The biological degradation of volatile halogenated hydrocarbons (chlorocarbons (VCCs) and chlorofluorocarbons (CFCs)) was investigated under simulated conditions of landfills in laboratory test digesters. Fully halogenated VCCs (tetrachloroethylene, 1,1,1-trichloroethane, tetrachloromethane and dichloromethane) and CFCs (trichlorofluoromethane (R11), dichlorodifluoromethane (R12) and 1,1,2-trichlorotrifluoroethane (R113)) were degraded under anaerobic conditions in addition to the methanogenic bacteria in municipal solid waste (MSW) and organic wastes. These substances showed different degradation reactions in the simulated acid and methanephases of MSW landfills. It is assumed that R11 and R113 could be decomposed completely under methanogenic conditions. Dichlorofluoromethane (R21) was oberved as the reductive degradation product of R11 and was further degraded during the methanephase, but hardly at all under acid conditions. Chlorodifluoromerhane (R22) as a degradation product of R12 was not degraded, even not in the methanephase. In the acidphase, R11 was the only CFC to be dechlorinated, although only in small quantities. The degradation products of tetrachloroethylene differed under the various environmental conditions. In the acidphase, 1,1-dichloroethylene was detected as the only dichloroethylene, whereas in particular cis-1,2-dichloroethylene but also trans-1,2-dichloroethylene, 1,1-dichloroethylene and vinyl chloride could be detected as metabolites in the methanephase. Dichloromethane and chloroethane, as metabolites of 1,1,1-trichloroethane, could hardly be degraded at all in the acidphase. The degradation of VCCs and CFCs is largely independent of the substrate used. The investigations have demonstrated that the measured biodegradation rates (0.3–15 mg/m³ ₘₐₜₑᵣᵢₐₗ ᵥₒₗ./h) cannot be improved considerably since they are limited by the inhibiting effect of the substances and their degradation products.

Supercritical carbon dioxide and supercritical propane were found to be effective solvents in extracting stickies and trace chlorinated organics, including dioxins, from recycled fibers. These undesirable components are not effectively removed with current recycled fiber processing techniques. It was also found that endogenous yeast and mold spores on the fibers were inactivated with supercritical carbon dioxide. An economic analysis was performed for a recycled paper pretreatment process which utilizes semi-batch supercritical fluid extraction. Matrix effects were ignored owing to lack of data. Results are encouraging, estimating cost ranges of 7-17 cents per pound of fibers treated -- costs well within reasonable price targets to pretreat premium paper and tissue products.

Analytical method for hydrophilic polar environmental pollutants was studied. Among these pollutants, the halogenated lower carboxylates were the target compounds of this investigation. A novel but simple derivatization method necessary for sample preparation for instrumental analysis was developed. The new derivatization method for the carboxylates is not a conventional chemical reaction in non-aqueous solvent following isolation from the environmental samples but rather, a direct aqueous reaction ; direct conversion of the carboxylates to amides using a carbodiimide in dilute aqueous solution. Halogenoanilines were selectively used with dicyclohexylcarbodiimide (DCC) under acidic conditions at room temperature to form the anilide derivatives. Moreover, this reaction proceeds while mixing the sample water, DCC, a halogenoaniline, and small volume of extracting solvent. Thus, for the first time, simultaneous derivatization of the carboxylates and extraction of the products into solvent was achieved. Based on the results, simple and practical determination methods by gas chromatography were developed for traces of these carboxylates in environmental samples and the proposed methods were applied to some real samples. Such analytical derivatization methods for carboxylates are useful and noteworthy because they can form C-N bonds in aqueous media under mild conditions with carbodiimides and N atoms of amino and other compounds.