Abstract：
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 continuous treatment of municipal wastewater to evaluate longrun 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 mg/L,100 % and 100 %.Under such conditions,the effluent quality could outperform the grade 1 level A in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918—2002),with COD,ammonia nitrogen and total nitrogen removal efficiencies reaching 95%,99% and 91%,respectively.
LIU Yaqin,XIE Jing,LIU Ningyu et al. Experimental Research of Nitrogen Removal from MunicipalWastewater by Inverted A/O Process with Circulating Zeolites[J]. Safety and Environmental Engineering, 2018, 25(06): 42-47.
