Nitrogen Removal from Groundwater Using a Swim-bed Biological Reactor

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 fi ber 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 fi xed-bed and fl uidized-bed such as a long sludge retention time, low effl uent suspended solids and turbidity, reduced sensitivity to toxic loads, high treatment effi ciency and no need for sludge recycle, etc. Denitrifi cation effi ciencies of (cid:3442)(cid:3434)~(cid:3443)(cid:3434)% at volumetric loading rates of up to (cid:3435).(cid:3438)(cid:3438) kg/m (cid:3437) /d were achieved in this study with the simple operation and easy maintenance of DNBF process. Clear effl uent with low SS levels of less than (cid:3435)(cid:3434) mg/ l were observed in whole experimental period. Sludge yield of (cid:3434).(cid:3436)(cid:3443) g VSS/g NO (cid:3437) (cid:244) N removed and the average sludge retention time of (cid:3438)(cid:3438) days were approximately calculated. The adaptation in denitrifi cation of DNBF to the change of reactor bulk DO level, stirrer speed, C/N ratio and infl uent NO (cid:3437)– concentration were also investigated in this study.