BDD electrochemical oxidation of neonicotinoid pesticides in natural surface waters. Operational, kinetic and energetic aspects

Neonicotinoids pesticides were introduced to the market in 1990s control various pests. Its accumulation environment supposes a severe problem that can affect human health. This study investigates electrochemical degradation of four common neonicotinoid pesticides; thiamethoxam (TMX), imidacloprid (ICP), acetamiprid (ACP) and thiacloprid (TCP), different natural surface waters by boron-doped diamond anode (BDD). The most influencing variable was current density (j), lesser extent, supporting electrolyte concentration (Ce). In optimal conditions (j = 34.14 mA cm−2 Ce 10.00 mM, using Na2SO4 as electrolyte) pesticide removals for TMX, ICP, ACP TCP 97.2, 96.9, 87.8 98.2 %, respectively. obtained results with support electrolytes (Na2SO4, NaCl, NaNO3 HK2PO4) suggest sulphate optimum ICP ACP. However, TCP, total removal achieved less than 10 min NaCl. It also verified initial pH solution did not significantly influence process range 3–9. All these rationalized this paper. Finally, evaluate matrix influence, some experiments carried out water matrices (river, reservoir two WWTP effluents). factors conductivity organic matter content. noticeable specific energy consumption (SEC) reduced approximately 15 % river effluent. High mineralization rates all matrices, TOC ranging between 60 80 %.