Premium
The biodegradation of methylene chloride in soils
Author(s) -
Davis John W.,
Madsen Steve S.
Publication year - 1991
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620100406
Subject(s) - loam , microcosm , biodegradation , environmental chemistry , anoxic waters , chemistry , chloride , soil water , anaerobic exercise , carbon dioxide , degradation (telecommunications) , environmental science , soil science , organic chemistry , biology , physiology , telecommunications , computer science
The aerobic biodegradation of methylene chloride was observed in a variety of surface soils including a sand, a sandy loam and a sandy clay loam, as well as a subsurface clay soil. Degradation was found to occur over concentrations ranging from approximately 0.1 ppm to 5.0 ppm. Degradation at higher concentrations was facilitated by the presence of an exogenous organic carbon source. No products other than carbon dioxide were detected in the biologically active microcosms. The time required for 50% disappearance of the parent compound varied over 100‐fold, ranging from 1.3 to 191.4 d. Preexposure of the soil to methylene chloride resulted in faster rates of degradation upon subsequent exposures. Methylene chloride degradation was also observed under anaerobic conditions in the sandy loam soil. In contrast to observations under aerobic conditions, a significant lag or acclimation period preceded biodegradation under anoxic conditions, and no loss of the parent compound was observed during the first 70 d. However, following the lag period, the rate of degradation was approximately 10‐fold higher under anaerobic conditions.