火力发电厂补给水处理受有机物污染强碱阴树脂的复苏

通过小型复苏实验确定了补给水处理受有机物污染强碱阴树脂的最佳复苏方案,分析了复苏机制,并结合实际生产运行条件对树脂进行复苏。经复苏后,阴床出水水质得到改善、周期制水量增加、酸碱耗降低,取得了一定的社会效益和经济效益。     

锅炉补给水除盐系统强碱阴树脂有机物污染的诊断及预防

结合东南沿海某电厂锅炉补给水处理一级除盐系统强碱阴树脂频繁遭受有机物污染的情况,探讨了强碱性阴树脂有机物污染的机理。针对树脂的污染情况,结合其机理研究了相关试验和检测手段,提出了诊断强碱阴树脂有机物污染的方法。结合对锅炉补给水预处理系统及除盐系统各工艺对有机物的去除情况检查,分析了该厂一级除盐系统强碱阴树脂频繁遭受有机物污染的原因,并结合国内外有机物污染的去除技术情况,提出了为预防阴树脂有机物污染,对锅炉补给水预处理系统进行改造和优化的相关措施。     

污染的阴树脂复苏处理

阴树脂在运行过程中容易遭受铁污染、有机物污染、胶体硅污染、本文根据现场试验,找到了一个除去阴树脂铁污染、有机物污染、恢复阴树脂全交换容量及强碱基团交换容量的最佳处理方法。     

强碱阴树脂受有机物污染的判断方法及其处理

强碱阴树脂易受水中有机物的污染,使树脂提前失效。采用出水水质曲线判断法和污染指数判断法可确定树脂是否被污染,从而有效地保证了离子交换水的质量。     

离子交换树脂的电再生机理研究

为探究无膜电去离子(MFEDI)的再生机理,采用不同树脂组合进行电再生研究。通过测定各组树脂的再生电压、再生液电导率、pH等参数,对阴阳离子电迁移路径和系统内水解离情况进行了分析。结果表明,阳离子几乎不通过弱酸树脂进行电迁移;阴离子主要在强碱树脂间迁移;水解离主要发生在弱酸树脂与强碱树脂之间,为2种树脂的再生提供82.4%以上的H~+和OH~-。     

解决阳床逆流多次重复再生问题

吴泾电厂化水甲站是六套出力100t/h一级除盐设备。 工艺流程:阳床—脱碳器—弱碱阴床—强碱阴床。 出水水质:电导率<5p√cm,硅酸根<100户e/L,Na~ <300pg/L。 阳床采用逆流再生,再生剂为30％工业盐酸,阴床顺流再生先再生强碱阴床,强碱阴床排放的废液用来再生弱碱阴床,再生剂为30％工业氢氧化钠。     

凝结水精处理树脂油污染的复苏方法

介绍了凝结水精处理树脂受锅炉点火柴油严重污染的原因.利用精处理再生系统进行复苏,复苏后的树脂产水指标达到污染前的水平,为火电厂树脂复苏提供了经济、可行的处理方法.     

脱盐水站离子交换树脂污染的复苏处理

脱盐水站采用空气擦洗法对阳树脂进行钙污染复苏处理,采用碱性食盐法对阴树脂有机物污染进行复苏处理,另外也采用适当的方法对阴树脂的铝、铁污染进行复苏处理,均取得较好效果。     

浅谈双室双层浮动床工艺设计及运行中的问题

根据运行经验,对有关专著和标准中提出的双室双层浮动床进水水质、工交的选择、自由空间的高度等问题提出了质疑,认为在暂硬大于2.0mmol/L,总强酸阴离子大于2.5mmol/L的条件下,阳、阴双室浮动床就可经济运行。强碱阴树脂再生在17~20℃时就能保证再生效果,不需要将再生碱液加热到35~40℃。     

固定床离子交换树脂复苏方法探讨

为了提高脱盐水水质 ,降低系统的腐蚀和结垢 ,本文通过实验方法对污染较严重的树脂进行复苏 ,从而达到提高树脂的工作交换容量和再生程度     

REMOVAL OF SULFATE FROM NATURAL WATERS BY CHLORIDE EXCHANGE

Sulfate can be replaced with chloride ion by anion exchange in a method analogous to water softening. A strong-base resin is used, and regeneration is with sodium chloride. Sulfate levels are reduced to below 1 ppm. Sulfate-chloride exchange is an interesting case in that both loading and regeneration can be carried out with favorable separation factors. Rough mass-action calculations can be used to approximate the solution concentrations at which selectivity reverses, and to estimate column loadings from influent composition.     

REMOVAL OF SULFATE FROM NATURAL WATERS BY CHLORIDE EXCHANGE

Sulfate can be replaced with chloride ion by anion exchange in a method analogous to water softening. A strong-base resin is used, and regeneration is with sodium chloride. Sulfate levels are reduced to below 1 ppm. Sulfate-chloride exchange is an interesting case in that both loading and regeneration can be carried out with favorable separation factors. Rough mass-action calculations can be used to approximate the solution concentrations at which selectivity reverses, and to estimate column loadings from influent composition.     

离子交换色谱法分离硼同位素的研究进展

综述了离子交换色谱法分离硼同位素的进展。在目前的研究方法中,主要采用强碱性阴离子交换树脂、弱碱性阴离子交换树脂和硼特效树脂作为柱填充材料,本文对于这3种树脂的优缺点进行了比较,最后对影响单级分离因子的因素进行了讨论。表明离子交换色谱法是一种极具潜力的硼同位素分离方法,具有高效节能的特点。     

REILLEXTM HPQ: A NEW,MACROPOROUS POLYVINYLPYRIDINE RESIN FOR SEPARATING PLUTONIUM USING NITRATE ANION EXCHANGE

Anion exchange in nitric acid is the major aqueous process used to recover and purify plutonium from impure scrap materials. Most strong-base anion exchange resins incorporate a styrene-divinylbenzene copolymer. A newly available, macroporous anion exchange resin based on a copolymer of l-methyl-4-vinylpyridine and divinylbenzene has been evaluated. Comparative data for Pu( IV) sorption kinetics and capacity are presented for this new resin and two other commonly used anion exchange resins. The new resin offers high capacity and rapid sorption kinetics for Pu( IV) from nitric acid, as well as greater stability to chemical and radiolytic degradation     

Multicomponent anion exchange with a resin having weakly and strongly basic groups

Multicomponent anion exchange with a resin having both weakly and strongly basic groups was investigated by means of modelling and column experiments. Our objective was to develop a model able to predict the evolution of the composition of a water treated by such a resin. The studied resin was Purolite S108, used for boron removal from water, on which ternary and quaternary amines were attached (additionally to boron complexing groups). Column dynamics were modelled with the computer code IMPACT, devoted to reactive transport in porous media. A reaction scheme was proposed to represent anion exchange on the two types of groups, with a quaternary anionic system including hydroxide, chloride, sulphate and nitrate at a given ionic concentration. This reaction scheme needed eight parameters: concentrations of weak and strong-base groups and the anion exchange selectivities. These parameters were measured through binary anion exchange, without or with pH step. The breakthrough curves of the binary experiments were in very good agreement with the experimental one. The model was then used to predict the results of a more complex experiment in which the column had been fed by a mixture of acids. The main features of the experimental behaviour were fairly well predicted, even if the agreement was not perfect. These discrepancies were attributed to the model assumptions, mainly to the expressions of anion exchange selectivities. These results enabled us to predict almost quantitatively the evolution of the water composition during its treatment. This point is an improvement in the prediction of the dynamics of an anion exchange with two types of groups. In the future, the model would have to be extended to take into account different expressions of the exchange selectivities, and nonequilibrium conditions.     

Parametric studies on the performance of anion exchange for nitrate removal

Ion exchange performance to remove nitrate in surface and underground water was studied experimentally in batch and continuous operation systems under various conditions. Data were collected by using commercially available strong-base anion-exchange resins of C1 and OH types. Equilibrium curves, obtained through the batch system and plotted as the concentration ratio versus run time, were used to evaluate the effects of temperature, resin type, and initial feed concentration on the equilibrium characteristics of nitrate. The selectivity coefficients of the resins were correlated as a function of temperature by using the Kraus-Raridon equation. Breakthrough curves, obtained through the continuous column system and plotted as the ratio of effluent to influent concentration versus solution volume passed through the experimental column, gave detailed results about the effects of the system parameters, such as temperature, resin type, feed concentration, volumetric flow rate, column diameter and height on the performance of the anion exchange to remove nitrate. The results of this study could be scaled up and used as a design tool for a water-purification system of real ground water and surface water treatment processes.     

Simultaneous removal and recovery of cadmium and cyanide ions in synthetic wastewater by ion exchange

Simultaneous removal and recovery of cyanide and cadmium ions using a strong-base anion exchange resin was studied on the basis of formation of Cd-CN complexes at high pH in synthetic wastewater containing cyanide and cadmium ions. Strong-base anion exchange resin particles, of Dowex1X8-50, were contacted with synthetic aqueous solutions. For different molar ratios between cyanide and cadmium, ion exchange characteristics of cadmium-cyanide complexes were studied experimentally in a batch reactor. Treatment efficiencies of packed and fluidized beds were compared under various conditions. Several regenerants, NaSCN, NaCN, and NaOH, were used to regenerate the exhausted resin. The rates of regeneration and recovery for the various regenerants were estimated and discussed. The resin used in this work, Dowex1X8-50, can exchange about 6.6 CIST meq./g resin and 3.2 Cd²⁺ meq./g resin of cyanide and cadmium ions as complexes, respectively. Free cyanide ion has a lower selectivity than Cd-CN complexes on the anion exchange resin. The degree of treatment efficiency applied in this study was greater in the fluidized bed than packed bed. NaSCN was the best regenerant among regenerants used for regeneration of resin saturated with Cd-CN complexes.     

Catalytic denitrification: direct and indirect removal of nitrates from potable water

A nitrate removal process that drastically reduces salt consumption and waste discharge has been developed on a bench scale. Nitrate is removed by chloride ion exchange, and the strong-base anion resin is completely regenerated at mild reaction conditions (i.e., ambient temperature, atmospheric pressure) in a closed circuit containing a single-flow fixed-bed reactor packed with a Pd–Cu/γ-Al₂O₃ catalyst. The combined treatment system avoids direct contact between the denitrification reactor and the water to be treated, and minimizes operational problems associated with each separate technique. No dissolution of Pd and Cu metallic-phases was observed at the given operating conditions.     

酸碱滴定分析法在脱盐水系统阴树脂复苏中的应用

通过自制微型阴树脂交换柱,将复苏过程中的阴树脂适时再生后,加入定量的硫酸溶液,测定经过微型树脂交换柱的硫酸溶液的质量,计算阴树脂交换率,从而判断阴树脂的复苏效果。     

Equilibrium studies of phenylalanine and tyrosine on ion-exchange resins

The ion exchange equilibria of amino acids (phenylalanine and tyrosine) on a strong-acid cation exchanger resin (PK220) and on a strong-base anion exchanger resin (PA316) has been investigated. Based on experimental fixed-bed saturations at constant pH, each of the resins was previously screened of a set of three commercial lots with different physical properties. Overall mass balances from the saturation curves enabled to evaluate the linear isotherm constants and its dependence with pH. An equilibrium model that takes into account energetic heterogeneities in ion exchangers was successfully used to correlate binary and multicomponent data.