scholarly journals Effects of ion-exchange treatment on bromate formation and oxidation efficiency during ozonation

2012 ◽  
Vol 12 (2) ◽  
pp. 187-192 ◽  
Author(s):  
S. Echigo ◽  
S. Itoh ◽  
A. Niwa
Keyword(s):  
Ion Exchange ◽  
Drinking Water Treatment ◽  
Ion Concentration ◽  
Promising Technique ◽  
Anion Exchange Resins ◽  
Radical Concentration ◽  
Hydrophilic Compounds ◽  
Bromide Removal ◽  
Oxidation Efficiency ◽  
Exchange Resins

Ion-exchange treatment is a promising technique for removing hydrophilic compounds during drinking water treatment. In this study, we applied several different ion exchangers (i.e., anion exchange resins and a hydrotalcite compound) to bromide removal to minimize bromate formation during ozonation. It was found that ion-exchange treatment affected ozone and hydroxyl radical concentration profiles as well as bromate ion concentration after ozonation. Selecting an appropriate ion exchanger is important to achieve both the oxidation of target contaminants and the reduction of bromate ion during ozonation.

Removal of Humic Substances by Adsorption/Ion Exchange

1999 ◽  
Vol 40 (9) ◽  
pp. 173-182 ◽  
Author(s):  
Joachim Fettig
Keyword(s):  
Activated Carbon ◽  
Ion Exchange ◽  
Metal Oxides ◽  
Humic Substances ◽  
Predictive Models ◽  
Anion Exchange Resins ◽  
Sorption Equilibria ◽  
Exchange Resins ◽  
Favorable Conditions ◽  
Solution Parameters

This paper gives an overview over the ability of four different sorbent media, activated carbon, anion exchange resins, carbonaceous resins and metal oxides, for the removal of humic sustances. Both sorbent characteristics and solution parameters that affect the ultimate capacities are discussed, and approaches developed in order to describe sorption equilibria and rate of uptake are reported. In addition, successes and failures of predictive models are described. Some general conclusions about favorable conditions for the removal of humic substances by sorption processes are given.

Prediction of breakthrough of pesticides in GAC-filters and breakthrough of colour in ion-exchange-filters

2002 ◽  
Vol 2 (1) ◽  
pp. 103-108 ◽  
Author(s):  
S.G.J. Heijman ◽  
W. Siegers ◽  
R. Sterk ◽  
R. Hopman
Keyword(s):  
Water Quality ◽  
Ion Exchange ◽  
Natural Water ◽  
Drinking Water Treatment ◽  
Breakthrough Curves ◽  
Quality Parameters ◽  
Independent Experiment ◽  
Process Conditions ◽  
Adsorption Parameters ◽  
Exchange Resins

Adsorption columns are widely used in drinking water treatment to improve a number of water quality parameters. Granular activated carbon filtration (GAC) can be used to decrease the concentration of DOC, colour, taste, odour and pesticides. Columns filled with ion-exchange resins are used to remove colour, nitrate and DOC. The regeneration frequency of these types of filters depends strongly on the natural water quality. Especially the DOC-concentration and DOC-composition determines the efficiency of the processes. Because pilot-plant experiments with realistic contact-times will last for more than a year (for GAC) there is a need for a prediction of breakthrough based on shorter and less expensive laboratory experiments. The available models are not accurate enough because the exact parameters are not available. In batch experiments with natural water, with realistic (low) pesticide concentrations and the full grain size of the adsorbent the adsorption parameters are measured in an independent experiment. With the parameters obtained with these experiments an accurate prediction of the breakthrough curve is possible. With the same parameters predictions of breakthrough curves are calculated under different process conditions. The possibilities of process optimisation can reduce the investment costs for new full-scale plants.

Effects of ion exchange resin pre-treatment on GAC adsorption

2008 ◽  
Vol 8 (2) ◽  
pp. 181-187
Author(s):  
B. Sani ◽  
L. Rossi ◽  
C. Lubello ◽  
S. Zacchei
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Ion Exchange ◽  
Drinking Water Treatment ◽  
Life Time ◽  
Ion Exchange Resins ◽  
Dissolved Organics ◽  
Pre Treatment ◽  
Exchange Resins ◽  
By Products

In Italian drinking water treatment plants (DWTP), the problem of chlorination by-products control is very important as the Italian drinking water regulations (Dlgs. 31/2001, as enactment of the CEU directive 98/83) set very strict limits for these compounds. A possible strategy for controlling the concentrations of DBPs (disinfection by-products) is the application of treatment processes able to reduce the concentration of dissolved organic matter, the main precursor of DBPs, before the dosage of chlorine-based disinfectants. Recently, ion exchange resins for the removal of dissolved organics have shown several applications in drinking water treatment. In this experimental study, the treatment with ion exchange resins MIEX®DOC and the treatment with GAC (granular activated carbon) were evaluated for the removal of dissolved organics. Moreover, the effects of MIEX® pre-treatment on the subsequent GAC filtration phase were evaluated, with particular attention to the effects on the life-time of the GAC filter. The GAC filter operation was simulated by rapid small scale column tests (RSSCT), which allow the evaluation of the GAC breakthrough curve in a shorter time with respect to a full plant and pilot plant trials. On the basis of the experimental results, the ion exchange process was very efficient in dissolved organics removal (60–70% UV254 removal). Moreover, the results indicated that the application of ion exchange resins as pre-treatment in a conventional drinking water treatment train could increase the filter life-time in the subsequent GAC adsorption phase (about 200%) resulting in potentially important cost benefits for the overall treatment process.

Determination of water in ion-exchange resins: anion exchange resins

1970 ◽  
Vol 42 (11) ◽  
pp. 1287-1290 ◽  
Author(s):  
Hari Dutta. Sharma ◽  
Natarajan. Subramanian
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Ion Exchange Resins ◽  
Anion Exchange Resins ◽  
Exchange Resins
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