency. The standard deviation, which represents the
uncertainty, is found lowest in pH. However, since the mean is already lower
for pH, this does not reflect the variation. Therefore a normalized parameter
such as CV has been used to compare the variability between the parameters.
CV is found lowest for NH4 removal efficiency. The highest CV of the removal
efficiency is observed for P showing a very high uncertainty in the P removal
process. Some of the parameters that are to be found with higher removal
efficiency include NH4 (98.4%), NO3-N (96.2%), TKN (90.6%), and COD
(46.9%). The uncertainty, in terms of CV, is found 0.04, 0.05, 0.2, and 0.32
respectively for NH4, NO3-N, TKN, and COD. A few parameters such as K and
Na are found with overall negative removal efficiency. Either the sample was
contaminated specifically for these parameters or somehow these parameters
were generated in the removal efficiency. Another important water quality
parameter BOD5 is found to have an overall efficiency of 23.5% with 0.63 of
0
50
100
150
200
250
300
350
400
450
Co
ncen
trati
on
(p
pm
)
Week
Before - Mean After - Mean
After - LB 99% After - UB 99%
Before - LB 99% Before - UB 99%
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PG&E’s Emerging Technologies Program ET 14PGE1511
CV. The 99% upper and lower limits provide a range in which the population
mean of the removal efficiency can fall. Figure 28 to Figure 42 show the
weekly mean removal efficiency with upper and lower limits.
TABLE 6. REMOVAL EFFICIENCY OF WATER QUALITY PARAMETERS AT CSUF DAIRY WASTEWATER TREATMENT PLANT
Water Quality Parameter
Removal Efficiency
Mean Std. Dev CV
B (ppm) 7.4% 3.8% 0.52
BOD5 (mg/L) 23.5% 14.8% 0.63
Ca (ppm) 16.8% 9.5% 0.56
COD (mg/L) 46.9% 15.2% 0.32
EC (mmhos/cm) 12.1% 11.2% 0.92
K (ppm) -2.6% 4.4% -1.69
Mg (ppm) 2.7% 7.6% 2.84
Na (ppm) -2.9% 4.4% -1.52
NH4 (mg/L) 98.4% 3.8% 0.04
NO3-N 96.2% 4.3% 0.05
P (ppm) 8.9% 23.9% 2.69
pH 2.9% 1.9% 0.67
Salt-Sol (ppm) 12.1% 11.2% 0.92
TDS (mg/L) 10.1% 11.6% 1.15
TKN (ppm) 90.6% 18.0% 0.20
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PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 28. REMOVAL EFFICIENCY AT CSUF: BORON (B)
FIGURE 29. REMOVAL EFFICIENCY AT CSUF: BOD5
0%
10%
20%
30%
40%
50%
60%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
Eff
icie
ncy (
%)
Week
Mean
LB 99%
UB 99%
36
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 30. REMOVAL EFFICIENCY AT CSUF: CALCIUM (CA)
FIGURE 31. REMOVAL EFFICIENCY AT CSUF: COD
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
Eff
icie
ncy (
%)
Week
Mean
LB 99%
UB 99%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
Week1 Week2 Week3 Week4 Week5 Week6 Week7 Week8
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
37
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 32. REMOVAL EFFICIENCY AT CSUF: EC
FIGURE 33. REMOVAL EFFICIENCY AT CSUF: POTASSIUM (K)
0%
5%
10%
15%
20%
25%
Eff
icie
ncy (
%)
Week
Mean LB 99%UB 99%
0%
1%
2%
3%
4%
5%
6%
7%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
38
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 34. REMOVAL EFFICIENCY AT CSUF: MAGNESIUM (MG)
FIGURE 35. REMOVAL EFFICIENCY AT CSUF: SODIUM (NA)
0%
2%
4%
6%
8%
10%
12%
14%
16%
18%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
0%
1%
1%
2%
2%
3%
3%
4%
4%
5%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
39
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 36. REMOVAL EFFICIENCY AT CSUF: AMMONIUM NITROGEN (NH4)
FIGURE 37. REMOVAL EFFICIENCY AT CSUF: NITRATE NITROGEN (NO3-N)
0%
20%
40%
60%
80%
100%
120%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
0%
20%
40%
60%
80%
100%
120%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
40
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 38. REMOVAL EFFICIENCY AT CSUF: PHOSPHORUS (P)
FIGURE 39. REMOVAL EFFICIENCY AT CSUF: PH
0%
5%
10%
15%
20%
25%
30%
35%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
0%
1%
2%
3%
4%
5%
6%
7%
8%
9%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
41
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 40. REMOVAL EFFICIENCY AT CSUF: SOLUBLE SALTS (SALT-SOL)
FIGURE 41. REMOVAL EFFICIENCY AT CSUF: TOTAL DISSOLVED SOLIDS (TDS)
0%
5%
10%
15%
20%
25%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
0%
5%
10%
15%
20%
25%
30%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
42
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 42. REMOVAL EFFICIENCY AT CSUF: TOTAL KJELDAHL NITROGEN (TKN)
Three pumps have been used to supply energy to the overall wastewater
treatment process. Specifically, Pump 1 provides energy for pre-treatment
(mechanical separation); Pump 2 provides energy for the main treatment
process using the BIDA® system, and Pump3 supplies energy to distribute
treated water. Pump2 is the main source of energy for the wastewater
treatment process using BIDA® system. The following table (Table 7) shows
the energy supply statistics by the three pumps. Pump 2 which is the main
source of energy to treat wastewater supplied the highest amount of energy.
Pump 3 that supplies energy to distribute the treated water supplied the
lowest amount of energy. The days in operation for all three pumps are not
same which means some pumps might not be in operation on some days.
There were various reasons why all the pumps were not in operation on same
days. Mechanical failure caused pumps to be non-operable while the other
means were used to supply wastewater and treated water.
The daily average energy requirements by three pumps are also listed in
Table 7. While Pump 3 requires the least daily average, Pump 2 requires the
highest daily average. Please note that pumps were running intermittently on
any given day meaning that not all three pumps were following the same
schedule with the same operating time in a given day. Pump 1 was used to
pump water for mechanical separation (pre-treat) and Pump 2 was used to
pump water to the treatment system. Since there was four hours of time
requirement to flow the water through the treatment system, the Pump 1,
Pump 2, and Pump 3 (for distributing treated water) were not likely to follow
the same operational schedule. As a result, the pump operation hours and
energy requirements vary. Also due to mechanical failure such as leaks,
plugged filters, and clogging some pumps needed to be turned off. During the
test, Pump 2 needed to be replaced as a result of mechanical failure. The
newer pump was not fine-tuned with the system requirement and as a result,
0%
20%
40%
60%
80%
100%
120%
Eff
icie
ncy (
%)
Week
Mean LB 99% UB 99%
43
PG&E’s Emerging Technologies Program ET 14PGE1511
it supplied more energy than the older pump which is reflected in Figure 44
showing higher energy requirements towards the end of the test.
TABLE 7. ENERGY SUPPLY STATISTICS FOR CSUF DAIRY WASTEWATER TREATMENT PLANT
Pump Pump1 Pump2 Pump3
Days in operation 134 146 148
Average daily hours in operation (hr) 14.1 10.4 10.4
Total consumption (kWh) 1040.7 1060.15 623.54
Daily average consumption (kWh) 7.8 7.3 4.2
Standard deviation (kWh) 3.8 6.7 4.1
FIGURE 43. ENERGY REQUIREMENT BY PUMP1 TO PRE-TREAT WASTEWATER AT CSUF
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
En
erg
y (
kw
h)
Date
Energy consumed (kWh) Daily average (kwh)
44
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 44. ENERGY REQUIREMENT BY PUMP2 TO TREAT WASTEWATER AT CSUF
FIGURE 45. ENERGY REQUIREMENT BY PUMP3 TO DISTRIBUTE TREATED WATER AT CSUF
0.0
5.0
10.0
15.0
20.0
25.0
En
erg
y (
kw
h)
Date
Energy consumed (kWh) Daily average (kwh)
0.0
2.0
4.0
6.0
8.0
10.0
12.0
En
erg
y (
kw
h)
Date
Energy consumed (kWh) Daily average (kwh)
45
PG&E’s Emerging Technologies Program ET 14PGE1511
Pump 3 has been used to collect the flow data. Since there is no loss of water,
except minimum evaporation and consumption by the earthworms, it is
assumed that a steady state flow was maintained in the system. As a result,
the same amount of flow was flowing through Pump 1, Pump 2, and Pump 3
(ignoring the minimum evaporation and the minimum water consumption by
the earthworms). Please note that due to mechanical failure on some days,
the flow data is not consistent with the pump data i.e., for any given day
while Pump 3 was running, the flow data shows no value. On an average,
Pump 3 was running about 10.4 hours but for some days the recorded flow
amount was very minimal. It is reported that this discrepancy also resulted
due to mechanical failure of the pump and the system. Mechanical failure
included system leakage, pipe clogging, plugged filters etc. A test was
conducted later to record the Pump 3 pressure. It was found that Pump3 was
running at approximately 3.25 psi (7.5 ft of head). Considering this operating
pressure (7.5 ft of head), maximum design head of the pump (20 ft), and the
maximum discharge capacity of the pump (1670 gph), the average daily
discharge was calculated following a linear pump curve. The calculated
average daily discharge is 1044 gpd. It was assumed that any discharge
lower than the 1044 gpd would be due to the mechanical failure at the pump
or in the system. As the main objective is to find out the energy requirement
to treat a unit amount of water (i.e., 1000 gallons) this assumption still can
maintain the correlations between the amount of water treated and the
energy requirement since the entire data for the days with lower flow would
be discarded. As a result, a total 104 days of data was considered in the
energy requirement analysis.
Table 8 shows the statistics of the amount of energy required by each pump
(after discarding some data due to mechanical failure). Figure 46 shows the
time series plot of these data. Generally in the beginning of the experiment,
energy requirements by each pump were lower than the energy requirement
towards the end of the experiment. Mechanical failure caused the old broken
pump to be replaced towards the end of test. The newer pump was not fine-
tuned with the system causing a higher energy requirement. Figure 47 shows
the sorted energy and flow data to illustrate any correlation between pump
energy usage and water flow. The energy requirement is high with the
increase of flow. This relationship is almost linear for Pump 1 but not for
Pump 2 and Pump 3 showing some mechanical issues with these two pumps
(Pump 2 and Pump 3). This is due to the mechanical failures that were
described earlier.
TABLE 8. ENERGY–WATER STATISTICS AT CSUF DAIRY WASTEWATER TREATMENT PLANT AFTER DISCARDING SOME DATA
DUE TO MECHANICAL FAILURE
Statistics Energy data (kWh) Flow
(gpd) Pump1 Pump2 Pump3
Days in operation 104 104 104 104
Daily average 7.9 7.8 4.1 2481.0
46
PG&E’s Emerging Technologies Program ET 14PGE1511
Daily maximum 13.2 19.6 9.7 4027.0
Daily minimum 0.0 0.1 0.0 1044.5
Standard deviation 3.8 6.8 4.1 848.9
Total 825 813 427 258,028
FIGURE 46. TIME SERIES PLOT OF ENERGY REQUIREMENT BY EACH PUMP AND FLOW AT CSUF DAIRY WASTEWATER
TREATMENT PLANT AFTER DISCARDING SOME DATA DUE TO MECHANICAL FAILURE
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0
5
10
15
20
25
1 11 21 31 41 51 61 71 81 91 101
Flo
w (
gp
d)
En
erg
y (
kw
h)
Days
Pump1 Pump2
Pump3 Flow
47
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 47. SORTED FLOW AND ENERGY AT CSUF DAIRY WASTEWATER TREATMENT PLANT AFTER DISCARDING SOME DATA
DUE TO MECHANICAL FAILURE
The energy required to treat 1000 gallons of wastewater has been calculated
for; pre-treatment (by Pump 1), main treatment (by Pump 2), and distribution
of treated water (by Pump 3). Table 9 shows the summary of the energy
requirements for these three conditions. On an average, while distribution of
treated water requires the least amount of energy (1.7 kWh/1000 gallons) the
pre-treatment requires the highest (3.7 kWh/1000 gallons). The energy
supplied by Pump 2 was used to treat the wastewater. The average energy
requirement (kWh/1000 gallons) to treat the wastewater (by Pump 2) is 3.2
kWh/1000 gallons. On a percentage basis, about 25% of the energy
requirement data is lower than the 1.0 kWh/1000 gallons and 50% of the
energy requirement data is lower than the 1.8 kWh/1000 gallons.
In the baseline study it is reported that the annual energy requirements for
secondary, tertiary, and overall treatments are about 771,357 kWh/MGD,
1,144,277 kWh/MGD, and 907,836 kWh/MGD (PG&E 2006). Converting these
numbers to the energy requirement per 1000 gallons of water per day gives us
2.1, 3.1, 2.5 kWh/1000 gallons. These numbers can be directly compared with
the energy requirement by Pump 2 in this study. About 55% of the data energy
requirement data are found lower than the baseline study. Figure 48 to Figure
50 show the non-exceedance probability plot of these energy requirements to
treat 1000 gallons of wastewater. As seen from the figures, about 50% of the
energy requirement data are found lower than the baseline information. It is
important to note that this is a pilot test and the plant was not running at a full
scale. Therefore, it is possible that some energy might have been wasted due
to lack of fine tuning (calibrating) the system parameters. Mechanical failure
0
500
1000
1500
2000
2500
3000
3500
4000
4500
0
5
10
15
20
25
1 11 21 31 41 51 61 71 81 91 101
Flo
w (
gp
d)
En
erg
y (
kw
h)
Rank
Pump1 Pump2
Pump3 Flow
48
PG&E’s Emerging Technologies Program ET 14PGE1511
might be another reason for seeing some energy requirement data higher than
the baseline study.
TABLE 9. ENERGY REQUIREMENT TO TREAT 1000 GALLONS OF WATER AT CSUF DAIRY WASTEWATER TREATMENT PLANT
Statistics Energy requirement (kWh) to treat 1000 gallons of waste water
Pre-treatment (Pump1)
Treatment (Pump2)
Distribution (Pump3)
Days in operation 104 104 104
Average 3.7 3.2 1.7
Max 12.2 14.4 8.4
Standard deviation 2.5 2.9 2.0
25 percentile 2.0 1.0 0.3
50 percentile (median) 3.1 1.8 0.4
75 percentile 4.8 5.0 2.8
90 percentile 7.1 6.7 4.1
49
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 48. NON-EXCEEDANCE PROBABILITY CURVE FOR ENERGY REQUIREMENT FOR THE PRE-TREATMENT OF
WASTEWATER (BY PUMP1) AT CSUF DAIRY WASTEWATER TREATMENT PLANT
FIGURE 49. NON-EXCEEDANCE PROBABILITY CURVE FOR ENERGY REQUIREMENT FOR THE TREATMENT OF WASTEWATER
(BY PUMP2) AT CSUF DAIRY WASTEWATER TREATMENT PLANT
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
No
n-E
xce
ed
an
ce
Pro
bab
ilit
y (
%)
Energy Requirement (kWh/1000 gallons of wastewater)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0
No
n-E
xce
ed
an
ce
Pro
bab
ilit
y (
%)
Energy Requirement (kWh/1000 gallons of wastewater)
Bas
elin
e Se
con
dar
y
Bas
elin
e O
vera
ll
Bas
elin
e Te
rtia
ry
50
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 50. NON-EXCEEDANCE PROBABILITY CURVE FOR ENERGY REQUIREMENT FOR THE DISTRIBUTION OF TREATED
WATER (BY PUMP3) AT CSUF DAIRY WASTEWATER TREATMENT PLANT
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0
No
n-E
xce
ed
an
ce
Pro
bab
ilit
y (
%)
Energy Requirement (kWh/1000 gallons of wastewater)
51
PG&E’s Emerging Technologies Program ET 14PGE1511
DATA ANALYSIS – RESULT (TOMATO PROCESSOR)
Weekly samples were collected from August 6 to October 16. Only two water
quality parameters, including BOD5 and TSS, were considered for this
wastewater treatment plant. The same method that was applied to analyze the
CSUF wastewater water quality data has been applied to this site. Table 10 lists
the basic statistical parameters and Figure 51 and Figure 52 show the time
series plot of the water quality data with its upper and lower 99% confidence
bounds. Except for a few spikes, both parameters show consistency throughout
the sample collection period. The statistics of removal efficiency were tabulated
in Table 11 and the weekly removal efficiencies are plotted in Figure 53 and
Figure 54. Unlike the CSUF wastewater treatment plant, the removal efficiency
of BOD5 and TSS for this plant is significantly higher as seen from the table and
figures. The overall mean removal efficiency for BOD5 is 96.4% and for the TSS
is 89.7% with lower CVs. The system design and the biological process of the
treatment plant are assumed to be the main reasons for the higher removal
rate.
Like the CSUF wastewater treatment plant, the same methodology was applied
to analyze energy data for the large tomato processor wastewater treatment
plant. Table 12 lists the energy requirement statistics and the energy
requirement time series (daily data) plots are shown in Figure 55 and Figure
56. Please note that only two pumps were used for this site. No pump was
assigned for the pre-treatment. For the consistency, these two pumps were
labeled Pump 2 (for treatment) and Pump 3 (for the distribution of treated
water). Similar to the CSUF wastewater treatment, some data was discarded
due to mechanical failure. Table 13 lists the statistics of the energy requirement
and water pumped by the pumps. Figure 57 shows the entire data set (both
energy and water) after some data has been discarded due to the mechanical
failure. As seen from the table and figure, the daily average energy
requirement for Pump 2 is lower than Pump 3. The energy requirement to treat
1000 gallons of wastewater has been tabulated in Table 14. Generally this
wastewater site requires more energy than the CSUF site.
TABLE 10. BASIC STATISTICAL PARAMETERS IN A LARGE TOMATO PROCESSOR WATER QUALITY DATA ANALYSIS
Water Quality Parameter
Before After
Mean Std. Dev CV Mean Std. Dev CV
BOD5 (mg/L) 1928.6 170.4 0.09 23.0 4.7 0.21
TSS (mg/L) 260.0 67.0 0.26 20.9 7.4 0.35
52
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 51. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT A LARGE TOMATO
PROCESSOR: BOD5
FIGURE 52. CONCENTRATION WITH CONFIDENCE LIMITS BEFORE AND AFTER THE TREATMENT AT A LARGE TOMATO
PROCESSOR: TSS
0
500
1,000
1,500
2,000
2,500
3,000
Co
nc
en
tra
tio
n (
mg
/L)
Week
Before - Mean Before - LB 99%
Before - UB 99% After - Mean
After - LB 99% After - UB 99%
0
100
200
300
400
500
600
700
800
900
1,000
Co
nc
en
tra
tio
n (
mg
/L)
Week
After - Mean Before - Mean
Before - LB 99% Before - UB 99%
After - LB 99% After - UB 99%
53
PG&E’s Emerging Technologies Program ET 14PGE1511
TABLE 11. REMOVAL EFFICIENCY OF WATER QUALITY PARAMETERS AT A LARGE TOMATO PROCESSOR WASTEWATER
TREATMENT PLANT
Water Quality Parameter
Removal Efficiency Confidence Interval
Mean Std. Dev CV 99% LB 99% UB
BOD5 (mg/L) 96.4% 6.9% 0.07 83.9% 100.0%
TSS (mg/L) 89.7% 9.5% 0.11 69.3% 100.0%
FIGURE 53. REMOVAL EFFICIENCY AT A LARGE TOMATO PROCESSOR: BOD5
0%
20%
40%
60%
80%
100%
120%
Eff
icie
nc
y (
%)
Week
Mean LB 99% UB 99%
54
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 54. REMOVAL EFFICIENCY AT A LARGE TOMATO PROCESSOR: TSS
TABLE 12. ENERGY SUPPLY STATISTICS FOR A LARGE TOMATO PROCESSOR WASTEWATER TREATMENT PLANT
Pump Pump1 Pump2 Pump3
Days in operation
Not in
used
87 86
Average daily hours in operation (hr) 9.7 10.4
Total consumption (kWh) 418.87 352.55
Daily average consumption (kWh) 4.8 4.1
Standard deviation (kWh) 2.0 2.3
0%
20%
40%
60%
80%
100%
120%
Eff
icie
nc
y (
%)
Week
Mean LB 99% UB 99%
55
PG&E’s Emerging Technologies Program ET 14PGE1511
FIGURE 55. ENERGY REQUIREMENT BY PUMP2 TO TREAT WASTEWATER AT A LARGE TOMATO PROCESSOR
FIGURE 56. ENERGY REQUIREMENT BY PUMP3 TO DISTRIBUTE TREATED WATER AT A LARGE TOMATO PROCESSOR
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
8/18/2014 9/18/2014 10/18/2014
En
erg
y (
kw
h)
Date
Energy consumed (kWh) Daily average (kwh)
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
8/18/2014 9/18/2014 10/18/2014
En
erg
y (
kw
h)
Date
Energy consumed (kWh) Daily average (kwh)
56
PG&E’s Emerging Technologies Program ET 14PGE1511
TABLE 13. ENERGY–WATER STATISTICS AT A LARGE TOMATO PROCESSOR WASTEWATER TREATMENT PLANT AFTER
DISCARDING SOME DATA DUE TO MECHANICAL FAILURE
Statistics
Energy data (kwh) Flow (gpd)
Pump1 Pump2 Pump3
Days in operation
Not in
used
21 21 24
Average 4.6 5.4 717.4
Max 7.0 6.2 1471.0
Min 0.9 0.2 557.0
Standard deviation 1.5 1.2 227.9
FIGURE 57. TIME SERIES PLOT OF ENERGY REQUIREMENT BY EACH PUMP AND FLOW AT A LARGE TOMATO PROCESSOR
WASTEWATER TREATMENT PLANT AFTER DISCARDING SOME DATA DUE TO MECHANICAL FAILURE
TABLE 14. ENERGY REQUIREMENT TO TREAT 1000 GALLONS OF WATER AT A LARGE TOMATO PROCESSOR WASTEWATER
TREATMENT PLANT
Statistics
Energy requirement (kWh) to treat per 1000 gallons
Pre-treatment (Pump1)
Treatment (Pump2)
Distribution (Pump3)
Days in operation
Not used
24 24
Average 5.9 7.1
Max 11.3 10.3
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
0
2
4
6
8
10
12
1 11 21
Flo
w (
gp
d)
En
erg
y (
kw
h)
Days
Pump2 Pump3 Flow
57
PG&E’s Emerging Technologies Program ET 14PGE1511
Statistics
Energy requirement (kWh) to treat per 1000 gallons
Pre-treatment (Pump1)
Treatment (Pump2)
Distribution (Pump3)
Min 0.1 0.2
Standard deviation 3.2 3.4
25 percentile 3.4 5.2
50 percentile (median) 6.5 8.7
75 percentile 8.2 9.4
90 percentile 10.0 9.7
EVALUATIONS
The performance of the BioFiltro or BIDA® wastewater treatment technology
was observed for its removal efficiency in terms of water quality parameters.
The removal efficiencies of the nitrogen-based water quality parameters such
as NH4, NO3-N, TKN are significantly high (above 90%). Other water quality
indicators such as BOD5 and COD show promising results. However, the
plant’s performance on other parameters was poor. Negative removal
efficiency was found for a few parameters showing the probable
contamination or generation of these parameters during the treatment
process. Since the CSUF site is a dairy farm, the interest perhaps is on the
nitrogen-based parameters. The BIDA® performance on these nitrogen-based
water quality measures is significantly high. The performance of BioFiltro
(BIDA® technology) in terms of water quality was very high at a large tomato
processor site. Two water quality parameters, BOD5 and TSS were considered
for this site and the removal efficiencies for both the parameters are found
90% or above.
The energy requirements to treat 1000 gallons of wastewater were calculated
for both CSUF and the large tomato processor site. Results were compared to
the baseline study information. For the CSUF site, about 25% of the data
shows better or extraordinary performance than the baseline study as the
energy requirement to treat 1000 gallons of wastewater was found to be
much lower. Refer to Table 9 and Figure 49 in the Results section for a
detailed analysis. About 50% of the data at both CSUF and the large tomato
processor site did not outperform the baseline study. Mechanical failure is
suspected to be one of the main reasons.
58
PG&E’s Emerging Technologies Program ET 14PGE1511
RECOMMENDATIONS Although the performance of the BioFiltro was found extraordinary for some
water quality parameters (such as nitrogen-based parameters at the CSUF
site and all the parameters at the large tomato processor site), the
performance for some parameters were not found high or satisfactory. Refer
to the Analysis section under Results for details. Measurement errors and
probable contaminations are suspected to be the reasons for this poor
performance. Therefore, extra caution and attention to testing protocols for
sampling, lab analysis, and data entry need to be maintained throughout the
process.
Both CSUF and the large tomato processor site are pilot studies. As such,
some system parameters were not fine-tuned and might have been the cause
of wasting some energy. Mechanical failure was also observed during the
testing process. It is important to understand the system parameters in depth
which will provide an insight to fine tune or calibrate the parameters properly.
Extra caution also needs to be maintained to avoid any mechanical failure.
Next steps: A full scale system is being built at a dairy near Hilmar, CA. It is
recommended that additional data be collected on a system of full,
commercial size to verify scalability of system and needed improvements in
operational efficiencies. The Hilmar system is planned to be fully operational
in January of 2015. This provides a perfect opportunity to collect data and
determine feasibility widespread adoption.
APPENDICES
All the data including raw and processed are attached in spreadsheet format.
The Appendices also includes all the statistical analysis and figures that were
made for this study.
59
PG&E’s Emerging Technologies Program ET 14PGE1511
REFERENCES BioFiltro. (2014). “What is BioFiltro.” Available: http://biofiltro.com/about/.
Clarke Prize. (2003). “Distributed_Wastewater_Management_Clarke_Prize_Lecture by
Tchobanoglous.”
Crites, R.W., and G. Tchobanoglous. (1998). Small and Decentralized Wastewater
Management Systems. McGraw-Hill Book Company, New York.
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