Aerobic digestion efficiency for mixed sludge (primary and secondary) of West Ahvaz wastewater Treatment plant in Batch reactor

Introduction: To stabilize organic matter of sludge, aerobic digestion is commonly applied for small wastewater treatment plants (0.2 m3/s), but recently it has also been used for large scale wastewater treatment plants. Digested sludge is readily dewatering and for use in agriculture. Methods and Materials: Aim of this Bench scale study is determination of aerobic digestion performance for mixed sludge of west Ahwaz sewage treatment plant by batch reactor. In this study cubic glacial bioreactor with (33×15×21) dimensions has been used. Then 7 liter of mixed sludge (3L from primary and 4 Lfrom secondary sludge) loaded. Aeration was carried out in 25 day by aquarium aerators.COD, VSS, TVS, TSS, TS,OUR tests examined in bioreactor. Results: Results showed that after 12 days 38% of TVS reduced. This meets the environmental standards. After 19 days detention time in the bioreactor, COD, VSS, TVS, TSS, TS, were 40 ,56, 54.5 ,50.4 ,44.7 percent respectively. Kd coefficient was,0.173day-1. Conclusions: aerobic digestion was useful for mixed sludge of west Ahwaz sewage treatment plant.