Applicability Of Volcanic Baf For Pretreatment Polluted Source Water

With the development of social economy, the quality of the source of drinking water in our country is getting worse day by day. The removal rate of ammonia nitrogen and organic matter in polluted source water by conventional treatment method is rather low, and disinfecting process can form organic halide which will do harm to person. So it has very important practical significance to seek an effective, practical and economical water treatment method. Tests show the biologic treatment technology isn’t economical and effective, but also is security in toxicology. Biological aerated filter (BAF) have many advantages, such as small volume, little covering earth and hydraulic retention time (HRT), high treatment efficiency and effluent water quality etc and has great potential of applicationIn this study, volcanic filler is used as biological carrier of biological aerated filter (BAF). A bench scale research on dealing polluted source water for pretreatment was earried out. The removal effect of ammonia, nitrite, CODMn, UV254, iron, manganese, and turbidity was investigated. Furthermore, several factors considered affecting biological aerated filter with volcanic filler process have been examined which are rate of filtration, water temperature, Media height of BAF, shut own of BAF, backwashing. A pilot-scale research on dealing polluted source water for pretreatment was carried out. The aeration biological filter treatment effect was mainly studied under low temperature.The bench scale experiment results show that the average removal rate of ammonia, nitrite, CODMn, UV254, iron, manganese and turbidity is95.17%,92.73%,22%,6.54%,48.49%,78%and45.56%, respectively under at the air/water ratio of1:1, rate of filtration of8m/h, when the water temperate of10-23.2℃. The average removal rate of ammonia, CODMn is73.42%and9.10%, respectively when the water temperate of4.8-10℃. Appropriate rate of filtration has little influence on the effect of BAF. The increaseing of media height of BAF can improve the removal effect of BAF to a certain extent. Backwashing and shut down for a long time of BAF has little impact on the removal effect of BAF.The pilot scale experiment results show that under at the air/water ratio of1:1, dealing water of4.2m3/h, the average removal rate of ammonia, nitrite, CODMn, UV254, iron, manganese and turbidity is93.66%,95.23%,20.32%,4.8%,48.49%,21.65%,64.49%and33.96%, respectively when water temperature of10-32.4℃; and the removal rate of ammonia nitrite and CODMn was83.32%,50.95%and12.26%, respectively when water temperature of5.5-10℃. There was no accumulation of nitrite in the reactor.Therefore, the volcanic BAF pretreating polluted source water is not only able to control the ammonia, nitrite, and the removal rate CODMn, iron, manganese et al is higher, so it can reduce the load on the subsequent treatment process.