Organophosphorous pesticide removal from water by graphene-based materials – Only adsorption or something else as well? Scientific paper

Abstract

The extensive use of pesticides requires innovative approaches to remove these compounds from the environment. Carbon materials are tradit­ion­ally used as adsorbents for removing pesticides, and the development of the new sorts of carbon materials allows more advanced approaches in environ­mental applications. Using density functional calculations, we have predicted chemical reaction between the S(O)=P moieties of the organophosphates with point defects in graphene – single vacancies, Stone–Wales defects and epoxy-
-groups. The reaction was confirmed using ultra high performance chro­mato­graphy for two graphene oxide samples and dimethoate as a representative of organophosphates. The exact reaction mechanism is still elusive, but it is unambiguously confirmed that no selective oxidation of dimethoate to more toxic oxo-analog occurs. The presented results can help to develop novel sys­tems for the irreversible conversion of organophosphates to non-toxic com­pounds, without using aggressive chemical agents or external physical factors like UV radiation.