Dissertations / Theses on the topic 'Synthetic anion exchange resins'

Landfill leachates are often discharged to wastewater treatment plants (WWTPs) but their highly varied composition makes their treatment in WWTPs difficult. Landfill leachates contain bio-refractory organic matter which easily passes the biological treatment processes at WWTPs and increases the organic matter in the effluent. Leachates also interfere with the UV disinfection process at treatment plants. Another concern is the presence of large amounts of bio-refractory organic nitrogen in the leachates which makes it difficult for WWTPs to meet the tightening total nitrogen requirements. Studies were conducted to evaluate the applicability of anion exchange resins to remove organic matter, UV quenching substance and organic nitrogen from landfill leachates. Leachate samples based on varying age and treatment methods were utilized. The anion exchange resins were found to work effectively for all studied leachates. The resins were found to remove more bio-refractory UV absorbing substances as compared to total organic carbon (TOC), suggesting that anion exchange resins could be employed for removal of UV absorbing substances. Multiple regenerations of the resin showed slight loss in the capacity to remove UV and organic carbon. Fractionation of leachate samples showed effective removal of humic acid (HA) fraction which is responsible for most of UV quenching. The resin was also found to effectively remove the bio-refractory hydrophilic (Hpi) fraction which tends to persist even after HA fraction has bio-degraded. Membrane filtration (1000 Da and 3000 Da Molecular weight cut off) in conjunction with ion exchange resins achieved better removal of organic matter and UV254 absorbing substances. In addition, this also significantly improved the performance of resins. Significant removal of organic nitrogen was also observed using anion exchange though it was less than both UV and TOC. Around 80% removal of organic nitrogen associated with bio-refractory Hpi fraction was achieved using anion exchange suggesting ion exchange as a viable alternative for removing organic nitrogen.
Master of Science

Harmful algal blooms have markedly increased in frequency over the past two decades, due to rising global temperatures and chemical runoff produced by modern farming practices. Cyanobacteria, also known as the blue green algae, are an essential part of the aquatic food chain. Cyanobacterial toxins, which are released from the algal biomass, can contaminate drinking, recreational and agricultural water reserves. Such environmental and health hazards pose a serious threat to communities and many aquatic ecosystems. In particular, small, shallow lakes that are sources of drinking water for rural communities have been particularly affected by elevated levels of algal toxins. Conventional water treatment systems are inefficient in removing these toxins, and may produce hazardous by-products. Additionally, the effectiveness of chemical oxidants, like chlorine and ozone, is hindered by the presence of natural organic matter (NOM) and inorganic ions in the contaminated water. Such challenges reveal the need for alternative treatment technologies capable of removing algal toxins. Anionic ion exchange (IX) resins offer a promising and cost-effective treatment alternative for natural waters affected by high algal content and high dissolved organic carbon (DOC) levels. This research investigates the efficiency of strongly basic ion exchange resins for the removal of microcystin-LR (MCLR), the most common toxin released from the algal biomass, inorganic ions, and NOM from natural water sources. We focused specifically on optimizing resin dosage, resin regeneration, and scaling up such procedures for particular source waters. Our results showed that the resin exhibited an excellent adsorption capacity of 3850 µg/L, removing more than 80% of the MCLR within 10 minutes at examined resin dosages (10 to 1000 mg/L; 1mL of resin = 221 mg). Additionally, we examined the influence of operating parameters such as pH and adsorption capacity of the resin, as well as the impact of NOM fractions on the uptake of MCLR. The charge density and molecular weight of the source water NOM were found to play a major competitive role in the uptake of Microcystin-LR. The results of this study bring the promising potential of IX resins for the removal of Microcystins and NOM from surface waters to light.
Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate

It is known in many gold operations that less than 2% of the cyanide consumed accounts for the gold and silver dissolution. The majority of the cyanide is consumed by minerals contained in the gold ore to produce many different cyanide soluble complexes or used in converting cyanide to other related species such as thiocyanate and cyanate. The high costs associated with cyanide and thiocyanate detoxification and excessive cyanide utilisation encountered when treating ores with high cyanide consumption constitutes a significant proportion of the overall processing costs. This study examines the possibility of recovering free cyanide from thiocyanate using a process based on the Acidification-Volatilisation-Regeneration (AVR) circuit in conjunction with a pre-concentration stage using commercially available ionexchange resin. From thermodynamic modelling based on the STABCAL program it was found that it was thermodynamically possible to recover cyanide from thiocyanate if the oxidation of cyanide to cyanate can be stopped. Addition of copper to the system found that the majority of the thiocyanate exists as copper(I) thiocyanate (CuSCN) solid. Using ion-exchange resins can be an effective way to concentrate thiocyanate from tailing solutions or slurries. Four different models were successfully used to model the equilibria between thiocyanate and chloride on commercial ion-exchange resins. By normalising the equilibria data when applying the Mass action law the equilibria becomes independent of ionic strength within the range of concentration considered. An advantage of this is that only one unique equilibrium constant is used to describe the ion-exchange process. The electrochemical and kinetic studies showed that the reaction between thiocyanate and hydrogen peroxide is catalysed by hydrogen ions. Secondly under acidic conditions the rate of cyanide recovery by the AVR circuit was faster than at higher pH conditions. The overall reaction of thiocyanate with respect to the concentration of thiocyanate and hydrogen peroxide is an overall third order reaction. The derived third order rate expression is first order with respect to thiocyanate concentration and second order with respect to hydrogen peroxide concentration. Previous studies showed that the production of cyanide inhibits the reactions between thiocyanate and hydrogen peroxide, but by removing cyanide from the reaction by air stripping, this was not observed. Addition of copper to the system did not show a catalytic effect on the reaction but it was found that copper (II) ions suppresses competing reactions that occurred without affecting the reaction between thiocyanate and hydrogen peroxide.

With growing environmental and occupational safety concerns over the use of cyanide in gold processing, more acceptable alternatives are receiving increased interest. The most promising of the possible alternatives is thiosulfate. However, as activated carbon is not an effective substrate for the adsorption of the gold thiosulfate complex, the thiosulfate process lacks a proven in-pulp method for recovering dissolved gold. Anion exchange resins offer a possible route for in-pulp recovery. This thesis describes work aimed at evaluating the effectiveness of commercially available anion exchange resins for the recovery of gold from thiosulfate leach liquors and pulps. It was found that Strong-base resins are superior at accommodating the gold thiosulfate complex compared to Weak-base resins, which means Strong-base resins have a greater capacity to compete with other anions in leach solutions. Strong-base resins were therefore the preferred choice of resin for recovery of gold from thiosulfate leach solutions and pulps. Work with a selected commercial Strong-base resin showed that competing polythionates (particularly tri- and tetrathionate) lower the maximum possible loading of gold but that gold is selectively recovered over other base-metal anions in typical leach solutions. From kinetic experiments, it was found that competing polythionates did not affect the initial rate of loading of gold but displaced the loaded gold at long times. Thus it would be important to minimise the contact time of the resin with the pulp. Equilibrium loading isotherms of gold in the presence of competing anions could be analysed by treating the ion exchange reaction as a simple chemical reaction. However, a stoichiometry and equilibrium quotient which does not follow that normally used for anion exchange, was required to describe the experimental data. A single value for the equilibrium constant also cannot be used to describe the data over the range of concentrations for a given competing anion. The order of selectivity of the anions for the anion exchange resin could be explained by the difference in structure and the charge of each anion. The rate of loading of gold is controlled by mass transport in the aqueous phase in the presence of weakly competing anions such as sulfate and thiosulfate. An attempt was made to describe the more complex loading curves obtained in the presence of stronger competing anions such as sulfite, trithionate and tetrathionate in which it was found that the loading of gold increased to a maximum before declining to a lower equilibrium value. The difference in the rate of loading between the macroporous and gel anion exchange resins was explained by the difference in the location of their functional groups. Operation of a small-scale resin-in-pulp plant showed that gold could be recovered from a leach pulp to yield loadings of gold of up to 6000 mg L-1 and loadings of copper below 100 mg L-1. Under ideal conditions, the gold concentration in the barren pulp could contain less than 0.01 mg L-1. Throughout the trial it was shown that loaded copper would be displaced by gold which would result in the loading of copper falling from 2000 mg L-1 in the last stage to lower than 100 mg L-1 on the resin in the first stage. It was observed that some of the dissolved gold precipitated or adsorbed on the solids during leaching. Some of this adsorbed gold was found to be recovered by the anion exchange resins that would have reported to the tails if a solid/liquid separation method was employed. Gold was efficiently eluted with a nitrate solution and the two-step elution process using aerated ammonia followed by nitrate effectively stripped all the copper and gold from the resin. This process was found not to materially affect the equilibrium gold concentration on the resin after eight cycles, thus allowing the resin to be recycled without the need for regeneration. Electrochemical studies showed that the gold thiosulfate complex was reduced on stainless steel from a nitrate solution. Conventional electrowinning could therefore be used to recover the gold from the eluant.

The present paper involves application of nondestructive radioactive tracer technique in characterization of Dowex 550A LC and Indion-820 anion exchange resins. The characterization study was based on kinetic of exchange reactions between inactive iodide/bromide ions on the resins with radioactive iodide/bromide ions in the solution. During iodide exchange reaction performed at a constant temperature of 40.00C, using 1.000 g of ion exchange resins and labeled iodide ion solution of concentration 0.003 mol/L, for Dowex 550A LC resin the specific reaction rate and initial rate of ion exchange was 0.271 min-1 and 0.141 mmol/min respectively, while the amount of iodide ions exchanged was 0.522 mmol, and log Kd was calculated to be 12.1. The above values calculated for Dowex 550A LC resin was higher than the respective values of 0.108, 0.330, 0.036 and 6.0 as obtained for Indion-820 resins. Similar results were obtained for the two resins during bromide exchange reactions, thereby indicating superior performance of Dowex 550A LC resin over Indion-820 resins.

The present paper involves application of nondestructive radioactive tracer technique in characterization of Dowex 550A LC and Indion-820 anion exchange resins. The characterization study was based on kinetic of exchange reactions between inactive iodide/bromide ions on the resins with radioactive iodide/bromide ions in the solution. During iodide exchange reaction performed at a constant temperature of 40.00C, using 1.000 g of ion exchange resins and labeled iodide ion solution of concentration 0.003 mol/L, for Dowex 550A LC resin the specific reaction rate and initial rate of ion exchange was 0.271 min-1 and 0.141 mmol/min respectively, while the amount of iodide ions exchanged was 0.522 mmol, and log Kd was calculated to be 12.1. The above values calculated for Dowex 550A LC resin was higher than the respective values of 0.108, 0.330, 0.036 and 6.0 as obtained for Indion-820 resins. Similar results were obtained for the two resins during bromide exchange reactions, thereby indicating superior performance of Dowex 550A LC resin over Indion-820 resins.

Civil Engineering
M.S.Env.E.
Priority organic and emerging contaminants are a growing concern for drinking water treatment due to their increasing presence in the environment. This study developed a predictive model for the sorption of anionic organic contaminants from drinking water on three anion exchange resins: a strong polystyrenic (IRA-910), weak polystyrenic (IRA-96), and a strong polacrylic (A860). The model quantifies the individual mechanisms of sorption using poly-parameter linear free energy relationships (pp-LFERs) and the feasibility of phase conversion (e.g., an ideal gas phase as the reference state) for ionic species was examined. To develop the model, a training set of isotherms was obtained using aliphatic and aromatic carboxylates, phenols, anilines, nitrobenzene, and ibuprofen. These compounds were chosen as model organic contaminants in the environment. The training set and 1-3 test compounds (3-methyl-2-nitrobenzoate, phenol, and 4-nitroaniline) were accurately predicted using the created model for each resin. An understanding of the effects of resin structure on sorption interactions was also developed that focused on ionic functional groups, resin matrix, and hydrophilicity (i.e. water content). It was shown that greater sorption efficiency was achieved when electrostatic (ion exchange) and nonelectrostatic (adsorption) interactions were present together to create a synergistic addition. However, sorption on ion exchangers was poor if the pH of the system approached levels lower than the sorbate pKa. Additionally, weak base exchanges lose exchange capacity as pH levels approach resin pKa (IRA-96 pKa = 6.0). Additional contributions to the sorption mechanisms were observed by studying various electron donating/withdrawing functional groups on the contaminants. It was concluded that π-π and H-bonding interactions contributed a greater amount to the nonelectrostatic mechanisms than cavity formation forces and nonspecific forces. A comparison between the three resins showed that IRA-96 (weak base polystyrenic) had a greater removal capacity than IRA-910 (strong base polystyrenic), followed far behind by A860 (strong base polyacrylate). This is due to differences between the resins, such as the hydrophilicity, the density of the ion exchange group, and the presence of aromatic rings within the matrix structure. Although the modeling method accurately predicted the phase change from aqueous to sorbent phases, it was shown that the SPARC calculated aqueous-gas ion transfer energies were poor estimations of the transfer energy to the ideal gas phase and further study is necessary to accurately determine this value. This modeling methodology is believed to be applicable to emerging contaminants such as pharmaceuticals in water systems and helps further new water treatment technologies while developing a mechanistic understanding of electrostatic and nonelectrostatic interactions in general. This can be applied to additional separation processes such as chemical purification and chromatographic separation.
Temple University--Theses

This study focuses on the development of novel two-stage esterification-transesterification synthesis of biodiesel from used cooking oil (UCO) using novel heterogeneous catalysts. The esterification of the UCO was investigated using three types of ion exchange resins catalysts including Purolite D5081, Purolite D5082 and Amberlyst 15. Of all the catalysts investigated, Purolite D5081 resin showed the best catalytic performance and was selected for further optimisation studies. From the optimisation study, it was found that the external and internal mass transfer resistance has negligible effect on the esterification reaction. At the optimum reaction conditions, Purolite D5081 achieved 92% conversion of FFA. During reusability study, the conversion of FFA dropped by 10% after each cycle and it was found that progressive pore blockage and sulphur leaching were dominant factors that decreased the catalytic performance of the Purolite D5081 catalyst. A kinetic modelling for FFA esterification was carried out using Purolite D5081 as a catalyst. Three types of kinetic models were investigated i.e. pseudo homogeneous (PH), Eley-Rideal (ER) and Langmuir-Hinshelwood-Hougen-Watson (LHHW). Experimental data obtained from the batch kinetic studies was successfully represented by the PH model and a good agreement between experimental and calculated values was obtained. The activation energy for esterification and hydrolysis reaction was found to be 53 and 107 kJ/moL. The transesterification of pre-treated cooking oil (P-UCO) was investigated using various types of heterogeneous catalysts including Purolite CT-122, Purolite CT-169, Purolite CT-175, Purolite CT-275, Purolite D5081, Diaion PA306s and Cs-supported heteropolyacids catalysts. Of all the catalysts investigated, Diaion PA306s catalyst showed the highest conversion of triglycerides and was selected for further optimisation studies. At the optimum reaction conditions, Diaion PA306s achieved ca. 75% of triglycerides conversion. During the reusability study, Diaion PA306s catalyst gave a similar conversion of triglycerides after being reused once. Therefore, it was concluded that the resin can be used several times without losing catalytic activity. Several purification methods have been investigated and dry washing method was chosen as the best alternative for biodiesel purification.

Tartaric acid is a dicarboxylic acid naturally present in grapes, and has many application areas with its salts. It can be produced synthetically, manufactured as a by-product in wine industry, or can be recovered by electrodialysis and solvent extraction methods. Since, ion exchange is one of the oldest processing techniques for the recovery and purification of valuable materials, it can be applied to obtain this valuable organic acid. In this study it is aimed to investigate the effects of resin basicity, initial concentration, and initial pH of the solution on ion exchange equilibrium. The model tartaric acid solutions were prepared for the equilibrium analysis with two different anion exchange resins in a batch type system. A shaker bath at 28 oC with 300-rpm agitation rate was used. The weakly basic resin Lewatit MP62, and strongly basic resin Lewatit M511, which are in polystyrene structure, was obtained from the producer Bayer AG. In the analysis, Shimadzu PDA Detector at 210 nm with Waters Atlantis dC18 column was used. 20 mM NaH2PO4 at pH = 2.7 was introduced to the HPLC as the mobile phase at 0.5 ml/min flow rate. In the investigation of the resin basicity, MP62 presented better performance than M511. The equilibrium experiments were performed at three different initial acid concentrations (0.01, 0.02, and 0.10 M) for both resin, and in the pH ranges pH <
pKa1, pKa1 <
pH <
pKa2, and pKa2 <
pH for weakly basic resin, and in the pH ranges pH <
pKa1, pKa1 <
pH <
pKa2 for strongly basic resin at each concentration. Results show that the pH of the solution is a more important parameter than the initial concentration that affects the ion exchange equilibrium. Also, Langmuir and Freundlich isotherms were plotted, and it was shown that they were in good agreement with the experimental data especially for the systems that are at low total ion concentrations.

Deals with the preparation, characterisation and testing of a series of new and improved synthetic anion exchange resins for selective absorption of the precious metals gold and silver, over the base metals, iron, copper, cobalt, zinc, nickel and aluminium, from an industrial leach solution.. The major method employed by industry, over the last thirty years, to abstract gold from low grade ore or tailings has been cyanide leaching followed by activated carbon concentration. The inherent problems with carbon prompted investigations into alternative methods for the concentration and abstraction of the metal cyano complexes. Ion exchange resins were employed for this purpose due to their versatility towards derivatisation and inertness to chemical and physical attack. The aims of this study were three-fold. The first aim was to design, synthesise and characterise a series of precious metal selective, strong and mixed base, anion exchange resins, where the cationic active site of each is sterically hindered to the approach of the base metal complexes. This aim also included development of the synthetic procedure to yield a resin with the highest degree of substitution possible. The second aim involved the synthesis of each resin on a variety of solid supports, from Merrifield (gel) type resins with different percentage crosslinking to highly crosslinked macroreticular (macroporous) matrices, and comparison of the degree of substitution, precious metal selectivity, equilibrium loading and loading rate achieved with each. This would then allow the identification and use of the most suitable resin base for this study. The final objective of this research involved an investigation into the performance of each resin employing both synthetic and industrial metal cyanide solutions. These investigations were performed under varying chemical and physical conditions (pH, temperature and concentration, etc.) and various kinetic models applied to each resin to mimic its loading characteristics. The selectivity and loading properties of the prepared resins were compared to those of commercial anion exchange resins, industrial activated carbon and other specific gold selective resins. Twenty-four resins were prepared by attaching tertiary amines to blank, chloromethylated poly-styrene/divinylbenzene copolymer resin matrices via seven day reactions in DMF at temperatures of 110°C, thus forming the strong base, quaternary ammonium anion exchanging active site. If required, the resins were then further functionalised to form the respective gold selective species. The degrees of substitution for the novel resins ranged from 0.2 meq/g to 2.5 meq/g depending upon the nature of the starting amine. As some resins are mixed base anion exchange, having one strong base site and one or more (up to four) weak/moderate base sites, gold loadings were obtained in the range 40 000 g Au/ton resin to 1 110 000 g Au/ton resin, or 4 % Au w/w to 110 % Au w/w. No obvious differences in substitution were noted between the different resin matrices trialed. The structure of these function-alised groups on the synthesised resins were characterised by microanalysis, difference infra-red and solid state nuclear magnetic resonance spectroscopy, atomic absorption spectrophotometry, and by comparison with model compounds. Similarities between the NMR spectral properties of the resins and model compounds as well as differences in these properties between the unattached amines and the resins were sought and inferences made as to the success of either the attachment or derivatisation reactions. Microanalysis and anion exchange were also employed to confirm the existence of each functionality and the type of novel resin formed. All the resins prepared show good to excellent selectivity for the precious metal cyano complexes, with four - NOTREN, TIPA, TIPAAPS and TEA-BE resins - displaying extra-ordinary discrimination at all pH values. The pH of the solution was observed to have no effect on the loading of strong base resins, however the equilibrium loading on the mixed base resins was limited by the acidity of the solution. Variation in solution temperature results in an almost linear increase in initial loading rate, indicating a first order process, with an average rate constant of 2 x 10-³sec-¹and activation energy of 55 kJ/mol. At 30 C the reactions were complete in about six hours, while at 80 C the resins were fully loaded in approximately 45 minutes. An increase in temperature also resulted in a linear decrease in equilibrium loading, indicating an exothermic process, with an average Hextraction of - 35 kJ/mol. Change in ionic strength of the solution resulted in a decrease in the final loading due to increased competition for the active site. Variation of resin matrix had little effect on the gold selectivity or loading of the respective resin. Each of the resins tested with the metal cyanide solutions (both synthetic and industrial) could be easily regenerated to their full capacity. The thiocyanate and thiourea elution procedures proved to be the most efficient for recovery of the precious metals with these selective resins. Rate constants of approximately 5 x 10-³sec-¹(first order process) for the thiourea method and 1.55 L/mol/sec (second order process) for the thiocyanate method were measured. The resins were recycled many times through loading, elution and regeneration cycles employing industrial leachate solutions for loading without any loss of selectivity or gold loading ability. There was also no evidence of the resins being poisoned by non-eluting metal cyano complexes during this trial. This reported research has thus led to the preparation of a series of resins which display a high selectivity for the precious metal cyano complexes while limiting the abstraction of the base metal cyano complexes. The performance of these resins compares favourably with that of other gold selective resins (some of which are being employed commercially as gold selective extractants ) and as a result show enormous potential to industry for use as selective auro- and argento-cyanide concentrators from cyanidation leachates.

碩士
高苑科技大學
化工與生化工程研究所
100
In general, transesterification reaction can produce in homogeneous system or through the non-homogeneous for catalytic systems, the homogeneous system such as containing alkali or acid catalysts. In the past literature, the most commonly used as base catalysts such like hydroxide, sodium methoxide. However, in alkali manufacturing process, although the rapid response of the advantages, but it has shortcomings of easy saponification, whereas acid processes has disadvantages of slow response time. When in the process of non-homogeneous for catalytic system, required more stringent reaction conditions; although the rate of transesterification reaction time is still less than in the alkali catalyst process, but in this reaction, it’s neutralize the unsaturated fatty acids that can avoid saponification reaction occurs. Due to the use of ion exchange resin as catalyst can be recycled, it is a green process, looking forward to this for the another production system for biodiesel production. In this study, anion-exchange resin (Amberlyst A-21、Ion exchanger III) as the catalyst for soybean oil and methanol as raw materials for transesterification reaction in the stirred batch reactor, thus producing biodiesel; and to explore the process and the reaction dynamics for biodiesel. Also explore its oil-alcohol ratio (1:1~1:6), reaction temperature (20~60℃), stirring rate (200~600rpm), addition of ion exchange resin (4.3~21.7wt%)and the use of its renewable (0~4times) for the relation between biodiesel conversion rate and reaction time, in order to achieve optimization of the reaction conditions. From the experimental results found that when set oil-alcohol ratio (1:5)、reaction temperature (50℃) 、stirring rate(400rpm) 、ion exchange resin(13.0wt%) was optimization of the reaction conditions. This study also discusses the mechanism in the reaction, and the kinetic model to describe the behavior of anion-exchange resin as catalyst; the results are very close to the experimental results with theoretical predictions.

碩士
國立臺灣大學
化學系研究所
85
In-situ chemical derivatization under supercritical carbon dioxide is an effective mean to increase the extraction efficiency for polar and ionic species. In addition , it conditions analytes for their subsequent chromatographic sepeation. In-situ chemical derivatization and extraction of acidic polluents including haloacetic acids, phenols and phenoxyacetic acids adsorbed onto a anion exchange resins was achieved by using either methyl iodide or pentafluorobenzyl bromide as derivatization agents. Phenols and phenoxyacetic acids were concentrated on 0.5 ml anion exchange resin and derivatized and extracted using pentafluorobenzyl bromide in supercritical carbon dioxide whereas haloacetic acids adsorbed on the resin were derivatized and extracted with methyl iodide in supercritical carbon dioxide. The derivatives were collected into organic solvent and analysed by capillary gas chromatography/mass spectrometry. 100ml 3 ppb of Phenols and phenoxyacetic acids can be detected by this method.

碩士
國立高雄師範大學
化學系
100
Chlorine dioxide (ClO2) has been widely used as a powerful disinfectant in many applications such as food processing, drinking water purification, medical sterilization and antibacterial use. In application practice, ClO2 is usually required to generate in situ by electrochemical methods. However, to increase the generator efficiency of ClO2 and to prevent the generation of chlorine, a harmful by-product, are always an important issue. This work mainly aims at studying effects of varying the composition of electrolytes in electrochemical cell by anion-exchange resins and recycled effluent on the production of chlorine dioxide. This experimentation was carried out in a redesigned divided electrochemical cell. All laboratory studies have been conducted under constant galvanic-static current and constant feed flow rate mode. The rate and amount of the electrochemical generation of ClO2 and Cl2 from aqueous solutions of sodium chlorite had been measured and used as main criteria for comparison among different tests. Varying the composition of electrolytes in electrochemical cell by SA-20 ion-exchange resin, the amount of ClO2 generation increased by 23.4% and the generation of Cl2 have been delayed. Although the negative effects of decreasing the ClO2 amount by 14.6% and increasing the amount of Cl2 have been displayed in the test of using recycled effluent. However, the usage of recycled effluent possesses the advantage of environment protection.