(279e) A Recycling System for Wastewater from Oil Refineries Using Hydrogen and Photocatalysis

In oil refineries, water is used for many different purposes and a substantial amount of wastewater is produced. The traditional wastewater treatment process in oil refineries, which is comprised of primary, secondary, and tertiary treatment, the organic sulfur, organic nitrogen, and other organic compounds are not fully removed. A treatment system for the wastewater from oil refineries to promote the recycling of industrial wastewater has been proposed. In addition to the traditional wastewater treatment process, the process to remove organic sulfur and the process to decompose organic compounds in wastewater have been implemented in the proposed system. To realize the proposed system, the removal of organic sulfur using hydrogen by simulation and photochemical reactions by experiments were studied. In the simulation of the removal of organic sulfur using hydrogen, oil refinery plant data which contain the structures of all components were analyzed. The results showed that organic sulfur was removed in the process, and the conversion ratio highly depended on the chemical structure of the components. As a representative of the remaining organic compound in the wastewater from the oil refinery, phenol, a compound toxic even in low concentrations, was chosen. In the experiment, the decomposition of phenol using UV and TiO2 was investigated. The experimental results show phenol was successfully decomposed. The proposed process may improve the treatment of industrial wastewater and contribute to the conservation of water resources.