改性活性炭处理污水厂低温尾水的中试研究

Pilot-scale study on treatment of low temperature tail water in wastewater treatment plant by modified activated carbon

采用Fe(NO3)3浸渍-煅烧联合改性的方法制备改性活性炭(Fe-AC),在冬季低温条件下处理东北某污水厂的尾水,开展中试试验研究。利用SEM、质量滴定、BET等手段对原活性炭(AC)及Fe-AC进行表征,对比分析AC与Fe-AC对水中氨氮、总磷和CODCr等污染指标的去除效果。经改性后活性炭的比表面积增大36.21 cm2/g,总孔体积增大0.037 cm3/g,零电点由8.11增大至10.08。相同条件下,Fe-AC对水中各污染指标的去除效果优于AC。活性炭滤柱的最佳运行条件为:滤速9 m/h,滤层高度120 cm。此时,尾水处理量为6.8 t/d,经改性活性炭滤柱处理后氨氮、总磷和CODCr的出水平均质量浓度分别可达0.2、0.07、25 mg/L左右,3种污染物出水指标均满足GB 3838-2002《地表水环境质量标准》的Ⅳ类水体标准。

Modified activated carbon(Fe-AC)prepared by Fe(NO3)2 dipping-calcination combined method was used to treat tail water from a sewage treatment plant in northeast of China,and then,a pilot-scale study was carried out.Using SEM,quality titration,BET and some other measures to characterize activated carbon(AC)and Fe-AC,the removal rates of ammonia nitrogen,total phosphorous,CODCr and some other pollutants by the above two reagents were comparatively analyzed.It could be seen that,through the modification,the specific surface area of activated carbon increased by 36.21 cm2/g;the total pore volume increased by 0.037 cm3/g,and the zero point increased from 8.11 to 10.08.Under the same condition,compared to AC,Fe-AC has better removal efficiency on various pollution indicators in water.The optimal operation condition was as follows:the filtration rate was 9 m/h,the filter layer height was 120 cm.At this time,the tail water treatment capacity was 6.8 t/d,the average mass concentrations of ammonia nitrogen,total phosphorous,and CODCr in the effluent water treated by the modified activated carbon reached about 0.2,0.07 and 25 mg/L respectively,which met the requirement of classⅣwater body standards in GB 3838—2002 Surface Water Environmental Quality Standards.