Granular Activated Carbon Supported Titanium Dioxide Photocatalytic Process for Carbofuran Removal

Abstract

In the present study, photocatalytic experiments were performed to investigate carbofuran removal from aqueous solution. The investigation was conducted in a batch-mode photocatalytic reactor. A novel granular activated carbon supported titanium dioxide (GAC-TiO2) was prepared and utilized in this investigation. Batch experiments were conducted for 240 min at a constant carbofuran concentration (250 mg L−1) and at varying GAC-TiO2 concentrations (as TiO2, 5 and 75 mg L−1) and pH (3, 7 and 11). Around 83 % carbofuran removal was observed at pH 7 and 75 mg/L TiO2 concentration after a reaction period of 240 min. Similar carbofuran removal (84 %) was observed under pH 7 and 5 mg/L of TiO2 concentration. On the other hand, the increase in pH from 7 to 11 and the simultaneous decrease in catalyst concentration from 75 to 5 mg/L enhanced the carbofuran removal from 83 to 100 %. The photocatalysis process conducted at acidic pH (i.e. pH 3) and 5 mg/L TiO2 concentration has shown a carbofuran removal of 77 %. The change in TiO2 concentration (i.e. from 5 to 75 mg/L) at pH 3 has not produced any significant increase in the carbofuran removal. The results show that carbofuran removal by photocatalysis was more favored under alkaline pH compared to neutral and acidic pH conditions. The overall observations indicate that the combined form of GAC-TiO2 could be effectively used for efficient treatment of carbofuran contaminated water in a batch-mode photocatalysis system.