Degradation of petroleum hydrocarbons in oil-based drilling cuttings by a zero-valent iron Fenton-like advanced oxidation system

• Published in: Process safety and environmental protection Vol. 168; pp. 883 - 891
• Main Authors: Mu, Shiqi, Chen, Xinglong, Luo, Yuanfeng, Zhang, Jingjing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2022
• Subjects: Advanced oxidation system; Oil-based drilling cuttings; Petroleum hydrocarbons; Zero-valent iron; Petroleum hydrocarbons; Oil-based drilling cuttings; Advanced oxidation system; Zero-valent iron
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2022.10.056

Oil-based drilling cuttings (OBDCs) containing large amounts of petroleum hydrocarbons generated from shale gas extraction constitute hazardous waste. In this study, the commonalities and differences of three systems, Fe0/peroxymonosulfate (PMS), Fe0/peroxydisulfate (PDS), and Fe0/H2O2, for treating OBDCs have been compared. The results show that oxidant initial concentration, Fe0 dosage, and reaction time are significantly positively correlated with the oil removal efficiency within certain ranges. Moreover, the initial pH is more critical in the Fe0/H2O2 and Fe0/PMS systems than in the Fe0/PDS system, with the oil removal efficiency being better under acidic conditions. FTIR and GC-MS analyses have shown that all three systems are effective in the removal of straight-chain alkanes, and the degradation ability decreases in the order Fe0/H2O2 > Fe0/PMS > Fe0/PDS. By characterizing the morphology, elemental composition, and crystal composition of OBDC before and after treatments, it showed that Fe0 was corroded and produced Fe2+, which benefited the formation of hydroxyl and sulfate radicals by reacting with oxidants (H2O2/PMS/PDS) and was responsible for the degradation of petroleum hydrocarbons of OBDCs. This study may provide theoretical support for the development and optimization of a technology for rendering OBDCs harmless. •The ZVI Fenton-like advanced oxidation system can efficiently treat OBDC.•Changes in petroleum hydrocarbon contents before and after treatment were analyzed.•Changes in the Fe0 material before and after treatment were characterized.•Mechanism of petroleum hydrocarbon removal by the Fenton-like system was analyzed.