Dichlorophenols, hazards

Conversion of a compound capable of becoming hazardous to another nonhazardous compound by circumventing the hazardous intermediate. This has been observed in the laboratory, but not identified in the environment. An example is the direct formation of 2,4-dichlorophenol from the corresponding butyrate of 2,4-D. 

Office of Pollution Prevention and Toxics, US EPA, OSHA, Div of Surveillance, Hazard Evaluations and Field Studies, NIOSH, CDC Occupational fatalities associated with 2,4-dichlorophenol (2,4-DCP) exposure, 1980-1998. MMWR Morb Mortal Wkly Rep 49(23) 516-518,Jun 16, 2000... 

Tang, W.Z. and Huang, C.P., pH effect on the oxidation pathways during photocat-alytic oxidation of 2,4-dichlorophenols by CdS, paper presented at Emerging Technologies in Hazardous Waste Management V, Atlanta, GA, Sept. 27-29, 1992. 

Phenol and its compounds are ubiquitous water pollutants that are present in the effluents of a variety of chemical industries such as coal refineries, phenol manufacturing, pharmaceuticals, and industries of resin, paint, dyeing, textile, leather, petrochemical, pulp mill, etc. [9]. Phenols are known to be toxic and also, some of them, hazardous carcinogenic that can accumulate in the food chain. Phenolic compounds are a public health risk and they are heavily regulated in many countries, and must be removed from wastewater before they are discharged into the environment [10], For example, a 10 days consumption of polluted water with low concentrations (3 ppm) of 2,4-dichlorophenol can cause vomiting, paralysis, and even death in children [11, 12]. Phenol, 2-chlorophenol, and 2,4-dichlorophenol are ranked within the 250 most hazardous pollutants [13]. In addition, chlorophenols are commonly found in chlorinated water, since phenol can react with chlorine [14],... 

Distribution of hazardous materials depends not only on the amount produced and its leakage to the environment, but also on its solubility in water. High concentrations of phenols in water are possible only in the case of highly soluble derivatives. The solubility of phenols depends mainly on the amount and nature of their substituents. For example, the solubility of unsubstituted phenol in water is 77.9 gl , 2,4-dichlorophenol solubility is 9.7 gr, that of 2,4,6-trichlorophenol is 0.8 gl and pentachlorophenol solubility is 14 mg r However, these data are presented for molecular (acidic or unionized) forms of phenolic pollutants and are dramatically different in the case of the ionized form. 

M. Akhtar, M.I. Bhanger, S. Iqbal, and S.M. Hasany, "Sorption potential of rice husk for the removal of 2,4-dichlorophenol from aqueous solutions Kinetic and thermodynamic investigations", Journal of Hazardous Materials, Vol. B128, pp. 44-52,2006. 

Fan XY, Wang H, Luo QS, Ma JW, Zhang XH. (2007). The use of 2D non-uniform electric field to enhance in situ bioremediation of 2,4-dichlorophenol-contaminated soil. Journal of Hazardous Materials B 148 29-37. 

Boufatit, M, Ait-Amar, H. McWhinnie, W. R. (2007). Development of an Algerian material montmorillonite clay. Adsorption of phenol, 2-dichlorophenol and 2,4,6-trichlorophenol from aqueous solutions onto montmorillonite exchanged with transition metal complexes. Desalination, vol. 206, pp. 394-406. ISSN 0011-9164. Burns, S. E., Bartelt-Hunt, S. L. Smith, J. (2003). Sorption and permeability of gasoline hydrocarbons in organobentonite porous media. Journal of Hazardous Materials, vol. 96, pp. 91-97. ISSN 0304-3894. 

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