Comprehensive evaluation on a prospective precipitation-flotation process for metal-ions removal from wastewater simulants.
Comprehensive evaluation on a prospective precipitation-flotation process for metal-ions removal from wastewater simulants.
复制标题
DOI：
10.1016/j.jhazmat.2019.03.048
复制
发表时间：
2019-06
影响因子：
13.6
通讯作者：
Hongyan Wu;Wenjuan Wang;Yan-fang Huang;Guihong Han;Shuzhen Yang;Shengpeng Su;Hafiza Sana;W. Peng-W.-P
中科院分区：
文献类型：
--
作者：
Hongyan Wu;Wenjuan Wang;Yan-fang Huang;Guihong Han;Shuzhen Yang;Shengpeng Su;Hafiza Sana;W. Peng-W.-P
有毒金属污染物威胁着水环境。常规沉淀浮选存在不期望的金属离子浓度限制。研究了一种高效去除二价金属离子的强化沉淀浮选体系。该系统涉及到添加腐殖酸和Fe 3+的生成和调节沉淀。通过颗粒分析、条件稳定常数和DLVO理论计算以及SEM和TEM图像研究了沉淀物的特征。结果表明，在低浓度下，金属离子与腐殖酸发生螯合作用，生成的沉淀颗粒粒径小于2.0 μm，分形维数为1.60-1.80，沉淀效率小于91.00%。加入三价Fe ~（3+）后，可得到粒度约为10.0 μm、分形维数为1.50-1.60的宏观沉淀，沉淀物几乎全部被浮选去除。Fe ~（3+）与腐殖酸的螯合作用是主要的调节机制，它能提高低浓度金属离子的条件稳定常数和沉淀效率。通过突破金属离子浓度的限制，最终获得所需的沉淀颗粒。对Cu ~（2+）、Pb ~（2+）和Zn ~（2+）的浮选去除率分别为99.10 ± 0.10%、99.60 ± 0.10%和94.30 ± 0.30%。因此，强化沉淀浮选法是一种有效的含金属废水净化方法。
Toxic metal pollutants threaten water environment. It exists undesirably metal-ion concentration limits with conventional precipitation flotation. An enhanced precipitation flotation system focusing on efficient removal for bivalent metal-ions was researched. The system involved the addition of humics and Fe3+to generate and regulate the precipitates. The characteristics of precipitates were investigated by particle analysis, conditional stability constants and DLVO theory calculations, and SEM&TEM imaging. The results reveal that metal-ions chelate with humics at low metal-ion concentration, with generating the limited micro-size precipitates of <2.0 μm, fractal dimension of 1.60–1.80 and precipitate efficiency of <91.00%. By adding trivalent Fe3+, the macro-size precipitates are obtained with particle size of approximate 10.0 μm, fractal dimension of 1.50–1.60, and nearly-total flotation removal of precipitate. The chelating interaction of Fe3+with humics is the mainly regulating mechanism, which could enhance the conditional stability constants and the precipitate efficiency of metal-ions at low concentration. The desired precipitate particles are finally obtained by breaking the limitations of metal-ion concentration. Finally, the flotation removal of metal-ions from single or mixed solutions is respectively 99.10 ± 0.10% for Cu2+, 99.60 ± 0.10% for Pb2+, and 94.30 ± 0.30% for Zn2+. Therefore, the enhanced precipitation flotation process is an efficient purification approach for metal-containing wastewaters.