Effective pharmaceutical wastewater degradation by Fenton oxidation with zero-valent iron

The pre-treatment of a pharmaceutical wastewater (PWW) by Fenton oxidation with zero-valent iron (ZVI) and hydrogen peroxide was investigated to improve the degradation of the complex-mixture of organic compounds present in the wastewater. The influence of different crucial parameters such as the initial hydrogen peroxide concentration, the ZVI concentration and the capacity of the ZVI/H2O2 system to treat different organic loading have been evaluated. The optimal conditions for degradation led to TOC reductions of up to 80% in only 1 h of treatment. This degree of organic mineralization was reached by using moderate loadings of ZVI and hydrogen peroxide (ZVI/TOC weight and H2O2/TOC molar ratios of 12 and 3.2, respectively). Moreover, the use of waste-metallic iron shavings in terms of TOC removal compared to commercial ZVI powder may be a promising and cheaper development.