Carbonaceous material prepared by pyrolysis of refinery oily sludge for removal of flotation collectors in wastewater

The carbonaceous material (CM) prepared by refinery oily sludge was proposed to remove flotation collectors, butyl xanthate (BX), and diethyldithiocarbamate (DDTC) in synthetic wastewater. The effects of the CM on removal efficiency, adsorption kinetics, and isotherms were experimentally carried out. The surface structure and composition of CM were characterized by BET isotherm, XRD, and SEM-EDS, and the concentration of BX and DDTC was tested by UV-VIS spectrometer. The adsorption behavior and removal mechanism were investigated by zeta potential, ToF-SIMS, FTIR, etc. The removal efficiencies of BX and DDTC were both more than 99%, and the maximum adsorption capacity peaked when the pH of the solution was neutral. The two collectors were heterogeneous adsorption on the surface of CM. BX, DDTC, and related metal compounds were found on the surface of carbonaceous material, confirming the existence of both physical and chemical adsorption, and physical adsorption accounted for the main mechanism. It is proved that BX and DDTC can be removed by carbonaceous material and realize the high-effective utilization of refinery oily sludge.

Automated summary

In this study, carbonaceous material (CM) prepared from refinery oily sludge was successfully used to remove butyl xanthate (BX) and diethyldithiocarbamate (DDTC) from synthetic wastewater. The results showed that CM had a high removal efficiency for both BX and DDTC, with the maximum adsorption capacity occurring at neutral pH. The coexistence of physical and chemical adsorption was confirmed by chemical analysis and characterization techniques, with physical adsorption being the main mechanism.