Soils biodegradation

P. M. DiGrazia, J. W. Blackburn, P. R. Bienkowski, B. Hilton, G. D. Reed, J. M. H. King, and G. S. Sayler. 1989. Development of a systems analysis approach for resolving the structure of biodegrading soil systems. Appl. Biochem. and Biotechnol. In Press. 

Kalbitz, K., Schwesig, D., Schmerwitz, J., Kaiser, K., Haumaier, L., Glaser, B., Ellerbrock, R., and Leinweber, P. (2003b). Changes in properties of soil-derived dissolved organic matter induced by biodegradation. Soil Biol. Biochem. 35,1129-1142. 

Biodegradation soil t,/2 = 9.5 d under aerobic conditions and t,/2 = 3 d under anaerobic conditions (Tomlin 1994). Biotransformation ... 

Plants. The a.i. is extensively metabolised Soil. Readily biodegradable. Soil DTJ0 0.6-2 days (lab., aerobic conditions, 20°C) rapidly mineralized... 

In general, it is not absorbed from the soil by plants. Dichlorvos undergoes hydrolysis and biodegradation. Soil pH influences dichlorvos degradation. 

BIOLOGICAL PROPERTIES Koc 160 and 44 low adsorption to sediment slightly persistent in water, half-life 2-20 days half-lives in river water 8-11 days and 0.2 days 100% removal reported from wastewater treatment plants resulting from biodegradation soil, surface water, and aerobic half-lives 1-7 days anaerobic half-life 4 days ground water half-life 2-14 days % removal under aerobic conditions 96% can be detected in water by EPA Method 606 methylene chloride extraction followed by gas chromatography with flame ionization or electron detection, or EPA Method 626 gas chromatography plus mass spectrometry... 

The data-quality requirements for QSAR models relate to several aspects of the experimental procedure, data transformation and the selection of the appropriate test compounds. Only if the input data of a QSAR meet the highest quality standards may a sound model be derived. Because the accuracy of predictions can never be better than the variability of the respective measurements (usually 20% and more), validity assessment of the activity and effects data is crucial in QSAR derivations. The data should be generated by tests that are methodologically and mechanistically defined. The latter is not trivial for parameters such as biodegradability, soil sorption and ecotoxicity. With regard to the considerable variability of measurements, inter- and also intra-laboratory, the test results, especially when collected from different literature sources, should be critically evaluated with respect to ... 

In this chapter, very effective, low molecular weight biosurfactants, called rhamnoUpids are discussed. In each case, envirorunental applications wiU be examined including enhancing solubilization and biodegradation, soil and waste treatment (in situ and ex situ) and water treatment. Areas of potential research will be identified. 

AIB-Vingotte International has a biodegradable home compost test certification for plastic products that references EN 13432 performance specification and other ISO biodegradable test methods. Biodegradation in soil environments is based on International OK Biodegradable Soil standards. Table 8.7 lists the biodegradation standards for home composing. 

For such substances, as well as for the biodegradation intermediates, the proposed scheme would first discriminate whether they are readily biodegradable, soil biodegradable or neither. If a substance (or metabolite thereof) is recognised as recalcitrant to biodegradation, the scheme would then offer guidance to understand its environmental partitioning and whether the substance could produce any adverse effect in the ultimate environmental compartment where the substance is predicted to end up. 

OK Biodegradable SOIL Initial Acceptance Tests, Program OK 10, Bioproducts - Degradation in Soil, VINC OTTE - CERTEST PRODUCTS, Vilvoorde, Belgium, 2001. 

OK Biodegradable Soil is based on a scheme developed by Vingotte itself and includes requirements with regard to biodegradation, chemical characteristics and ecotoxicity. Disintegration is not included as for applications in soil it is supposed to be a product requirement instead of an environmental requirement. 

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