Biodegradation and speciation of residual SS-ethylenediaminedisuccinic acid (EDDS) in soil solution left after soil washing.
This paper aims to investigate the degradation and speciation of EDDS-complexes (SS-ethylenediaminedisuccinic acid) in soil following soil washing. The changes in soil solution metal and EDDS concentrations were investigated for three polluted soils. EDDS was degraded after a lag phase of 7-11 days with a half-life of 4.18-5.60 days. No influence of EDDS-speciation on the reaction was observed. The decrease in EDDS resulted in a corresponding decrease in solubilized metals. Changes in EDDS speciation can be related to (1) initial composition of the soil, (2) temporarily anoxic conditions in the soil slurry after soil washing, (3) exchange of EDDS complexes with Cu even in soils without elevated Cu and (4) formation of NiEDDS. Dissolved organic matter is important for metal speciation at low EDDS concentrations. Our results show that even in polluted soils EDDS is degraded from a level of several hundred micromoles to below 1 microM within 50 days.
Tandy
Susan
S
Institute of Terrestrial Ecology, Swiss Federal Institute of Technology (ETH), Universitätstrasse 16, CH-8092 Zürich, Switzerland.
Ammann
Adrian
A
Schulin
Rainer
R
Nowack
Bernd
B
D002614:Chelating Agents / Q000032:analysis / Q000737:chemistry; D003300:Copper / Q000032:analysis / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005029:Ethylenediamines / Q000032:analysis / Q000737:chemistry; D006812:Humic Substances; D008670:Metals / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry; D013386:Succinates / Q000032:analysis / Q000737:chemistry; D013997:Time Factors; D014867:Water
D002614:Chelating Agents; D005029:Ethylenediamines; D006812:Humic Substances; D008670:Metals; D012989:Soil Pollutants; D013386:Succinates; D014867:Water; C041447:N,N'-ethylenediamine disuccinic acid; D003300:Copper