Electrokinetic remediation of clayey soils containing copper(II)-oxinate using humic acid as a surfactant.
The utility of humic acid (HA) as a surfactant for use in the electrokinetic remediation (ER) of the clayey soils containing copper(II)-oxinate (Cu(OX)(2)) was examined. A small simulator of ER was devised, which consisted of three types of artificial soils on the basis of the commercial kaolin: kaolin, kaolin + HA and kaolin + Cu(OX)(2). The layers of kaolin containing HA and Cu(OX)(2) were sandwiched between two kaolin layers. In all experiments, a constant dc voltage gradient of 2.2V/cm was applied through the soil for 30h, and the pH of the solution in the anodic chamber was maintained at 7.0. Generally, HA has a negative charge at a neutral pH. However, the HA was mainly transferred to the cathodic chamber. This shows that the driving force of the HA in the system used herein is predominantly due to electroosmotic flow. Moreover, the amount of Cu(OX)(2) removed from the clayey soils in the presence of HA was three times larger than those in the absence of HA. This can be attributed to the fact that the water solubility of Cu(OX)(2) is enhanced by the presence of HA. Thus, we conclude that HA has a potential for use as an amendment for the ER of hydrophobic chemicals, such as Cu(OX)(2).
Sawada
Akira
A
Division of Material Science, Graduate School of Environmental Earth Science, Hokkaido University, Kita-10, Nishi-5, Kita-ku, Sapporo 060-0810, Hokkaido, Japan.
Tanaka
Shunitz
S
Fukushima
Masami
M
Tatsumi
Kenji
K
D000538:Aluminum Silicates; D000077215:Clay; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D006812:Humic Substances / Q000737:chemistry; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry / Q000302:isolation & purification*; D015125:Oxyquinoline / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification*; D012989:Soil Pollutants / Q000302:isolation & purification*; D013501:Surface-Active Agents / Q000737:chemistry
D000538:Aluminum Silicates; D006812:Humic Substances; D009942:Organometallic Compounds; D012989:Soil Pollutants; D013501:Surface-Active Agents; C047488:bis(8-quinolinolato)copper(II); D015125:Oxyquinoline; D003300:Copper; D000077215:Clay