城市污水二级硝化出水的离子交换脱氮除磷

SIMULTANEOUS NITROGEN AND PHOSPHORUS REMOVAL FROM MUNICIPAL SECONDARY TREATMENT EFFLUENT BY ION EXCHANGE

以城市污水二级硝化出水为原水,对比研究了3种强碱性阴离子交换树脂(201×4、D296、D301T)动态脱氮除磷情况,并以201×4树脂为模式树脂考察了树脂活化方式(常规酸碱交替活化与NaCl再生液活化)、腐殖酸(HA)浓度(1.1,2.8和9.4mg.l-1)对树脂动态脱氮除磷的影响.结果表明,3种树脂都具有较好的脱氮除磷效果,达到TP穿透点(0.1mg.l-1,去除率92%)时,201×4树脂具有最大的穿透体积(418BV),但其对NO3--N的去除率(69%)明显低于其它树脂(97%—98%);3种树脂对SO42-和HA的去除率分别为97%—99%,71%—80%;常规酸碱活化使树脂穿透体积较再生液活化仅提高了12%;超滤膜法和臭氧氧化法预处理对原水HA的去除率分别为27%和68%;原水HA浓度增加使树脂穿透体积从281BV降至239BV,同时NO3--N去除率从80%上升至92%.

Simultaneous removal of nitrogen and phosphorous from municipal secondary nitrification effluent by ion exchange were investigated using 3 kinds of strong-base anion-exchange resins（201 ×4, D296, D301T）in a dynamic mode in a column reactor. Subsequently, the effects of resin activation methods （conventional acid-base alternate activation, NaC1 regenerant activation）, the concentration of humic acid（HA） （ 1.1, 2. 8 and 9. 4 mg · l^-1 ） on the dynamic adsorption performance of the 201 x 4 resin were also investigated. The following results were obtained ： （ 1 ） All 3 resins showed excellent simultaneous phosphorus and nitrogen （ nitrate） removal performance while 201 x4 resin achieved the largest breakthrough volumes of 418 BV at a leakage level of 0. 1 mg P · l^-1 and the lowest NO3--N removal efficiency（69% ） , and its SO2- and HA removal amounted to 97%--99% and 71%--80% respectively. （2） The breakthrough volumes of 201 x 4 resin increased by only 12% using conventional acid-base alternate activation rather than NaCl regenerant. （3） The HA removal efficiency were 27% and 68%, respectively when ultrafiltration and ozonation were individually used as pretreatment procedure. With the increase in HA concentration in raw wastewater, breakthrough volumes decreased from 281BV to 239 BV and NO3 -N removal efficiency increased from 80% to 92%.