Li Xiumin, Xu Jinlan, Tian Guiyong, Sun Yanjie, Yang Zhengli, Yang Zhilin
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 710055, Shaanxi, Xi'an, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, China; Key Laboratory of Environmental Engineering, Shaanxi Province, China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, 710055, Shaanxi, Xi'an, China; Key Laboratory of Northwest Water Resources, Environment and Ecology, MOE, China; Key Laboratory of Environmental Engineering, Shaanxi Province, China.
J Environ Manage. 2022 Jul 15;314:115055. doi: 10.1016/j.jenvman.2022.115055. Epub 2022 Apr 13.
Modified Fenton technique has been widely used to remediate soils contaminated with crude oil but significantly limited to soil organic matter (SOM) consuming oxidants. In this study, soils with developed SOM inactivation by FeOOH formed in situ were created and spiked with crude oil (total petroleum hydrocarbons (TPH): 19453 mg/kg), then treated by modified Fenton reagents. The reaction activity of hydroxyl radicals (•OH) relative to TPH (K) notably increased to 0.65 when the degree of developed inactivation of the SOM (β) was 100% (DIS-100), which was 1.45, 2.03 and 2.83-fold than that of DIS-50, DIS-15 and control (CK), respectively. Meanwhile, the higher the K, the more •OH transferred, which realized the efficient oriented oxidation of TPH. Moreover, improving the transfer of •OH from SOM to TPH was more important than increasing •OH production in soil remediation. With the β increasing to 100%, the ratio of invalid HO decomposition to produce O decreased to 22%, equal to 25% reduction compared to CK. Therefore, when β was 100%, the utilization efficiency of HO was improved to 1.48 mg/mmol, which was approximately 1.39, 3.35 and 5.43-fold higher than the efficiency got by DIS-50, DIS-15 and CK, respectively, achieving the cost-effective dedicated oxidation of TPH. In addition, the FeOOH cross-linked with SOM via Fe-O-C and Fe-N bonds to develop inactivation of SOM. In general, this study highlighted a new insight into the effect of developed inactivation of SOM on soil remediation.
改良芬顿技术已被广泛用于修复受原油污染的土壤，但由于土壤有机质（SOM）消耗氧化剂，该技术受到显著限制。在本研究中，通过原位形成的FeOOH使SOM失活，制备了土壤并添加原油（总石油烃（TPH）：19453mg/kg），然后用改良芬顿试剂处理。当SOM失活程度（β）为100%（DIS-100）时，羟基自由基（•OH）相对于TPH的反应活性（K）显著增加至0.65，分别是DIS-50、DIS-15和对照（CK）的1.45、2.03和2.83倍。同时，K值越高，转移的•OH越多，实现了TPH的高效定向氧化。此外，在土壤修复中，提高•OH从SOM向TPH的转移比增加•OH的产生更重要。随着β增加到100%，无效HO分解产生O的比例降至22%，与CK相比降低了25%。因此，当β为100%时，HO的利用效率提高到1.48mg/mmol，分别比DIS-50、DIS-15和CK获得的效率高约1.39、3.35和5.43倍，实现了TPH的经济高效定向氧化。此外，FeOOH通过Fe-O-C和Fe-N键与SOM交联，使SOM失活。总的来说，本研究突出了对SOM失活对土壤修复影响的新见解。
