Combined electrocoagulation and TiO(2) photoassisted treatment applied to wastewater effluents from pharmaceutical and cosmetic industries.

The treated wastewater consists of refractory materials and high organic content of hydrolyzed peptone residues from pharmaceutical factory. The combination of electrocoagulation (EC) followed by heterogeneous photocatalysis (TiO(2)) conditions was maximized. The EC: iron cathode/anode (12.50 cmx2.50 cmx0.10 cm), current density 763Am(-2), 90min and initial pH 6.0. As EC consequence, the majority of the dissolved organic and suspended material was removed (about 91% and 86% of the turbidity and chemical oxygen demand (COD), respectively). After EC, refractory residues still remained in the effluent. The subsequent photocatalysis: UV/TiO(2)/H(2)O(2) (mercury lamps), pH 3.0, 4h irradiation, 0.25gL(-1) TiO(2) and 10mmolL(-1) H(2)O(2) shows high levels of inorganic and organic compounds eliminations. The obtained COD values: 1753mgL(-1) for the sample from the factory, 160mgL(-1) after EC and 50mgL(-1) after EC/photocatalyzed effluents pointed out that the combined treatment stresses this water purification.