Pharmaceutical psychotropics degradation by photocatalisys and electrochemical oxidation and neurotoxicity evalution

Abstract

A large amount and variety of recalcitrant compounds are eliminated daily in water bodies, for this reason it is necessary to use processes that are capable of eliminating these substances. This work evaluated the degradation of alprazolam, clonazepam, diazepam, lorazepam and carbamazepine in different aqueous matrices by heterogeneous photocatalysis and electrochemical oxidation. In the electrochemical oxidation the neurotoxicity of some solutions was also evaluated. In the heterogeneous photocatalysis the best results were obtained when using TiO2 (0.1 g L-1) in suspension. It has been found that the combination of more than one advanced oxidative process may be required for both mineralization and disinfection of the treated solution to occur simultaneously. In electrochemical oxidation the increase in current density and electrolyte concentration are directly linked to the increase in the degradation of the compounds. The best results were detected with the use of BDD, applying a current density of 75 A m-2, the compounds were completely degraded in less than 5 min. When using effluent from a pharmaceutical industry, it was possible to remove 71 and 75% of COT and COD, respectively. Neurotoxicity was evaluated in different solutions before and after the electrochemical oxidation, the application of the advanced oxidative process was efficient to eliminate the neutotoxicity of the effluent from the pharmaceutical industry. It was possible to detect that the solutions studied could directly influence the production of reactive oxygen species inside the cells.