Electrochemical methods applied to pharmaceutically active compounds degradation from wastewaters

Abstract

The release of the pharmaceuticals in the environment is a topic of growing concern. The representative sources of pharmaceuticals in the environment are: human medicine (untreated sewage, wastewater and hospital effluent), veterinary medicine (wastewater, untreated sewage) and effluents of pharmaceutical production facilities. Some of pharmaceutically active compounds have negative impact on living organisms and ecosystems. Thus, it is important to pretreat the wastewater with content of pharmaceuticals prior to its discharge to the sewer system. The electrochemical methods are ones of the promising methods of removing pharmaceuticals from the wastewater. This paper was focused on the electrochemical degradation of the diclofenac (DCF) by using dimensionally stables anodes (DSA). DCF is a non-steroidal anti-inflammatory drug used in extent scale worldwide and it was found as persistent waste in the aquatic environment. The composition of DSA was Ti/Ru0.3Ti0.7O2 and the electrodes were prepared by thermal decomposition of appropriate precursors. The experiments were carried out in basic medium by using solutions of 50 and 100 mg/L DCF in 0.1 M Na2SO4 as supporting electrolyte. The applied current densities were 100, 200 and 300 A/m2 at various electrolysis times. The degradation process of DCF was assessed by recording the UV spectra and determining the total organic carbon (TOC). At 300 A/m2 and 120 min of electrolysis for each initial concentration the DCF mineralization was about 40 - 50%.