The document summarizes a study on nutrient removal from slaughterhouse wastewater using an intermittently aerated sequencing batch reactor (SBR). The study used a laboratory-scale SBR system that was fed slaughterhouse wastewater. The SBR was able to achieve high removal rates of over 96% for COD, total nitrogen, and total phosphorus. Analysis showed that two-thirds of nitrogen removal was due to denitrification and one-third was used for biomass synthesis by microorganisms. Partial nitrification occurred due to the intermittent aeration pattern, with 95% of nitrogen removal via denitrification occurring through nitrite.

1. Nutrient R emoval from S laughterhouse W astewater in an I ntermittently A erated S equencing Ba tch R eactor

2. Outline Introduction Method 1. Laboratory-Scale Sequencing Batch Reactors (SBR) System 2. Slaughterhouse Wastewater 3. Operation of the System 4. Analytical Methods Results and Discussions 1. Overall Performance of the SBR Reactor 2. Cycle Performance Conclusions Reference

3. Introduction Slaughterhouses produce high-strength wastewater. The amount of wastewater generated per cow is approximately 2 m 3 per day . In pig slaughterhouses, 1.6 – 8.3 m 3 of water per tonne . S laughterhouse w astewater can be variable . - S uspended S olids (SS) - Chemical Oxygen Demand ( COD ) - Total Nitrogen ( TN ) - Total Phosphorus ( TP )

4. Introduction O n-site biological treatment by European Commission - R emove O rganic C arbon (C) - R emove N utrients The European Commission also recommends that Sequencing Batch Reactors (SBRs) be amongst the Best Available Techniques (BATs) for Slaughterhouse wastewater treatment.

5. Introduction SBRs are capable o f: - R emoving organic C - R emoving nutrients - R emoving SS - H ave low capital - Low operational costs SBRs are not able to remove nitrogen (N) as efficiently as COD. Anoxic heterotrophic denitrifiers reduce nitrate-N (NO 3 -N)/nitrite-N (NO 2 -N), which is produced in the preceding operational cycle and remains in the reactor after the draw phase, to nitrogen gas (N 2 )

6. Introduction P accumulating organisms (PAOs) will compete with denitrifiers for rbCOD for anaerobic P release. A conventionally operated SBR can be changed to an intermittently aerated SBR, where one complete operational cycle comprises four phases – fill, react, settle and draw. If the DO in the reactor tank is controlled properly by means of intermittent aeration, NH 4 -N will be partially oxidized to NO 2 -N and then in the mixing period, NO 2 -N will be reduced to N 2 gas. the performance of a laboratory-scale, intermittently aerated SBR for simultaneous N and P removal from slaughterhouse water was investigated.

7. Method Laboratory- S cale Sequencing Batch Reactors (SBR) System Slaughterhouse W astewater Operation of the S ystem Analytical M ethods

8. Method Laboratory- S cale Sequencing Batch Reactors (SBR) System

9. Method Collected from the conditioning tank in the wastewater treatment plant (WTP) Reduce COD and N Tertiary treatment (chemical coagulation) Reduce P The WTP comprises: - Preliminary treatment (screening and dissolved air flotation) - A conditioning tank - Primary treatment (sedimentation) - Secondary treatment (conventional activated sludge pre-denitrification process) Slaughterhouse W astewater

10. Method Operation of the S ystem

11. Method COD, BOD5 and SS were measured in accordance with the standard APHA methods Where: TN i is the amount of N (mg) contained in the influent wastewater fed into the reactor tank during the fill phase TN o is the amount of N (mg) contained in the effluent wastewater leaving the reactor tank during the draw phase TN M is the amount of N (mg) utilized by microorganisms for biomass synthesis (TND) i is the amount of N (mg)removed from the reactor tank by means of denitrification in the i th non-aeration stage (i = 1, 2, 3, 4) Analytical M ethods

12. Results and D iscussions Overall P erformance of the SBR R eactor Cycle P erformance

13. Results and D iscussions Overall P erformance of the SBR R eactor

14. Results and D iscussions Cycle P erformance

15. Conclusions At an influent OLR of 1.2 g COD/(L d), average effluent concentrations of COD, TN and TP were 150 mg/L, 15 mg/L and 0.8 mg/L, respectively. This represented COD, TN and TP removals of 96%, 96% and 99%, respectively. A nitrogen balance was carried out and showed that 66% of N removed was due to denitrification and 34% was consumed by microorganisms for biomass synthesis. Partial nitrification occurred in the system, possibly due to the intermittent aeration pattern employed in the SBR system. 95% of N removal by means of denitrification was via NO2-N.

16. Reference Nutrient Removal from Slaughterhouse Wastewater in an Intermittently Aerated Sequencing Batch Reactor - Bioresource Technology, Volume 99, Issue 16, November 2008, Pages 7644-7650 J . P . Li, M . G . Healy, X . M . Zhan, M . Rodgers