重金属废水处理技术的研究

【作者】 陈剑虹；

【导师】 曾光明； 莫建炎；

【作者基本信息】 湖南大学 ， 环境工程， 2003， 硕士

【摘要】 本论文综合了国内外大量的调查、研究报告等文献资料，对镉、汞、铅、砷、铬等重金属污染的问题作了探讨，涉及重金属向环境的输入、在水——土壤——植物——动物链中的迁移转化、对生物的影响与危害、控制重金属的排放、治理重金属污染的环境。 目前，重金属污染仍很严重，全世界年排放量砷为47000t／a，汞为20000t/a，所以重金属污染仍是当今世界上备受重视的一个公害问题。 重金属排入环境后，有复杂的化学过程，形成多样化的形态或结构的污染物，如土壤中的重金属离子或类金属离子可分为五种形态：①水溶态的；②弱代换剂可代换的；③强代换剂提取的；④次生矿物中的；⑤原生矿物中的。 重金属离子在大气、水体、土壤、生物间迁移转化，实质是重金属离子在土壤、水体、大气环境中的长期污染，它可在生物体内浓缩，并可通过食物链最终危害人体健康。如汞从水体到无脊椎动物体内的浓缩放大可达10万倍：对人类而言，甲基汞损害造成小脑性运动（肌肉运动）失调、视野缩小、发音困难三大主要特征损害，它还是胎毒物质和生殖毒物质。 可以利用重金属离子的各种化学特性，设计各种处理技术控制重金属的排放，并对重金属污染的环境进行治理。如化学法、反渗透法、吸附法、蒸发浓缩法、电解法、电渗析法等都有成功运用，生物法处理无机重金属离子废水的技术正在积极的研究和试用中。 微生物在控制与治理重金属污染方面是有潜力的。①活性污泥可作为治理重金属污染的一种新选择，它可使共存系统中的生物免受后续输入的重金属的毒害。②浮游水生藻类和酵母菌等制成的干燥吸附剂都有较强的净化重金属离子的能力。③新型微生物材料——有效微生物——对汞废水的净化实验研究的阶段成果显示，汞对EM有毒性作用，EM对汞有耐受适应性(至少能耐受5mg／L Hg²⁺，并能在8d左右适应2.5mg／LHg²⁺，在2d左右适应1.25mg／LHg²⁺)，这是发挥和进一步挖掘EM对重金属生物治进作用潜力的基础性工作。更多还原

【Abstract】 The article discusses the questions about the pollution of heavy metal such as Cd, Hg, Pb, As, Cr based the large numbers of research or study literatures and datas. The questions involved many sides such as the input of heavy metal to environment, the transferring and transforming of heavy metal in chain which be formed with water, soil, plant and animal, the influence and harm of heavy metal to life-forms, the purifying of heavy metal in every kinds of waste and environment.As the gross of As and Hg that input to environment approaches 47000t/a and 20000t/a, we have to think the pollution of heavy metal is very serious at present. We must pay attention to it.After enter to environment and occur complicated chemistry process, heavy metal may become many kinds of pollutions which be in different shape and different struction. For example, in soil, heavy metal can be differentiated five shapes generally, namely, dissolved, permutable by feeble permutoid, permutable by strong permutoid, original mineral, secondary mineral.The transferring and transforming mean the long period pollution of heavy metal in chain which formed with water, soil, plant and animal. Actually, heavy metal may be concentrated in the body of life-forms. They can harm the health of human through the food chain finally. Hg may be concentrated 105 times from water to invertebrate. The harm of methyl mercury compound cause the three main symptoms in human, namely, cerebell-muscle locomotion malajustment, eyeshot shrinking, pronunciation embarrassment. Hg is embryo-poison and procreation -poison also.We designed some treatment schniques to control the input and harness the pollution bases the chemistry characteristi of hevy metal. Chemistry method, reverse-infiltration method, adsorption method, evaporation-concentration method, electroanlysis method, electrodialysis method have been used successfully.Thebiology-technique for treating the abio-heavy metal hydronium in liquid waste have been investigated and tryouted positively at present.Microorganism have the potential power to central or treat and harness heavy metal pollutions. (1)Activated sludge is a new kind material for treating heavy metal pollution perhaps. Activated sludge can protect the live-forms in coexisted system from harm of heavy metal intut to later. (2)Dryness sorbent be made of float-swim hydrophily algaes and microzyme have the ability to purify the heavy metal in wastes and environment. (3)The phase fruit of experimental study that EM a new kind of microorganism material purify the mercury wastewater shows, mercury can poison EM, EM have tolerance and adaptability for mercury (tolerance 5mg/L Hg"+ at least, adapt 2.5mg/L Hg2+ with 8d, adapt 1.25mg/L Hg2+ with 2d) . The experimental study is a fundamental work for exerting and digging the potential of EM in biological treatment and harnessing for heavy metl pollution more.更多还原