高锰酸钾法去除水中有机物

目前，饮用水源被有机物污染的问题已引起世界性关注，预氯化是传统的去除有机质的方法，它能有效地破坏、分解有机物，然而高浓度氯和水中腐植质间的化学反应会产生高浓度的ＴＨＭｓ，这种物质能够致癌危及人体健康。在这篇文章中，详细地研究了高锰酸钾用作氧化剂和助凝剂去除有机物的作用。结果表明，高锰酸钾可以替代预氯化，它既可作为消毒剂抑制细菌还可作为氧化剂分解有机物，同时它还可为助凝剂增强混凝效果，最重要的是高锰     

饮用水中天然有机物去除技术的研究进展

水中存在的天然有机物(NOM)在饮用水处理过程中不仅会增加消毒副产物(DBPs)的数量,影响后续工艺处理,还会和水中的其他物质结合生成毒性更强的物质(有机金属络合物),严重危害人类身体健康。因此,研究NOM的去除对水质安全意义重大。文中介绍了NOM的种类及其危害,根据国内外去除NOM技术的研究现状,综述了混凝、吸附、高级氧化、膜处理和离子交换等技术去除NOM的效果及机理,重点阐述了以混凝为核心单元的耦合工艺对NOM去除的研究进展,分析了各种耦合工艺的优势与局限性,并对今后混凝技术的研究方向进行了展望。     

氧化法去除饮用水中的农药和氯代有机物

饮用水中的农药和氯代有机物，能用化学氧化的方法去除，这些氧化方法包括Ｃｌ２，ＣｌＯ２和Ｏ３氧化法，还有使用氧化剂，紫外线照射和催化剂相互组合的高级氧化法，如Ｏ３－Ｈ２Ｏ２，Ｏ３－ＵＶ，Ｈ２Ｏ２－ＵＶ，ＵＶ／ＴｉＯ２等。本文对这些氧化方法的特点，研究现状有在饮用水处理中的应用进行了评述。     

生物过滤去除饮用水中微量有机物的研究与发展

简要回顾了最近20多年来国内外对饮用水生物过滤的研究历史，运用Lawrence-McCarty公式和微生物增殖基本方程式，推导了最小基质浓度Smin的计算公式，阐明了第二级利用机理是生物过滤去除饮用水中微量的合成有机物的主要机理，自然有机物是降解微量合成有机物的微生物的主要碳源和能源。探讨了过滤介质、空床接触时间、反冲洗方式、水温、水源水质和预氧化等因素对生物过滤效果的影响，展望了饮用水生物过滤的发展方向及在我国微污染饮用水处理方面的应用前景。     

纳滤膜去除饮用水中微量有机物的研究进展

对近年来国内外采用纳滤膜脱除饮用水中微最有害有机物的应用研究做了初步的归纳与综述,将饮用水中的有害有机物按其在水体中的常见性和重要性划分为消毒复产物(DBPs)和前驱物(FP)、环境内分泌干扰物(EDCs )、持久性有机物(POPS)、医药与个人护理品(PCPPS)、生物可同化有机物(A0C)、微囊藻毒素(MC)等6类,并对这儿类有机物的纳滤膜脱除效果与机理进行较为深入的分析与讨论,认为纳滤膜能脱除饮用水中大部分微量有害有机物,对于提高饮用水水质和安全饮水起到保证作用.     

饮用水中有机物的危害及对策

饮用水有机物污染日益加重,其危害性也逐渐被人们所重视,随着科学发展,许多更新更好水处理方法不断开发,确保了人们的饮水健康.     

三维荧光光谱表征饮用水中溶解性有机物研究进展

荧光技术目前已经被广泛地应用于溶解性有机物(DOM)的表征。其中荧光激发发射矩阵光谱(EEM),也称为三维荧光(3D-EEM)或荧光指纹是最主要的方法之一。目前,三维荧光已经被开发并用于表征饮用水处理工艺对有机物的去除效果。该文综述了目前主要的三维荧光分析方法,并总结了三维荧光在饮用水处理工艺中的运用及其存在的问题。     

饮用水中的天然有机物去除方法探讨

天然有机物的去除对保证水质是至关重要的。本文阐述了天然有机物的性质和危害 ,并对天然有机物的去除方法进行了探讨     

电厂反渗透及离子交换除盐系统去除水中有机物的试验

该文介绍了安徽省火电厂锅炉补给水处理系统中反渗透及离子交换除盐系统去除水中TOC的情况,比较了不同水处理工艺去除水中TOC的情况。结果表明省内火电厂的除盐水TOC含量基本上都能满足《火力发电机组及蒸汽动力设备水汽质量》(GB/T 12145—2008)中对除盐水TOC含量的要求。除盐水TOC含量主要取决于所采用的水处理工艺流程,基于反渗透的水处理工艺对水中的TOC去除率最高,除盐水的TOC含量也最低。     

给水处理工程中去除有机物的方法

给水处理工程中有机物的去除问题一直是国内外水处理工作者主要研究方向,而且越来受重视,因为水中有机物的去除效果直接影响到给水处理的质量,在国内外多年研究、实践的基础上,评述了给水处理中去除有机物的各种材料和方法。并对这一领域做了一些展望。     

饮用水除砷技术研究新进展

重点介绍了近年来各种除砷新技术的研究进展,内容包括:强化混凝、吸附、离子交换、膜法、预氧化除砷技术。评价了各除砷技术的优缺点与适用范围,并认为饮用水除砷技术的发展将呈现出以下特点:As(Ⅲ)和As(V)同步去除技术的开发;易于取得或制备、生物化学稳定性高、吸附容量大、选择性高、再生能力强的新型除砷吸附剂的开发;多种除砷技术联合,多重去除机理协同的除砷流程的开发;低能耗、低成本除砷技术的开发;生物除砷技术的开发。     

Continuous removal of ammonium ion by ion exchange in the presence of organic compounds in packed columns

The removal of ammonia from wastewaters after secondary biological treatment can successfully be achieved by ion exchange. However, the presence of residual organic compounds can impart significant influence on the uptake and their presence may need to be considered during the design of a treatment system. The aim of this work was to determine the effect of the presence of certain organic compounds upon the uptake of ammonium ion and column breakthrough. Two organic contaminants were considered, including citric acid and protein (as whey protein isolate). Three cationic exchangers were used and included the natural zeolite clinoptilolite, the gel resin Dowex 50w‐x8, and a macronet resin, Purolite MN‐500. The influence of regeneration upon column breakthrough behaviour was also determined. The results showed that the presence of organic compounds had variable effects on ammonium ion uptake. In the case of clinoptilolite the presence of protein appeared to have very little effect upon breakthrough capacity. In the case of the clinoptilolite and the MN500 a substantial reduction of breakthrough capacity was observed in the presence of citric acid. In the case of clinoptilolite a very significant increase in column breakthrough performance was observed after cycles of exhaustion and regeneration. This was not observed in the case of the synthetic resins, which showed a more consistent performance from run to run. Overall the Dowex50w‐x8 gave the highest breakthrough capacity for ammonium ion removal of 700 bed volumes. Regenerated clinoptilolite showed a maximum breakthrough capacity of 450 bed volumes, and MN‐500 a consistent breakthrough capacity of 300 bed volumes. Copyright © 2006 Society of Chemical Industry     

磁性离子交换树脂强化水源中有机物去除性能研究

在调查某水厂水源水质及传统工艺处理效能的基础上,对比探讨了粉末活性炭和磁性离子交换树脂分别以预吸附、预吸附-混凝、混凝沉淀-吸附等不同工艺对水源水中溶解性有机物的去除效能,确定了最佳工艺。该水源存在季节性有机物污染,亲水性有机质占比80%。水厂传统工艺对有机物的去除能力约20%~30%。与其他工艺相比,树脂预吸附-混凝对有机物的去除功效最好,DOC和UV254的去除率分别达到41.48%和80.0%,与单独强化混凝相比,该工艺可将DOC和UV254的去除效率分别提高17.7和35.49个百分点,且可减少86.67%的混凝剂投加量。Langmuir等温线模型和拟二级动力学方程可定量描述树脂吸附有机物平衡和动力学。磁性离子交换树脂预吸附可作为该水厂强化去除水源中溶解性有机物的可靠技术。     

Removal of inorganic mercury from mine waste water by ion exchange

The present study has been undertaken to investigate a process that might remove inorganic mercury from mine waste water streams by use an ion exchange resin system. A number of commercial resins have been evaluated as ion exchangers and the mercury content of the waste water, ranging from 70 to 90 ppm, is reduced to a permitted level of 34 ppb. Dowex XZS‐1, a strong cationic ion exchanger in a gel Form, has the most pronounced selectivity for mercury. The loaded resin was regenerated efficiently using HCl solutions, due to increased competition between Hg and hydronium ions and formation of an HgCl ₄ ²⁻ ionic complex. © 2000 Society of Chemical Industry     

离子交换水软化技术研究与应用进展

离子交换法是目前最常见的水软化技术之一,其基于可逆的离子交换反应将溶液中的硬度离子选择性去除,属于典型的特种分离过程。本文介绍并总结了离子交换水软化的基本原理、水软化用离子交换树脂的结构和分类、离子交换水软化技术研究和应用,并针对离子交换水软化存在的问题提出了相应的解决思路。     

Purification of glycerol/water solutions from biodiesel synthesis by ion exchange: sodium removal Part I

BACKGROUND: In this study, equilibrium and kinetic data of the ion exchange of sodium from glycerol–water mixtures on the strong acid resin Amberlite‐252 were obtained. Basic parameters for the design of ion exchange units for the purification of the crude glycerol phase from biodiesel production have been determined. RESULTS: Equilibrium uptake of sodium ions with the strong acid ion exchanger Amberlite‐252 was studied at three temperatures. The Langmuir equation and the mass action law model were used to fit the experimental equilibrium data. Equilibrium constants and thermodynamic parameters were obtained at each temperature. Kinetic experiments were carried out to evaluate the effective diffusion coefficients of sodium on the resin Amberlite‐252 in glycerine–water media. CONCLUSIONS: Equilibrium results indicate that this process is favourable and also that its selectivity decreases with temperature increase from 303 to 333 K. Both models were able to fit the experimental equilibrium data. Kinetic experiments showed that the rate of mass transfer in this binary system is high. An Arrhenius type equation allowed the correlation of effective diffusion coefficients and temperature. The results indicate that the macroporous resin Amberlite‐252 could be useful for removal of sodium ions from glycerine/water solutions with a high salt concentration. Copyright © 2008 Society of Chemical Industry     

饮用水除砷吸附剂的研究进展

砷在水体中主要以As(Ⅲ)和As(Ⅴ)的无机酸形式存在,对人体的危害很大,吸附法是国内外研究最广泛的饮用水除砷技术之一.详细说明了饮用水除砷的吸附剂类型,指出:复合材料效率高、费用低,目前应用最为广泛;纳米材料与砷结合后性质稳定,除砷效率最高,是今后的主要发展方向;生物吸附材料以其高吸附率、低成本成为研究的热点.     

离子交换微碱化处理发电机内冷水试验研究

采用离子交换微碱化技术处理发电机内冷水,将内冷水中微量溶解的中性盐Cu(HCO3)2转化为Na0H,调节溶液成微碱性,从而有效地抑制了铜导线的腐蚀。现场旁路模拟试验结果表明：在小交换柱内填装等工作交换容量的钠型、氢氧型离子交换树脂后,能将Cu^2 平均质量浓度为371．0μg/L的微酸性内冷水转变成几乎不含Cu^2 的微碱性水,出水pH的变化范围为7．60～8．95。离子交换柱之前和之后的铜试片试验结果显示：交换柱前的内冷水具有腐蚀性．而经交换柱处理后的内冷水具有抑制铜导线腐蚀的功效。     

离子交换树脂去除水中硝酸盐的研究

对比研究了国内生产的5种阴离子交换树脂(D201、D301、D407、330、717)对水中NO3-的吸附解吸情况。动态吸附饱和曲线表明,717和D407对NO3-的吸附较好,饱和吸附量分别为82.8mg/mL和54.8mg/mL,其他3种树脂效果很差;717和D407对NO3-的吸附速率也相对较快。5种树脂吸附等温线与经验公式拟合的线性相关性显著,其中330树脂符合BET经验公式,另外4种树脂符合Langmuir经验公式;再生试验表明5种树脂再生率均能达到85%以上。综合研究结果认为,强碱性苯乙烯系阴离子交换树脂717和螯合树脂D407对NO3-具有较好的吸附解吸性能,可作为去除硝酸盐的选用树脂。     

Selective iron removal from spent passivation baths by ion exchange

BACKGROUND: Post‐treatment of zinc plated surfaces is required to provide corrosion protection; for this purpose chromium passivation is usually used. In the EU, the older hexavalent chromium passivation baths have been replaced by trivalent chromium conversion coatings. However, the life of Cr(III) passivation baths is reduced due to iron and zinc impurities generated in the process. Thus, the objective of this work was to investigate the regeneration of spent passivation baths from the plating industry by ion exchange using a new chelating resin (Purolite S‐957). RESULTS: Three genuine passivation baths with different iron and zinc concentrations were investigated; the effect of loading flow rate, temperature and resin regeneration conditions on the uptake of iron ions was also studied. The removal performance of iron was increased at higher temperature (55 °C) and lower flow rates. The best regeneration conditions were found to be 6 bed volumes (BV) of 30 wt% HCl. CONCLUSION: This work has shown that iron can be selectively removed from trivalent chromium passivation baths using a new chelating resin (Purolite S‐957) and no addition of chromium (III) is required. Low feed flow rate and high bath temperature (up to 55 °C) are recommended for high iron uptake. Copyright © 2008 Society of Chemical Industry