生活污水深度处理后作电厂循环冷却水试验研究——以东滩煤矿为例

Experimental study on advanced treatment of domestic sewage used as recirculating cooling water of a power plant: a case study of Dongtan mine

针对东滩煤矿生活污水二级生化处理后的水量和水质特点,采用同步生物氧化池(SBOT)、澄清池和砂滤池相结合的深度处理工艺进行生产性试验.结果表明:SBOT水力停留时间3.6h,平均气水体积比3∶1,澄清池清水区液面负荷2.17m3/(m2.h),砂滤池滤速7.7m/h;在澄清池进水中投加NaOH 110mg/L、聚合氯化铝(PAC)25mg/L,滤池进水中投加H2SO420mg/L;总出水平均质量浓度CODCr15.6mg/L,NH4+-N 0.54mg/L、钙硬度229mg/L(以CaCO3计)、甲基橙碱度175mg/L(以CaCO3计)、悬浮物(SS)0.81mg/L;相应平均去除率分别为66.6%,96.6%,38.7%,43.3%,92.9%,均达到《工业循环冷却水处理设计规范》(GB50050-2007)的要求.

According to the characteristics of water quality and quantity after the secondary biochemical treatment of domestic sewage at Dongtan coal mine,the research adopts simultaneous biological oxidation tank （SBOT）, clarifier and sand filter to carry out the production test. The results show that： Under the conditions of the mean hydrodynamic retention time （HRT） of 3.6 h and the mean air-water ratio of 3 ：1 of SBOT, the mean surface setting rate of 2. 17 ma/（m2 ·h） of clarifier,the mean filtration rate of 7.7 m/h of filter,the sodium hydroxide dosage of 110 mg/L and the polymeric-aluminium dosage of 25 mg/L in the inlet of clarifer,and the H2SO4 dosage of 20 mg/L in the inlet of filter,the mean concentrations of CODcr ,NH 4 -N,caleium hardness, methyl orange alkalinity and suspended solids in the last effluent are 15. 6 rag/L,0.54 rag/L,229 mg/L（as CaCO3）,175 mg/L（as CaCO3） and 0.81 mg/L,with the mean removal rates of 66.6%,96.6% ,38.7%,43.3% and 92.9% ,respectively. The effluent quality can meet the demands of China＇s code for design of industrial recirculating cooling water treatment （GB50050-2007）.