【作者】 张栋；

【导师】 王三反；

【作者基本信息】 兰州交通大学 ， 环境工程， 2014， 硕士

【摘要】 随着工业的不断发展，重金属污染已成为一项主要的环境污染问题。重金属污染具有累积性，对环境的毒害作用大等特点，已经造成了许多如水俣病、痛痛病等的严重污染事件。而对于重金属污染的治理主要集中在对重金属废水治理方面，治理后产生的重金属污泥沉淀往往很少处理。这种重金属污泥在自然条件下会由于外部环境的转变而发生重金属泄漏事故，造成二次污染。本实验的主要研究目的是针对重金属污水治理过程中产生的重金属污泥进行处理，通过浓浆铁氧体技术将其转化具有较好稳定性的铁氧体沉淀，从而有效避免重金属污泥的泄漏，并生成可以循环利用的处理产物。本实验主要通过三种药剂投加方式对处理状况进行研究，并通过在极端条件下的反溶实验来对生成物的稳定性进行实验研究。对重金属污泥的药剂投加采用Fe3+投加、Fe2+和Fe3+混合投加与Fe2+和H2O2混合投加三种投加方式。经过实验可以看出，采用Fe3+投加方式生成物的反溶率最高，生成铁氧体较少。Fe2+和Fe3+混合投加与Fe2+和H2O2混合投加生成物的反溶率较低，生成铁氧体较多。相比较而言，采用Fe2+和Fe3+混合投加对重金属污泥处理比Fe2+和H2O2混合投加处理效果稳定，是最好的药剂投加方式。对重金属污泥的处理主要分为模拟污泥处理实验与实际污泥处理实验。模拟污泥处理实验是通过对Ni(OH)2沉淀与Cr(OH)3沉淀进行处理实现的。实验通过对药剂投加比、药剂投加量、pH、反应时间、反应温度以及陈化时间的研究，来确定最佳反应条件。通过实验可以看出，在反应pH为9时能够取得最佳效果，重金属转化为铁氧体的量最多。反应效果随反应时间的延长，反应温度的增加而变好，通过实验观察，并结合经济成本分析，在反应时间为4h，反应温度为75℃时可以取得理想效果。对实际污泥的处理实验选取某镍网公司电解废渣，通过对废渣的分析，其中的主要金属元素为镍与铬，并包含铜、镉、铅、锌等金属元素。对实际污泥的处理过程参照模拟污泥处理，通过研究发现在pH为9时取得最好效果，并能够对其他重金属元素进行一定程度的稳定作用，其他反应条件与模拟实验相同，能够取得对实际污泥有效的稳定化作用。对于主要元素铬的反溶率在5%~7%，镍的反溶率33~35%。处理试验后将生成的处理产物进行毒性浸出实验与生成物理化性质检测，利用X射线衍射仪、场发射扫描电子显微镜以及振动样品磁强计等对进行检测。通过检测可知处理后生成物中的铁氧体主要为NiFe2O4与FeCr2O4，结晶度较好，并具备较好的磁学性质，可以通过后续处理进行利用，实现了重金属污泥的稳定化、无害化、资源化处理。更多还原

【Abstract】 With the continuous development of industry, heavy metal pollution has become a majorenvironmental problems. Heavy metal pollution has cumulative toxic effects on theenvironment, and has caused a lot of pollution incidents, such as Minamata disease, Itai-itaidisease and so on. For the treatment of heavy metal pollution is mainly concentrated in areasof heavy metal wastewater treatment, heavy metals precipitation sludge generated aftertreatment is often little processing. This heavy metal sludge leaked heavy metal intoenvironment due to the changing of natural conditions, causing secondary pollution. The mainpurpose of this experiment is to be treated for heavy metal sludge of heavy metal wastewatertreatment process, through thick ferrite technology to convert it to ferrite precipitation whichhas good stability, so as to effectively prevent the leakage of heavy metals in sludge andgenerating a processed recycled product.In this study, processing conditions is researched by three ways of drug dosing situation,and by anti-solvent experiments under extreme conditions to carry out experimental study onthe stability of the product. Heavy metal sludge drug dosings use Fe3+, Fe2+/Fe3+mixeddosing, and Fe2+/H2O2mixed dosing three kinds of ways. After the experiment can be seen,the drug dosing of Fe3+had the maximum anti-solvent rate, and made less generation ferrite.The drug dosing of Fe2+/Fe3+and Fe2+/H2O2had the lower anti-solvent rate, and made moregeneration ferrite. In comparison, the best way of drug dosing is Fe2+/Fe3+mixed dosing, andhad the more stable treatment effect than the drug dosing of Fe2+/H2O2mixed dosing.Sludge treatment for heavy metal sludge is divided into simulated and actual sludgetreatment experiments. Simulation sludge treatment experiments is researched by thetreatment of Ni(OH)2precipitate and Cr(OH)3precipitate. This experiment is studied of drugdosage, pH, reaction time, reaction temperature, and aging time to determine the optimalreaction conditions. Experiments can be seen, the best results can be obtained at pH9, andmaximum amount of heavy metals changed into the ferrite. Through experimental observation,the reaction results become better when the reaction time extended and the reactiontemperature rise. Combined with the economic cost analysis, the optimal results is gottenwhen the reaction time is4h, and the reaction temperature is75℃. For the majorThe actual sludge treatment experiments select the electrolysis sludge of a nickelcompany. Through the sludge analysis, nickel and chromium are the main metallic elements,and contains copper, cadmium, lead, zinc and other metal elements. With reference to theSimulation sludge treatment experiments, the optimal results is gotten at pH9, and otherreaction conditions were the same as simulated sludge treatment experiments. Under thisconditions, the stabilization of actual sludge can be gotten, and other heavy metal elements can be stabilized at the same time. For the major chemical element, the anti-solvent rate of thechromium is5%~7%, and the anti-solvent rate of the nickel is33~35%.The resulting processed products are tested for toxicity leaching experiment andproperties detection by X-ray diffraction (XRD), field emission scanning electron microscopyand vibrating sample magnetometer. Through the tests can be seen, the majority of theproducts is NiFe2O4and FeCr2O4, with the good crystallinity and good magnetic properties.Finally, used by subsequent processing, heavy metal sludge has realized the stabilization,harmless and recycling treatment.更多还原