Biodegradable products

Use nonhazardous degreasers - Spent conventional degreaser solvents can be reduced or eliminated through substitution with less toxic and/or 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). 

Elliott SL, Fromstein JD, Santerre JP, and Woodhouse KA. Identification of biodegradation products formed by L-phenylalanine based segmented polyurethaneureas. J Biomater Sci Polym Ed, 2001, 13(6), 691-711. 

However, studies dealing with identification of biodegradation products of drugs in wastewater treatment plants (WWTPs) are very scarce, possibly due to the complexity of screening and structural elucidation studies in environmental matrices such as wastewater and sludge. 

Sulfonated azo dyes are widely used in different industries [16]. Some structure of sulfonated and unsulfonated azo dyes is shown in Fig. 1. These water-soluble azo dyes will enter the environment generally with wastewater discharge. Also, these sulfonated and unsulfonated azo dyes have a negative aesthetic effect on the wastewater, and some of these compounds and biodegraded products are also toxic, carcinogenic, and mutagenic [17]. There exists clear evidence that sulfonated azo dyes show decreased or no mutagenic effect compared to unsulfonated azo dyes... 

Biodegradable polymer networks, with shape memory, 22 364 Biodegradable products, 12 812 Biodegradation... 

Treatment process for partial oxidation of recalcitrantly biodegradable organic pollutants. Aim is to make this recalcitrantly biodegradable products biodegradable in conventional aerobic and anaerobic wastewater treatment systems... 

Main biodegradation products of LAS, sulfophenyl carboxylates (SPCs), were separated by CE using a-cyclodextrin as the chiral selector [6]. The best separation of enantiomers was achieved with 60 mM a-cyclodextrin in a 20 mM citrate buffer at pH 4.0 with an uncoated fused-silica capillary. The method was applied for the qualitative and quantitative analysis of SPC in primary sewage effluents with a detection limit of 1 p,g L-1. 

A PPG biodegradation product as metabolite of PPG generated by metabolisation of AP could be observed and verified by MS-MS(+) when WWTP effluents were examined by APCI-FIA-MS(+) and selected compounds were identified by FIA-MS-MS(+). In the SPE effluent extracts, two ions at m/z 266 and 324 were observed, which... 

Analytical methods used for the determination of surfactants and biodegradation products in subsurface and groundwaters... 

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). 

This chapter presents a summary of the available information regarding the toxicity of surfactants in the aquatic environment and also the new data with special emphasis on the marine environment, the use of microalgae and early life-stages of fish in toxicity assays. In the last few years, one aspect related to the impact of biodegradation products of surfactants in the environment has acquired a significant relevance—the estrogenic effect—and this subject is treated in depth in Chapter 7.3 of this book. 

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). 

Some quality factors, especially secondary ones, depend directly on material or structural attributes of the product. These product quality factors are often arbitrary and can only be qualitatively evaluated by panels of consumers or experts. Convenience for use, product stability, and ability for human skin protection are all examples of these quality factors. Each arbitrary performance index has specific relationships with the material/structural attributes. In such cases, the desirable quality factor can be realized by directly changing the formulation without concerning any of the performance indices. An example can be that to make a laundry detergent product more convenient to use, the product form can be changed from powder to tablet. Another example is that to make a highly biodegradable product, surfactants with less branching should be used. 

At the Olympic Winter Games in Lillehammer, biodegradable products were used for catering. 

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). 

Biological. Reported biodegradation products include 8-chloro-l,2-dihydro-l,2-dihydroxynaphthalene and 3-chlorosalicylic acid (Callahan et al., 1979). When 2-chloro-naphthalene was statically incubated in the dark at 25 °C with yeast extract and settled domestic wastewater inoculum, complete biodegradation was observed after 7 d (Tabak et al., 1981). 

Soil Metabolites of endosulfan identified in seven soils were endosulfan diol, endosulfanhydroxy ether, endosulfan lactone, and endosulfan sulfate (Dreher and Podratzki, 1988 Martens, 1977). Endosulfan sulfate was the major biodegradation product in soils under aerobic, anaerobic, and flooded conditions. 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). These compounds, including endosulfan ether, were also reported as metabolites identified in aquatic systems (Day, 1991). 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). 

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-... 

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