Effects of zero-valent iron (Fe0) and temperature on the transformation of DDT and its metabolites in lake sediment.
Zero-valent iron improves the transformation of DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] and its metabolites in aged and highly contaminated lake sediment under biotic conditions. The addition of Fe0 has a strong effect on transformation rates at 22 degrees C and 9 degrees C, the most enhanced degradation being obtained for DDT and DDOH [2,2-bis(p-chlorophenyl)ethanol]. At 22 degrees C and 10 weeks' incubation, the DDT concentration is reduced from 2.75 micromol g(-1) (974 mg kg(-1)) to 0.98 micromol g(-1) (346 mg kg(-1)) and 1.98 micromol g(-1) (702 mg kg(-1)) in samples with and without the addition of iron, respectively. After 40 weeks' incubation these concentrations have further decreased to 0.19 micromol g(-1) (66 mg kg(-1)) and 0.74 micromol g(-1) (264 mg kg(-1)). There is no significant transformation of any of the compounds at 9 degrees C without the addition of Fe0. In the presence of iron, however, DDT is reduced to 1.25 micromol g(-1) (442 mg kg(-1)) within 40 weeks' incubation. This study demonstrates the ability of adapted microorganisms to transform DDT under elevated temperatures in original, aged sediments, and also the stimulating effect of zero-valent iron, which is significant even at low temperatures.
Eggen
Trine
T
Jordforsk-Norwegian Centre for Soil and Environmental Research, c/o The Norwegian Crop Research Institute, Postveien 213, Klepp St. 4353, Norway. trine.eggen@jordforsk.no
Majcherczyk
Andrzej
A
D003634:DDT / Q000737:chemistry*; D005618:Fresh Water / Q000032:analysis*; D019015:Geologic Sediments / Q000032:analysis*; D007501:Iron / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D010084:Oxidation-Reduction; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000032:analysis*
D014874:Water Pollutants, Chemical; D003634:DDT; D007501:Iron