融入城市生态景观的地下式再生水厂设计与运行--以安康市江南再生水厂为例

Design and operation of und erground reclaimed water plant merging into urban eco-landscape:A case study of Ankang Jiangnan reclaimed water plant

再生水厂建设对节约水资源具有重要意义。安康市江南再生水厂为地下式再生水厂,其建设规模为8×10^(4) m^(3)·d^(−1)。该再生水厂主要处理该市江南城区的生活污水,无工业有毒难降解废水,主要污染物为耗氧有机物(以COD、BOD5计)、SS、NH_(3)-N、TN、TP等,满足可生化条件。针对生活污水的水质特点,该再生水厂采用“改良A^(2)O+悬浮填料+高效沉淀”工艺。再生水厂出水COD和NH_(3)-N执行地表水准Ⅳ类标准,即COD和NH3-N分别为30 mg·L^(−1)和1.5 mg·L^(−1),出水其余指标执行《城镇污水处理厂污染物排放标准》(GB18918-2002)中的一级A标准。剩余污泥经“离心浓缩脱水+低温干化”处理至含水率≤60%后,进行外运处置。该再生水厂投产至今运行稳定,出水水质稳定达标。此外,该再生水厂采用地下式设计使其融入城市景观,可为同类城市的市政工程建设提供参考。

The construction of reclaimed water plant is critical for water saving.The scale of the underground Jiangnan Reclaimed water Plant in Ankang city is 8×10^(4) m^(3)·d^(−1).The Plant mainly treats domestic sewage in Jiangnan region of the city and receives no toxic and difficult-to-degrade industrial wastewater.The main pollutants are oxygen-consuming organics(COD,BOD5),SS,NH_(3)-N,TN,TP,etc.,which meet the biochemical degradable standards.According to this characteristic,the reclaimed water Plant adopts the improved A2O+suspended filler+efficient precipitation process.Effluent is subject to Class Ⅳ surface water quality standards,with limits on COD and NH3-N being 30 mg·L^(-1) and 1.5 mg·L^(-1) respectively.Other water quality parameters are subject to class 1A standard of the Discharge Standard of pollutants for municipal wastewater treatment plant(GB18918-2002).After centrifugal concentration and dehydration+low-temperature drying treatment,the waste sludge has a moisture content lower than 60%and is then transported for disposal.The plant has been running stably since it was put into operation,and the effluent water quality has reached the standard.The design of the underground reclaimed water plant provides reference for the construction of similar works.