title: Application of an electrochemical treatment for EDDS soil washing solution regeneration and reuse in a multi-step soil washing process: Case of a Cu contaminated soil.
abstract: Soil washing is an extensively used process for remediation of heavy metals contaminated soils. However the amount of fresh washing solution to be used represents a significant economical drawback of this process. This paper investigates the application of an electrochemical process (Fe/Fe electrodes couple) for the regeneration of a spent EDDS solution, containing Cu and major competitor cations (Ca, Fe, Mg, and Mn). The effect of current density, pH and conductivity of the washing solution on the recovery process performances was investigated. Current density showed the highest influence on Cu, Mg and Mn removal yields. Maximum removal yields reached 99% for Cu, 77% for Mn and 49% for Mg. No influence of the investigated parameters on Ca removal was observed, while an increase of Fe concentration due to anode dissolution occurred. Characterization of sludge produced from the 2 h electrochemical test (5 mA cm(-2), pH = 8, 8 mS cm(-1)) displayed concentrations of 2.8 g kg(-1) for Ca, 0.4 g kg(-1) for Cu, 535.6 g kg(-1) for Fe, 2.6 g kg(-1) for Mg. TCLP tests at pH 2.88 and 4.93 showed a low leaching percentage (Ca, 10-21%; Cu, 6-12%; Fe, 0.22% Mg, 27-36%). Multi-washing tests were carried out to assess the decrease of the chelating ability of the regenerated washing solution and the Cu extraction efficiency.
authors: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via di Biasio 43, 03043 Cassino, Italy; Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France; Department of Civil, Architectural and Environmental Engineering, University of Naples "Federico II", Via Claudio 21, 80125 Naples, Italy. Electronic address: alberto.ferraro3@gmail.com.
authors: Alberto
authors: A
authors: Ferraro
authors: Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France.
authors: Eric D
authors: ED
authors: van Hullebusch
authors: Université Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France.
authors: David
authors: D
authors: Huguenot
authors: Department of Civil, Architectural and Environmental Engineering, University of Naples "Federico II", Via Claudio 21, 80125 Naples, Italy.
authors: Massimiliano
authors: M
authors: Fabbricino
authors: Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via di Biasio 43, 03043 Cassino, Italy.
authors: Giovanni
authors: G
authors: Esposito
mesh_terms: D002614:Chelating Agents / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D055664:Electrochemical Techniques / Q000295:instrumentation; D004566:Electrodes; D052918:Environmental Restoration and Remediation; D005029:Ethylenediamines / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D019216:Metals, Heavy / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013386:Succinates / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D005029:Ethylenediamines; D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D012996:Solutions; D013386:Succinates; C041447:N,N'-ethylenediamine disuccinic acid; D003300:Copper; D007501:Iron
keywords: EDDS recovery; Electrochemical treatment; HMs removal; Multistep washing; Soil washing