Effect of different extracting solutions on the electrodialytic remediation of CCA-treated wood waste Part I.

Velizarova, Emiliya; Ribeiro, Alexandra B.; Mateus, Eduardo P.; Ottosen, Lisbeth M.

doi:10.1016/j.jhazmat.2003.09.011

Cited by 21 publications

(17 citation statements)

References 22 publications

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“…The small decrease of the voltage after 4 days of operation might be due to a lack of charged particles at the beginning of electrokinetic experiments, as proposed by Velizarova et al (2004). Lee and Yang (2000) showed similar voltage fluctuations in the electrokinetic Pb removal from contaminated soils.…”

Section: Variation Of the Overall Voltagesupporting

confidence: 57%

Electrokinetic Copper and Iron Migration in Anaerobic Granular Sludge

Virkutytė

Sillanpää

Lens

2006

Water Air Soil Pollut

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Abstract. The application of low-level direct electric current (0.15 mA cm −2 ) as an electrokinetic technique to treat copper-contaminated mesophilic anaerobic granular sludge was investigated. The sludge was obtained from a full scale UASB reactor treating paper-mill wastewater and was artificially contaminated by Cu(NO 3 ) 2 or CuEDTA 2− with initial copper concentrations of 1000 mg · kg −1 wet sludge. The effect of different electrokinetic cell layouts, pH and EDTA concentrations on the migration of copper and iron during electrokinetic treatment were evaluated. Both, the pH of the sludge cake or the copper complexation with EDTA significantly affected the migration direction of copper.In an 'open' cell (sludge cake in direct contact with air), the highest copper mobility was observed at pH 2.5 in both Cu(NO 3 ) 2 or CuEDTA 2− amended sludge. The highest copper accumulation was at the cathode (22 ± 2)% with CuEDTA 2− as contaminant. In a 'closed' cell (sludge cake not in contact with air), the highest accumulation was obtained for CuEDTA 2− at the anode and amounted to 4(± 0.5)% and 2(± 0.05)%, respectively, at a final pH of 4.2 and 7.7 in the sludge cake.

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Section: Variation Of the Overall Voltagesupporting

confidence: 57%

Electrokinetic Copper and Iron Migration in Anaerobic Granular Sludge

Virkutytė

Sillanpää

Lens

2006

Water Air Soil Pollut

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“…It is widely documented that oxalic acid is strongly reducing and chelating agent (pKa 1 = 1.19), which is used to extract heavy metals from CCA-treated timber waste (Velizarova et al, 2004;Kartal, 2003;Kartal and Clausen, 2001;Clausen, 2000;Smith, 1998, Green andHigley, 1997). The carboxylate group of oxalic acid acts as a ligand that bond with metals forming water-soluble complexes (Hingston et al, 2001).…”

Section: Resultsmentioning

confidence: 99%

Copper and Chromium Electrodialytic Migration in CCA-Treated Timber Waste

Virkutytė

Velizarova

Ribeiro

et al. 2005

Water Air Soil Pollut

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Chromated copper arsenate (CCA)-treated timber waste is hazardous for the environment due to the leakage of copper, chromium as well as arsenic to the soil and the groundwater. The study concentrates on electrodialytic removal of copper and chromium and their migration behavior in the wood chips and sawdust matrix in an applied electric field. The method is based on the movement of the charged particles in the electric field, enhanced by incubation with oxalic acid (2.5% w/w) and various placement of the contaminated waste in the electrodialytic cell area to analyze the distribution of chemicals in the proposed matrix. The method was tested in laboratory scale experiments where the CCA contaminated wood chips and clean sawdust were placed in various places of the cell, i.e., adjacent to the cathode and anode compartments and in the mid-section of the cell. The duration of each experiment was 14 days and the current was kept constant at 40 mA. During the electrodialytic treatment negative copper and chromium compounds were mostly found in the anolyte or accumulated in the anion-exchange membrane. The amount of positive compounds found in the catholyte is negligible. The placement of contaminated chips close to the anode and cathode showed that copper and chromium moved towards the positively charged anode. If placed in the mid section of the cell, significant amount of contaminants remained bound to the wood matrix or slightly migrated towards the anode. To predict the formation of copper and chromium species at certain pH and Eh, the computer-modeling program MTDATA to generate Pourbaix diagrams was used.

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“…In our previous studies, a comparison between ED and DI processes was carried out for the remediation of CCA treated wood [11,13]. The present work extends those ones, adding the following new features: (i) the use of different assisting agents; (ii) the comparison between a stationary cell and a stirring cell, which is closer to pure electrodialysis/dialysis; (iii) the development of a onedimensional model for simulating the ED and DI treatment of a fly ash containing Cd, Cu and Pb, incorporating information obtained by chemical characterization, X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), as well as by previous equilibrium simulation using Visual Minteq at zero time.…”

Section: Introductionmentioning

confidence: 99%

Experimental and modeling of the electrodialytic and dialytic treatment of a fly ash containing Cd, Cu and Pb

et al. 2010

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A one-dimensional model is developed for simulating the electrodialytic and dialytic treatment of a fly ash containing cadmium, copper and lead. Two experimental systems have been used, a column of ash and a stirred ash suspension. The movement of Cd, Cu and Pb has been modeled taking into account the diffusion transport resulting from the concentration gradients of their compounds through the membranes and boundary layers and the electromigration of their ionic, simple and complex species during the operation. The model also includes the electromigration of the non-contaminant most important principal ionic species in the system, H ? and OH -, proceeding of the electrolysis at the electrodes, Ca 2? , CO 3 = , SO 4 = , etc. proceeding from the ash and Na ? and NO 3 -, or citrate and ammonium ions incorporated as electrolyte solutions and/or as agent solution during the ash treatment. The simulation also takes into account that OH -generated on the cathode, during the electrodialytic remediation, is periodically neutralized by the addition of nitric acid in the cathode compartment. The anion and cation-exchange membranes are simply represented as ionic filters that preclude the transport of the cations and anions, respectively, with the exception of H ? which is retarded but pass through the anion-exchange membrane.

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Effect of different extracting solutions on the electrodialytic remediation of CCA-treated wood waste Part I.

Cited by 21 publications

References 22 publications

Electrokinetic Copper and Iron Migration in Anaerobic Granular Sludge

Electrokinetic Copper and Iron Migration in Anaerobic Granular Sludge

Copper and Chromium Electrodialytic Migration in CCA-Treated Timber Waste

Experimental and modeling of the electrodialytic and dialytic treatment of a fly ash containing Cd, Cu and Pb

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