多糖型微生物絮凝剂处理方铅矿浮选废水的效能研究

Study on the Efficiency of Polysaccharide-type Microbial Bio-flocculant in Treating Galena Flotation Wastewater

方铅矿浮选废水包含微细矿物颗粒、重金属离子与有机药剂三种复合污染源,为实现其一步深度净化处理,探究了绿色环保的多糖型微生物絮凝剂(MBF)对微细方铅矿颗粒的絮凝沉降及对Pb^(2+)与丁基黄药的吸附去除作用,并对其作用机理进行了研究。结果表明,MBF可吸附于方铅矿表面使其稳定悬浮于矿浆中,但吸附黄药后的方铅矿颗粒可被MBF有效絮凝沉降,絮凝率最高为82.5%;MBF对黄药与Pb^(2+)有较强的吸附性,黄药与Pb^(2+)最高去除率分别为94.3%与86.7%。Zeta电位、红外光谱分析表明,MBF主要通过羟基与方铅矿表面的Pb^(2+)发生化学作用而吸附于矿物表面;与方铅表面形成的黄原酸铅疏水基团形成氢键或缔合,使微细方铅矿颗粒快速絮凝沉降;MBF也可通过静电作用吸附去除废水中的Pb^(2+).

In order to improve the problem of one-step deep purification treatment of galena flotation wastewater which contained three compound pollution sources of fine mineral particles,heavy metal ions and organic chemicals,the flocculation sedimentation of fine galena particles and the adsorption and removal of Pb^(2+) and butyl xanthate by green polysaccharide-based microbial bio-flocculant(MBF)were practices and its mechanism were studied.The results showed that MBF could be adsorbed on the surface of galena to make it stably suspended in pulp,while the galena particles adsorbed xanthate could be effectively flocculated and settled by MBF,and the highest flocculation rate was 82.5%.MBF had strong adsorption capacity for butyl xanthate and Pb^(2+),and the highest removal rates of butyl xanthate and Pb^(2+) were 94.3%and 86.7%,respectively.Zeta potential and infrared spectrum analysis showed that MBF was mainly adsorbed on galena surface through the chemical interaction of hydroxyl group and Pb^(2+).MBF forms hydrogen bond or association with the hydrophobic group of lead xanthate formed into the galena surface,which made the fine galena particles flocculate and settle rapidly.MBF could also remove Pb^(2+) from wastewater by electrostatic adsorption.