AMMONIA REMOVAL FROM SEWAGE USING NATURAL AUSTRALIAN ZEOLITE

A rapid adsorption process, which utilises the ammonium ion selectivit y of a natural Australian zeolite, is being developed for removal of a mmonia from sewage. The study reported in this paper claims not to hav e invented nor discovered this technique of ammonia removal from waste water, but aims to realise the value of this natural Australian resour ce as an efficient alternative to existing treatment processes. An und erstanding of the equilibrium and kinetic behaviour of this material p rovided insight into its expected capacity as an adsorption media. Fav ourable results led to pilot scale trials, which revealed excellent pe rformance of the zeolite under continuous column operation. The zeolit e adsorption process has proved effective, at pilot scale, in reducing ammonium ions in sewage from concentrations ranging from 25 to 50 mg NH4-N/L down to levels below 1 mg NH4-N/L. Under optimised operating c onditions, the adsorption capacity of the zeolite for this range of in fluent ammonium concentrations was about 4.5 mg NH4-N/g. The rate of t reatment by the pilot zeolite column makes it ideally suited as a retr ofit to high rate secondary sewage treatment processes, for removal of the soluble ammonium component. Copyright (C) 1996 IAWQ. Published by Elsevier Science Ltd.