TREATMENT OF A DAIRY FARM WASTEWATER TREATMENT OF A DAIRY FARM WASTEWATER USING A PILOT SCALE UPFLOW ANAEROBIC USING A PILOT SCALE UPFLOW ANAEROBIC

SLUDGE BLANKET (UASB) PROCESSSLUDGE BLANKET (UASB) PROCESS

By

Ashveen Deerpaul & Arvinda Kumar RAGEN

PRESENTATION PLAN

Introduction

Aim & Objectives

Methodology

Results & Discussions

Conclusions

INTRODUCTION

Dairy Farming in Mauritius

Water consumption in a dairy farm• 175 L per cow per day

Water usage in a dairy farm:• Direct water usage• Indirect water usage

INTRODUCTION

Dairy FarmWastewater

Organic MatterPathogens

Suspended Solids

Nutrients

AIM & OBJECTIVES

Aim:• Assess the performance of a Pilot Scale UASB reactor during the

treatment of dairy farm wastewater

Objectives:• Characterize the dairy farm wastewater.• Characterize the influent and effluent in terms of COD, VFA, TSS,

pH.• Evaluate the performance of the UASB reactor at varying HRT.• Characterize the biogas produced.• Perform a preliminary design of an industrial scale UASB reactor for

a local dairy farm.

METHODOLOGY

Collection of raw wastewater

METHODOLOGY

Experimental Set up

METHODOLOGY

Set up of UASB reactor

METHODOLOGY

Pre-treatment of wastewater

Sampling Protocol

Stream Sampling Type

Raw Wastewater Composite

Reactor Influent Grab

Reactor Effluent Grab

Sludge Grab

METHODOLOGY

Analytical Parameters

• The raw wastewater was analyzed for COD, pH, TSS, nutrients, TKN and Total Coliform.

• The UASB influent and effluent were sampled and analyzed for COD, VFA, pH, Temperature and TSS

• The Sludge was analyzed for VSS, TSS, SV and Sludge Activity Test (SAT)

METHODOLOGY

RESULTS & DISCUSSIONS

Parameter Range Mean

pH

Temperature, C

COD, mg/L

TSS, mg/L

TKN, mg/L

NH3 – N, mg/L

PO42-, mg/L

Total Coliforms, CFU/100ml

7.8 – 8.4

23.7 – 28.4

7840 – 11220

23560 – 33432

358 – 528

150 – 325

32 – 93

1.7 108

8.0

25.9

9550

29123

448

261

62

-

Characteristics of raw wastewater

RESULTS & DISCUSSIONS

Parameter Range Mean

pH

Temperature, C

CODt, mg/l

CODs, mg/l

TSS, mg/l

VFA, mg/l

VFA/COD

6.7 – 7.2

28.8 – 35.5

5980 – 8020

2400 – 3460

2296 – 13468

283.3 – 986.2

0.09 – 0.29

7.0

32.5

6735

2843

7159

439.2

0.15

Characteristics of Influent

RESULTS & DISCUSSIONS

Appearance of UASB Effluent

RESULTS & DISCUSSIONS

Characteristics of effluent

Parameter Range Mean

pH

CODt, mg/l

CODs, mg/l

VFA, mg/l

TSS, mg/l

7.2 – 7.5

790 – 6080

240 – 2570

49.6 – 277.7

86 – 1188

7.3

2762

1006

116.5

430

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96

Day of Operation

CO

Dt

(mg/

l)

CODt-influent CODt-effluent

RESULTS & DISCUSSIONS

Effluent COD profile

0

10

20

30

40

50

60

70

80

90

100

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96

Day of Operation

% C

OD

rem

oval

% CODt % CODs

RESULTS & DISCUSSIONS

Performance of UASB reactor (% COD removal efficiency)

Average COD removal efficiency = 78.7%

0

10

20

30

40

50

60

70

80

90

100

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96

Days of Operation

% V

FA

co

nver

ted

RESULTS & DISCUSSIONS

Performance of UASB reactor (% VFA conversion)

Average VFA converted = 72.9%

0

10

20

30

40

50

60

70

80

90

100

57 60 63 66 69 72 75 78 81 84 87 90 93 96

Days of Operation

%C

OD

rem

ov

al

HRT 12h - % CODt HRT 12h - % CODs HRT 8h - % CODt

HRT 8h - % CODs HRT 6h - % CODt HRT 6h - % CODs

Performance of UASB reactor at varying HRT

RESULTS & DISCUSSIONS

RESULTS & DISCUSSIONS

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96

Days of Operation

Gas

pro

du

ced

(l/

d)

Biogas production

PRELIMINARY DESIGN

Drawn by: DEERPAUL Ashveen

Date: 01 April 2008

Title: Process Instru. Diagram

UASB treatment Plant

Scale: Not to Scale

Figure 5.19

Pump

Safety relief Valve

Non-return Valve

Flow Control Valve

LT Level Transmitter

FT Flow Transmitter

T.I Temperature Indicator

p.H pH Transmitter

Flow arrows and controls

NaOH flow

Biogas flow

Effluent flow

Wastewater flow

Legend

wastewater

Screen

Holding tank EQ tank

NaOH

UASB reactor

Final effluent

Biogas

Effluent Tank

PRELIMINARY COSTING

Summary of costs Cost (Rs)Equipment costs:UASB reactorEqualisation tankCentrifugal pumpNaOH Dosing pumpAgitatorTotal purchased equipment cost

455,706141,850

28,85027,20048,000

701,606

Total Direct costs   1,547,042

Total Indirect costs   739,891

Total Fixed Capital Investment   2,286,933

Working Capital   403,576

TOTAL CAPITAL INVESTMENTTOTAL ANNUAL COST

  2,690,509220,000

CONCLUSIONS

COD removal efficiencies: 78.7%

VFA conversion: 72.9%

TSS removal efficiencies: 94.2%

Optimum HRT of 8 hrs

Maximum gas production: 8.89 L/d

In light of this study, it can be concluded that the UASB process is appropriate for the treatment of wastewater generated by a local dairy farm.

• Adopt a tertiary treatment using a Horizontal Subsurface Constructed Wetland

• Use of the biogas emanating from the UASB reactor:

• Cooking purposes• Produce electricity• Alternative fuel

RECOMMENDATIONS

• Energy recovery potential from the biogas produced from the UASB reactor.

• Effect of VFA toxicity and shock loads on the methanogenic sludge can be investigated.

• Variation of methanogenic activity along the height of the UASB reactor.

• Image characterization of the sludge.

• Possibility of integrated farming using the treated effluent.

FUTURE WORKS

THANK YOU FOR YOUR KIND ATTENTION