Biological treatment of greywater using sequencing batch reactor technology

A pilot scale sequencing batch reactor (SBR) was operated to study removal of organics from greywater. The study consisted of two stages of experiments. The first stage investigated the effect of cycle time. Results of the first stage were employed to conduct the second stage of experiments that investigated the effect of the fill and react phases for the cycle time with a better performance. All experiments were run in a 25-litre bench scale single tank reactor, where the react phase period was 1.5 times the fill phase period. Results of the first stage indicated the highest COD and SS removals for the cycle time of six hours, with removal percentages ranging between 50% to 83% for COD and 90% to 100% for SS. Results of second stage indicated that the operational mode of 2 hrs fill and 3 hrs react achieved highest treatment efficiency, with an overall COD percent removal ranging between 75% and 94%.