采用电化学方法再生低温生物沸石的参数优化及效果评价

Parameter optimization and evaluation of regenerating biological zeolite at low-temperature by electro-chemical method

低温环境下（1~5℃）,受生物膜包裹的沸石（以下简称低温生物沸石）对氨氮的去除效率较低。研究通过电化学氧化技术对低温生物沸石进行再生,促进了氨氮在水溶液和沸石内部的持续转移和转换。采用平面响应曲面法对电化学再生低温生物沸石进行参数优化和硝化能力评价。结果表明,高浓度的氯化钠有利于提升再生率,但会降低硝化能力的恢复率;硫酸钠的影响次之。再生时间越长再生效果越好,但影响度逐渐趋弱,同时再生时间长会制约硝化能力的恢复。经模型拟合预测,采用电化学再生的最优参数和运行条件为：电解液采用286.30mg/L氯化钠和554.15mg/L硫酸钠配制,再生时间设置为2.66h。此条件下,能实现90.75%的再生率,61%的硝化能力恢复率。将优化后的参数应用于悬浮填料-沸石曝气生物滤池的电化学再生试验中表明,实际硝化能力恢复率为78%,较模型预测值大,而再生率与预测值基本吻合。

At low temperatures（1~5 ℃）,zeolite wrapped by biofilm（hereinafter referred to bio-zeolite）performed low ammonia nitrogen removal efficiency.A research was carried out to promote continuous transfer and conversion of ammonia in an aqueous solution and inside the zeolite by electrochemical technology.For the purpose of parameter optimization and performance evaluation,response surface methodology（RSM）was used.The results showed that high concentration of sodium chloride was conducive to enhance the regeneration rate,but it would also reduce nitrification recovery rate;the impacts of sodium sulfate concentration would follow that of sodium chloride.The longer regeneration time was,the better the regeneration rate would be;however,its affecting efficiency was gradually weakening.Meanwhile,long regeneration time would restrict the recovery of nitrification.By fitting the prediction model,the optimal parameters and operating conditions of the electrochemical regeneration method was as follows：using 286.30mg/L NaCl and 554.15mg/L NaSO_4 to prepare the electrolyte,setting the regeneration time at 2.66 h.This could achieve 90.75% of regeneration rate and 61% of nitrification recovery rate.The optimized parameters wereapplied in a suspended media-zeolite biological aerated filter experiment,it was showed that actual nitrification recovery rate was 78%,better than the value predicted by the model,and the regeneration rate was almost consistent.