Nutrient removal in grey water from wet market using sequencing batch reactor

Abstract

Fresh water scarcity has become an important issue in this world today. Water reuse was known as one of the strategies to overcome this problem. Grey water is one of the sources of reused water. Several researches were carried out on water reuse, but limited attention was focused on reusing grey water from wet market, which contains high nutrient and organic matters. This study was carried out on nutrient removal from grey water using sequencing batch reactor (SBR). The grey water sample was taken from a wet market (Pasar Peladang, Skudai). About 1L of grey water was fed into the reactor with a total volume of 4L. Anoxic-aerobic phase were divided with a ratio of 30%-70% of total time respectively. Mixing was maintained at 30 rpm during the start of each cycle until settling phase to achieve uniform condition. Influent and effluent were set for 30 minutes. The SBR was operated with 3 cycles/day, temperature 30°C, cycle time 8 hours and hydraulic retention time (HRT) 1.2 days. Aeration at 35 L/min was induced for ammonia conversion and nitrification purpose. The results show that the bacteria growing in alternating anoxic/aerobic systems could remove organic substrates and nutrient. The COD, Total Nitrogen and Total Phosphorus removal efficiencies were maximum at the levels of 94%, 88% and 70% respectively. Anaerobic-Aerobic-Anoxic phase was proposed to increase the removal percentage.