Chlorinated compounds aliphatic hydrocarbon

Polyallomer is highly resistant to chemical attack and to stress-cracking. However, a few chemicals produce swelling and attack the surface slightly. These chemicals are mainly chlorinated compounds, aromatic hydrocarbons, and the higher aliphatic hydrocarbons, such as gasoline. 

Although limited to electron-rich aromatic compounds and alkenes, the Vilsmeier reaction is an important formylation method. When yV,A-dimethylformamide is used in excess, the use of an additional solvent is not necessary. In other cases toluene, dichlorobenzene or a chlorinated aliphatic hydrocarbon is used as solvent. ... 

Although these issues have already been briefly noted, they deserve a few additional comments. For freely water-soluble substrates that have low volatility, there are few difficulties in carrying out the appropriate experiments described above. There is, however, increasing interest in xenobiotics such as polycyclic aromatic hydrocarbons (PAHs) and highly chlorinated compounds including, for example, PCBs, which have only low water solubility. In addition, attention has been focused on volatile chlorinated aliphatic compounds such as the chloroethenes, dichloromethane, and carbon tetrachloride. All of these substrates present experimental difficulties of greater or lesser severity. 

A fiber-optic device has been described that can monitor chlorinated hydrocarbons in water (Gobel et al. 1994). The sensor is based on the diffusion of chlorinated hydrocarbons into a polymeric layer surrounding a silver halide optical fiber through which is passed broad-band mid-infrared radiation. The chlorinated compounds concentrated in the polymer absorb some of the radiation that escapes the liber (evanescent wave) this technique is a variant of attenuated total reflection (ATR) spectroscopy. A LOD for chloroform was stated to be 5 mg/L (5 ppm). This sensor does not have a high degree of selectivity for chloroform over other chlorinated aliphatic hydrocarbons, but appears to be useful for continuous monitoring purposes. 

Such xenobiotics as aliphatic hydrocarbons and derivatives, chlorinated ahphatic compounds (methyl, ethyl, methylene, and ethylene chlorides), aromatic hydrocarbons and derivatives (benzene, toluene, phthalate, ethylbenzene, xylenes, and phenol), polycyclic aromatic hydrocarbons, halogenated aromatic compounds (chlorophenols, polychlorinated biphenyls, dioxins and relatives, DDT and relatives), AZO dyes, compounds with nitrogroups (explosive-contaminated waste and herbicides), and organophosphate wastes can be treated effectively by aerobic microorganisms. 

The /i-(dimethylamino)vinyl 2-pyridyl ketone is a yellow, crystalline solid which is stable for long periods of time at room temperature. The compound is soluble in polar organic solvents and chlorinated solvents, slightly soluble in toluene, and nearly insoluble in aliphatic hydrocarbons. The 1H NMR (80 MHz, CDC13) exhibits signals at S 3.07 (brs,6H), 6.45 (d, 1 H,... 

Anaerobic-aerobic processes have a high potential for the treatment of pulp mill wastewater containing xenobiotic compounds. The pulp and paper industry is under great pressure to remove chlorophenols, chlorinated aliphatic hydrocarbons, and chlorinated dioxins and furans from wastewater. The Canadian government requires that pulp mill effluent contain no measurable level of dioxins or furans (Murray Richardson, 1993)- Such regulations require novel wastewater treatment technologies for the complete removal of target compounds. 

The solvent extracts can be cleaned up by traditional column chromatography or by solid-phase extraction cartridges. This is a common cleanup method that is widely used in biological, clinical, and environmental sample preparation. More details are presented in Chapter 2. Some examples include the cleanup of pesticide residues and chlorinated hydrocarbons, the separation of nitrogen compounds from hydrocarbons, the separation of aromatic compounds from an aliphatic-aromatic mixture, and similar applications for use with fats, oils, and waxes. This approach provides efficient cleanup of steroids, esters, ketones, glycerides, alkaloids, and carbohydrates as well. Cations, anions, metals, and inorganic compounds are also candidates for this method [7],... 

As a by-product in the chlorination of both aromatic and aliphatic hydrocarbons or from the thermal degradation of organic chlorine compounds,... 

Gas chromatography has also been applied to the determination of the following types of organic compounds in potable waters (see Table 15.11) aliphatic hydrocarbons, phenols, nitrophenols, chlorinated dioxins, anticholisterinase insecticides, chlorinated humic acid and chlorolignosulphonic acids. 

Chlorinated Hydrocarbons Other Chlorinated Compounds. The substitution of chlorine atom for hydrogen in a compd greatly increases the anesthetic action of the derivative. In addn, the chlorine deriv is less specific than the parent hydrocarbon in its action, and may affect other tissues along with those of the central nervous system of this body. The chlorine deriv is generally quite toxic and may cause liver, heart Sc kidney damage. As a rule, unsaturated chlorine derivs are highly narcotic but less toxic than saturated derivs. Sax(Ref 4) has discussed in detail the toxicities Sc hazards of a number of chlorinated compds, including Chlorinated Diphenyls Chlorinated Hydrocarbons, Aromatic Aliphatic Chlorinated Naphthalenes Chlorinated Phenols Chlorinated Triphenyls others. 

Tellurium (0-ethyl dithiocarbonate) halides are red-brown crystalline materials that are slightly soluble in aromatic and chlorinated solvents but insoluble in aliphatic hydrocarbons. In ethanol solution the compounds slowly decompose4. In the bromide derivative, the tellurium atom is surrounded by the two sulfur atoms from the bidentate dithiocarbonate and two bromine atoms, one of which belongs to a neighboring molecule. These four atoms form a planar trapezoid around the tellurium atom. The molecules are arranged in a helix held together by Te—Br—Te bridges4. 

Much effort has been concentrated on the fate of chlorinated aliphatic hydrocarbons in aquifers (e.g., trichloroethylene, dichloroethylene). These chemicals undergo reductive dehalogenation under anaerobic conditions. By contrast, these compounds are degraded under aerobic conditions by methane-utilizing bacteria. For example, methan-otrophic bacteria can transform more than 50% of trichloroethane into CO2 and bacterial biomass. 

Reductive Dechlorination. Such reduction of chlorinated aliphatic hydrocarbons, eg, lindane, has been known since the 1960s. More recendy, the dechlorination of aromatic pesticides, eg, 2,4,5-T, or pesticide products, eg, chlorophenols, has also been documented (eq. 10) (20). These reactions are of particular interest because chlorinated compounds are generally persistent under aerobic conditions. 

Xenobiotic organic compounds (XOCs) originating from household or industrial chemicals and present in relatively low concentrations in the leachate (usually less than ImgL of individual compounds). These compounds include, among others, a variety of aromatic hydrocarbons, phenols, chlorinated aliphatic hydrocarbons, and pesticides. 

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