Decomposition of Organic Compounds in Water from Oil Refineries

Abstract

Abstract In oil refineries, water is used for many different purposes and a substantial amount of wastewater is generated. The traditional wastewater treatment process in oil refineries is comprised of primary and secondary treatment, and the treated water is discharged to water bodies. By recycling the treated water, water withdrawal from the environment can be reduced. Additionally, the organic sulfur, organic nitrogen, and other organic compounds may not be fully removed by biological treatment. For the treatment of these organics and for the recycling of wastewater from oil refineries, a wastewater treatment system for oil refineries has been proposed. The proposed process consists of 1) primary and secondary treatment 2) the removal of remaining organic sulfur and nitrogen using hydrogen, and 3) the removal of remaining organics by photocatalysis. To realize the proposed system, the removal of organic sulfur using hydrogen by simulation and photochemical reactions by experiments were studied. The removal of organic sulfur using hydrogen was analyzed using oil refinery plant data. The results showed that organic sulfur and nitrogen were removed in the process, and the conversion ratio highly depended on the chemical structure of the components. For the experiment, as a representative of the remaining organic compound in the wastewater from the oil refinery, phenol was chosen. In the experiment, the decomposition of phenol using UV and TiO 2 was investigated. The results showed that phenol was successfully decomposed. From the results of the investigations, this process shows promise to improve the treatment of industrial wastewater and contribute to the conservation of water resources.