How Municipal Incinerators Make Dioxins from Chlorophenols and Remediation. 1987. Karasek, FW and LC Dixon. and More. JEC Consulting.

Mechanism of formation of polychlorinated dibenzo-p-dioxins produced on municipal incinerator flyash from reactions of chlorinated phenols{Fly ash had 600 different organic molecues adsorbed onto it}

Richmond Incinerator was aditted by Feds to produce dioxins and I pointed out to them that these were dispersed over the lower Fraser River market garden croplands. Author links open overlay panelL.C.DicksonF.W.Karasek https://doi.org/10.1016/S0021-9673(01)94417-6Get rights and content Abstract All incinerators burning municipal waste produce chlorinated dioxins. The mechanism by which these compounds are formed is unknown. Experiments were performed that show these compounds can be produced from known precursors by surface catalysed reactions on the flyash particulates present in the incineration process. A full range of the tetra- through octachlorinated dibenzo-p-dioxins were produced from 13C-labelled pentachlorophenol and two trichlorophenols on the surface of flyash from an Ontario municipal incinerator that had been previously freed from organic material. A simple flow-tube apparatus at 300°C under a 10-ml/min nitrogen flow was used for the experiments. The use of 13C-labelled pentachlorophenol gave a direct measure of the extent of the catalytic reactivity of the flyash surface. Much lower amounts of chlorinated dioxins were produced in similar experiments with flyash from a modern Japanese incinerator whose effluents are normally extremely low in these compounds. Only small amounts of octachlorodioxin, the thermal condensation product expected, were formed using ground firebrick or an empty flow-tube for the reactive surface. These results indicate that the flyash surface has constituents and properties that promote the production of chlorinated dioxins from chlorinated phenols and support the catalysed surface reaction mechanism previously proposed. Remediation. https://www.sciencedirect.com/science/article/pii/S0301479718307473 Abstract Rapid urbanization and industrialization of anthropogenic activities have exerted immense pressure on the environment. Polyhalogenated organic compounds, especially dioxins and furans are regarded as ubiquitously persistent environmental pollutants in the ecosystem. The recalcitrant nature of dioxins and furans induce toxicity in both humans and wildlife. Dioxins and furans are generated by defective technological chemical processes that occur during the manufacture of herbicides and pesticides, use of fertilizers, bleaching of paper and wood pulp and incomplete combustion process. However, incineration and incomplete combustion of solid waste are the main cause for the discharge of dioxins and furans to the environment. During incineration and incomplete combustion, noxious flue gas and ashes are released into the atmosphere and contaminate the soil and water systems; thereby affecting the ecology. According to World Health Organization fact sheet 2016, more than 90% of human exposure to dioxins is through the food chain, especially from dairy products, seafood and meat. These pollutants are mutagenic, carcinogenic, immunotoxic and teratogenic for lower and higher forms of life i.e. microorganisms to humans. This review describes the sources of dioxins and furans pollution, hazardous effects on the ecosystem and recent techniques to minimize and treat dioxins and furans contaminants in the environment. This paper also previews the significance of conventional and latest remediation techniques prevailing around the globe for treating dioxins and furans entry into the ecosystem.