Penyingkiran ammonia secara biologi menggunakan bakteria semulajadi dalam biopenuras pasir

Abstract

Drinking water treatment through biological process is commonly applied in developed countries, but not yet in developing countries such as Malaysia. The non-existence of biological treatment has urged drinking water treatment plant operator in Malaysia to shut down the plants whenever there are ammonia contaminations. This is to avoid the formation of disinfection byproducts (DBPs), which are toxic and carcinogenic, when ammonia reacts with chlorine as the disinfectant. The study aims to develop a biological drinking water treatment for to remove ammonia in a biological sand filter column. The derived biofilm, a mixed bacterial consortium is naturally cultured from surface lake water, hence eliminating the potential of pathogenic microorganism occurrence, which is not suitable for drinking water application. The biofilm was inoculated in the batch down flow column consisting of heterogeneous fine sand with diameter of 1.2 mm (top layer) and 6.7 mm (bottom layer). The study was conducted by varying the flowrate (0.09, 0.13, and 0.18 m/h) and hydraulic retention time (HRT) (5 and 24 hours). The water sample was taken at different depths of 0.05 m (SP4), 0.1 m (SP3) and 0.2 m (SP2) from the column base for the ammonia analysis. Significant reduction of ammonia with 96-98% was observed at 0.09 m/h and 24 hours and the final treated effluent had complied with the stringent regulation stipulated by the Malaysia, Ministry of Health that is lower than 1.5 mg/L.