Electron beam-persulfate system effectively reduces polycyclic aromatic hydrocarbons and Cr(VI) emissions: Environmental matrix impact and mechanism analysis

Abstract

Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) are prevalent pollutants in the environment, and their intricate interactions amplify the challenges of remediating complex contaminations. There is an urgent need for effective methods to treat these composite pollutants. This study innovatively demonstrates that the electron beam-persulfate system can effectively remove PAHs and reduce heavy metals. Compared to the sole use of electron beam irradiation, the degradation rate of naphthalene in the electron beam-persulfate system increased by 2.5 times, and the reduction efficiency for hexavalent chromium reached 97.6 %. In comparison with persulfate alone, the treatment efficiency of the electron beam-persulfate system for NAP increased by 8 times, achieving complete degradation at 10 kGy, with the degradation process conforming to pseudo-first-order kinetics. The experimental results indicate that the electron beam-persulfate system is a stable operational system, with pH, liquid depth, types and concentrations of inorganic ions exerting a minor influence on the system. Experimental analysis confirmed that hydroxyl and sulfate radicals play vital roles in PAH removal, while hydrated electrons and sulfate radicals are crucial for the reduction of heavy metals. Toxicity analysis also revealed that the electron beam-persulfate system achieves harmless treatment of complex pollutants. Therefore, the electron beam-persulfate system offers an efficient technology that maintains stability in various environments, providing novel pathways and methods for pollutant removal.