Treatment of oily sludge by two-stage wet air oxidation

• Published in: Journal of the Energy Institute Vol. 92; no. 5; pp. 1451 - 1457
• Main Authors: Zhao, Yanan, Yan, Xiuyi, Zhou, Jinghui, Li, Rui, Yang, Shuai, Wang, Baofeng, Deng, Ruonan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2019
• Subjects: Oily sludge; Oxidation; Removal efficiency of oil content; Volume removal ratio; WAO; Removal efficiency of oil content; Oxidation; Oily sludge; WAO; Volume removal ratio
• ISSN: 1743-9671
• DOI: 10.1016/j.joei.2018.08.006

Oily sludge produced in petrochemical industries contains a large amount of toxic and hazardous substances. High oil sludge yield and high treatment cost have become major obstacles to the development of the petrochemical industry. In this study, the treatment and disposal of oily sludge using the wet oxidation method was investigated. Firstly, the orthogonal optimization experiment was designed to discuss the influence of reaction time, reaction temperature, oxidant amount, and emulsion splitter amount on the removal efficiency of oil and sludge volume. On this basis, a two-stage wet air oxidation method was employed to treat oily sludge. The results show that the two-stage oxidation method could remove 93.1% oil from the oil sludge and reduce the volume of oil sludge by 85.4%. Furthermore, the oil sludge treated with wet oxidation could be more easily separated from water, and the waste oil could be recycled. The proposed two-stage wet oxidation method shows excellent performance in treating oily sludge, from which resources can be recycled while reducing the amount of sludge.
•The oil sludge treated with wet oxidation could be more easily separated from water.•The waste oil could be recycled.•The biodegradability of oily sludge was enhanced.•The maximum oil content removal ratio of 93.1% and the maximum volume removal ratio of 85.4%.