“复合A/O硅藻精土”工艺小型城镇生活污水DESAR处理系统的处理效果研究

摘要

For quality and quantity characteristics of sewage,task force developed the“composite A/O di-atomite” process system,examine its effect on the treatment of urban sewage. Results show:①In the diat-omite dosage of 150 mg/L,the system is running a load of 80%,system processing effect is the best,the removal rate of COD is 40% ~50%,the removal rate of NH3-N is only about 30%,and the TP removal rate can reach 70% ~80%;②The sludge inoculation period compared with conventional activated sludge process significantly shorter,and without adding nutrients to the growth of micro-organisms will be able to well.③Sludge and the mixture refluxed had great affect on treated water quality. Water reflux is not obvi-ous to the system treatment. Take aerobic tank gas-water ratio 2. 5∶1 to 7. 5∶1,the removal rate of N-NH3 can reach above 85%,and the operating cost is the least.④Opened mixture reflux,diatomite dosage is 150 mg/L,when the operation load of 80%,the anaerobic pool HRT is 1. 5 h,the aerobic pool HRT is 2. 0 h,sludge recycle ratio of 50% ~100%,the gas-water ratio between 2. 5∶1 to 7. 5∶1,the removal effi-ciency of each pollutant index was the best. Water quality and stability to achieve China’ s“urban sewage discharge standards” (GB 18918—2002) A standard.%针对城镇污水的水质、水量特性,设计了“复合A/O硅藻精土”工艺的小型城镇生活污水处理系统,考察其对城镇生活污水的处理效果。结果表明：①硅藻精土投药量150 mg/L、系统运行负荷80%时,处理效果最佳,COD去除率40%~50%、NH3-N的去除率仅为30%左右,TP去除率可达70%~80%；②本系统污泥接种周期较传统活性污泥法明显缩短,且无需投加营养物质,微生物便能很好生长；③污泥回流和混合液回流对系统出水水质影响较大,清水回流对系统处理效果不明显。好氧池气水比2.5∶1~7.5∶1(体积比)时,系统对N-NH3去除效果能达到85%以上；④开启混合液回流的状态下,硅藻精土投加量150 mg/L,运行负荷为80%时,厌氧池HRT为1.5 h,好氧池HRT为2.0 h,污泥回流比50%~100%,好氧池气水比2.5∶1~7.5∶1时,出水水质稳定达到我国《城镇生活污水排放标准》(GB 18918—2002)一级A标准。