| Abstrakt: |
In this study, Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were assessed for their ability to enhance the activity of persulfate (PS). Various controlling factors including PS dosages, initial pH, water-soil ratio, ratio of Fe2+, and Fe3O4 MNPs to PS were considered in both the Fe2+/PS system and the Fe3O4 MNPs/PS system. Results showed that the Fe3O4 MNP–activated PS system exhibited high processing efficiency owing to the gradual release of Fe2+. This process occurred in a wide pH range (5–11), attributed to the synergistic action of sulfate radicals (SO4−·) and hydroxyl radicals (OH·) under alkaline conditions, effectively mitigating soil acidification. The ratio of Fe3O4 MNPs to PS and water-soil ratio significantly influenced the degradation rate with the highest petroleum hydrocarbon degradation rate exceeding 80% (82.31%). This rate was 3.1% higher than that achieved by the Fe2+/PS system under specific conditions: PS dosage of 0.05 mol/L, Fe3O4 MNPs to PS ratio of 1:10, water-soil ratio of 2:1, and initial pH of 11. Meanwhile, oxidant consumption in the Fe3O4 MNPs/PS system was halved compared to the Fe2+/PS system due to the slow release of Fe2+ and less ineffective consumption of SO4−·. Mechanistically, the possible degradation process was divided into three parts: the initial chain reaction, the proliferating chain reaction, and the terminating chain reaction. The introduction of Fe3O4 MNPs accelerated the degradation rate of pentadecane, heneicosane, eicosane, tritetracontane, and 9-methylnonadecane. [ABSTRACT FROM AUTHOR] |
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