Simultaneous Biological Removal of Iron, Manganese and Ammonium Nitrogen in Simulated Groundwater Using Biological Aerated Filter

Abstract

The simultaneous biological removal of iron, manganese and ammonia from simulated contaminated groundwater was studied by biological aerated filter using dual layer ceramsite as support material in the lab. The system was simultaneously inoculated with iron and manganese oxidizing bacteria, nitrifying bacteria and nitrification bacteria and a series of experiments was performed to investigate simultaneous removal performance of the filter. The influence of variation flow rate on simultaneous removal of manganese, iron and ammonia nitrogen was studied. At the mean time effluent concentration and removal ratio of manganese, iron and ammonia nitrogen along the filter depth were analysized. The results showed that the simultaneous removal of the aforementioned pollutants can be achieved by single-step filtration for high pollutants load (influent concentration 2.52~4.22mg/l, 1.22~3.97mg/l, 1.24~3.92 mg/l, respectively). Biofiltration ability to remove Mn for mixed bacteria on the filter can be improved by a sudden increase of flow rate(flow rate was 20l/h, 40l/h, 60l/h and 80l/h,respectively). But iron and ammonia removal were unaffected by a sudden increase of flow rate. Manganese was the rate-limiting pollutant.