基于沸石循环的倒置A/O工艺对市政污水脱氮效果试验研究

Experimental Research of Nitrogen Removal from Municipal Wastewater by Inverted A/O Process with Circulating Zeolites

针对市政污水处理成本高、出水总氮含量不达标的问题,提出了一种基于沸石循环的倒置A/O生物脱氮工艺用于处理市政污水,并采用正交试验方法研究了溶解氧(DO)、内回流比(r)和污泥回流比(R)对该工艺脱氮效果的影响,且在最佳运行条件下进行了模拟市政污水连续稳定运行试验以及实际市政污水处理效果验证试验。结果表明:该工艺去除COD的能力较强且稳定;DO和r对该工艺脱氮效果的影响显著;当DO为1.0mg/L、r为100%、R为100%时,该工艺可实现优化稳定运行,其出水水质优于我国《城镇污水处理厂污染物排放标准》(GB18918—2002)中一级A标准限值的要求,可使COD的平均去除率达到95%以上,NH3-N的平均去除率高达99%,TN的平均去除率达到91%以上。

Considering the high cost and incomplete nitrogen removal in municipal wastewater treatment, this paper proposes an inverted A/O process with circulating zeolites to treat municipal wastewater. The paper studies the effects of dissolved oxygen （DO） ,internal reflux ratio and sludge reflux ratio on nitrogen removal efficiency through orthogonal test. Under optimal operation conditions,the paper conducts contin uous treatment of municipal wastewater to evaluate long run performance of the system. The results show that this system could achieve stable and higher COD removal efficiency,with DO and internal reflux ratio being two major parameters affecting the denitrification. The optimal operating conditions are defined, with DO,internal reflux ratio and sludge reflux ratio set at 1.0 rag/L,100 % and 100 %. Under such conditions, the effluent quality could outperform the grade 1 level A in Discharge Standard of Pollutants for Munici pal Wastewater Treat,%ent Plant （GB 18918 2002） ,with COD,ammonia nitrogen and total nitrogen re moval efficiencies reaching 95 %, 99 % and 91 %, respectively.