Recycling of chelant decreases the cost of EDTA-based soil washing. Current methods, however, are not effective when the spent soil washing solution contains more than one contaminating metal. In this study, we applied electrochemical treatment of the washing solution obtained after EDTA extraction of Pb, Zn and Cd contaminated soil. A sacrificial Al anode and stainless steel cathode in a conventional electrolytic cell at pH 10 efficiently removed toxic metals from the solution, leaving chelant in active Al-EDTA form.
COBISS.SI-ID: 6691193
In a laboratory study, formulations of ordinary Portland cement, calcium aluminate cement and pozzolanic cement and additives: plasticizers, polypropylene fibers, surfactatnts, and aqueous acrylic polymer dispersions were used for solidification/stabilization (S/S) of soils from an industrial brownfield contaminated with Cd, Pb, Zn, Cu, Ni and As. Soils formed solid monoliths with all cementitious formulations tested. To assess the S/S efficiency of the used formulations we proposed an empirical model in which data on equilibrium leaching and the mass transfer of elements from soil monoliths were weighed against the toxicity of the particular element.
COBISS.SI-ID: 6690937
Soil washing with EDTA is known to be an effective means of removing toxic metals from contaminated soil. A practical way of recycling of used soil washing solution remains, however, an unsolved technical problem. We demonstrate here, in a laboratory scale experiment, the feasibility of using acid precipitation to recover EDTA from used soil washing solution obtained after extraction of Pb, Zn, Cd and As contaminated soil. EDTA and toxic metals residual in the washing solution were almost quantitatively removed from the solution in an electrolytic cell using a graphite anode.
COBISS.SI-ID: 6904441
Various artificial soil mixtures were prepared by mixing two different toxic metals containing sewage sludges with natural mineral soil. The plots with mixtures were exposed to field environmental conditions for a period of 1 year, after which we assessed soil toxicity (germination test with Lactuca sativa), potential metal phyto-accessibility (diethylenetriamine pentaacetic acid – DTPA extraction test), soil functioning (by soil enzymes activity) and conducted a field growth test with Lollium perenne L. as a metal bio-indicator plant.
COBISS.SI-ID: 6813817
Soil washing with chelatning agents is known to be an effective means of removing toxic metals from contaminated soils and sediments. Current state of the art of recycling of used chelating agents after soil washing using different electrochemical methods is described.
COBISS.SI-ID: 7197561