微生物法在去除污泥重金属中的研究进展及对比分析

文章介绍了微生物法在污泥重金属去除中的应用,分别从生物淋滤的菌种、污泥中重金属的形态特征和污泥重金属生物淋滤的工艺流程三个方面介绍了生物淋滤法在污泥重金属去除中的研究进展。对现阶段研究的新型技术对污泥重金属去除研究进行了陈述。另外将生物淋滤法与其他方法进行对比分析,针对所面临的问题提出了一些建议。     

微生物淋滤技术在去除城市污泥重金属中的应用

重金属是目前污泥土地利用的最大障碍,有效去除污泥中的重金属成为污泥再次利用的关键。微生物淋滤法作为一种高效、低成本、绿色的污泥重金属的处理方法,展现出广阔的应用前景。综述了污泥重金属去除技术的优缺点,分析了微生物淋滤技术的优越性及去除效果,展望了微生物淋滤技术的前景与方向。     

污泥重金属去除技术研究现状

针对污水处理厂污泥可能造成的重金属”二次污染”问题,介绍了微生物方法、化学方法、电化学方法、植物修复法在去除污水处理厂污泥中重金属中的技术研究现状,并对其目前存在的技术问题进行了简单阐述。     

生物淋滤技术在污泥重金属处理中的效果研究进展及对比分析

文章阐述了生物淋滤法在去除污泥重金属中的机理、影响因素以及处理效果,并与植物提取、电动修复、化学法去除污泥重金属等方法的应用进行了对比。生物淋滤法去除污泥重金属表现出了较好的应用前景,未来从污泥中筛选淋滤菌种,开展生物淋滤工艺研究和配套设备开发将成为生物淋滤技术规模化应用的研究重点。     

城镇污泥重金属去除技术研究进展

基于当前城镇污泥中重金属的污染现状,结合化学浸提法、生物淋滤法、动电修复法、植物提取法等几种主要的污泥重金属去除技术,着重阐述了目前国内外重金属去除技术的的一些方法和实践。针对单一处理技术的不足,提出了重金属联合去除技术,可进一步提高重金属去除率,降低处理成本。探索联合技术的最优工艺操作条件是未来污泥无害化、资源化的研究方向,以期为城镇污泥的安全土地利用提供科学依据。     

城镇污泥重金属去除技术研究进展

基于当前城镇污泥中重金属的污染现状,结合化学浸提法、生物淋滤法、动电修复法、植物提取法等几种主要的污泥重金属去除技术,着重阐述了目前国内外重金属去除技术的的一些方法和实践。针对单一处理技术的不足,提出了重金属联合去除技术,可进一步提高重金属去除率,降低处理成本。探索联合技术的最优工艺操作条件是未来污泥无害化、资源化的研究方向,以期为城镇污泥的安全土地利用提供科学依据。     

城市污泥中重金属处理方法研究进展

城市污水处理中产生的剩余污泥量大且富含多种生物可利用成分,资源化利用潜力大。城市污泥中的重金属是影响城市污泥无害化和资源化的主要因素之一,如何有效去除城市污泥中重金属是环境科学、环境工程研究热点。文章介绍了络合去除、电动修复、酸化溶出、微波等污泥中重金属去除技术,分析了其中存在的问题与发展趋势。     

生物法去除城市污泥中重金属的分析与研究

综述了生物法去除城市污泥中重金属的主要技术并着重讨论了所利用微生物的相关特性、反应机理以及影响去除效率的因素.介绍了生物法去除城市污泥中重金属的相对优势,分析了其今后的发展方向,认为开发高效的生物淋滤一体化反应器和工艺是当前急需解决的问题.     

城市污泥中重金属存在形态、去除及稳定化研究进展

城市污水处理厂污泥产生量大,含有丰富的有机质、氮、磷、钾等农作物所需营养物质,但由于受重金属的污染使污泥无法直接农用。本文简述了城市污泥重金属的来源、特点及危害。重点论述了城市污泥中重金属去除和稳定方法,包括化学法（电化学法、化学试剂法）、生物法（微生物法、植物法、低等动物法）、物理法（超临界流体萃取、微波和超声）及联合技术。分析了各种方法处理污泥重金属过程中重金属的形态变化及其对处理效果的影响,对比各种方法的优缺点、影响因素及适用范围。指出污泥中重金属形态分布是影响去除效果的关键因素,污泥中重金属形态分布差异性大,且大部分重金属以稳定或相对稳定的状态存在,导致物理法和生物法去除效率较低,微生物和低等动物处理法相比植物法（备受时空限制）则表现出更好的适应性;电化学法对可氧化、可还原态分布的重金属都能起到较好的转化去除作用,但往往受由污泥向污泥液相中转移过程的控制,电损耗较突出;化学试剂浸提剂是目前效率较高的方法,但强酸环境常导致污泥营养物质流失和酸根离子累积,农用时容易板结而不利于污泥土地利用。因此,以土地利用为前提的条件下,将各种处理技术联合运用以提高污泥重金属去除率有待于进一步研究。     

去除城市污泥中的重金属中试研究

文章以含有重金属的城市污水处理厂污泥为研究对象,在实验室研究的基础上,采用吸附法去除城市污泥中的重金属,选用合适的中试设备,找到了的最佳吸附工艺条件:p H=4和反应时间为3小时下重金属的去除效率最高。     

污泥中重金属去除的技术

介绍了污泥中重金属存在的形态,综述了污泥中重金属去除的常用的四种技术化学浸出、生物浸出、电分离和超临界流体萃取,重点介绍了化学浸取技术的原理和特点,并对诸项技术的优点以及存在的问题进行了评述。     

城市污泥重金属电动修复技术与应用研究进展

重金属污染是目前城市污水处理厂污泥农用的主要障碍之一。电动修复作为一门新兴的污染环境介质绿色修复技术,具有投资少、去除效率高和处理时间短等优点。特别是对于水力渗透性差的污泥,电动修复技术具有良好的应用前景。论文介绍了城市污泥重金属电动去除技术原理,并综述了近几年国内外在修复效果及其影响因素等方面的研究现状。同时,对该技术应用过程中存在的问题和未来研究方向进行了讨论和展望。     

城市污泥中重金属去除技术研究

重金属污染是目前城市污水处理厂污泥农用的主要障碍之一。综述了城市污泥中重金属去除的常用四种技术：化学浸提、生物淋滤、动电技术和固化-稳定化,同时分析了污泥中重金属去除技术的发展方向。     

超声协同硝酸提取城市污泥重金属的研究

主要通过超声技术协同硝酸提取城市污泥重金属,以研究重金属的去除效果。文章阐明了超声波技术在不同pH、酸化时间时对城市污泥重金属去除的影响。     

Electrodialytic Separation of Phosphorus and Heavy Metals from Two Types of Sewage Sludge Ash

During sewage sludge incineration phosphorus (P) is retained in the ash in a form not directly available to plants. As P is a sparse resource, it is important to develop techniques for recovery of P from incinerated sewage sludge ashes (ISSA). Heavy metals are concentrated in ISSA and separation of P and heavy metals is required. The present work is an experimental screening of a new combination of acid extraction and electrodialysis–electrodialytic separation (EDS) for simultaneous P recovery and removal of heavy metals. Experiments were conducted with two different ashes; rich in Fe or Al. The separation method was best suited for the Fe-rich ash, where it was possible to separate P into one processing solution, heavy metals (Cu, Zn, Ni, Pb) into another, keeping the ash suspended in a third solution (which though still contained P after 1 week of EDS). For the Al rich ash, the separation was not similarly encouraging. The high release of Al during the extraction influenced the speciation of P and negatively charged P complexes were not prevailing. On the contrary to Al, the Fe containing ash particles were insoluble so Fe did not interfere with P speciation and separation after extraction.     

污泥热解残渣中重金属形态分布的研究进展

目前，我国城市及工业污水产生量已达7.34×10¹⁰ t/a，对其处理产生的污泥量达7.29×10⁷ t/a。污泥的主要去向为土地利用、焚烧发电和建材利用等。在这些再利用过程中，重金属特别是Cr、Cu、Zn、Ni等对其再利用影响较大。污泥处理多采用热解处理，重金属在处理过程中会富集在热解残渣中。阐释重金属在热解残渣中的形态分布，对于其再利用过程意义重大。本文以改进的欧共体物质标准局(BCR)连续提取法为基础，总结了污泥热解残渣中重金属的形态分布，阐述了热解工况(热解温度、停留时间、催化剂)、共热解及预处理对热解残渣中重金属形态分布的影响，探讨了污泥热解残渣中重金属未来的研究趋势。     

Heavy Metals Precipitation in Sewage Sludge

Abstract

There is a great need for heavy metal removal from strongly metal‐polluted sewage sludges. One of the advantages of heavy metal removal from this type of sludge is the possibility of the sludge disposal to landfill with reduced risk of metals being leached to the surface and groundwater. Another advantage is the application of the sludge as soil improver. The use of chemical precipitation to remove dissolved heavy metals from sewage sludge implies a high cost for chemicals. This work shows, for real sewage sludge for the first time that the addition of NaOH as first precipitating agent considerably saves the addition of Na₂S, that is one of the most effective metal precipitating agents and also expensive. After solubilization of heavy metals by chemical leaching with previous aeration, the next step was the separation of the sludge solids from the metal‐rich acidic liquid (leachate) by centrifugation and filtration. Afterwards, the filtered leachate was submitted to the application of NaOH and Na₂S, separately and in combination, followed by filtration. The results showed that when iron and aluminium are present in the leachate, adsorption and/or coprecipitation of Cr, Pb, and Zn with Fe(OH)₃ and Al(OH)₃ might occur at increasing pH conditions. The combination of hydroxide and sulfide precipitation was able to promote an effective removal of heavy metals from leachate. Applying NaOH at a pH of 4–5 as a first precipitation step, followed by filtration and further addition of Na₂S to the filtered liquid at pH of 7–8 as a second precipitation step, decreased considerably the dosage of the second precipitant (almost 200 times), compared to when it was solely applied. This has practical applications, as the claimed costs drawbacks of H₂S addition is considerably reduced by the addition of the less expensive NaOH. The best removal efficiencies obtained were: Pb: ～100%, Cr: 99.9%, Cu: 99.7%, and Zn: 99.9%.     

污水污泥页岩烧结制品的重金属固化与水环境浸出稳定性

提高重金属固化程度与浸出稳定性是含重金属污水污泥处置和利用的前提。采用污水污泥并模拟提高其重金属Cr、Cu、Pb的含量,与页岩混合制备烧结砖和陶粒制品,研究重金属在页岩制品高温烧制过程中的固化率以及制品中重金属的水环境浸出稳定性,通过X射线衍射和扫描电子显微镜分析含重金属矿物的赋存形态和页岩制品微观形貌对重金属固化与浸出稳定性影响。与相同条件下焚烧纯污水污泥相比,重金属在页岩制品烧制过程中固化率明显提高,浸出毒性明显降低,重金属在页岩制品中易形成稳定的尖晶石型矿物以及页岩制品所具有的致密微观结构;相比烧结砖,陶粒中重金属固化程度和浸出稳定性更高,因为陶粒在更高温度下有利于尖晶石型矿物和致密结构形成。     

Bioleaching of heavy metals from dewatered sludge by Acidithiobacillus ferrooxidans

The feasibility of bioleaching for removal of heavy metals from dewatered sewage sludge using an iron‐oxidizing bacterium Acidithiobacillus ferrooxidans was investigated. The influence of seven process parameters including cell adaptation, total amount and particle size of the sludge, initial concentrations of Fe²⁺ and At ferrooxidans, and addition of inorganic nutrients and sulfur were evaluated in terms of the solubilization of Zn, Cu and Cr. When sludge‐adapted cells, addition of inorganic nutrients and lower sludge content were involved, higher yields of metal extraction were obtained. However, higher initial concentrations of At ferrooxidans and Fe²⁺, fine particle size of the sludge and S addition did not improve the metals' solubilization during an experimental period of 7 days. As a result of a long‐term (40 days) bioleaching experiment, 42% of Zn (1300–1648 mg kg^?1), 39% of Cu (613–774 mg kg^?1) and 10% of Cr (37–44 mg kg^?1) in the sludge were leached into the solution. The results indicate that a bioleaching process conducted under operationally optimal conditions can be effectively employed for the removal of heavy metals from sewage sludge before land application. Copyright © 2005 Society of Chemical Industry