A Study of Photocatalytic Processes Involving the Degradation of the Organic Load and Amoxicillin in Hospital Wastewater

An investigation Was carried Out into the treatment of wastewater from the University Hospital of Santa Maria (HUSM) by means of it heterogeneous photocalalytic process (HPP) and a photo-Fenton process (PFP) using Response Surface Methodology (RSM) for maximizing the removal efficiency of the chemical oxygen demand, COD. The rates of COD reduction obtained by HPP and PFP were 44 and 64.6%, respectively. The toxicity (LC50 values) of the hospital wastewater (pre- and post-treatment) were determined by means of the bioassay Artemia salina. During the treatment a toxicity inhibition of 43.5%. was achieved by photo-Fenton and 46.3% by TiO2 photocatalysis. Spiked samples of hospital effluent with amoxicillin were degraded by 100% after treatment by HPP for 30 min and 85%, after treatment by PFP for 60 min, as measured by high performance liquid chromatography (HPLC). All the treatments were conducted on a bench scale using a batch recirculation 2 L Dewar-like photoreactor provided with a light intensity of 401 W/m(2), which was irradiated by a 125 W medium pressure mercury vapor lamp. Ferrioxalate actinometry solution was used to measure the photon flux (q = 1.71 . 10(-5), 1.25 . 10(-7)). The photonic efficiency was 30.00 +/- 0.67% for PFP and 19.02 +/- 0.88% for HPP.