Abstract: In light of the inadequate treatment effectiveness exhibited by contemporary technologies in eradicating oil and coke powder from sulfur-containing wastewater, a phenomenon that has given rise to challenges concerning coking and blockage within downstream stripping units, this study proffers a novel chemical-free pretreatment process, predicated on the "cyclone dissolved air flotation + coalescence oil removal" technology. This process is further augmented by filtration mechanisms that are designed for the elimination of coke powder, thereby functioning as a pretreatment for the stripping apparatus. The experimental results demonstrate that, during the non-small steam blowing phase, the process achieves an average oil removal efficiency of 98.93%.The average mass concentration of suspended solids at the outlet is 7 mg/L. This is calculated using the average mass concentration of suspended solids at the inlet, which is 353 mg/L. In the small steam blowing phase, oil removal efficiency and suspended solids removal rate have been improved to different degrees. It is also notable that high-quality light pollution oil can be recycled and reused, providing a valuable reference for the effective treatment of similar wastewater.

Key words: delayed coking, sulfur-containing wastewater, coke powder, cyclonic dissolved air flotation, coalescence oil removal