间歇曝气SBR处理火力发电厂废水的脱氮性能研究

Study on Denitrification of Thermal Power Plant Wastewater by an Intermittently Aeratated Sequencing Batch Reactor

采用间歇曝气序批式膜生物反应器(IASBR)合并处理火力发电厂的脱硝氨站废水和再生废水,研究不同再生废水水质和m(COD)/m(TN)运行条件下的脱氮性能。结果表明,进水Ca^(2+)浓度对脱氮稳定性影响大,m(COD)/m(TN)对脱氮效率影响大,当进水Ca^(2+)为332 mg/L时,NH_4^+-N去除率为96.0%,TN去除率分别为71.0%(m(COD)/m(TN)=1.7)和88.9%(m(COD)/m(TN)=3.7)。当进水Ca^(2+)质量浓度提高至750 mg/L时,NH_4^+-N和TN的去除率降至31.5%和29.8%,w(MLVSS)/w(MLSS)从61%降低至21%。将进水Ca^(2+)质量浓度降至61 mg/L并间歇排泥,w(MLVSS)/w(MLSS)和NH_4^+-N去除率分别提高至71%和99.1%,但TN去除率仅为26.0%(m(COD)/m(TN)=3.2),说明反应器遭受高Ca^(2+)冲击后,脱氮性能难以在短期内恢复。IASBR实现了在低碳氮比条件下的高效脱氮,在处理高氨氮低碳氮比废水上具有优越性,但控制进水Ca^(2+)质量浓度是稳定运行的关键。

The ammonia station wastewater and regenerating wastewater from thermal power plant were treated by intermittently aerated sequencing batch reactor （IASBR）, the effect of regenerating wastewater characteristics and the ration of chemical oxygen demand to total nitrogen （COD/TN） on denitdfication were investigated. The results showed that, the stability of nitrogen removal performance was mainly impact by the calcium ion （Ca2＋ in the influent, and the nitrogen removal rate was greatly influenced by the COD/TN ratio. When Ca2＋ concentration was 332 mg/L, the NH4＋N removal rate was 96.0% and the TN removal rates were 71.0% and 88.9% when COD/TN was 1.7 and 3.7 respectively. When the Ca2＋ concentration was increased to 750 mg/L, the removal rates of NH4＋-N and TN were sharply decreased to 31.5 % and 29.8%, respectively, and the mixed liquor volatile suspended solids to mixed liquid suspended solids （MLVSS/MLSS） ratio was dropped from 61% to 21%. Aider decreased the Ca2＋ concentration to 61 mg/L and intermittent discharged the sludge, MLVSS/MLSS ratio and Nh4＋-N removal were increased to 71% and 99.1%, respectively, while the removal rate of TN was only 26% with COD/TN ratio of 3.2, revealing that the TN removal was difficult to recover in a short time after suffering from a higher Ca2＋ cuncentration shock loads. IASBR achieved a high TN removal when wastewater treated with high cuncentration of ammonia while low COD/TN ratio, and the influent of the Ca2＋ concentration was a key factor to maintain a stable operation.