Biological treatment of grey water using sequencing batch reactor

The aim of this study was to investigate the application of sequencing batch reactor (SBR) technology for treating grey water collected at outlet of showers room of students. The performance of SBR was satisfactory as the effluent had respectively 20 and 5 mg/L of COD and BOD. Applied two hydraulic retention times (HRTs) showed that the nitrogen and phosphorus removal could be improved while adapting to load variations.

The SBR system can effectively remove nutrients and promote biodegradation of organic matter for domestic grey water. The SBR reactor achieved 90% COD removal and good sludge settling properties (SVI < 100 mL/g). When the reactor operated with 2.5 d HRT the nitrification rate increased and the effluent is exempted of ammonium but the performance of system to remove phosphorus is decreased. The application of two HRTs showed that the nitrogen and phosphorus removal could be improved while adapting to load variations.