以印染废水为主的某城镇污水处理厂提标改造工程实例

Upgrading and Reconstruction Project of an Urban WWTP Mainly Engaged in Printing and Dyeing Wastewater Treatment

嘉兴市某城镇污水处理厂为印染废水高占比污水处理厂,其接纳污水中55.2%为印染废水。污水厂原有处理规模为3.0万m^(3)/d,采用AO工艺,出水排放执行《城镇污水处理厂污染物排放标准》(GB 18918—2002)一级B标准。本次提标改造工程增加污水处理量至4.0万m^(3)/d,出水指标提升至浙江省《城镇污水处理厂主要水污染物排放标准》(DB 33/2169—2018),在原处理工艺末端新增“活性炭吸附池-终沉池-滤池-消毒池”,利用粉末活性炭吸附尾水中SS和难生物降解的有机物。提标改造后工艺平稳运行,出水的CODCr、BOD5、SS、TN、氨氮和TP平均值分别为37.99、7.98、7.50、5.22、0.83 mg/L和0.10 mg/L,出水水质稳定达标,提标后污水处理成本增加0.34元/m^(3)。运行结果表明,对于有提标改造需求的城镇污水处理厂,在经济和技术上都是可行的。

An urban wastewater treatment plant(WWTP)in Jiaxing City receives 55.2%of the wastewater as printing and dyeing wastewater,which is a high proportion of printing and dyeing wastewater WWTP.The original design scale of this urban WWTP in Jiaxing is 30000 m^(3)/d,adopting AO process,and the effluent reaches the first class B criteria in the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB 18918—2002).The wastewater discharge is increased to 40000 m^(3)/d after upgrading and reconstruction,and the effluent standard is raised to the Discharge Standard of Major Water Pollutants for Municipal Wastewater Treatment Plants(DB 33/2169—2018),at the end of the original treatment process,“activated carbon adsorption tank,final sedimentation tank,filter tank and disinfection tank”are added to remove suspended solids and refractory organics.The average values of CODCr,BOD5,SS,TN,ammonia nitrogen and TP are 37.99,7.98,7.50,5.22,0.83 mg/L and 0.10 mg/L,respectively.The effluent quality is stable and up to standard.After upgrading and reconstruction,the added cost of wastewater treatment is about 0.34 yuan/m^(3).The operation results show that it is feasible in economy and technology for urban WWTPs that need to upgrade their standards.