title: New biodegradable organic-soluble chelating agents for simultaneous removal of heavy metals and organic pollutants from contaminated media.
abstract: Advanced biodegradable and non-toxic organic chelators, which are soluble in organic media, were synthesized on the basis of the S,S-ethylenediamine-disuccinate (S,S-EDDS) ligand. The modifications suggested in this work include attachment of a lipophilic hydrocarbon chain ("tail") to one or both nitrogen atoms of the S,S-EDDS. The new ligands were designed and evaluated for application in the Sediments Remediation Phase Transition Extraction (SR-PTE) process. This novel process is being developed for the simultaneous removal of both heavy metals and organic pollutants from contaminated soils, sediments or sludge. The new chelators were designed to bind various target metal ions, to promote extraction of these ions into organic solvents. Several variations of attached tails were synthesized and tested. The results for one of them, N,N'-bis-dodecyl-S,S-EDDS (C24-EDDS), showed that the metal-ligand complexes are concentrated in the organic-rich phase in the Phase Transition Extraction process (more than 80%). Preliminary applications of the SR-PTE process with the C24-EDDS ligand were conducted also on actually contaminated sludge (field samples). The extraction of five toxic metals, namely, Cd, Cu, Ni, Pb and Zn was examined. In general, the extraction performance of the new ligand was not less than that of S,S-EDDS when a sufficient ligand-to-extracted ion ratio (about 4:1 was applied.
authors.affiliation: Faculty of Engineering, School of Mechanical Engineering, Tel Aviv University, Tel Aviv 69978, Israel. Ullmann@eng.tau.ac.il
authors.forename: Amos
authors.initials: A
authors.lastname: Ullmann
authors.forename: Neima
authors.initials: N
authors.lastname: Brauner
authors.forename: Shlomi
authors.initials: S
authors.lastname: Vazana
authors.forename: Zhanna
authors.initials: Z
authors.lastname: Katz
authors.forename: Roman
authors.initials: R
authors.lastname: Goikhman
authors.forename: Boaz
authors.initials: B
authors.lastname: Seemann
authors.forename: Hanit
authors.initials: H
authors.lastname: Marom
authors.forename: Michael
authors.initials: M
authors.lastname: Gozin
mesh_terms: D001681:Biological Assay; D002104:Cadmium / Q000737:chemistry; D002614:Chelating Agents / Q000737:chemistry*; D004787:Environmental Pollution; D052918:Environmental Restoration and Remediation / Q000379:methods; D004926:Escherichia coli / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007854:Lead / Q000737:chemistry; D008024:Ligands; D008670:Metals / Q000737:chemistry; D019216:Metals, Heavy / Q000032:analysis* / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D009930:Organic Chemicals / Q000032:analysis* / Q000737:chemistry; D012722:Sewage; D012989:Soil Pollutants / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D014876:Water Pollution
chemical_list: D002614:Chelating Agents; D007477:Ions; D008024:Ligands; D008670:Metals; D019216:Metals, Heavy; D009930:Organic Chemicals; D012722:Sewage; D012989:Soil Pollutants; D012997:Solvents; D014874:Water Pollutants, Chemical; D002104:Cadmium; D007854:Lead; D009584:Nitrogen
keywords: Biodegradable; Chelating agents; Extraction; Heavy metals; Partially miscible solvents; Remediation