Contaminants, chloro-organic

By-product HCl from the heavy organic-chemicals industry (p, 798) now accounts for over 90% of the HCl produced in the USA, Where such petrochemical industries are less extensive this source of HCl becomes correspondingly smaller. The crude HCl so produced may be contaminated with unreacted CI2, organics, chloro-organics or entrained solids (catalyst supports, etc,), all of which must be removed. 

There is increasing evidence that pesticides have contaminated extensive areas of the world not directly treated with pesticides. In many instances, the translocation can be attributed to food or water as the transmission vehicle. Another medium of dispersal of pesticides is the atmosphere. Analyses of rainwater and dust have revealed the presence of chloro-organic substances in all samples examined. Identification of specific pesticides has demonstrated that at least some of the chloro-organic compounds are pesticidal in origin. An analysis of dust, whose distant origin was documented by meteorological evidence, proved that pesticide-laden dust can be transported over great distances via the atmosphere and can be deposited over land surfaces remote from the point of application. 

The results presented here show the general trend if chloro-organic compounds are present in the feedstock. The amount of chloro-organics in the feedstock used here were somewhat unrealistic but selected to better understand and measure PCDD/F formation and concentration in the products of fast pyrolysis. In reality, there are no mono-fractions of wood contaminated only with chloro-organic compounds, Generally, pyrolysis of waste wood mixtures results in a much less contaminated oil as presented in this study. However, further investigations are necessary to prove if de novo synthesis takes place during fast pyrolysis of contaminated waste wood. 

A number of organic chlorine, or chloramine, compounds are now available for disinfection and antisepsis. These are the N-chloro (=N-C1) derivatives of, for example, sulphonamides giving compounds such as chloramine-T and dichloramine-T and halazone (Fig. 10.5), which may be used for the disinfection of contaminated drinking water. 

Phenols, particularly the highly chloro-or nitro-substituted variety, are an important group of organic contaminants which, at typical ambient pH, can be present in groundwater predominantly as phenolate anions. Ulibarri et al. [154] studied the adsorption capacity of 2,4,6-trinitrophenol (TNP) on Mg/Al LDHs and their calcined products. The adsorption of TNP on LDHs by anionic exchange is dramatically affected by the identity of the interlayer anion and LDH chlorides have an adsorption capacity of more than 4 times that of LDH carbonates. However, calcined LDH carbonates are more effective adsorbents than those derived by calcination of LDH chloride samples. This possibly reflects the higher surface area of the former species. 

Measurable long-distance transport (>100 km) of organic halides (such as chloro-guaiacols), thereby contaminating remote parts of seas and lakes [5]. 

Approximately 30,000 gallons of contaminated Trimsol cutting oil have also accumulated at DOE sites. The organic fraction of this mixed waste is believed to contain a hydrocarbon oil, 4-chloro-3-methyl phenol, diethyleneglycol ether, and propylene glycol. 

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