Degradation in soil and sediment

Processes that control degradation in soils and sediments and transformations during atmospheric transport (Swackhamer and McConnell 1993)... 

Di- -butyl phthalate also rapidly degrades in soil and sediments (Staples et al. 1997). For example,... 

The SEHSC research efforts combined with those by the GSC resulted in the development of a comprehensive environmental database for PDMS, a material that has both industrial and consumer product applications. The results of this five-year research effort demonstrated that most PDMS used in down-the-drain applications enters the terrestrial environment as a component of wastewater treatment plant sludge, with aquatic sediments receiving between 3 to 6 % of this mass. Laboratory and field studies demonstrated the potential for PDMS degradation in soils and sediments. The rate of degradation is slow in sediment and wet soil and increases as a function of decreased moisture level to half-life values of days in dry soil. No adverse ecological effects are indicated from the effects testing. 

In soil and sediments, methyl parathion adsorbs to soil and is expected to display moderate mobility (EPA 1980c). The major degradation process of methyl parathion in soil is biodegradation by microbes (Badway and El-Dib 1984). Degradation by hydrolysis has been observed to occur at higher temperatures... 

In soils and sediments, microbial degradation and hydrolysis are important degradation processes. 

Oremland RS, DJ Lonrergan, CW Culbertson, DR Lovley (1996) Microbial degradation of hydrochloroflnoro-carbons (CHCljF and CHCljCFj) in soils and sediments. Appl Environ Microbiol 62 1818-1821. 

In contrast to hydrolysis and photolysis, an enantioselective and/or regioselective degradation of pyrethroids is expected since various kinds of enzymes in microbes participate in their metabolism in soil and sediment. The diastereomers should be separated by using a chiral GC or HPLC to examine the fate of each isomer [85]. Sakata et al. [86] have conducted the first extensive aerobic soil metabolism study... 

Qin S, Gan J (2006) Enantiomeric differences in permethrin degradation pathways in soil and sediment. J Agric Food Chem 54 9145-9151... 

Chlordecone is similar to mirex in structure and is also highly persistent in soils and sediments (halflife expected to be analogous to 10 years duration for mirex) because of its resistance to biodegradation, although some microbial metabolism of chlordecone has been reported (Lai and Saxena 1982 Ordorff and Colwell 1980). No evidence of microbial degradation was detected for chlordecone exposed to hydrosoils from a reservoir (not previously contaminated with chlordecone) and from Bailey Creek (contaminated with chlordecone) under either anaerobic or aerobic conditions for 56 days (Huckins et al. 1982). 

No other information was found in the literature about the transformation and degradation processes for PBDEs in soils and sediment. 

In general, turnover rates tend to be faster in soils and sediments with long-term exposure to PAHs, but Shiaris (1989a,b) made the interesting observation that high rates of benzoMpyrene degradation in Boston Harbor sediments — with a significant history of PAH exposure - resulted in the production of considerable... 

Of the 5.34 x 1051 of toxaphene that were used in North America (includes the United States and Mexico), 1.541 (3%) was estimated to remain in active circulation as of the year 2000, 6.5 x 1041 (12%) had been removed from the continental environment by advection of air and water and burial in soils and sediments, and 4.54 x 1051 (85%) had been removed by degradation reactions. Most of the toxaphene in active circulation resides in the soils of the southern U.S. and Mexico (83%). The efficiency of toxaphene transfer to the Great Lakes from its usage within the basin was estimated to be 78 to 220 times greater than transfer from the southern United States. However, load-... 

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