Activated Charcoal Treatment

If after the above-mentioned treatment steps, water still contains nonionic organic impurities e.g. phenolic matter or chloro/bromohydrocarbons from chlorination, adsorption by treatment with activated charcoal is advisable. 

Activated charcoal provides an additional safety element for dealing with sporadic discharges, e.g. accidental, into river-water of organic substances e.g. mineral oil, tempering oils. 

So-called absorber resins based on poly(styrene) are recommended as an alternative to activated charcoal, but have as yet found little application. Chlorohydrocarbons and phenols are efficiently adsorbed by activated charcoal. Humic acid is less well adsorbed, its detection being a sign of activated charcoal filter exhaustion. 

If powdered charcoal is added (widely used in the USA) adsorption can be carried out simultaneously with flocculation, but passing through a bed of granular activated charcoal beds is more widely used in Europe. 

Use of powdered charcoal has the advantage that the amount used can be easily adjusted to the impurity level of the water and that the investment costs are low. Powdered charcoal is, however, not easy to regenerate, whereas granular activated charcoal can be regenerated thermally. Since the composition of the impurities varies from water to water, the conditions required for the treatment of water with granular activated charcoal (e.g. number of filters, contact time) have to be established empirically. The release of already adsorbed compounds e.g. chloro-alkanes into the eluant due to displacement by more easily adsorbed compounds (chromatographic effect) has, however, to be avoided. 

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To evaluate the degree of microbial growth inhibition caused by the hydrolysate used, Debaryomyces hansenii was grown in detoxified hydrolysates and in a hydrolysate only subjected to a pH correction, both nonsupple-mented and supplemented. As detoxification methods, anion-exchange resins and activated charcoal treatments were chosen because both enable the reduction of most of the fermentation-inhibiting compounds (7,38,39). 

Polyethylene glycol48 Hydrogen peroxide Followed by an activated charcoal treatment... 

The activated charcoal treatment also has effects other than the elimination of dissolved organic impurities ... 

Reserpine is adsorbed by activated charcoal. Treatment is largely symptomatic and supportive. Standard supportive therapies, such as vasopressors, should be utilized as clinically indicated. Because symptoms may be delayed, observation for up to 72 h may be indicated. 

Tomaszewski C. Activated charcoal Treatment or toxin (editorial). Clin Toxicol 1999 37 17-18. 

Treatment is supportive in all cases. Critical care management may be required for severe systemic cases. Activated charcoal treatment may be advocated with the rapid recognition of toxin ingestion. 

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