AWWA QTC97144

In recent years, many Asian countries have found their water supply sources have become contaminated with human and livestock wastes leading to high levels of ammonia nitrogen in the water sources. As most Asian countries practice breakpoint chlorination, high ammonia is a serious water treatment problem that requires increases in chlorine dosage. A new water treatment works is under construction in Hong Kong for the treatment of water drawn from a river or reservoir. As the river water is high in ammonia, different treatment processes from those currently in use were recommended for the new plant. A pilot plant study was conducted to evaluate the recommended processes and to establish design criteria and operational parameters. This paper discusses the pilot-scale study of ammonia removal by biological filters. Parameters including start up time, filter media and configuration, ammonia levels, pH, alkalinity, and dissolved oxygen were investigated in order to optimize the ammonia removal efficiency of the filters.