城市污水二级硝化出水的离子交换脱氮除磷

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9.4 mg·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(0.1 mg·l~(-1),去除率92%)时,201×4树脂具有最大的穿透体积(418 BV),但其对NO_3~--N的去除率(69%)明显低于其它树脂(97%-98%);3种树脂对SO_4~(2-)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28lBV降至239BV,同时NO_3~-去除率从80%上升至92%.

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

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, NaCI 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 × 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 × 4 resin achieved the largest breakthrough volumes of 418 BV at a leakage level of 0.1 mg P ·l~(-1) and the lowest NO_3~--N removal efficiency(69%), and its SO_4~(2-) and HA removal amounted to 97%-99% and 71%-80% respectively. (2) The breakthrough volumes of 201 × 4 resin increased by only 12% using conventional acid-base alternate activation rather than NaC1 regenerant. (3) The HA removal efficiency were 27% and 68%, respectively when uhrafihration 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 NO_3~--N removal efficiency increased from 80% to 92%.