Degradation dissolved organics

In the modified OECD Screening Test (OECD 301E), which indicates complete degradation or elimination according to the German Chemical Substances Control Act, alkanesulfonates are biodegradable to 95% (decrease in DOC, the dissolved organic carbon). 

For aerobic degradation, uptake of oxygen or the evolution of carbon dioxide is most widely used. Use of the concentration of dissolved organic carbon may present technical problems when particulate matter is present, though analysis of dissolved inorganic carbon in a closed system has been advocated (Birch and Fletcher 1991), and may simultaneously overcome problems with poorly soluble or volatile compounds. 

The degradation of DEHP is directly related to releasable TOCw, perhaps the presence of TOCw improved the solubility and microbial degradability under thermophilic conditions in several studies [61, 62], Bauer and Herrmann [18] revealed that the elution of DEHP from MSW was facilitated by the presence of dissolved organic matter (DOM) even under anaerobic conditions. 

Exposure pathways were estimated using the modified soil module of the MSCE-POP model (http //www.msceast.org). At present the scheme is complemented with the fraction of dissolved organic matter (/doc) and with the fraction of the chemical non-equilibrium adsorbed by solid phase (/n0n-equii) or low available with individual degradation rate. The scheme of a pollutant distribution between different soil components is shown in Figure 16. 

Degradation of Dissolved Organic Carbon and its Impact on the Oceanic Carbon Cycle", Nature 353, 60-62. 

Dissolved humic substances (DHS) are the main constituents of the dissolved organic carbon (DOC) pool in surface waters (freshwaters and marine waters), groundwaters, and soil porewaters and commonly impart a yellowish-brown color to the water system. Despite the different origins responsible for the main structural characteristics of DHS, they all constitute refractory products of chemical and biological degradation and condensation reactions from plant or animal residues and play a crucial role in many biogeochemical processes. 

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