Chlorine-insecticide oxidation

Since most water treatment plants practice pre- and post-chlorination, an attempt was made to determine the influence of various doses of chlorine on parathion and paraoxon and to study how pH affects the chlorine—insecticide oxidation reaction. Chlorine dioxide was tested under the same environmental conditions as chlorine to compare their oxidative capacities. 

The deodorization of cocoa butter is necessary to reduce free fatty acid content and to give a product that satisfies the present day requirement of a neutral bland flavor. Deodorization is a suitable method for partially eliminating chlorinated insecticides from cocoa butter. The normal deodorization temperatures are in the range 160-180°C. The oxidative stability of various cocoa butters listed in Table 4 shows extremely high values, and these are unaffected during the deodorization process. Stability against oxidation depends on natural antioxidants present in cocoa butters. The tocopherol composition in Table 5 shows a predominance of... 

Uses. /-Butyl hypochlorite has been found useful in upgrading vegetable oils (273) and in the preparation of a-substituted acryflc acid esters (274) and esters of isoprene halohydrins (275). Numerous patents describe its use in cross-linking of polymers (qv) (276), in surface treatment of mbber (qv) (277), and in odor control of polymer latexes (278). It is used in the preparation of propylene oxide (qv) in high yield with Httle or no by-products (269,279). Fluoroalkyl hypochlorites are useful as insecticides, initiators for polymerizations, and bleaching and chlorinating agents (280). 

Degradation of the insecticide chlorpyrifos has been examined in solutions of aqueous chlorine in which the primary oxidant is hypochlorous acid/hypochlorite. The final product was 2,3,5-trichloropyrid-2-one produced either directly, or via initial oxidative conversion of the thioate ester by replacement of the sulfur with oxygen (Duirk and Collette 2006). An analogous oxidation was found with diazinon (Zhang and Pehkonen 1999). 

Lidov A process for chlorinating cyclopentadiene to octachloropentadiene, which is then thermally dechlorinated to hexachlorocyclopentadiene (HCCP), used as an intermediate in the manufacture of insecticides and flame retardants. The initial chlorination is catalyzed by phosphoms pentachloride or arsenious oxide. Invented by R. E. Lidov in The Netherlands and commercialized by the Shell Chemical Company. 

Insects have developed resistance to cyanide, chlorinated hydrocarbons, organophosfiiates, carbamates, synthetic pyrethroids, and other insecticides ( ). This is not surprising vrtien considering the same complex of detoxifying enzymes, mainly r resented by hydrolytic, conjugative, and oxidative enzymes 9) is capable of detoxifying natural toxins as well as man-made materials. This ability is due to apprcpriate enzymes and/or isozymes that results in broad-substrate capabilities. For insects that feed on a wide variety of hosts (polyphagy), the spectrum of toxins that can be dealt with is truly remarkable. 

Masten et al. (1996) investigated the oxidation of chlorinated benzenes such as 1,2-dichlorobenzene (1,2-DCB), 1,3,5-trichlorobenzene (1,3,5-TCB), and pentanoic acid (PA). TCB is often generated as a by-product of pesticide manufacturing, while DCB is commonly manufactured as an insecticide or a fumigant for industrial odor control. Due to their resistance to biological treatments, PA is usually nonreactive with ozone but can react with hydroxyl radicals (Masten et al., 1996). 

Fem complexes were reported as effective photocatalysts for oxidation of many different organic pollutants, eg alcohols and their derivatives [20,29] organic acids, such as formic [50,53,56], oxalic [37], citric [57], and maleic [58] EDTA [11,20-23], phenol and its derivatives [35, 36, 45,59,60], other aromatic pollutants [38,43,51, 61-64], non-biodegradable azo dyes [40, 41, 48, 55, 59, 65], herbicides [54, 66-70], pesticides [32, 46, 71, 72], insecticides [44], pharmaceuticals and wastewater from medical laboratories [39,47,73], chlorinated solvents [33,74], municipal wastewater [75], and many others [20], The photo-Fenton process was explored as photochemical pre-treatment to improve its biodegradability, especially of biorecalcitrant wastewater from the textile industry [76, 77] the method was also proposed for water disinfection [78,79],... 

Tphe search for insecticides with modes of action different from the A well-known acetylcholinesterase inhibition led us to uncouplers of oxidative phosphorylation (1, 2). An inherent advantage of such pesticides would be the absence of cross-resistance with organophosphorus compounds and chlorinated hydrocarbons. The number of commercial pesticides which are likely to act by uncoupling of oxidative phosphorylation is small. All of them can be regarded as derivatives of the... 

Applications 45 10 t of thionyl chloride was consumed worldwide in 1992. It is utilized as a chlorination agent e.g. for the manufacture of organic intermediates, pesticides, insecticides, pharmaceuticals, dyes and pigments. It is also utilized for the dehydration of metal chloride hydrates, the chlorination of metal oxides, as a non-aqueous electrolyte and as a cathodic material in particular types of lithium batteries. 

During the last decade parathion has been the most used organo-phosphorus insecticide. It has been proved to be valuable in crop protection 27). However, using this compound so much has also resulted in numerous accidental intoxications, and many have been lethal 28). In aquatic environments parathion hydrolyzes to yield p-nitro-phenol or oxidizes to yield paraoxon (25, 26). Baker (29) has shown that substituted phenols aflFect the odor quality of drinking water. p-Nitrophenol may be chlorinated at a water treatment plant to produce an odorous product. The U. S. Public Health Service has adopted 1 /xg/liter as a limit for phenolic compounds in water (10). Paraoxon is more toxic to insects and mammals than the parent compound parathion (27). The lethal dose (LD50) for male white rats is 14 mg/kg for parathion while that determined for paraoxon is only 3 mg/kg (30). Bioassay studies with fathead minnows indicated a Median Tolerance Limit (TLni) (96 hours) for parathion of 1.4 mg/liter and 0.3 mg/liter for paraoxon. 

Endosulfan (CAS 115-29-7) Inhalation and skin absorption are major routes of exposure. Symptoms Include nausea, confusion, excitement, twitching, and convulsions. Animal studies suggest liver and kidney Injury from very high exposures. Limited evidence for adverse effects on male reproduction and fetal development In animal studies. See also p 161. 0.1 mg/m S Chlorinated hydrocarbon insecticide. Tan, waxy solid with a mild sulfur dioxide odor. Thermal-breakdown products include oxides of sulfur and hydrogen chloride. 

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