膨润土的改性方法及其在废水处理中的应用

对膨润土的结构及其基本性质做了简单介绍,重点探讨了膨润土的改性及改性膨润土在去除重金属离子、去除有机污染物、除磷及脱色等废水处理领域中的应用,并指出了目前改性膨润土在废水处理中存在的问题。     

改性膨润土吸附处理含Cr（Ⅵ）废水的研究

用阳离子表面活性剂十六烷基三甲基溴化铵（CTMAB）对钙基膨润土进行活化改性,并用制备的改性膨润土对含Cr（VI）模拟废水进行吸附实验,研究了改性膨润土去除模拟水样中重金属Cr（VI）的适宜条件。结果表明,用质量分数为5%的CTMAB溶液改性后的膨润土去除Cr（VI）效果较好,当改性膨润土用量为10g/L、搅拌时间30min、pH值为3～5时、有机膨润土对含Cr（VI）废水的去除率超过85%。     

有机改性膨润土防渗抗污染性能的研究进展

本文综述了国内外在防渗膨润土有机改性方面的最新进展 ,具体介绍了膨润土的基本性质 ,有机膨润土的制备、性质及影响因素 ,对有机污染物的吸附行为及机理研究以及在填埋防渗土壤垫层和油罐保护垫层中的应用进行了讨论     

宁国膨润土提纯及钠化改性研究

宁国膨润土原矿的主要矿物为钙基蒙脱石,杂质矿物为沸石、长石、石英等。采用精细沉降法对原矿进行提纯,提纯后的钙基膨润土采用碳酸钠进行钠化改性。利用粉末X-射线衍射、红外光谱、扫描电子显微镜、热重分析等手段,对钠化改性膨润土进行测试,结果表明,经钠化改性的膨润土具有良好的分散性,其膨胀容、阳离子交换容量均显著增加,为其工业应用提供了试验依据。     

膨润土在环保中的应用

膨润土是以蒙脱石为主要成分的粘土类矿物。由于其结构比较特殊,比表面较大,因而具有诸如粘结性、吸附性、催化活化性、触变性、悬浮性和阳离子交换性等多种性能。据报道,它在世界上 24个领域的 100多个部门中得到了广泛利用。 　　自 80年代以来,膨润土应用于环保方面在国外有了较大的发展,尤其是利用其所具有的阳离子交换性,可根据需要,改性为特殊性能的膨润土类型。总结近十几年来膨润土在环保方面的应用,可以归纳为五个方面：①污水净化处理。主要是利用其可改性,经过一次或两次改性处理,其吸附能力达到或超过活性炭,起到吸…     

改性粉煤灰处理废水的研究进展

介绍了粉煤灰的性质及处理废水的机理,从热改性、碱改性、酸改性、金属离子改性、微波活化改性、表面活性剂改性五个方面阐述了当前粉煤灰改性的主要方式及机理,概述了改性粉煤灰在废水处理中的应用,并对改性粉煤灰的进一步研究做了展望。     

改性膨润土处理油田废水实验研究

通过高温焙烧和交联改性两种方法制备出改性膨润土,研究其在不同条件下对油田废水CODCr的去除效果。结果表明：改性膨润土对油田废水CODCr的去除效率有显著提高,最高可达65.32％。为膨润土的改性及其在油田废水处理中的应用提供了参考依据。     

碳纳米管对水体污染物吸附的研究进展

碳纳米管是目前备受关注的一类新型碳材料.碳纳米管独特的结构赋予了其优异的吸附能力,从而碳纳米管被广泛应用于水体处理领域,去除水体污染物.本文重点介绍近些年来碳纳米管在处理水污染中的应用,包括重金属离子、非金属离子和有机污染物等.     

用于水处理的纳米技术和纳米材料

纳米技术和纳米材料在污水处理中极具优势.用于污水处理的纳米技术所涉及的主要纳米结构包括有纳米吸附剂,纳米膜,纳米催化剂,生物活性纳米颗粒,分子印迹聚合物等,它们能够去除有毒金属离子,致病微生物,水中有害的有机、无机溶质等.纳米材料具有高的比表面积,能够有效消除污水中的有毒金属离子,降解水中有害的有机溶质等.对现有的用于污水处理的纳米技术和半导体纳米材料进行了简单介绍,重点评述了半导体纳米催化剂和相关的纳米复合材料光催化剂的研究和进展.     

水中重金属离子吸附材料的研究现状与发展趋势

系统介绍了无机吸附材料（碳质类、矿物类、金属氧化物类）、有机高分子吸附材料（纤维素、壳聚糖、农林废弃物、离子交换树脂等）和复合型吸附材料（有机/有机型、无机/无机型、有机/无机型）等重金属离子吸附材料的物化特性和结构特点,对上述材料去除水体典型重金属离子的吸附容量、吸附机理、工程应用进展等进行了综述。阐述了纳米材料、离子选择性材料和可降解生物质材料等新型重金属离子吸附材料的研究现状及发展趋势。结果表明:开发价格低廉、吸附容量高、选择性高、可再生且环境友好的吸附材料是重金属离子吸附研究的重要方向;结合现代化检测技术和分析手段,探索吸附过程中吸附剂与重金属离子间相互作用的本质,对于拓展吸附机理和开发性能优良的吸附材料具有重要的理论和实际意义。     

膨润土基化工和环境新材料的开发与应用研究

本文介绍了作者的课题组在膨润土基化工和环境新材料的开发和应用研究上若干进展,主要涉及膨润土基酸催化剂和多孔催化材料等的制备、结构及催化应用研究。通过采用天然膨润土为原料,用酸溶液进行活化,能得到酸性膨润土;将金属卤化物等负载到膨润土载体上可制得新型固体酸催化剂;利用粘土矿物膨润土作母体,通过多羟基铝、锆、硅等交联剂插层可制成大孔径、高比表面积的层柱多孔材料,并可通过对层柱粘土结构的调控来改善其催化性能;用膨润土作为包裹剂,将氮、磷、钾肥在不同分散剂中进行包裹处理,对氮、钾肥等易溶肥有良好的缓释效果,而对磷肥等难溶肥有促释效果;以天然膨润土或改性膨润土为吸附剂,在废水处理上显示了很好的吸附性能,可吸附重金属离子、非极性有机物、极性有机物及各类有毒和难生物降解有机物等。膨润土基复合材料在催化、环保和材料等领域中显示了广阔的应用前景。     

Removal of phenol from water by adsorption-flocculation using organobentonite

Bentonite modified with short chain cationic surfactant might be the basis of a new approach to removing organic pollutants from water. The treatment process involves dispersing bentonite to the contaminated water and then adding a small cationic surfactant so as to result in flocs which are agglomerates of organobentonite and bound organic pollutants. The flocs are then removed from the solution by sedimentation. Experimental results indicate that BTMA-bentonite displays a high affinity for phenol, possibly because phenol molecules interact favorably with the benzene ring in BTMA ion through increased pi-pi type interactions. Under appropriate operating conditions, 90% phenol removal and nearly 100% bentonite recovery could be achieved by the adsorption flocculation process using BTMA-bentonite. Additionally, the insensitivity of the process to the changing ionic strength of the solution and rapid adsorption kinetics made adsorption-flocculation with BTMA-bentonite attractive for continuous treatment of large volumes of industrial wastewater. The bentonite may function as a recyclable surfactant support for the adsorption and subsequent combustion of organic pollutants.     

Utilization of clays and zeolites for coagulation treatment of municipal wastewater

This study is to evaluate the role of clays and zeolites on the coagulation and ion exchange treatment of municipal wastewater. Clay minerals used included kaolinite, montmorillonite, halloysite, and bentonite. Zeolites used included mordenite, faujasite, silicalite, and synthetic zeolite‐A. Clays and zeolites proved to be rather ineffective in decreasing the turbidity. Clays and zeolites showed a limited succes in removing Na from the wastewater. Most zeolites appeared to be quite effective in removing Ca and Mg from the wastewater with about 100% removal efficiency for Ca at a dosage of 2.0 g/l. The TOC removal efficiency of primary effluent ranged from 14 to 34% at a dosage of 1.0 g/l. Bentonite and silicalite were most effective in removing organic carbon from primary effluent.     

无机—有机复合膨润土用于焦化废水的深度处理

对辽宁省黑山钙基膨润土进行有机—无机复合改性,开发了一种高效、廉价的吸附剂,并将其用于焦化废水的深度处理,考察了膨润土粒径、反应温度、吸附剂投量、反应时间、pH等因素的影响。结果表明,经5g/L的Al2（SO4）3及0．02mol／L的十六烷基三甲基溴化铵（CTMAB）复合改性的膨润土,能同时去除焦化废水二级生化出水中残留的氨氮和COD,在投量为40g/L、反应时间为30min、反应温度为25℃、pH值为9的条件下,对氨氮和COD的去除率可分别达75％和47％,处理出水的氨氮和COD可分别降至25mg／L和150mg／L以下,为焦化废水的再生回用创造了条件。     

改性沸石吸附处理氨氮废水试验研究

在静态条件下研究了改性沸石对氨氮的吸附特性,考察了不同条件下改性沸石对含氨氮废水的处理能力。结果表明：热改性温度为500℃、pH值为7、改性沸石加入量为30g／L、吸附时间120min条件下,改性沸石对氨氮的去除率可达95％以上。     

生物沥浸改性后污泥基生物炭对Pb^2+和Cd^2+的吸附

为探索利用生物沥浸改性后污泥基生物炭去除废水中Pb^2+和Cd^2+的可行性,以生物沥浸改性后污泥为原料制备生物炭,并测定了该材料的性能和吸附特性。通过单因素试验研究了pH值、生物炭投加量对吸附Pb^2+、Cd^2+性能的影响,并利用吸附动力学和热力学来揭示吸附机制。试验结果表明,经生物沥浸改性后污泥基生物炭的重金属含量降低;吸附Pb^2+和Cd^2+的最佳pH值分别为5、6,最佳生物炭投加量均为2 g/L;其对Pb^2+和Cd^2+的吸附均能较好地符合准二级动力学方程和Langmuir等温线模型,在25、35、45℃三种温度下对Pb^2+、Cd^2+的饱和吸附量分别为30.68、39.95、43.93 mg/g和19.82、28.58、32.29 mg/g,吸附过程均主要以物理吸附为主,且为吸热过程。     

Selected organic pesticides, behavior and removal from domestic wastewater by chemical and physical processes

A study was conducted to evaluate the effectiveness of chemical and physical wastewater treatment processes in removing selected organic pesticides from domestic wastewater. A 3785 m³ day⁻¹ (1 MGD) nominal capacity pilot plant consisting of biological, chemical and physical units was used for the study. Biologically treated domestic wastewater was subjected to chemical coagulation, multimedia filtration, and activated carbon adsorption. Eight sequences of treatment processes were studied. Influent and effluent samples were analyzed for selected chlorinated hydrocarbon pesticides and chlorophenoxy herbicides using EC-GC. Confirmatory tests such as TLC, extraction of p-value and CPU-MS-GC were applied on selected samples. Results of the study provided qualitative and quantitative evaluation of the performance of the treatment processes studied. Qualitatively characteristic profiles consisting of a limited number of refractory organic residues were detected as peaks on EC chromatograms of extracts from each treatment unit. Thirteen compounds were confirmed in the biologically treated wastewater. These included DDT and its metabolites, aldrin, dieldrin, and 2,4-D alkyl esters and salts. Concentration levels of these compounds in wastewaters were at the ng l⁻¹ (part per trillion) level. Chemical coagulation with alum-lime or lime-ferric chloride was found to effect slight reduction of the organic residues detected on EC chromatograms. Quantitatively only DDT compounds were more completely removed by chemical treatment. Multimedia filters had no discernible effect in removing organic residues from biologically and chemically treated wastewater. Activated carbon columns were found to be the most effective means for removing the refractory organic residues detected. However, breakthrough of some organic residues was noted after usage of the carbon for over 1 year. The overall results of the study showed that application of several sequences of treatment processes on domestic wastewater can produce a high quality effluent which is virtually free from EC detectable organic residues.     

Analysis of anaerobic sludge containing heavy metals: A novel technique

Heavy metal ions are accumulated in anaerobic digesters outside the bacterial cells by precipitation and adsorption reactions, and inside the cells by microbial absorption. In order to gain a better understanding of the mechanisms which are involved in processes removing heavy metal ions from wastewater, and to be able to optimize the overall process, a novel analytical technique has been developed to separate heavy metal ions accumulated inside the bacterial cell from heavy metal ions accumulated outside the cell. This method has major advantages in comparison to existing methods, since it provides accurate and replicable results rapidly and requires only small sample volumes (< 10 ml). An illustration is given of the information gained about the nature of the biomass found in laboratory-scale UASB reactors, removing heavy metals from synthetic wastewater.