Treatment Of Slaughterhouse Effluent Using Upflow Anaerobic Packed Bed Reactor

Most of the slaughterhouses in the state of Kerala (India) do not have proper and effective effluent treatment facilities. Collection of blood and separation of manure to reduce the very high organic load of the effluent are also not practiced. As a result, large volumes of extremely complex effluents with high content of fat, grease, and protein are discharged into land or water bodies causing severe pollution. This study evaluated the performance of an upflow anaerobic packed bed reactor (APBR) with randomly packed PVC pipe pieces as packing media, in treating effluent from a municipal slaughterhouse. (pH 7, suspended solids 1673 ±857 mg/L, total dissolved solids (TDS) 4017 ± 1704 mg/L, oil and grease 107±54 mg/L, chemical oxygen demand (COD) 7600 ±3445 mg/L, ammonia nitrogen 102±57 mg/L and total phosphates 123±76 mg/L). The effluent responded well to treatment in APBR with a significant reduction (>80%) of COD when operated for about 200 days. Pretreatment using aluminium chloride (AlCl3 at 100 mg/L) was found essential for removing oil and grease. For an organic loading rate (OLR) of 4-5 kg of COD/m3/day, and 24 hour hydraulic retention time (HRT) about 88% COD reduction, 85-98% suspended solid removal, 30% reduction of ammonia nitrogen and phosphates and 15% TDS removal were observed. A post treatment of the effluent was however found necessary to achieve land or inland water discharge standard.