Recent Papers in Adsorption and Ion Exchange Processes

Content Table

Magnetic ion exchange resin treatment for drinking water production

Journal of Water Supply: Research and Technology—AQUA Vol 58 No 1 pp 41–50 © IWA Publishing 2009 doi:10.2166/aqua.2009.081

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B. Sani, E. Basile, L. Rossi and C. Lubello

Department of Civil and Environmental Engineering, University of Florence, Via S. Marta 3, I-50139, Florence, Italy Tel.: +39 55 479 6317 E-mail: beatrice.sani@dicea.unifi.it
Publiacqua SpA, Via Villamagna 39, I-50126, Florence, Italy

Abstract

Italian drinking water treatment plants (DWTP) generally use chlorine-based chemicals to achieve the oxidation/disinfection phases of their treatment trains. The main problem related to the application of such disinfectants consists in the formation of disinfection by-products (DBPs) as a result of the reaction with organic substances in the water. Italian regulations set very strict limits for the maximum concentration of chlorine DBPs and, for many DWTPs, the compliance with such a regulation is difficult. Non-oxidative pre-treatments, able to remove organic substances from the water prior to chlorination, could be a suitable solution to overcome this problem. These treatments could increase the water quality, decrease the oxidant demand and, hence, reduce the formation of DBPs. This paper presents an experimental investigation of ion exchange processes for the dissolved organic carbon (DOC) removal by using MIEX® resin. The process was studied as a pre-treatment on raw river water. The DOC removal efficiency and the effects on downstream processes of the treatment train were evaluated.

Removal of radiocobalt from EDTA-complexes using oxidation and selective ion exchange

Water Science & Technology—WST Vol 60 No 4 pp 1097–1101 © IWA Publishing 2009 doi:10.2166/wst.2009.458

org.xwiki.gwt.dom.client.Element#placeholderhttp://www.iwaponline.com/wst/06004/wst060041097.htm">Link to Summary Page

L. K. Malinen, R. Koivula and R. Harjula

Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A. I. Virtasen aukio 1), FI-00014, Finland E-mail: leena.k.malinen@helsinki.fi; risto.koivula@helsinki.fi; risto.harjula@helsinki.fi

Abstract

Methods for the removal of radiocobalt from an ethylenediaminetetraacetic acid (EDTA) complex of Co(II) (aqueous solution containing 10 mM Co(II) and 10 mM or 50 mM EDTA traced with 57Co) are presented. The studies examined a combination of different oxidation methods and the sorption of 57Co on a selective inorganic ion exchange material, CoTreat. The oxidation methods used were ultraviolet (UV) irradiation with and without hydrogen peroxide (H2O2), as well as ozonation alone or in combination with UV irradiation. Also, the possible contribution of Degussa P25 TiO2 photocatalyst to degradation of EDTA was studied. The best results for the equimolar solution of Co(II) and EDTA were achieved by combining ozonation, UV irradiation, Degussa P25 TiO2 and CoTreat, with approximately 94% sorption of 57Co. High values for the 57Co sorption were also achieved by ozonation (~88%) and UV irradiation (~90%) in the presence of CoTreat and Degussa P25 TiO2. A surplus of EDTA over Co(II) was also tested using 10 mM Co(II) and 50 mM EDTA. Only a slight decrease, to ~88% sorption of 57Co, was detected compared to the value (~90%) obtained with 10 mM EDTA.

Ammonium removal from anaerobic digester effluent by ion exchange

Water Science & Technology—WST Vol 60 No 1 pp 201–210 © IWA Publishing 2009 doi:10.2166/wst.2009.317

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T. Wirthensohn, F. Waeger, L. Jelinek and W. Fuchs

Department of IFA-Tulln, Institute for Environmental Biotechnology, University of Natural Resources and Applied Life Sciences—Vienna, Konrad Lorenz Strasse 20, 3430 Tulln, Austria E-mail: thomas.wirthensohn@boku.ac.at; frank.waeger@boku.ac.at; werner.fuchs@boku.ac.at
Department of Power Engineering, Faculty of Environmental Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6, Czech Republic E-mail: Ludek.Jelinek@vscht.cz

Abstract

The effluent of a 500 kW biogas plant is treated with a solid separation, a micro filtration and a reverse osmosis to achieve nutrient recovery and an effluent quality which should meet disposal quality into public water bodies. After the reverse osmosis, the ammonium concentration is still high (NH4-N = 467 mg/l), amongst other cations (K+=85 mg/l; Na+=67 mg/l; Mg2 + =0.74 mg/l; Ca2 + =1.79 mg/l). The aim of this study was to remove this ammonium by ion exchange. Acidic gel cation exchange resins and clinoptilolite were tested in column experiments to evaluate their capacity, flow rates and pH. Amberjet 1,500 H was the most efficient resin, 57 BV of the substrate could be treated, 1.97 mol NH4-N/l resin were removed. The ammonium removal was more than 99% and the quality of the effluent was very satisfactory (NH4-N < 2 mg/l). The breakthrough of the observed parameters happened suddenly, the order was sodium—pH—ammonium—potassium. The sharp increase of the pH facilitates the online control, while the change in conductivity is less significant. A regeneration with 3 bed volumes of 2  M HCl recovered 91.7% of the original cation exchange capacity.

A hybrid ion exchange-nanofiltration (HIX-NF) process for energy efficient desalination of brackish/seawater

Water Science & Technology: Water Supply—WSTWS Vol 9 No 4 pp 369–377 © IWA Publishing 2009 doi:10.2166/ws.2009.634

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S. Sarkar and A. K. SenGupta

Department of Civil and Environmental Engineering, Lehigh University, Fritz Engineering Laboratory, 13 E Packer Avenue, Bethlehem PA, 18015, USA E-mail: sus9@lehigh.edu; arup.sengupta@lehigh.edu

Abstract

This study reports a new hybrid ion exchange-nanofiltration (HIX-NF) process for desalination of sea and brackish water that can attain significant energy economy over the conventional membrane-based pressure driven processes. In this hybrid process, an ion exchange step converts monovalent chloride ions of saline water to divalent sulfate ions and the resulting solution, having a reduced osmotic pressure than the feed, is desalinated using a nanofiltration (NF) membrane. The sulfate rich reject stream from the NF process is used to regenerate the anion exchanger. Results validate that NF membranes can desalinate sodium sulfate solution at a much lower transmembrane pressure compared to RO membranes as well as yield a higher permeate flux. The sulfate-chloride selectivity of the anion exchangers plays important role in sustainability of the process. Laboratory studies have revealed that a single type of anion exchanger cannot sustain the process for saline water with different salt concentrations. However, anion exchangers with different sizes of amine functional groups (e.g. quaternary-, tertiary-, secondary- and primary amine) hold the promise that the process can be tailored to achieve sustainability. Laboratory studies have validated the basic premise of the hybrid process including greater than two times less energy requirement than RO process for the same feed water and same permeate recovery condition.

Adsorption kinetics and isotherm characteristics of selected endocrine disrupting compounds on activated carbon in natural waters

Water Science & Technology: Water Supply—WSTWS Vol 9 No 1 pp 51–58 © IWA Publishing 2009 doi:10.2166/ws.2009.063

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A. Assoumani, L. Favier-Teodorescu and D. Wolbert

Ecole Nationale Supérieure de Chimie de Rennes,CNRS, UMR 6226, Avenue du Général Leclerc, CS 50837, 35700, Rennes Cedex 4, France E-mail: azziz.assoumani@ensc-rennes.fr

Abstract

Bisphenol A (BPA) and ethynylestradiol (EE2), two representative endocrine disrupting compounds (EDCs), were tested for their adsorbabilities onto two powdered activated carbons (PACs). The main aim of the study was to create a prediction tool for the determination of the EDCs adsorbabilities at low ng.L-1 level. Single solute solution adsorption isotherms at high concentrations, for prediction purposes, and low concentrations, for verification of the prediction, were performed for one EDC/PAC couple. Over the whole range of concentration, results showed that the Langmuir-Freundlich model better suits the adsorption phenomenon than the Freundlich or Langmuir model. Kinetics experiments were carried out on the same EDC/PAC couple. HSDM modelling of single solute adsorption kinetics at high concentration allowed determining the kinetic coefficients kf and Ds; both were shown to dominate the mass transfer mechanism. Competitive adsorption isotherms at high and low concentrations showed that downward extrapolation of low concentration adsorption capacities from solely high concentration information results in acceptable error compared to the total range isotherm. The IAST-EBC approach combined with the Langmuir-Freundlich single solute model, for the target compound, and the Langmuir model, for the EBC, appears as an acceptable global model.

Influence of hybrid coagulation-ultrafiltration pretreatment on trace organics adsorption in drinking water treatment

Journal of Water Supply: Research and Technology—AQUA Vol 58 No 3 pp 170–180 © IWA Publishing 2009 doi:10.2166/aqua.2009.071

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S. Müller and W. Uhl

Institute of Urban Water Management (ISI), Chair of Water Supply Engineering, Technische Universität Dresden, Dresden, 01062, Germany Tel.: +49-(0)351-46333126 Fax: +49-(0)351-46337204 E-mail: wolfgang.uhl@tu-dresden.de

Abstract

The treatment of raw water by hybrid coagulation-ultrafiltration was investigated. Coagulation-ultrafiltration removed high molecular weight organics, preferentially humics. Adsorption of the trace compound cis-1,2-dichloroethene, present in raw water, on granular activated carbon was improved considerably as compounds competing for adsorption space had been removed. This was shown in isotherms and breakthrough curves. Aeration during filtration did not affect membrane performance as expressed in permeability. However, aeration in the submerged membrane container resulted in a release of organic matter from the flocs, which resulted in higher concentrations of dissolved organic carbon in the filtrate.

Phosphorus adsorption on water treatment residual solids

Journal of Water Supply: Research and Technology—AQUA Vol 58 No 1 pp 1–10 © IWA Publishing 2009 doi:10.2166/aqua.2009.017

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Meaghan K. Gibbons, Md. Maruf Mortula and Graham A. Gagnon

Department of Civil and Resource Engineering, Dalhousie University, Halifax, Nova Scotia, B3J 1X1, Canada Tel.: +1 902 494 3268 Fax:+1 902 494 3108 E-mail: graham.gagnon@dal.ca
Department of Civil Engineering, American University of Sharjah, Sharjah, PO Box, 26666, UAE

Abstract

The treatment and disposal of water treatment plant residual solids has become an increasingly important environmental priority for drinking water utilities. This study examines water treatment residual solids (WTRSs) from four North American water treatment plants to determine the role that coagulant types play in phosphate adsorption by the residual solids. In total, two alum residual solids (one solid from a plant that has a raw water with low alkalinity and one solid from a plant that has a raw water with high alkalinity), one lime residual solid and one ferric residual solid were used in batch adsorption experiments with deionized water at a pH of 6.2±0.2 and secondary municipal wastewater effluent at a pH of 6.8. Langmuir isotherm modeling showed that ferric residuals had the highest adsorptive capacity for phosphate (Qmax=2,960 mg/kg), followed by lime (Qmax=1,390 mg/kg) and alum (Qmax=1,110 mg/kg and 1,030 mg/kg) for adsorption experiments with P-spiked deionized water. Of the two alum residuals, the residual with a higher weight percent of metal oxides had a higher adsorptive capacity. The ferric residuals were less affected by competing species in the wastewater effluent, while the lime and alum residuals had a higher rate of phosphate removal from the deionized water compared to the wastewater effluent. Overall, ferric water treatment residuals were the best adsorbent for phosphate adsorption, followed by lime and alum residuals.

Influence of surface chemistry and structure of activated carbon on adsorption of fulvic acids from water solution

Water Science & Technology—WST Vol 60 No 2 pp 441–447 © IWA Publishing 2009 doi:10.2166/wst.2009.344

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L. A. Savchyna, I. P. Kozyatnyk, T. V. Poliakova and N. A. Klymenko

Institute of Colloid Chemistry and Chemistry of Water, Ukrainian National Academy of Sciences, 42 Vernadsky Avenue, Kiev 03680, Ukraine E-mail: klimenko@carrier.kiev.ua

Abstract

The adsorption of fulvic acids (FA) from aqueous solutions on activated carbon (AC) with different characteristics of surface chemical state has been investigated. To characterize the adsorbability of FA with complex fractional composition, a method of estimation of modified Freundlich equation constants was employed, and “conventional component” was used to evaluate the change in Gibbs free adsorption energy. It has been shown that change in activated carbon surface energy in-homogeneity due to oxidation leads mainly to a decrease in the adsorption energy of fulvic acids and to an increase of the concentration range of the conventional portion of the low adsorbable fraction. Decrease in the adsorption energy of organic substrate may result in higher degree of spontaneous bioregeneration of activated carbon and hence in its longer life in the processes of FA solutions filtration.

Synthesis of carboxylated chitosan and its adsorption properties for cadmium (II), lead (II) and copper (II) from aqueous solutions

Water Science & Technology—WST Vol 60 No 2 pp 467–474 © IWA Publishing 2009 doi:10.2166/wst.2009.369

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K. L. Lv, Y. L. Du and C. M. Wang

Department of Chemistry, Lanzhou University, Lanzhou 730000, China E-mail: wangcm@lzu.edu.cn

Abstract

Carboxylated chitosan (CKCTS) was prepared for the removal of Cd(II), Pb(II), and Cu(II) from aqueous solutions. The effects of experimental parameters such as pH value, initial concentration, contact time and temperature on the adsorption were studied. From the results we can see that the adsorption capacities of Cd(II), Pb(II), and Cu(II) increase with increasing pH of the solution. The kinetic rates were best fitted to the pseudo-second-order model. The adsorption equilibrium data were fitted well with the Langmuir isotherm, which revealed that the maximum adsorption capacities for monolayer saturation of Cd(II), Pb(II), and Cu(II) were 0.555, 0.733 and 0.827 mmol/g, respectively. The adsorption was an exothermic process.

Competitive adsorption of heavy metals in soil underlying an infiltration facility installed in an urban area

Water Science & Technology—WST Vol 59 No 2 pp 303–310 © IWA Publishing 2009 doi:10.2166/wst.2009.865

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M. A. Hossain, H. Furumai and F. Nakajima

Institute of Water and Flood Management, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh E-mail: abed@iwfm.buet.ac.bd; abed.hossain@gmail.com
Research Center for Water Environment Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan E-mail: furumai@env.t.u-tokyo.ac.jp
Environmental Science Center, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan E-mail- nakajima@esc.u-tokyo.ac.jp

Abstract

Accumulation of heavy metals at elevated concentration and potential of considerable amount of the accumulated heavy metals to reach the soil system was observed from earlier studies in soakaways sediments within an infiltration facility in Tokyo, Japan. In order to understand the competitive adsorption behaviour of heavy metals Zn, Ni and Cu in soil, competitive batch adsorption experiments were carried out using single metal and binary metal combinations on soil samples representative of underlying soil and surface soil at the site. Speciation analysis of the adsorbed metals was carried out through BCR sequential extraction method. Among the metals, Cu was not affected by competition while Zn and Ni were affected by competition of coexisting metals. The parameters of fitted ‘Freundlich’ and ‘Langmuir’ isotherms indicated more intense competition in underlying soil compared to surface soil for adsorption of Zn and Ni. The speciation of adsorbed metals revealed less selectivity of Zn and Ni to soil organic matter, while dominance of organic bound fraction was observed for Cu, especially in organic rich surface soil. Compared to underlying soil, the surface soil is expected to provide greater adsorption to heavy metals as well as provide greater stability to adsorbed metals, especially for Cu.

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