Removal of Cu(II)-EDTA complex using TiO2/solar light: the effect of operational parameters and feasibility of solar light application.

The photocatalytic oxidation (PCO) of Cu(II)-ethylene diamine tetra acetic acid (EDTA) was investigated at 38 degrees latitude, using natural sunlight instead of artificial UV light. In order to investigate the optimum conditions for the PCO of Cu(II)-EDTA, the effects of several parameters, such as the type and angle of solar collector, solar light intensity, area of the solar reactor and flow rate, on the removals of Cu(II) and dissolved organic carbon (DOC) were examined with 20 L of 10(-4) M Cu(II)-EDTA at pH 4 in a circulating reactor. The removals (%) of Cu(II) and DOC were favorable with the use of a hemispherical collector, with a 38 degrees tilt angle when flat, on a sunny day, and a solar collector with a high area, in a TiO(2) slurry system. On the basis of these experimental results, PCO with solar light irradiation could be used as a feasible technique in the treatment of Cu(II)-EDTA. In addition, PCO with solar light irradiation is regarded as a potential technique in the treatment of real electroplating wastewater when considering the quite similar removal efficiency of Cu(II)-EDTA, with the subsequent removal of the liberated Cu(2+) by adsorption onto the TiO(2) compared to that of synthetic wastewater.