Evaluation of sequencing batch reactor performance in handling organic shock loads of ammonia wastewater

Abstract The urea fertilizer industry, in its production process, produces wastewater with a very high ammonia content, which can reach up to 20.000 mg/L. Therefore, before being discharged into water bodies, wastewater needs to be treated, one of which is using a sequential reactor named Sequencing Batch Reactor (SBR). SBR technology is a simpler technology compared to conventional activated sludge because in its whole process, SBR only needs one reactor. SBR is also able to handle organic and hydraulic shock loads that often occur in industry. The aim of this research is to evaluate the performance of SBR in reducing ammonia and COD contents in wastewater during normal organic loads and when organic shock loads occur. The research results showed that seeding and acclimatization processes were successfully conducted. SBR was fairly capable in reducing ammonia and COD levels in wastewater during normal loading (16.478 mg/L of ammonia) and during organic shock loading (20.198 mg/L of ammonia). The efficiency of reducing ammonia and COD levels was 68.16% and 79.43%, respectively during normal loading; 37.5% and 85.72% during organic shock loading; 36.11% and 93.98% when organic shock loading was continued for 15 days without addition of wastewater feeding for 7 days.