AAO-生物膜工艺处理电镀废水的脱氮除磷性能

NITROGEN AND PHOSPHORUS REMOVAL PERFORMANCE OF AAO-BIOFILM PROCESS FOR ELECTROPLATING WASTEWATER TREATMENT

为提高电镀废水的污染物去除效率,探讨厌氧-缺氧-好氧(AAO)-生物膜耦合工艺的有机物去除和脱氮除磷效能。结果表明:AAO-生物膜工艺处理电镀难降解有机废水运行效果良好,COD去除率稳定在89%左右;脱氮主要途径是好氧硝化,缺氧反硝化,60 d运行中系统脱氮率达到70%~80%;难降解有机物影响NH_(4)^(+)-N和COD的去除效率,且存在时间差距,在其影响下,NH_(4)^(+)-N的变化稍滞后于COD。AAO-生物膜工艺的除磷效果经50 d运行后趋于稳定,出水TP浓度低于1 mg/L,去除率>65%,除磷主要依靠厌氧释磷和好氧吸磷过程。

To improve the pollutant removal efficiency of electroplating wastewater, the removal efficiencies of organic matter, nitrogen and phosphorus by anaerobic anoxic aerobic(AAO)-biofilm coupling process were discussed. The experimental results showed that the AAO-biofilm process owned good operation performance for treating refractory organic matters in electroplating wastewater, and the COD removal rate was stable at about 89%. The majority of nitrogen was removed through nitrification in the aerobic tank and denitrification in the anoxic tank. The nitrogen removal rate of the system reached 70%~80% after 60 days operation. Refractory organics affected the removal efficiency of NH_(4)^(+)-N and COD and made a time gap between them. The change of NH_(4)^(+)-N lagged behind COD. The phosphorus removal performance of the AAO-biofilm process tended to be stable after 50 days operation, the effluent concentration was less than 1 mg/L, and the removal rate was more than 65%. Phosphorus was mainly removed through anaerobic release and aerobic absorption of the functional microorganisms.