State of the art of the environmental behaviour and removal techniques of the endocrine disruptor 3,4-dichloroaniline

In recent years, the presence of Endocrine Disrupting Chemicals (EDCs) in wastewater discharges from agricultural and industrial sources, fresh- and estuarine-waters, as well as soils, has been reported in the literature. Studies of adverse changes in wildlife, linked to environmental exposure to these substances, and the suggestion that humans could also be at similar risk of adverse health effects, have raised concern for urgent action to understand and reduce such risks. 3,4-dichloroaniline (3,4-DCA) has been recognized as an EDC, with regards to endocrine disruption data for both wildlife populations and human health. 3,4-DCA is present in the environment as a product of the biodegradation of phenylurea and phenylcarbamate pesticides; furthermore, it can be introduced from industrial and municipal wastewater that is insufficiently purified, or via accidental spills. Increasing concentrations of 3,4-DCA in soil and water are the result of its high persistence and accumulation, as well as its low biodegradability. Hence, remediation techniques require in-depth study, especially when considering the low removal achieved by traditional activated sludge treatments, and the generation of carcinogenic trihalomethanes as a consequence of the chlorine oxidation methods frequently used in drinking water plants. Fe0/H2O2 systems, photodegradation using doped TiO2, and the use of dielectric barrier discharge reactors, seem to be the most promising techniques for the removal of 3,4-DCA from water.