Phenol- halogen compounds

Water purification, including removal of phenol, halogenated compounds, pesticides, caprolactam, chlorine... 

The common chemical classes of antimicrobial agents used in industry are phenolics, halogen compounds, quaternary ammonium compounds, metal derivatives, amines, alkanol amines, nitro derivatives, anilides, organo-sulfur and sulfur nitrogen compounds. Some recommended agents for latex use are pentachlorophenol, tetrachloroisophthalonitrile, o-phenylphenol, tributyltin oxide, 2-n-octyl-4-isothiazolin-3-one, l-(3-chloroallyl)-3,5,7-tri-aza-l-azoniaadamantane chloride [119],... 

Methane has also been used in aerobic bioreactors that are part of a pump-and-treat operation, and toluene and phenol have also been used as co-substrates at the pilot scale (29). Anaerobic reactors have also been developed for treating trichloroethylene. Eor example, Wu and co-workers (30) have developed a successful upflow anaerobic methanogenic bioreactor that converts trichloroethylene and several other halogenated compounds to ethylene. 

Organie ehemieal manufaeture Intermediate organic chemicals and byproducts Phenols, halogenated hydrocarbons, polymers, tars, cyanide, sulfated hydrocarbons, ammonium compounds... 

Suitable fire retardant materials include halogen compounds in combination with antimony compounds, including, tetrabromobis-phenol A and antimony trioxide. Examples for halogen free flame retardants are phosphate esters, such as Hoechst Celanese AP422 or Hoechst Celanese IFR 23. 

There has been a growing interest in applying high performance liquid chromatography, to the determination of the not only volatile compounds, such as aliphatic and polyaromatic hydrocarbons, saturated and unsaturated aliphatic and polyaromatic hydrocarbons, saturated and unsaturated aliphatic halogen compounds, haloforms and some esters, phenols and others but also non volatile components of water. 

Carbonyl compounds, -halogenated anilines, benzidines, nitro compounds, phenols, polychlorinated compounds, alkylbenzene, sulphonates, alkyl sulphonates, alkylbenzene sulphonates, carbamates [155]... 

The nature of the cathode has been found to have major effect on the efficiency of electrochemical HDH of halogenated compounds. For instance, the HDH of 12 mM chlorobenzene at carbon cloth or lead cathodes gave conversions up to 95% with a current efficiency of 20%, lower conversion and efficiency (<5%) were observed using platinum, titanium or nickel cathodes (Zanaveskin et al. 1996). A 100% electrochemical HDH of 153 ppm 4-chlorophenol to phenol was achieved using a palladium-coated carbon cloth cathode (Balko et al. 1993). Unfortunately, several environmentally unacceptable materials, such as Hg and Pb, have also been used as cathodes (Bonfatti et al. 1999 Kulikov et al. 1996). 

In principle, oxidation could occur simultaneously during a HDH (reduction) reaction. For example any de-halogenated compounds could be oxidised to C02 in the anode compartment. Thus in the case of pentachlorophenol the phenol produced by the HDH could be oxidised at a suitable anode (e.g. boron-doped diamond) to C02 ... 

Fig. 2. Re-establishment of Hammett correlation for halogen-substituted phenols in the reaction with polyvinyl acetate radical. The straight line represents the Hammett equation found for 26 compounds (No. 12 in Table 3). Key o non-halogen substituted phenols including 2,6-dimethylphenols, excluding 2,6-t-Bu2-4-substituted-phenols halogen-substituted phenols.

The alkyl ethers of phenols, naphthols and hydroxyanthraquinones can be prepared, in many cases, by treatment of the halogen compounds with alcoholates at high temperature under pressure (e.g., anisole, page 97). Of course, the phenols themselves can be etherified (cf., page 148), and the cheaper method is used in each case. The dialkyl sulfates serve as active alkylating reagents in certain instances, as in the preparation of Caledon jade green (dimethoxydibenzanthrone). 

These processes are applied to organic compounds including phenols, aromatic amines, halogenated compounds, nitrated derivatives, fecal wastes, dyes, aldehydes, carboxylic acid anions, and others. The inorganic substance that has probably been the most commonly treated through the electrochemical route is cyanide its main product is the much less toxic cyanate ion. 

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