A polychlorinated biphenyl isomer was irradiated in aqueous solution and in deoxygenated alkaline 2-propanol /0.3M KOH/. Recovery of original PCB was diminished in aqueous solution but no degradation products were seen. Degradation in alkaline 2-propanol was readily achieved by a chain reaction. Polychlorinated biphenyl adsorbed on activated carbon was also irradiated, but no degradation was evident.
Experimental data is presented on the effective removal of heavy metals such as cadmium, copper, nickel and zinc by absorption onto ferric hydroxide flocs. Ferric sulphate is used as the source of ferric ions along with a small amount of magnetite which is added to make use of high gradient magnetic separation. This paper examines the use of HGMS for this operation. The role of pH, flow rate through the filter, magnetic field strength and collection tube diameter is discussed in detail.
sirable fungi, bacteria, insects, weeds, mol lusks, and other nuisance biota.1 In cur rent practice, pentachlorophenol is prima rily used as a wood preservative. Although under certain conditions it may be con sidered an environmental pollutant having potentially hazardous properties commonly ascribed to chlorinated hydrocarbons, it is not disseminated broadly over fields and crops as are the common agricultural pes ticides. Pentachlorophenol is localized in treated wood and owes its lasting preserva tive effect to its resistance to biological or chemical degradation and leaching. Never theless, potential pollution arises mainly during its manufacture and in the wood treatment plant where the environment may become polluted during processing. It is therefore of interest to investigate the potential for biod?gradation of pentachloro phenol by soil or aquatic microorganisms. Information regarding the biodecomposi tion of pep is relatively scarce and quite vague. Toxicity and biocidal activity of pep have been shown to disappear in soil. The extent of disappearance depends on the type of soil, moisture content, tempera ture, and sunlight.2-5 Kincannon et al.6 were unable to observe disappearance of pep in activated sludge systems although pcp-acclimated sludge was considerably more tolerant to pcp than unacclimated sludge. Ingols et al.7 attempted to accli mate activated sludge to pcp but were unable to demonstrate ring degradation or chlorine removal. Suggestive information related to pcp biod?gradation by three spe cies of Trichoderma has been reported by Cserjesi,8 who measured disappearance of 88 percent pop over a 12-day incubation period in malt extract solution. The purpose of this investigation was to obtain definitive evidence of pcp biod?gra dation in heterogeneous cultures of micro organisms.
AbstractPentachlorophenol−14C6 was synthesized by chlorinating phenol−14C6 using aluminum chloride as a catalyst. Purification of the labeled pentachlorophenol involved the precipitation of the labeled product from an aqueous alkali solution with hydrochloric acid and two sublimations. Proof of radiochemical purity was determined using thick layer chromatography and autoradiography. Internal liquid scintillation counting techniques were used to determine the specific activity of the compound.
Sewage sludge conditioning and disinfection by gamma irradiation. J E Etzel, G S Born, J Stein, T J Helbing, and G BaneyCopyRight https://doi.org/10.2105/AJPH.59.11.2067 Published Online: August 29, 2011
