title: Role of DDL processes during electrolytic reduction of Cu(II) in a low oxygen environment.
abstract: Heavy metals typically accumulate in reduced bottom sediments after being discharged into waterways by industrial and municipal processes. A laboratory experiment was conducted in order to determine if abundance of clay in the bottom sediments of a Cu-contaminated aqueous ecosystem could enhance electrolytic reduction of the heavy metal. Cu(NO3)2 · 2.5H2O was added to simulate a moderately contaminated system with 650 μg Cu/ml kaolinite clay-water slurry. A constant electrical potential of 1.0 V/cm was applied across platinum wire electrodes inserted into the continuously stirred system for four days while the system ORP(2) was monitored and periodic sub-samples were taken for analysis. The electrical as well as the chemical results indicate that the quantity of Cu(II) being reduced to Cu(I), especially within the aqueous phase, is increased within the first 48 h of experimentation by the presence of kaolinite clay up to 0.05 mg clay/l slurry.
authors.affiliation: Department of Civil and Environmental Engineering, Lehigh University, 1 West Packer Avenue Bethlehem, PA 18015, United States. Electronic address: reb@moravian.edu.
authors.forename: Rebekah T
authors.initials: RT
authors.lastname: Brosky
authors.forename: Sibel
authors.initials: S
authors.lastname: Pamukcu
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D000077215:Clay; D003102:Colloids / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004058:Diffusion; D004563:Electrochemistry; D004566:Electrodes; D004572:Electrolysis; D004784:Environmental Monitoring / Q000379:methods; D004867:Equipment Design; D005618:Fresh Water; D019015:Geologic Sediments; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D007616:Kaolin / Q000737:chemistry; D007700:Kinetics; D019216:Metals, Heavy / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D019163:Reducing Agents / Q000737:chemistry; D012987:Soil; D012989:Soil Pollutants; D013499:Surface Properties; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
chemical_list: D000538:Aluminum Silicates; D003102:Colloids; D019216:Metals, Heavy; D019163:Reducing Agents; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D007616:Kaolin; D003300:Copper; D007501:Iron; D010100:Oxygen; D000077215:Clay
keywords: DDL; DO; Electrokinetics; Kaolinite; OM; ORP; PZC; Redox potential; SSA; Zeta potential; diffuse double layer; dissolved oxygen; organic matter; oxidation-reduction potential; point of zero charge; specific surface area