OZONE CASE STUDY

Military Installation

Central Georgia

Ex-Situ Ozone System

Background

The impacted site is a former military landfill, located on a Military Installation in Central Georgia, where several Contaminants of Con-cern (COC) had been identified within the phreatic zone which re-quire continuous remediation.

Currently, a groundwater treatment plant located approximately two miles from the former landfill treats groundwater and some additional wastewater streams (typically decon water or purge water). The cur-rent groundwater treatment plant is fed groundwater by 7 extraction wells and by 10 Leachate Collection and Dual Phase wells.

Piper Environmental Group, Inc. Ozone Solutions for a Cleaner Earth TM

DNAPL is collected in a wet well and disposed. Groundwater is transferred to the current groundwater treatment plant (GWTP) for treatment.1

The existing GWTP was inefficient and had very high operation and maintenance costs. CAPE Environ-mental proposed to improve their existing plant by re-moval of existing UV treatment system and adding ozone to treat source landfill wastewater streams.

The Challenge

Criteria 1: Offer innovative treatment solution package that will surpass effectiveness of existing processes.

Criteria 2: Reduce operation and maintenance costs significantly.

Criteria 3: Premier solution must treat 50GPM and at-tain contaminant reduction to non-detect or below ac-ceptable levels based on NPDES permit and Georgia In-Stream Water Quality Criteria (GA ISWQC).

The Solution

Design a pilot study to demonstrate effectiveness and viability of innovative alternative to traditional method-ology. Analyze results and design-build a full scale ozone treatment system to fulfill challenges noted above and reduce Operation & Maintenance costs as-sociated with frequent Granular Activated Carbon (GAC) media change outs and UV bulb maintenance.

Ozone equipment installed inside existing Groundwater treatment plant in Central Georgia

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Pilot Study

Piper Environmental Group, Inc. (Piper) proposed a pilot study to prove the effectiveness of ozone at re-ducing Contaminants of Concern (COC). The Pilot study supplied a turn-key ozone system for Volatile Organic Carbon (VOC) and Semi-Volatile Organic Carbon (SVOC) contaminant reduction and a sepa-rate iron filtration system for iron reduction. A pilot study consisted of a two week on-site test period with longer, subsequent data evaluation. This data collec-tion and analysis was invaluable as it allowed or a high degree of accuracy in determining the ozone system size necessary to reach cleanup goals.

Cape prepared the batch of water to be used during the pilot study. This water was intended to be repre-sentative of the total loading that would be seen by the full-scale system. The groundwater actually con-sisted of the worst water quality possible, with higher levels of contaminants and iron than what was origi-nally specified. Typically, this water quality is a side-stream of the typical total waste water to be proc-essed by the future full-scale system.

The pilot system also involved precipitation iron chemistry. This can be a challenging process as ideal blends are achieved. Iron chemistry is very site spe-cific and there are many different iron molecules, compounds, configurations, and structures. Some iron chemistry is dependent on pH, ORP and other water quality conditions. Some iron compounds have good flocculation, bonding, and/or settling characteristics and some do not. It was vastly important to perform a pilot study which determined a proven approach for controlling the iron.

As desired by Cape, preliminary testing with ozone without addition of hydrogen peroxide or UV indicated a variety of results with both the ozone and iron con-trol agents. The pictures on the following page indi-cate the variety of tests using flocculent polymer, co-agulants and sequestering agents to assist with high levels of iron. One of the goals was to reduce sus-pended solids loading and maintain the iron in solu-tion to reduce ozone demand and eliminate additional filtration following ozone generator.

Piper Environmental Group, Inc. Ozone Solutions for a Cleaner Earth TM

Pilot System Components

1. Oxygen concentrator (14 grams per hour) 2. Ozone generator produces .7 pounds per day

(PPD) @ 1% 3. Mazzei injector for gas injection 4. Pressurized contacting vessel 5. Recirculation loop - 1 GPM 6. Degas valve for venting excess ozone (flows

to destruct unit) Not pictured: UV lamp and H2O2 injection

This unit accepts flows up to one gallon per minute, with recirculation rates up to 10 gpm. The unit is powered by a single phase 120-volt circuit, drawing about 12 amps.

Rotameters indicate various flows and recirculation rate.

Various controls are used to operate and adjust the oxygen and ozone generators. UV lamp and H2O2 injection are not pictured here and were not utilized for this pilot study, but available for test purposes.

Figure 1: Ozone Pilot Skid Mounted System

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The pilot study extended an extra week to try various combinations of iron filtration, coagulants, and floccu-lants that are ozone resistant. A successful combina-tion was found to maintain the 60 ppm iron in solution.

One gpm of groundwater was fed to the ozone pilot system, with the picture on the left indicating clear wa-ter at the effluent. Foaming was evident in the relief valve purge line post the ozone contact chamber. This was alleviated by altering the chemical injection.

The success of the pilot study paved the way for full scale implementation of full scale ozone system.

Summary

Pilot ozone system operational for 2 weeks, June 13-29, 2012 Final Pilot Study report issued August 28, 2012 Approximately 1500 gallons of water was treated with ozone and iron filtration. Significant reductions in COC’s observed in post ozone groundwater samples. Equipment performed safely, effectively, relia-bly, and produced desired results.

(2) It was clear some contaminants were only partially oxidized. However, an extensive analysis of data was performed and the data interpretation followed this analysis. The purpose of the thorough analysis was to confirm initial design-build concept validity, verify iron sequestering chemical and injection methodology, and ensure complete COC oxidation occurred.

Military Installation, Central Georgia

Water Samples taken during Pilot Test demon-strating optimization of iron control (Left to Right)

1. Raw water (cloudy, red suspended particles) 2. Coagulant only (fluffy, slowly settling pinfloc) 3. Too much flocculent polymer (iron, sludge) 4. Just right flocculent polymer (tight sludge,

large floc) 5. Too little flocculent polymer (green iron, but

not dense) 6. Feed to ozone contacting skid

The initial, quick evaluation of results above indicated we did not achieve results expected. This is due to two factors: (1) Groundwater received during pilot study was more concentrated with contamination and iron than expected. Cape intended to operate with a low ozone mass to contaminant ratio in order to fully evaluate formation of daughter products.

Sample Location Influent Effluent Influent Effluent Influent Effluent Influent Effluent

Date 6/19/12 6/19/12 6/20/12 6/20/12 6/21/12 6/21/12 6/26/12 6/26/12

ug/L ug/L % ug/L ug/L % ug/L ug/L % ug/L ug/L %

Chlorobenzene 3,030 1,170 61% 3,220 1,050 67% 3,330 1,470 56% 2,760 0.001 100%

1,2-Dichlorobenzene 26,700 8,130 70% 22,700 6,370 72% 23,800 8,320 65% 17,600 6,530 63%

1,3-Dichlorobenzene 1,220 234 81% 1,070 0.001 100% 1,180 300 75% 0.001 0.001 --

1,4-Dichlorobenzene 4,250 1,080 75% 4,040 858 79% 4,020 1,070 73% 2,870 0.001 100%

cis-1,2-Dichloroethene 6,730 3,300 51% 6,330 3,170 50% 6,870 3,650 47% 6,680 4,030 40%

Methylene chloride 3,980 2,390 40% 3,600 1,950 46% 3,700 2,110 43% 2,600 1,720 34%

Toluene 2,050 724 65% 1,780 0.001 100% 1,860 803 57% 1,520 599 61%

Trichloroethene 38,400 12,100 68% 34,600 10,100 71% 35,400 12,900 64% 25,900 9,980 61%

Total VOCs / % Reduction 86,360 29,128 66% 77,340 23,498 70% 80,160 30,623 62% 59,930 22859 62%

Pilot Study VOC Percent Reduction Data Table

Figure 2: Sequential Water Samples during Pilot

Figure 3: Data Summary Table for VOC Reduction Pilot Study Results (June 19-28, 2012)

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Interpretation of Pilot Study Results

Much of what we know about the degradation path-ways ,which define organic contaminant breakdown in reactions with ozone, are derived from the application of Ozonolysis. This is an analytical method, in which organics are broken down to elucidate their molecular structure. The degradation pathway during ozonation involves at least two reactions in series. Specifically alkenes (all of the primary contaminants analyzed in this study are chlorinated alkenes) react with ozone through two possible pathways forming either (1) a ketone and an aldehyde or (2) a ketone and an or-ganic acid.3

Breakdown of organics occurs along certain preferen-tial pathways in which the weakest bonds are broken first (or more rapidly and in greater numbers). In the case of chlorinated alkenes these bonds are (1) dou-ble bonds, which are converted to single bonds, and (2) chlorine/carbon bonds, which are converted to hy-drogen/ carbon bonds. This latter process (dechlor-ination) is less preferential and a much slower reac-tion. Knowing these few facts, we surmise degrada-tion pathways to divide contaminants into likely pri-mary reactants and likely daughter products or secon-dary reactants.

Analytes were divided into primary reactants and daughter products in order to analyze the degree of “incomplete oxidation.” This was used to determine theoretical ozone demand, which is then used to ex-trapolate a full scale design, based on pilot data. It is also utilized to estimate total ozone contact time with groundwater. It is critical to note in pilot studies where oxidation is complete, full-scale design basis cannot be accurately predicted, since “degree of oxidation” cannot be quantified. This situation can result in an unnecessary, but common, over sizing of full scale ozonation systems. As higher concentration ozone generators (16 % concentration by weight) are util-ized, it is suspected the rate of contaminant reaction will increase and overall ozone demand will decrease.

Depending upon the relative reaction rate of two reac-tions in series, the concentration of daughter products may increase in the reaction solution. The concentra-tion of primary reactants cannot increase in the reac-tion solution. With this information, we can conclude that daughter products, including ketones and other reactants, have concentrations which increase with statistical significance. We can also surmise that a

chemical could theoretically be a daughter product by verifying that its molecular structure is (in a physical sense) a component of the molecular structure of a primary (“parent” or “superior”) reactant. Primary re-actants can be identified in at least two ways: (1) they are the most complex (or “larger”) molecules and (2) they are known to have been a chemical that was likely to have been disposed of on site.

As part of the process to identify primary reactants, several compounds presented a challenge. In some cases, this was because compounds could be daugh-ter products, based upon their molecular structure or primary contaminants, based upon their commercial significance, potential use and/or subsequent disposal at the site. In other cases, compounds could be con-sidered primary contaminants, based upon their mo-lecular structure, but relative concentrations sug-gested they were not. In all cases, distinguishing be-tween primary and daughter compounds required an understanding of 1) the historical use of the com-pound, and 2) the chemical makeup and unintended chemical reaction byproducts which are supplied with all commercial chemicals. An example to illustrate this process: 1,2 dichlorobenzene (Ortho DCB or ODCB) which is present at some of the highest concentra-tions at the site, but based upon current commercial use, it would not be deemed a primary reactant. Closely related Chlorobenzene seems to be a degra-dation product of ODCB, based upon its molecular structure, and its concentration increased in one data set. However, Chlorobenzene is a used as a solvent today, with ODCB as a trace contaminant in the com-mercially available product. An important detail in this analysis was the finding that ODCB was widely used in the past for a very specific application: to soften and remove carbon deposits from metal parts, such as in engine rebuilding operations. In this product the other two DCB’s (also found at the site at lesser con-centrations) are common minor contaminants.

Percent removal of individual organic compounds were accurately estimated. Removal of primary con-taminants, was good, but not complete. Removal of daughter products varied greatly. Ketones (acetone, 2-butanone and 4-methyl-2-pentanone) had poor overall removal as these are primary structural daugh-ter products of various primary reactants, and with insufficient oxidizer, they are generated as fast or faster than they are degraded. Chlorobenzene and1,2 dichloroethane are also daughter products that are

Piper Environmental Group, Inc. Ozone Solutions for a Cleaner Earth TM

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more chemically stable than the “superior” product from which they derive, and thus also can be gener-ated faster than they are degraded with insufficient oxidizer. Solution

Piper’s successful pilot confirmed the proposed inno-vative design-build ozone solution to effectively de-stroy Contaminants of Concern (COC). To be suc-cessful, a complete, in depth analysis of SVOC, VOC, metals and bacteria was completed. Interpretation of these results included primary contaminants, degra-dation pathways and daughter product formation. This was extremely critical to determine ozone demand as ozone is non-preferential and will attempt to reduce all oxidizable compounds, including other oxidizers.

Determining maximum levels of contamination and predicting daughter product formation (indicating in-complete oxidation) was a complex mathematical model including maximum expected COC levels. This analysis was completed and an ozone generator pro-ducing 100 pound per day (PPD) at 10% concentra-tion by weight was verified to be sufficiently sized In order to handle expected 45—55GPM continuous wa-ter flow rate with 8 SCFM gas flow rate. Several addi-tional factors were taken into consideration: To en-sure complete oxidation of COC and reduction in daughter product formation, a sophisticated contact, mixing, and degassing solution was designed. Liquid to gas ratios were evaluated, optimal injection pres-sure for eduction determined, and degas relief valves, backflow prevention, ozone destruct units sized for the 8 SCFM maximum flow. Ultimately, Piper dou-bled the capacity of the ozone contact tank to ensure sufficient contact time due to the information discov-ered during the pilot study. This particularly relates to extensive daughter product formation.

Our experience has shown that waste water and groundwater which has been treated by properly de-signed ozone systems, followed by Granular Acti-vated Carbon (GAC), extends carbon life signifi-cantly. Other ozone + GAC systems have run for eight (8) years without media replacement. This is due to GAC acting 1) as ozone removal/destruct, 2) to elimi-nate bacteria in the media, and 3) as a polisher and not the primary treatment. This greatly reduces the long term operation and maintenance cost at the groundwater treatment facility.

This unique Piper ozone system, mounted solid on two individual steel skid, delivers 100 pounds per day (PPD) of ozone, and processes incoming water at up to 55 GPM. The ozone system was designed to re-duce levels of contaminants to below acceptable lev-els while significantly reducing O&M costs over the long term.

Full Scale Ozone Specifications

100-PPD Ozone generator @ 10% concentra-tion by weight 40-HP rotary screw air compressor at 166 SCFM feed gas 750 SCFH Oxygen concentrator Proprietary ozone mixing, contacting, and de-gassing 1,915-gallon stainless steel ozone contact tank ORP and Ambient Ozone monitors PLC and HMI integrated Control Panel

Timeline

Ozone pilot system :June 13-29, 2012 Ozone full scale system startup: February 27, 2014 Ozone system intended to run for 20 years

Payback Estimate

This system has been estimated to be eighteen (18) months.

Figure 4: Manufacture & Assembly in California

Military Installation, Central Georgia

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Results

The ozone system was fully functional on Febru-ary 27, 2014 and testing was initiated. The first Sampling event, noted to the right indicates imme-diate reductions of all Volatile Organic Com-pounds (all VOC tests included here via EPA SW-8260B). The below graph (Figure 5) indicates only measureable com-pounds tested. It was as-sumed that any non-detect level in effluent was provided a numerical level of 0.001. The increase in Acetone was consistent throughout sampling and is a daughter product of multiple degra-

Piper Environmental Group, Inc. Ozone Solutions for a Cleaner Earth TM

Figures 5 & 6 indicate immediate reduction post ozone of all measureable COCs. The standard to be met was Georgia’s ISWQC. Initial indicator contaminant Trichloro-ethylene (TCE) was not present. It is believed the new indicator will likely be Chlorobenzene. Figure 6 indicates an av-erage Chlorobenzene and 1,4-Dichlorobenze levels at 0.44 ug/l and 0.08 ug/l respectively post ozone with non-detect post GAC. The ozone sample is taken from sample point on the recirculation skid and the post GAC sample is taken post GAC. Figure 6: Average VOC concentrations through first 5 samples

Figure 5: First Ozone Sampling Event

0.001

0.01

0.1

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1000

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INFLUENT POST-OZONE POST-GAC

Co

nce

ntr

atio

n, u

g/L

(PP

B)

Sampled Points

Average VOC Concentrations

Vinyl Chloride

Acetone

cis-1,2-dichloroethene

Benzene

Toluene

Chlorobenzene

Ethylbenzene

1,2,4-Trimethylbenzene

1,3-Dichlorobenzene

1,4-Dichlorobenzene

1,2-Dichlorobenzene

Xylenes (total)

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INFLUENT POST-OZ POST-GAC

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VOC Reduction: First Sampling Event

Vinyl Chloride

Acetone

cis-1,2-dichloroethene

Benzene

Chlorobenzene

Ethylbenzene

1,3-Dichlorobenzene

1,4-Dichlorobenzene

1,2-Dichlorobenzene

Xylenes (total)

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Military Installation, Central Georgia

Figure 8: Average Percent VOC Reduction for Pilot and Full Scale

Figure 8 indicates the Av-erage Percent VOC re-duction in Pilot Study and Full Scale System. The importance of this is two-fold:

While able to estimate fi-nal full scale system cor-rectly prior to Pilot Study, the pilot study results pro-vided opportunity for in-depth analysis of COC, percent reduction, under-standing of daughter prod-ucts observed and con-firmed initial sizing need. Ozone was ideal solution even with incomplete oxi-dation during Pilot.

It is not known defi-nitely yet if the ex-tended contact time from the ozone skid to the GAC is re-sponsible for total destruction or if the GAC is polishing these contaminants.

Regardless, much like sizing waste stream for GAC us-age, it is critical to focus on all com-pounds and ions that contribute to treatment media, ozone requires the same attention to detail and a thor-ough understanding of all contaminants (metals, bacteria, VOC, SVOC, COD, BOD, etc) to prop-erly size for excel-lent results. Figure 7: Final installation at Military Installation in Central Georgia

0%

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Average Percent VOC ReductionPilot Study and Full Scale Results

Pilot Study Results

Full Scale Results

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Challenges Overcome during Startup:

1. Delays in delivery of process feed pumps due to inadequate procurement tracking

2. Power harmonic issues internal to ozone genera-tor prevented ozone production

3. Influent and Effluent flowmeters reading discrep-ancy

4. Air Compressor experienced low temperature alarms on integrated refrigerated air dryer due to uncharacteristically low temperatures during ex-treme winter event

5. Demister addition to mitigate excessive moisture carry over from tank off gas into the destruct

6. Back pressure on backflow prevention and de-struct

7. Contact tank lost prime, pressure, and volume during water processing

8. Ambient ozone alarms from ozone destructs and GAC sample point

9. Iron precipitation in GAC and neutralization tank , a consequence of iron solution chemical not 100% effective

10. Software upgrades to adjust based on changes above

11. Controls integration took approximately 4 itera-tions

12. GAC expansion joints

13. Foaming post iron solution injection

Summary

Overall, reduction of the COC’s and daughter prod-ucts has been extremely successful. Post GAC re-sults indicate this Military Installation in Central Geor-gia fully meets ISWQC target values and NPDES per-mit values for cleanup standards.

None of the VOC’s exceeded the ISWQC’s in either the post-ozone water samples or the post-GAC water samples.

This installation is expected to be a tremendous cost saving move for this Military Installation in Central Georgia.

Piper Environmental Group, Inc. Ozone Solutions for a Cleaner Earth TM

11600 California Street Castroville, California 95012

Phone: 831- 632-2700 Fax: 831- 632- 2701

For more information, visit www.peg-inc.com Ozone Solutions for a Cleaner Earth TM

Piper Environmental Group, Inc.

With special consideration and appreciation to our innovation seeking project partners:

Mr. David Fortune,

Mr. John Thomas, and

Mr. Nelson Rosa of Cape

Visit: www.cape-inc.com

Cape is Recognized by their clients as best provider of safe, innovative, cost efficient remediation and construction solutions.

Sources 1 Fortune, David, and Miller, Merle. RFQ: Robins AFB—

Provide an Equipment System Designed to Treat the Land-fill 3 Extracted Groundwater, March 09, 2012. Print. 2 Piper, Jane and Horn, Brad. Summary Report: Robins Air

Force Base—Landfill 003, Groundwater Treatment Pilot Test for Ozonation System, August 2012. Print. 3 Fessenden, RJ et al, Organic Chemistry, 4th Ed, Brooks/

Cole Publishing, Pacific Grove, CA 1990, pages 433-434

Company Profile

Piper Environmental Group, Inc. offers ozone technology,

equipment, and services for a wide-range of environmental

applications. The company designs, manufactures, and

integrates ozone systems and related equipment for short

and long-term projects, offering equipment for rent or pur-

chase. Services include project design assistance, oxida-

tion pilot studies, contract service, equipment repair, con-

sulting.

Our area of expertise is large, custom remediation projects

within the United States.

500 Pinnacle Court Norcross, GA 30071

(770) 908-7200