Abstract
High nitrate concentrations in drinking water cause a potential risk to public health, especially for infants. In this study, nitrate removal process using a novel acryl resin fiber biofringe (BF) material as biomass carrier and swim-bed technology was performed in a biological denitrifying reactor (DNBF). This process combines many advantages of both fixed-bed and fluidized-bed such as a long sludge retention time, low effluent suspended solids and turbidity, reduced sensitivity to toxic loads, high treatment efficiency and no need for sludge recycle, etc. Denitrification efficiencies of 80~90% at volumetric loading rates of up to 1.44 kg/m3/d were achieved in this study with the simple operation and easy maintenance of DNBF process. Clear effluent with low SS levels of less than 10 mg/l were observed in whole experimental period. Sludge yield of 0.29 g VSS/g NO3-Nremoved and the average sludge retention time of 44 days were approximately calculated. The adaptation in denitrification of DNBF to the change of reactor bulk DO level, stirrer speed, C/N ratio and influent NO3– concentration were also investigated in this study.
