Photocatalytic mineralisation of mercaptans as environmental pollutants in aquatic system using TiO_2 suspension

摘要

The photocatalytic oxidation of aqueous solutions of 2-mercaptobenzothiazole (MBT), 2-mercaptobenzimidazole (MBI), 2-mercaptobenzoxazole (MBO), 2-mercaptopyridine (MP), para-tolylmercaptan (PTM) was investigated over a heterogeneous catalyst of TiO_2, in a photocatalytic reactor. The effect of some physical and chemical parameters such as amount of catalyst, flow of oxygen, pH and time of irradiation were studied in order to optimise the proscess. These mercaptans are almost completely mineralised to carbon dioxide, ammonia and sulphate ion by photocatalytic method. The results obtained from photocatalytic oxidation of MBT have led us to propose a compound with the sujm formula of benzothizol-2-sulfonate (BTSO_3) to be a main intermediate.