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During the treatment of sewage, a huge volume of sludge is generated, which is disposed of on land as soil fertilizer/conditioner due to the presence of nitrogen, phosphorus, potassium and other nutrients. However, the presence of toxic heavy metals and other toxic compounds in the sludge restricts its use as a fertilizer. Over the years, bioleaching has been developed as an environmentally friendly and cost-effective technology for the removal of heavy metals from the sludge. The present paper gives an overview of the various bioleaching studies carried out in different modes of operation. The various important aspects such as pathogen destruction, odor reduction and metal recovery from acidic leachate also have been discussed. Further, a detailed discussion was made on the various technical problems associated with the bioleaching process, which need to be addressed while developing the process on a larger scale. 相似文献
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Toxic metals removal from wastewater sewage sludge can be achieved through microbial processes involving Acidithiobacillus ferrooxidans. The oxidation of ferrous ions by A. ferrooxidans, cultured in sewage sludge filtrate, was studied in both batch and continuous flow stirred tank reactors. Sewage sludge filtrate containing natural nutrients (phosphorus and nitrogen) was recovered as effluent following the dehydration of a primary and secondary sludge mixture. Batch and continuous flow stirred tank reactor tests demonstrated that A. ferrooxidans were able to grow and completely oxidize ferrous iron in a culture medium containing more than 80% (v v(-1)) sewage sludge filtrate with 10 g Fe(II) L(-1) added. Toxic levels were reached when total organic carbon in the sewage sludge filtrate exceeded 250 mg L(-1). The ferric iron solution produced in the sludge filtrate by A. ferrooxidans was used to solubilize heavy metals in primary and secondary sludge. The solubilization of Cu, Cr, and Zn yielded 71, 49, and 80%, respectively. This is comparable with the yield percentages obtained using a FeCl(3) solution. The cost of treating wastewater sewage sludge by bioproducing a ferric ion solution from sewage sludge is three times less expensive than the conventional method requiring a commercial ferric chloride solution. 相似文献
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黄强 《环境保护与循环经济》2021,41(1):39-41
面对日趋严格的重金属排放标准,许多传统处理技术,如化学沉淀法、生化法、吸附法等,在某种程度上都难以单独胜任.与此同时,膜技术的快速发展为含重金属废水的深度处理提供了一个崭新的方向.某钢丝绳企业采用超滤技术对含铅废水进行深度处理,由于其过滤精度达0.002~0.1μm,可过滤铅离子组成的胶体(0.05~0.1μm范围),... 相似文献
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处理重金属废水的传统方法在投资和运行费用上都较高,加之沉淀去除效果不太理想,近年来国内外进行了大量的生化法去除重金属的研究。本文介绍了生物吸附法、生物絮凝法、微生物代谢法和植物吸收法。生化法处理重金属废水,成本低,效益高,易管理,可回收重金属,有利于生态环境的改善,具有十分广阔的应用前号。 相似文献
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An investigation was conducted to examine aerobic digestion of the phosphorus-laden sludge produced at the Regina Wastewater Treatment Plant and feasibility of land use of this sludge combined with the dewatered anaerobically digested primary sludge from this plant. Experimental studies showed that aerobic digestion can be employed for the stabilization of the chemical sludge. Results of the feasibility analysis showed that mixing the two digested sludges met the heavy metal criteria set by various guidelines for agricultural use, presented the advantage of an increased concentration of nutrients and a decreased concentration of heavy metals, and a longer useful life of the agricultural site compared to using dewatered anaerobically digested primary sludge alone. Land application of the mixed digested sludges would be a more appropriate method of sludge disposal compared to the present practice of landfilling the dewatered sludge and lagooning the chemical sludge. 相似文献
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Two pulp and paper industrial wastes, lime mud (LM) and recovery boiler ash (RB), have low moisture contents, low heavy metal contaminations and contain various carbonate compounds which contribute to a high pH. Metal finishing wastewater (MF-WW) has a low pH, high levels of TDS and high contaminations from Cr, Cu, Pb and Zn. The heavy metals from MF-WW were removed by sorption and precipitation mechanisms. LM gave better results in removing heavy metals from MF-WW than RB. At a reaction time of 45 min, the maximum removal efficiencies for Cr (93%) and Cu (99%) were obtained at 110 g L−1 of LM, but at 80 g L−1 for Pb (96%) and Zn (99%). Treatment with LM gives a higher sludge volume than with RB. However, the leachability of heavy metals from LM is lower. Leachability of heavy metals in the sediment for all selected treatment conditions is within government standards. 相似文献
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Reducing the negative impact from on-site systems and promoting recycling are important tasks for municipal authorities, especially as regards phosphorus. The objective of this scenario study was to compare energy turnover in a life cycle perspective, recycling potential and expected reduction of nitrogen and phosphorus emissions for three upgraded small-scale wastewater systems based on local recycling of plant nutrients. The systems studied were urine separation, blackwater separation and chemical precipitation in the septic tank. The urine was sanitised through storage, the blackwater through liquid composting and the precipitated sludge through chemical treatment with urea before reuse in agriculture. The system boundaries included the operational phase as well as investment in capital goods required for upgrading the existing on-site systems.The urine separation system used least energy. The potential recycling and reduction of phosphorus was lower than for the other two systems, while that of nitrogen was higher than for the chemical precipitation system but lower than for the blackwater separation system. The blackwater separation system reduced both nitrogen and phosphorus to a high extent and also enabled a large proportion of both nitrogen and phosphorus to be recycled to arable land. However, a major drawback with this system was its significantly higher use of electricity, related to the aeration and stirring required when sanitising the blackwater by liquid composting. When urea treatment replaced liquid composting, the use of electricity decreased substantially in the blackwater separation system. The chemical precipitation system was efficient in reducing and recycling phosphorus, while inefficient for nitrogen. The use of fossil fuels was significantly higher than for the other two systems, primarily due to the production of the precipitation chemical. 相似文献
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文章阐述了辽河油田黄金带炼油厂废水处理现状,简要介绍了活性污泥好氧生化处理工艺,分析了污水处理技术改造的原因和必要性,根据稠油加工过程中产生污水水质的特性,如何对原有污水处理工艺技术进行研究和改进。介绍了改造后的A/O生物膜法处理工艺的技术特点,处理结果表明:化学需氧量等污染物排放浓度大幅降低,污水排放各项指标均符合DB 21/1627-2008《辽宁省污水综合排放标准》的要求。 相似文献
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污泥中重金属的稳定化研究进展与去除方法简述 总被引:1,自引:0,他引:1
通过"十一五"污水处理厂的建设,我国污泥产量也随之大幅增长,污泥的处理处置已经成为制约社会经济发展的重要问题。国际上的经验表明土地利用是污泥最终处置的主要发展方向,然而污泥中的重金属成为其土地利用的主要障碍。越来越多的研究者意识到,重金属的环境危害不仅仅取决于其总量,更取决于重金属存在形态。目前,Tessier分步提取法作为主流的污泥重金属划分方法,取得了广泛应用,该法将污泥中的重金属分成5种形态,分别为可交换态、碳酸盐结合态、铁锰氧化物结合态、有机结合态和残渣态。本文以此为基础综述了目前国内外主要的污泥重金属稳定和去除方法的原理及研究进展,比较了不同重金属稳定及去除方法的优点与不足,并提出了新的展望。 相似文献
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石油矿区生活污染源排放的污染物问题越来越突出。生活污水的治理可采用建设集中生活污水处理厂,处理后的污水用于绿化。生活垃圾实行分类、袋装化,对各种垃圾进行分类处理。做好油田矿区生活污染物治理,管理部门应制定相应管理办法和有关规定。环卫系统与物资回收部门,应搞好实施方案 相似文献
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"第一类污染物"是指会对人体健康产生长远不良影响的污染物,包括8种重金属和类金属。已经证实,工业源重金属超量排放严重,使水土及生态环境遭受到"第一类污染物"的严重污染,面临的"第一类污染物"防治形势更加紧迫。本文在重金属污染现状与治理需求分析的基础上,通过长期调研,针对重点行业提出了6项综合防治措施,建议从源头严格控制排放总量,对重点企业进行监管与治理,总结与创新重金属修复新技术等,旨在推动第一类污染物的污染防治。 相似文献
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Recycling contaminated soil as alternative raw material in cement facilities: Life cycle assessment 总被引:1,自引:0,他引:1
Volcanic soil can be used to remove metals from wastewaters. Once used, it is disposed in landfills. The utilization of this material in the cement industry as an alternative raw material was evaluated using life cycle assessment (LCA) methodology. This possibility has been studied from an environmental point of view in a Chilean cement facility, representative of the current operation state of art, including both technical and economic analysis. Two scenarios were compared: Scenario 1, which corresponds to the existing cement production process, and Scenario 2, which represents cement production using spent volcanic soil. With the exception of the categories of carcinogens (C) and minerals (M), the comparative results are favourable to Scenario 2, specially regarding to the category of ecotoxicity (E), mainly due to the avoided landfilling emissions of the volcanic soil. When considering the damage assessment, damage to human health (HH), ecosystem quality (EQ) and resources (R) are lower in Scenario 2. In addition, sensitivity analyses were performed to study the influence of particular parameters (i.e., transport of spent volcanic soil, CO2 emissions from the clinkerization process and heavy metals leaching from the spent volcanic soil) on the results of the assessment. The use of alternative raw materials (in this case, spent volcanic soil), which present the advantage to be wastes from other technical systems, appear to allow the development of cement production in a more sustainable way, slightly improving the economy of the process. The spent volcanic soil can be treated with zero cost for the wastewater treatment plant with savings of 0.23€ for each tonne of clinker production. Establishing a sound management way for the spent volcanic soil could foment its possible use as mineral adsorbent in industrial wastewater treatment facilities. 相似文献
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辽河油田稠油泥砂综合处理工艺的研究* 总被引:5,自引:3,他引:2
稠油污泥作为含油污泥的典型代表,其成分极为复杂、处理难度极大,由于目前国内外尚无成熟工艺可完全实现其"减量化、资源化、无害化处理",给油田生产和环境保护带来了严重影响。文章分析了稠油污泥的组成及性质,根据稠油污泥来源不同实施分类预处理,利用热风干化技术将其减量,经热解气化焚烧和热能利用,为实现含油污泥无害化处理进行了有益探索。 相似文献
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Pankaj Kumar Vandana Mishra Saiyami Bhardwaj Shafali Garg Ludovic F. Dumée Radhey Shyam Sharma 《环境质量管理》2023,32(4):9-17
Sectorial approach for monitoring heavy metal pollution in rivers has failed to report realistic pollution status and associated ecological and human health risks. The increasing spread of heavy metals from different sources and emerging risks to human and environmental health call for reexamining heavy metal pollution monitoring frameworks. Also, the sources, spread, and load of heavy metals in the environment have changed significantly over time, requiring consequent modification in the monitoring frameworks. Therefore, studies on heavy metal monitoring in rivers conducted in the last decade were evaluated for experimental designs, research frameworks, and data presentations. Most studies (∼99%) (i) lacked inclusiveness of all environmental compartments; (ii) focused on “one pollutant – one/two compartment” or sometimes “one pollutant – one compartment – one effect” approach; and (iii) remained “data-rich but information poor.” An ecological approach with integrative system thinking is proposed to develop a holistic approach for monitoring river pollution. It is visualized that heavy metal monitoring, risk analyses, and water management must incorporate tracking pollutants in different environmental compartments of a river (water, sediment, and floodplain/bank soil) and consider correlating it with riverbank land use. The systems-based pollution monitoring and assessment studies will reveal the critical factors that drive heavy metals pollutant movement in ecosystems and associated potential risks to the environment, wildlife, and humans. Also, water quality and pollution indexing tools would help better communicate complex pollution data and associated risks among all stakeholders. Therefore, integrating systems approaches in scientific- and policy-based tools would help sustainably manage the health of rivers, wildlife, and humans. 相似文献