【作者】 林丹；

【导师】 曾光明； 黄瑾辉；

【作者基本信息】 湖南大学 ， 环境工程， 2010， 硕士

【摘要】 镉类金属毒性较大,对人、植物和动物都能产生极大危害。水体中的镉污染主要来自于电镀厂、有色金属冶炼厂和矿山的废水排放。胶团强化超滤是基于表面活性剂独特的双亲分子结构特征,使表面活性剂和超滤技术相结合用以处理低浓度的金属离子的新方法。与传统的超滤相比,胶团强化超滤有许多的优点。如技术的成本降低了很多,而且更能有效地去除水中的镉金属离子。同时,与吸附、蒸馏和萃取法相比,胶团强化超滤法能耗低,无相交,且处理后的水可直接回用。但经胶团强化超滤处理重金属离子废水的浓缩液中含有高浓度的重金属离子和表面活性剂,需进行进一步处理,使重金属得到回收,表面活性剂得到回收利用。本研究采用电解法回收胶团强化超滤浓缩液中的Cd2+。我们考察了电极种类、电压、电解时间、pH、SDS与Cd2+摩尔浓度比等5个条件对Cd2+回收率的影响,对这五个影响因素进行了最优化。实验得到最佳条件为：不锈钢(阳极)-石墨(阴极),电压U为2.8V,电解时间为100min,溶液pH为4,[SDS]/[Cd2+]=5。在此条件下浓缩液中的Cd2+的回收率达到了50.26%。本实验还进一步研究了电解液中各种物质对电解过程的影响。研究发现表面活性剂SDS对电解有一定的阻碍作用,在电解条件相同的情况下,溶液中含有SDS时Cd2+回收率为50.26%,无SDS时回收率为72.11%。且在电解对SDS影响实验中发现SDS在电解作用下浓度有一定的减小,但并不影响SDS的重复利用。在向胶团强化超滤浓缩液中加入电解质NaCl以提高Cd2+回收率实验中,NaCl浓度为0.3mol/L时,Cd2+回收率达到60.05%。加入电解质NaCl使Cd2+回收率从50.26%增加到60.05%。更多还原

【Abstract】 The high toxicity of metal cadmium on human,plangts and animals can be extremely harmful. Wast waters containing dissolved cadmium come from many sources such as electroplating industries, nonferrous metals smelting,mine tailing. Micellar enhanced ultrafiltration(MEUF) is a new method which is based on the surfactant of the unique characteristic of parental molecular structure that can remove low concentration heavy metals in the water.It is a technology that combined the surface active agent with ultrafiltration. Compare with the traditional ultrafiltration, MEUF has many advantages.Such as lessen cost, and more effective removal of cadmium ions.Meanwhile,MEUF compared to the method of adsorption,distillation and extraction that has low energy consumtion and no intercsction.The most important is the treated water from MEUF can be directly recycled. But the concentrated solution by dealing with the MEUF contains high concenttation of heavy meatal ions and surface active agent,so it must be need to further processing for revovering heavy metals and recycling surface active agent.In this study, the electrolysis method was employed to recovery Cd2+ from the concentrated solution of MEUF..Effects of type of electrode, electrolysis voltage(U) and time(t),solution pH, surfactant to Cd2+ molar ratio ([SDS]/[Cd2+]) on Cd2+ reconery efficiency were investigated.And these five factors were optimized. The optimum experimental conditions were obtained:stainless steel(anode)- graphite(catho-de),U=2V,t=100min,pH=4,[SDS]/[Cd2+]=5.And the recovery efficiency of Cd2+ in the concentrated solution was 50.26%.This research also further studied the electrolyte of various substances on the process of electrolysis. The study found that the surfactant has some effect of resistance to electrolysis process. The same conditions in electrolysis, the recovery efficiency of Cd2+ was 50.26% that the solution containing SDS but 72.11% without SDS. Impact on the SDS in the electrolysis experiments,the experimental results showed that SDS concentration had a certain decrease under the action of electrolysis. But did not affect the SDS reuse. Added to the concentrated liquid electrolyte NaCl to enhance the recovery efficiency of Cd2+ experiments, the recovery efficiency of Cd2+ is 60.05% when the concentration of electrolyte NaCl is 0.3mol/L. The recovery efficiency of Cd2+ from 50.26% to 60.05% by adding electrolyte NaCl.更多还原