Li Yuanyuan, Yang Jinqiang, Wei Mingli, Song Yaru
School of Civil Engineering, Qingdao University of Technology, Qingdao, Shandong, China.
Jiangsu Institute of Zoneco Co., Ltd., Yixing, Jiangsu, China.
PLoS One. 2025 Sep 12;20(9):e0331869. doi: 10.1371/journal.pone.0331869. eCollection 2025.
Petroleum hydrocarbon (TPH) contamination at industrial sites poses severe ecological and health risks to humans. However, conventional persulfate oxidation suffers from low efficiency and high oxidant demand requirements. To address this limitation, we employed citric acid-FeSO₄-modified sodium persulfate (FNS) for soil remediation.In this study, the petroleum hydrocarbon (TPH)-contaminated soil of a chemically contaminated site was used as the test object, and sodium persulfate modified by citric acid-FeSO4 (FNS) was selected as the oxidant. Based on laboratory tests, quantifying TPH degradation efficiency, soil pH variation, and sulfate leaching concentrations, the effects of oxidant dosage, oxidant dosage times, and CaO dosage on the remediation effect of petroleum hydrocarbon-contaminated soil were systematically investigated. The results demonstrated that citric acicd-FeSO4 significantly enhanced sodium persulfate activation (p < 0.01), achieving within 28 days a 36% higher TPH degradation efficiency than unmodified persulfate at 2% dosage. This modification amplified oxidation intensity and efficiency by up to 2.3-fold over the remediation period.For the contaminated soil with a petroleum hydrocarbon content of 16524 mg/kg, after a 28-day remediation period,FNS amendment achieved significant TPH reductions of 76.9% (to 3820 mg/kg) at 4% dosage-below Class II construction land in China's soil environmental quality standard (4500 mg/kg). At a 6% dosage, after the same 28-day remediation period,reduction efficiency reached 95.5% (to 750 mg/kg) lower than the screening value of soil contamination risk for Class I construction land in China's Soil Environmental Quality Standard (826 mg/kg). The FNS agent can significantly improve the oxidation strength and efficiency of sodium persulfate, but it causes soil acidification and exceeds the SO42- leaching concentration standard, among other things. The restored soil needs to be conditioned with CaO neutralization. In addition, FNS must be applied at one time and cannot be applied separately.
工业场地的石油烃（TPH）污染对人类构成严重的生态和健康风险。然而，传统的过硫酸盐氧化存在效率低和氧化剂需求量大的问题。为了解决这一局限性，我们采用柠檬酸 - 硫酸亚铁改性过硫酸钠（FNS）进行土壤修复。在本研究中，以某化学污染场地的石油烃（TPH）污染土壤为试验对象，选用柠檬酸 - 硫酸亚铁改性的过硫酸钠（FNS）作为氧化剂。基于实验室测试，通过量化TPH降解效率、土壤pH值变化和硫酸盐淋溶浓度，系统研究了氧化剂用量、氧化剂投加次数和CaO用量对石油烃污染土壤修复效果的影响。结果表明，柠檬酸 - 硫酸亚铁显著增强了过硫酸钠的活化效果（p < 0.01），在2%的用量下，28天内TPH降解效率比未改性的过硫酸盐高出36%。在修复期间，这种改性使氧化强度和效率提高了2.3倍。对于石油烃含量为16524 mg/kg的污染土壤，经过28天的修复期，4%用量的FNS处理使TPH显著降低了76.9%（降至3820 mg/kg），低于中国土壤环境质量标准中二类建设用地的标准（4500 mg/kg）。在6%的用量下，经过相同的28天修复期，降解效率达到95.5%（降至750 mg/kg），低于中国土壤环境质量标准中一类建设用地土壤污染风险筛选值（826 mg/kg）。FNS药剂能显著提高过硫酸钠的氧化强度和效率，但会导致土壤酸化，且硫酸盐淋溶浓度超标等。修复后的土壤需要用CaO进行中和调理。此外，FNS必须一次性施用，不能分开施用。
