Abstract

5 bed sand filter, applying biological oxidation, was designed and studied on the treatment of water works. Never using any coagulant agent (drugs), which may cause water pollution in pre-treatment of head water, the author attempt a high rate filtration by the microorganism (nitrofication bacteria) end plant which populate in multi layer sand beds. The result are as follows ; In order to evaluate the oxygen effect on filtration, oxygen was injected in aeration tank attached to each filter tank while filtration, and NH3 was tested as a representative ingredient. It was found out that the aeration method was more effective, with over 33% of NH3 removal capacity, than the anerobic and this 5 bed filter showed double removal capacity of NH3 by comparing with conventional sand bed (2 stage bed). According to the examination of two kind of head water, pre-treated with coagulant agent and activated carben, the filtration capacity was affected by the polluted condition of head water, resulting that lower value of pollution and slower velocity of filtration showed more efficiency of NH3 removal. In this experiment NH3 content tested in treated water had a fairly good correlation with others.