Solar photo-degradation of a pharmaceutical wastewater effluent in a semi-industrial autonomous plant

An industrial wastewater effluent coming from a pharmaceutical laboratory has been treated in a semi-industrial autonomous solar compound parabolic collector (CPC) plant. A photo-Fenton process assisted with ferrioxalate has been used. Up to 79% of TOC can be removed in 2 h depending on initial conditions when treating an aqueous effluent containing up to 400 ppm of initial organic carbon concentration (TOC). An initial ratio of Fe(II)/TOC higher than 0.5 guarantees a high removal.It can be seen that most of TOC removal occurs early in the first hour of reaction. After this time, mineralization was very slow, although H₂O₂ was still present in solution. Indeed it decomposed to form oxygen in inefficient reactions. It is clear that remaining TOC was mainly due to the presence of acetates which are difficult to degrade.