Surface water, transformation product

Keywords Groimd water Surface water Transformation products... 

The detection of DDT in surface waters as (DDE + DDD)/DDT < 1 reflects minor transformation of the initial insecticide in the soil and hence the toxicants loss or leaching from recently formed RPA or so-called local pedogeochemical anomalies, LPA (former action zone of plants for DDT preparations production places of accidental spillage or output of the preparations areas of storage or burial—tombs, etc. that are characterized by extremely high contamination level (Lunev, 1997 Silowiecki et al., 1998). 

Mirex is a very persistent compound in the environment and is highly resistant to both chemical and biological degradation. The primary process for the degradation of mirex is photolysis in water or on soil surfaces photomirex is the major transformation product of photolysis. In soil or sediments, anaerobic biodegradation is also a major removal mechanism whereby mirex is slowly dechlorinated to the 10-monohydro derivative. Aerobic biodegradation on soil is a very slow and minor degradation process. Twelve years after the application of mirex to soil, 50% of the mirex and mirex-related compounds remained on the soil. Between 65--73% of the residues recovered were mirex and 3-6% were chlordecone, a transformation product (Carlson et al. 1976). 

You might find heptachlor or heptachlor epoxide in the soil or air of homes treated for termites, dissolved in surface water or groundwater, or in the air near hazardous waste sites. You might also find heptachlor or its by-product, heptachlor epoxide, in plants and animals near hazardous waste sites. Heptachlor can no longer be used to kill insects on crops or in homes and buildings. However, heptachlor is still approved by EPA for killing fire ants in power transformers. More information on the... 

CASRN 2032-59-9 molecular formula C11H16N2O2 FW 208.26 Plant/Surface Water. Several transformation products reported by Day (1991) include 4-amino-/n-tolyl-7V-methylcarbamate (AA), 4-amino-3-methylphenol (AC), 4-formamido-/n-tolyl-TV-methylcarbamate (FA), 7V-(4-hydroxy-2-methylphenyl)-yV-methylformamide (FC), 4-methyl-formamido-/n-tolyl-7V-methylcarbamate (MFA), 4-methylamino-/n-tolyl-Wmethylcarbamate (MAA), 3-methyl-4-(methylamino)phenyl-Wmethylcarbamate (MAC), phenol, methylamine, and carbon dioxide. MAA was not detected in natural water but was detected in fish tissues following exposure to aminocarb-treated water in the laboratory. The metabolites FA, AC, and MAC were detected in Canadian forests treated with aminocarb but the metabolites AA, MAA, and FC were not detected (Day, 1991). 

Day, K.E. Pesticide transformation products in surface waters, in Pesticide Transformation Products, Fate and Significance in the Environment, ACS Symposium Series 459, Somasundaram, L. and Coats, J.R., Eds. (Washington, DC American Chemical Society, 1991), pp. 217-241. 

Trifluoroacetic acid is an atmospheric transformation product of freon substitutes. It enters surface waters by precipitation where it dissociates into its ionic form trifluoroacetate and then remains virtually inert. 

Schroyer, B. and P. Capel (1996). A high-performance liquid chromatography-based screening method for the analysis of atrazine, alachlor, and ten of their transformation products. In M.T. Meyer and E.M. Thurman, eds., Herbicides Metabolites in Surface Water and Ground Water. ACS Symposium Series 630. Washington, DC American Chemical Society, pp. 34-42. 

Lai MG, Rosenblatt DH. 1977a. Identification of transformation products of white phosphorus in water. Naval Surface Weapons Center, Silver Spring, MD. Final Report No. 

Based on effects observed in water (Navy 1984b), tetryl released to soil is expected to be susceptible to slow hydrolysis in acidic and neutral soils and to relatively rapid hydrolysis in highly alkaline soils (HSDB 1994). Samples of water collected from lysimeters containing tetryl-contaminated soil indicated that the major transformation products were picric acid (5-14%) and other polar, water- soluble decomposition products no tetryl was detected in the water, or in the soil at the end of the study, suggesting complete hydrolysis (Kayser and Burlinson 1988 Navy 1982). The specific reaction leading to these products was not determined. Because tetryl is subject to photolysis in water, it may be susceptible to photolysis on sunlit soil surfaces (HSDB 1994). 

Si is produced in the atmosphere by the reaction " Ar(p,p2a) Si. It is oxidized to Si02 and stays in the atmosphere for some time in the form of fine particles, until it comes down with the precipitations. It is found in surface waters, glaciem, polar ice and marine sediments. Due to the low production rate of Si (Table 16.1), the measurement of its radioactivity in water samples requires processing of large amounts of water or ice of the order of tons, from which hydrous SiOa XH2O has to be separated. Si changes into stable S by a sequence of two transformations,... 

---