海藻酸钠-超滤组合处理含铅废水

胶团强化超滤技术(MEUF)中通常采用表面活性剂作为外加有机物,存在价格昂贵且具有二次污染的风险。本研究选取天然有机物海藻酸钠作为外加物,研究了海藻酸钠强化超滤去除含Pb废水的特性及影响因素。实验结果表明,Freundlich模型可用于海藻酸钠溶液对Pb2+的吸附过程;海藻酸钠及其与Pb络合物的红外光谱分析表明,海藻酸钠中的OC-OH基团在吸附Pb2+中起着重要的作用。当Pb2+的浓度40 mg/L,海藻酸钠投加量为100 mg/L,pH7时,MWCO为4 kDa、6 kDa、10 kDa、30 kDa、50 kDa和70 kDa的膜均可实现对其的高效截留,截留效率均达到95%以上。随着pH值的升高,超滤膜对于Pb2+的截留效果越好。超滤浓缩液在pH值调节到13时,可将几乎100%的Pb回收。

Alginate enhanced ultrafiltration for treatment of lead-containing wastewater

Micellar-enhanced ultrafiltration (MEUF) usually takes surfactants as the additional organics and it may cause secondary pollution and cost expensively. Alginate as a kind of natural organic was used in the MEUF process and the effective factors and characteristics were investigated in this paper. The experimental results showed that the adsorption process of between alginate and lead could be expressed by the Freundlich isotherm model. The infra-red spectrum analysis on the alginate and the alginate-Pb compound demonstrated that the OC-OH group taken great effects on the adsorption process. The UF membranes with MWCO 4 kDa,6kDa, 10 kDa, 30 kDa, 50 kDa, 70 kDa could remove the lead ion with the efficiency of more than 95% under the conditions of the initial Pb²⁺ concentration less than 40 mg/L, the alginate concentration of 100 mg/L, pH=7. The lead rejection rate increased with the pH increasing. More than ninety-nine percent of the total lead in the concentrated solution could be recovered by increasing the pH value to 13.