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Rice husk as a potentially low-cost biosorbent for heavy metal and dye removal: an overview 总被引:2,自引:0,他引:2
Rice husk as a low-value agricultural by-product can be made into sorbent materials which are used in heavy metal and dye removal. It has been investigated as a replacement for currently expensive methods of heavy metal removal from solutions. Currently, the study of rice husk as a low-cost sorbent for removing heavy metals has regained attention. The heavy metals being studied are: As(V) [1], Au [2,3], Cr(IV) [4], Cu and Pb [5,6], Fe, Mn, Zn, Cu [7] and Cd(II) [8-10]. Rice husk is also being used to treat textile dyes such as like malachite green [11,12] and acid yellow 36 [13]. The treatment and preparation of rice husk activated carbon are of importance and became a subject of study [14-16]. In this review an extensive list of previous and current literature on rice husk activated carbons in removing heavy metals and dyes, their preparation or treatment and isotherms studies were complied to provide a summary of available information on rice husk and its potential as a low-cost sorbent. 相似文献
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氢氧化镁在工业废水处理中应用研究进展 总被引:4,自引:0,他引:4
郭如新 《精细与专用化学品》2010,18(4):42-47
对氢氧化镁在工业废水处理中应用研究进展进行了评述;介绍了环保级氢氧化镁性能特征及其在酸性废水处理、废水中重金属离子脱除、印染废水脱色与有机物脱除以及硫化氢脱除方面的应用;展望了氢氧化镁的发展前景。 相似文献
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介绍了硫酸厂酸性污水减排技术进展。探讨了酸性污水处理中的关键技术如中和、固-液分离、污泥处理、稀酸及中和水回用的特点与应用情况。我国硫酸厂酸性污水减排仍要立足于源头治理,尽量减少污水产生量;利用好现有成熟的石灰-铁盐法、硫化法、电絮凝法等中和技术及污水、污泥分离回收技术,确保硫酸厂污水达标排放和有效利用。建议在提高传统铁盐法和硫化法的脱除效率、降低成本方面继续深入研究,加快吸附法、萃取法、膜过滤法等新技术脱除酸性污水中砷及重金属离子的工业化应用。 相似文献
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A novel, highly stable, selective and efficient sorption medium was synthesized for the removal of toxic metals from industrial effluents by coupling a chelating agent Ammonium pyrrolidine dithiocarbamate (APDC) with flexible open cell polyether polyurethane foam. The performance efficiency of the new sorbent was evaluated by static and dynamic methods for removing toxic heavy metals Hg, Cd and Pb from effluents. In fixed bed downflow column studies, a quantitative uptake of Hg (II) 400 mg/L, Cd (II) and Pb (II) 60 mg/L was attained at flow rates of 3.68 L/m2s. The design parameters using the APDC‐PUF as sorption material for a batch reactor and for column reactor and cost effectiveness of the process were evaluated. The sorption potential of the APDC‐PUF was demonstrated for the treatment of real industrial wastes from a common effluent treatment plant, Chloro alkali industry and municipal sewage. 相似文献
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重金属污染物具有毒性和不可降解等特点,对生态环境及生物多样性构成威胁,危害人类健康。处理重金属废水的方法很多,电化学方法是其中一种重要的清洁技术,其用途广泛,可以有效去除和回收废水中的重金属离子。本文聚焦于电沉积法,介绍其在重金属废水处理过程中的反应原理和传质机理,重点阐述影响其处理重金属废水效率的主要因素,包括反应器结构、电极材料、电压、电流密度、pH、废水温度、重金属浓度、杂质离子、电流形式、电沉积时间等。同时概括了电沉积技术在重金属废水处理方面的应用情况,并指出了电沉积法处理重金属废水的重要研究方向,如三维电极及新型电极材料的研发、能耗优化、不同重金属离子的分离等,为重金属废水的治理和电沉积技术的研究与应用提供指导。 相似文献
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吸附法处理重金属废水的研究进展 总被引:3,自引:0,他引:3
重金属废水是对环境污染最严重和对人类危害最大的工业废水之一,吸附法作为一种重要的处理重金属废水的方法已经得到广泛应用。本文介绍了近年来利用吸附法处理重金属废水的研究进展。根据吸附机理将吸附剂吸附重金属的方法分为化学吸附和物理吸附两大类,并对其研究现状进行了介绍。指出温度、吸附剂的用量、吸附时间、重金属离子的初始浓度以及溶液的pH值等吸附条件对吸附剂吸附重金属的影响,介绍了活性炭、沸石、壳聚糖、膨润土、生物吸附剂、废弃农作物、纳米材料、离子交换树脂、高分子吸附材料等9种吸附剂处理重金属废水的研究进展,同时对吸附法处理重金属废水的发展方向进行了展望。 相似文献
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《分离科学与技术》2012,47(1-4):793-811
Abstract Natural chabazite zeolite has been selected as the baseline treatment technology to compare the performance of emerging sorbent materials for the removal of 90Sr and 137Cs from contaminated process water. The resorcinol-formaldehyde resin, developed at Savannah River Site, is the first sorbent to be evaluated in this study. This paper summarizes the required contact times for maximum strontium and cesium removal, presents sorption isotherms in wastewater simulant and authentic wastewater, and defines the effects of elevated concentrations of K, Mg, Ca, and Na in wastewater for both sorbents. 相似文献
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Different treatment technologies have been efficiently applied to remove heavy metals from wastewater. Efforts have been made to find out the most economic water treatment technology by using low cost and easily accessible natural materials. On the other hand, heavy metals are the most threatening groundwater contaminants because of their toxicity and harmful effects on human and biota. This review discusses the use of natural geological materials for heavy metal removal in aqueous systems. Special attention has been devoted to natural limestone through a systematic inventory of relevant published reports. The removal of toxic metals may include different mechanisms (e.g., physisorption, chemisorptions, precipitation, etc.), depending on the physico-chemical properties of the material and the removed metal. Sorption of toxic metals (e.g., Pb, Cu, Cd, Zn, Cr, Hg, etc.) onto natural limestone involved precipitation of metal carbonate as a predominant removal process, but often subordinated by adsorption and ion exchange, depending on the physico-chemical properties of the studied limestone. 相似文献
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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。 相似文献
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结合含氰、含铬、酸洗电镀废水的特点,采用氧化法破氰;6价铬还原,碱性沉淀后,加入重金属捕集剂反应,再利用铁碳还原法进一步降低废水中的重金属含量,达到深度去除重金属的目的;采用接触氧化法降解污水中的有机污染物,各级沉淀池的污泥通过静水压定期排入集泥池,然后通过机械压滤后作无害化处理.运行结果表明,该工艺处理效果稳定可靠,... 相似文献
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重金属污染后的土壤严重威胁着环境安全,植物的土壤修复技术是当前的研究热点。利用植物的萃取、挥发、稳定、根系过滤等不同方法对土壤中的重金属吸收富集,达到去除重金属的目的。土壤的性质和重金属在土壤中的存在形态是影响超富集植物吸收富集重金属的影响因素。植物修复技术是新兴高效、绿色廉价的修复途径,具有良好的经济和生态综合效益。 相似文献
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分子筛对重金属废水吸附性能的实验研究 总被引:1,自引:0,他引:1
为验证分子筛对重金属废水的处理效果,以实际含锰废水为研究对象,采用13X分子筛,通过实验研究了吸附材料用量、吸附时间、搅拌转速和溶液pH对Ca2+、Mn2+、Mg2+吸附效果的影响。结果表明:吸附材料用量增加对Mn2+、Mg2+的吸附影响较大;随着吸附时间增长,各金属离子去除率增加;适当的转速有利于金属离子的吸附,但各金属离子对应的最佳转速各不相同;pH提高,能够促进分子筛对金属离子的吸附。13X分子筛对金属离子的吸附机理为离子交换吸附和表面吸附。研究表明,13X分子筛在处理低浓度含锰重金属废水方面表现出良好的应用前景。 相似文献