PENENTUAN KOEFISIEN YIELD (Y) DAN KOEFISIEN ENDOGENOUS DECAY (kd) PADA PROSES LUMPUR AKTIF TERHADAP AIR TERPRODUKSI DENGAN REAKTOR BATCH

Abstract

Produced water is a waste material in drilling activity of oil and gas industry, containing high salinity, dissolved organics, suspended organics and heavy metals. The application of biotechnology using activated sludge was begun with planning and designing the wastewater treatment installation. Activated sludge coefficients, the yield coefficient (Y) and the endogenous decay (k_d) were needed in the reactor dimension design, sludge production estimation and oxygen required. Determination of the acclimated mixed-culture’s Y and k_d toward produced water, taken from oil and gas drilling area in Poleng, Java Sea, was set aerobically in batch reactor for 24 hours. The best nutrient composition (BOD₅ : N : P) was determined for 96 hours aeration time, considering the highest efficiency removal of COD, TSS and oil and grease among variations given.

The results showed that the best nutrient composition in removing COD, TSS and oil and grease was 100 : 10 : 1, with removal efficiency up to 70,59%, 63% and 81,41%. Y and k_d of mixed-culture toward produced water with additional nutrient were 0,3806 mg VSS/mg COD and 0,0602 day^-1. Whereas, non-additional nutrient showed a result of Y and k_d: 0,3684 mg VSS/mg COD and 0,0736.day^-1.