1. TREATMENT OF A DAIRY FARM WASTEWATER USING A PILOT SCALE UPFLOW ANAEROBIC SLUDGE BLANKET (UASB) PROCESS By Ashveen Deerpaul & Arvinda Kumar RAGEN

2. PRESENTATION PLAN Introduction Aim & Objectives Methodology Results & Discussions Conclusions

3. 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

4. INTRODUCTION Dairy Farm Wastewater Organic Matter Pathogens Suspended Solids Nutrients

5. 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.

6. METHODOLOGY Collection of dairy farm wastewater Pre-treatment of the wastewater Set-up of UASB reactor Sampling Protocol Analytical Method

7. METHODOLOGY Collection of raw wastewater

8. METHODOLOGY Experimental Set up

9. METHODOLOGY Set up of UASB reactor

10. METHODOLOGY Pre-treatment of wastewater

11. METHODOLOGY Operating conditions WeekFlow rate (L/h) HRT (hours) OLR (KgCOD/m 3.d) Upflow velocity (m/h) 1, 2, 5 6-8 9-10 11-12 13-14 0.44 0.73 1.21 1.81 2.42 33 20 12 8 6 4.9 8.1 13.1 20.8 26.8 0.06 0.09 0.15 0.23 0.31

12. Sampling Protocol StreamSampling Type Raw WastewaterComposite Reactor InfluentGrab Reactor EffluentGrab SludgeGrab METHODOLOGY

13. 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

14. RESULTS & DISCUSSIONS ParameterRangeMean pH Temperature,  C COD, mg/L TSS, mg/L TKN, mg/L NH 3 – N, mg/L PO 4 2-, 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  10 8 8.0 25.9 9550 29123 448 261 62 - Characteristics of raw wastewater

15. RESULTS & DISCUSSIONS Characteristics of Sludge ParameterConcentration pH Temperature,  C TSS, mg/l VSS, mg/l SAT, gCOD rem /gVSS.d 7.14 32 9744 7795 0.95

16. RESULTS & DISCUSSIONS ParameterRangeMean pH Temperature,  C COD t, mg/l COD s, 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

17. RESULTS & DISCUSSIONS Appearance of UASB Effluent

18. RESULTS & DISCUSSIONS Characteristics of effluent ParameterRangeMean 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

19. RESULTS & DISCUSSIONS Effluent COD profile

20. RESULTS & DISCUSSIONS Performance of UASB reactor (% COD removal efficiency) Average COD removal efficiency = 78.7%

21. RESULTS & DISCUSSIONS Performance of UASB reactor (% VFA conversion) Average VFA converted = 72.9%

22. Performance of UASB reactor at varying HRT RESULTS & DISCUSSIONS

23. Biogas production

24. PRELIMINARY DESIGN Volume of EQ tank30 m 3 Height of tank4300 mm Diameter of tank - at bottom - at center 3000 mm 3200 mm Thickness - at bottom - on top 25 mm 12 mm Construction materialFibre glass Equalization Tank

25. PRELIMINARY DESIGN Volume of reactor Height of reactor 40 m 3 4000 mm Diameter of reactor3600 mm Thickness of wall200 mm Material of construction Height of the GLS separator No. of gas dome Base diameter of dome Top diameter of dome (W t ) Depth from top of the dome,  h Height of inclined wall of dome, h Length of inclined wall of dome Width of the water surface (Ws) Reinforced concrete 1330 mm 1 3200 mm 500 mm 200 mm 1350 mm 1760 mm 2900 mm UASB reactor

26. PRELIMINARY DESIGN

27. wastewater Screen Holding tankEQ tank NaOH UASB reactor Final effluent Biogas Effluent Tank

28. PRELIMINARY COSTING Summary of costsCost (Rs) Equipment costs: UASB reactor Equalisation tank Centrifugal pump NaOH Dosing pump Agitator Total purchased equipment cost 455,706 141,850 28,850 27,200 48,000 701,606 Total Direct costs 1,547,042 Total Indirect costs 739,891 Total Fixed Capital Investment 2,286,933 Working Capital 403,576 TOTAL CAPITAL INVESTMENT TOTAL ANNUAL COST 2,690,509 220,000

29. 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.

30. 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

31. 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

32. THANK YOU FOR YOUR KIND ATTENTION