浙江某工业废水处理厂升级改造运行效果解析

Analysis on Upgrading and Retrofitting Effect of an Industrial Wastewater Treatment Plant in Zhejiang

浙江某工业废水处理厂升级改造,采用AAO—MBBR复合生物膜工艺,在未新增建设用地和扩建池容的基础上,日处理量由3×10^(4)m^(3)/d提高至6×10^(4)m^(3)/d。改造后实际运行出水COD、TP、NH_(3)-N和TN浓度分别为(37.7±6.61)、(0.09±0.03)、(0.25±0.14)和(5.87±1.54)mg/L,出水水质稳定达到一级A标准。实际监测表明,在好氧MBBR区存在TN去除现象,约占TN总去除量的10.36%。系统内的优势硝化菌属为硝化螺旋菌属Nitrospira,其在悬浮载体生物膜和活性污泥中的相对丰度分别为8.98%和0.92%,悬浮载体的投加使硝化细菌得到有效富集;反硝化菌在生物膜中的占比为7.94%,为悬浮载体同步硝化反硝化(SND)效果的发生提供了微观保证,提高了TN去除率。

An industrial wastewater treatment plant in Zhejiang was upgraded by a combined process consisting of anaerobic/anoxic/oxic activated sludge process and moving bed biofilm reactor(AAO-MBBR).Without changing the footprint and increasing the reactor volume,the treatment capacity increased from 30000 m^(3)/d to 60000 m^(3)/d after retrofitting.Concentrations of COD,TP,NH3-N and TN in effluent were(37.7±6.61)mg/L,(0.09±0.03)mg/L,(0.25±0.14)mg/L and(5.87±1.54)mg/L,respectively,which met the first class A standard.Actual operation data indicated that TN removal existed in the aerobic MBBR zone(accounting for 10.36%of total TN removal).Nitrospira was the dominant nitrifying bacteria in the system,and its relative abundance in the suspended carrier and activated sludge was 8.98%and 0.92%,respectively,indicating that the addition of suspended carrier could effectively enrich the nitrifying bacteria.The proportion of denitrifying bacteria on biofilm was 7.94%,which created a microenvironment for the occurrence of simultaneous nitrification and denitrification(SND)in the suspended carrier and improved the TN removal efficiency.