Bleaching organic chlorinated compounds

Enhanced levels of chlorinated compounds have been observed indoors due to human activity as well. For example, increased levels of perchloroethylene have been observed from unvented dry-cleaning units (e.g., Moschandreas and O Dea, 1995) and volatilization of chlorinated organics such as chloroform from treated tap water can occur (e.g., McKone, 1987). Other sources include the use of household products. For example, chloroform emissions have been observed from washing machines when bleach containing hypochlorite was used (Shepherd et al., 1996). It is interesting that emissions of organics associated with the use of washing machines are decreased when the machine is operated with clothes inside (Howard and Corsi, 1998). 

A measure of the amount of chlorine that is chemically bound to the soluble organic pollutants in the effluent. Collective term for the several hundred chlorinated compounds formed during bleaching with chlorinated chemicals. It is also formed naturally. Some of these substances accumulate in fish and fish-eating birds. 

Environment Canada estimates that 100 to 150 g per year of 2,3,7,8-tetra-chlorodibenzodioxin and 2,000 to 3,000 g per year of 2,3,7,8-tetrachlorodibenzofuran are discharged in bleached pulp mill effluents (Phenicie, 1993). It is estimated that only 10 to 40% of small chlorinated organic compounds in bleached pulp mill effluents have been identified. Some of the other substances detected are chlorinated phenols, chlorinated acids, alcohols, aldehydes, ketones, sugars, aliphatic and aromatic hydrocarbons, trihalomethanes, chlorobenzenes, and aromatic thio ethers. Concentrations of individual chlorinated compound such as dichlorophenol, trichlorophenol, trichloroguaiacol, and tetrachloroguaiacol have been measured at 23%, 29%, 50%, and 95% of their respective LCjoS. 

The major uses for elemental CI2 are the production of organic and inorganic compounds and bleaches. Some of the more important chlorinated compounds are used as solvents, antifreeze, and plastics (e.g., polyvinyl chloride). 

Chlorine (usually as NaOCl) is an excellent universal biocide. Problems Chlorine compounds are corrosive to metals (only slightly with stainless steels). Chlorine is neutralized by organic matter (but a more concentrated solution, e.g., 1% NaOCl, will probably overcome the problem). Many of the chlorine household bleaches make effective and economical biocides. NaOCl (10%) stored in brown plastic bottles was stable for two years at 4°C and 1% solution for 20 weeks at 24 °C. Addition of 0.1% anionic detergent increases the power of hypochlorite (a useful anionic agent is sodium lauryl sulfate, 496). CAUTION A few anionic and some nonionic detergents will reduce active chlorine compounds. 

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