Study On Filature Wastewater Reuse With Biological Aerated Filter

In this study, to settle the main problems existing in the field of sewage difficult to treat reuse in filature plant, a method of filature sewage which uses aerobic biological aerated filter (BAF) craft was discussed. In this technics, Plastic as the biological aerated filter biological media. Based on the lab-scale experiment systemietrial was processed and considering the water quality demand of reuse water, BAF experimentwas conducted, the treated object is domestic sewage comes from filature plant . According to the experiment datum and theoretical analysis, a new proeess of low-strength domestic sewage treatment in filature plant was provided with the merits such as low investment,low operation cost and simple management.In lab-scale experiment, designed a complete treatment process for the filature wastewater treatment, the performance of BAF is studied.The main objects studied here are the disposal effieieneies of color,COD,BOD5,Ammonium-nitrogen,SS and other factors which can influence the efficiency. The experiment reaches a conelusion that:When using plastic as the media, the factors that can influence the performance of BAF are: the media height,the ratio of gas to lid,the ratio of gas to liquid, hydraulic loading and so on.When the ratio of gas to liquid is change, the color, the removal effect of SS is little. The ratio of gas to liquid is set at 3:1 the removal efficient of ammonium-nitrogen and COD is the most; The hydraulic loading is in the scope of 0.23-0.6 m3 / (m2 ? h) , the BAF has better removal efficiency of suspend, The hydraulic loading is in the scope of 0.18-0.6 m3 / (m2 ? h) , the reactor remove organic matter efficiency will not be affected, The hydraulic loading from 0.15 m3 / (m2 ? h) rose to 0.23 m3 / (m2 ? h), the removal ammonium-nitrogen rate changes smaller, this reaches a conelusion that in the scope of the hydraulic loading the ammonium-nitrogen removal rate are stable, But when the hydraulic loading from 0.15 m3 / (m2 ? h) rose to 0.6 m3 / (m2 ? h), the average ammonium-nitrogen removal rate droped 24.7 percentage points, it's make out that HRT to the nitrification reactor capacity is impact. For the up flow BAF, when the media height is 2m, the best media height for the removal of most COD, most ammonium-nitrogen and most SS is at 40-60cm, 80-90cm and 30cm from bottom respectively.The results of a set process lab-scale treat filature wastewater BAF experiment shows: The removal efficient of the pollutants is best when the best acidification HRT is 20h, the BAF aeration time is 8h, hydraulic loading is 0.23 m3 / ( m2 ? h), the ratio of gas to liquid is 3:1. The color removal rate is 95.5%, SS total removal rate is 89.1%, COD total removal rate is 85.2%, The total ammonium-nitrogen removal rate is 78.8%, BOD5 total removal rate is 82.9 percent, and corresponding concentration of effluent is color 15 degrees, SS25mg / L, COD35mg / L, ammonium-nitrogen 7.5 mg / L, BOD58.6mg / L, can be achieved (GB/T18920-2002) the request of reuse.