Degradation biodegradable products

In freshwater systems, the only biodegradation product detected was 4-nitrophenol, which was rapidly utilized and transformed to undetectable metabolites by the microorganisms present. In seawater, the main initial product was methyl aminoparathion, formed by reduction of the nitro group (Badawy and El-Dib 1984). Studies in raw river water showed that 4-nitrophenol and dimethyl thiophosphoric acid are the main degradation products (Eichelberger and Lichtenberg 1971). 

The presence of surfactants and their biodegradation products in different environmental compartments can invoke a negative effect on the biota. The ecotoxicity of surfactants to aquatic life has been summarised in the scientific literature [1—5]. Nevertheless, some information is still lacking in relation to the aquatic toxicity of surfactants, especially knowledge regarding the toxicity of the degradation products, the effect of surfactants on marine species, the ecotoxicity of mixtures of chemical compounds with surfactants, the relationship between toxicity and chemical residue and the effect of surfactant presence in specific environmental compartments (water, particulate matter, pore-water, sediment). 

Cyanide metabolizes in the human body to thiocyanate, and its biodegradation products include ammonia, carbon dioxide, nitrate, or nitrogen (Richards and Shieh 1989). The detection of thiocyanate in body fluids may indicate cyanide exposure. Similarly, the amounts of cyanide degradation products formed in an environmental medium could be used to measure cyanide s biodegradation rate. A summary of methods for determining environmental degradation products is shown in Table 6-4. Suitable analytical methods are available to detect all of these compounds (Pettigrew and Fell 1973 Richards and Shieh 1989). 

Biological. Reported biodegradation products include 2,3-dihydro-2,3-dihydroxybiphenyl, 2,3-dihydroxybiphenyl, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoate, 2-hydroxy-3-phenyl-6-oxohexa-2,4-dienoate, 2-oxopenta-4-enoate, phenylpyruvic acid (quoted, Verschueren, 1983), 2-hydroxy-biphenyl, 4-hydroxybiphenyl, and 4,4 -dihydroxybiphenyl (Smith and Rosazza, 1974). The microbe Candida lipolytica degraded biphenyl into the following products 2-, 3-, and 4-hydroxy-biphenyl, 4,4 -dihydroxybiphenyl, and 3-methoxy-4-hydroxybiphenyl (Cerniglia and Crow, 1981). 

Soil. Metabolites of endosulfan identified in seven soils were endosulfan diol, endosulfanhydroxy ether, endosulfan lactone, and endosulfan sulfate (Martens, 1977 Dreher and Podratzki, 1988). These compounds, including endosulfan ether, were also reported as metabolites identified in aquatic systems (Day, 1991). In soils under aerobic conditions, p-endosulfan is converted to P-endosulfan alcohol and p-endosulfan ether (Perscheid et al., 1973). Endosulfan sulfate was the major biodegradation product in soils under aerobic, anaerobic, and flooded conditions (Martens, 1977). In flooded soils, endolactone was detected only once whereas endodiol and endohydroxy ether were identified in all soils under these conditions. Under anaerobic conditions, endodiol formed in low amounts in two soils (Martens, 1977). Indigenous microorganisms obtained from a sandy loam degraded p-endosulfan to endosulfan diol. This diol was converted to endosulfan a-hydroxy ether and trace amounts of endosulfan ether and both were degraded to endosulfan lactone (Miles and Moy, 1979). 

Biological. Biodegradation products reported include formic acid and ethanol, each of which can degrade to carbon dioxide (quoted, Verschueren, 1983). 

Soil. Lindane degraded rapidly in flooded rice soils (Raghu and MacRae, 1966). In moist soils, lindane biodegraded to (y-PCCH) (Eisner et al., 1972 Kearney and Kaufman, 1976 Fuhremann and Lichtenstein, 1980). Under anaerobic conditions, degradation by soil bacteria yielded y-BTC and a-BHC (Kobayashi and Rittman, 1982). Other reported biodegradation products include pentachlorocyclohexane, pentachlorobenzene, tetrachlorocyclohex-l-enes, and tetrachloro-benzenes (Moore and Ramamoorthy, 1984). Incubation of lindane for 6 wk in a sandy loam soil under flooded conditions yielded y-TCCH, y-2,3,4,5,6-pentachlorocyclohex-l-ene, and small amounts of 1,2,4-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3,5-, and/or 1,2,4,5-tetrachloro-benzene (Mathur and Saha, 1975). Incubation of lindane in moist soil for 8 wk yielded the follow-... 

The migration of PAEs from the polymers leads emissions to the environment during their production, transport, storage, manufacture, use, and disposal [8, 15, 40, 69]. Once in the different environmental compartments phthalates are subject to photo degradation, biodegradation, aerobic and anaerobic degradation and, thus, generally do not persist in the outdoor environment [8, 70]. 

The advantages of the unit would be its mobility relative ease of operation low operating cost production of less toxic, biodegradable products and assurance of extensive degradation in a relatively short period of time when compared to ground disposal. 

Microbial Degradation of Catechin. Since (+) catechin is a possible biodegradation product from condensed tannins, its utilization and bioconversion have been extensively examined by several research groups using fungi, bacteria and yeasts. 

Degraded Carotenoids. Several compounds have been described and characterized which are related structurally to carotenoids and may be biodegradation products of carotenoids. The structure of the vitamin A dimer kitol has been determined as... 

Marchesi J.R., S.A. Owen, G.E. White, W.A. House, and N.J. Russell (1994). SDS-degrading bacteria attach to riverine sediment in response to the surfactant or its primary biodegradation product dodecan-l-ol. Microbiology 140 2999-3006. 

In 2005, BIOTA introduced NatureWorks PLA for packaging its natural spring water. BIOTA was the first beverage company in the world to exclusively use NatureWorks PLA to bottle its products. BIOTA water bottles are completely compostable. They are approved and certified as commercially compostable by the Biodegradable Products Institute (BPI). Initial testing has demonstrated that a BIOTA water botde will degrade within 75 to 80 days in a commercial composting situation. PLA bottles are also approved by the FDA for food and water contact. 

Polyhydroxybutyrate Biodegradable polyester used in degradable plastic products. 

Stranger-Johannessen, M. (1985). Microbial degradation ofpolyurethane products in service. In Biodeterioration and Biodegradation of Polymers 1, ed. K. J. Seal. New York Biodeterioration Society, pp. 264-7. 

Phenols of enviromnental interest are derived from a wide variety of industrial sources, or present as biodegradation products of humic substances, tannins, and lignins, and as degradation products of many chlorinated phenoxyacid herbicides and organophosphorous pesticides. Phenols, especially chlorophenols, are persistent, and toxic at a few pg/1. Therefore, phenols are hsted at the US-EPA hst of priority pollutants and the EU Directive 76/464/EEC as dangerous substances. The samples to be analysed can be surface waters or industrial effluents. 

Cuzzola et al. [25-26] identified and characterized Fenton oxidation products of lauryl sulfate and AES. The Fenton reaction is a frequently applied oxidative treatment in STPs. The degradation prodncts of anionic surfactants have been objects of stndy as well, because their biodegradation products might involve the loss of the snlfate group, resulting in essentially nonionic surfactants (see below). According to Schroder [27], the biodegradation of nonylphenol ethoxy sulfates does not involve a loss of the sulfate. 

If a scaffold is transplanted, the rate of biodegradability is important to ensure that the scaffold remains to support a transplant until a natural ECM replaces it. The biodegradation or resorption rate is a function of the scaffold composition, structure, and the mechanical load present at the site of transplantation. The necessary rate at which the scaffold is degraded varies according to the tissue type. For example, slow degradation is allowable in bone tissue, whereas in other tissues chronic inflammation may occur if the rate is too low.f It is important that the degradation by-products are nontoxic to the body. 

Limited available data suggest that NDMA would be subject to slow photolysis in natural waters exposed to sunlight (Polo and Chow 1976 Callahan et al. 1979). In unlit waters, it appears that NDMA would be rather persistent, eventually degrading as the result of microbial transformation (Kaplan and Kaplan 1985, Kobayashi and Tchan 1978, Tate and Alexander 1975). There is evidence which suggests that formaldehyde and methylamine may form as biodegradation products of NDMA (Kaplan and Kaplan 1985). Insufficient data are available to predict the rate at which NDMA would degrade in water. NDMA is not expected to chemically react under the conditions found in natural waters (Callahan et al. 1979, O.liver et al. 1979). ... 

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