本研究以H_2O_2作为氧化剂模拟生物炭在土壤中的化学老化过程,并通过其被氧化前后表面性质和对双酚A吸附能力的差异,来评估生物炭在土壤中的稳定性及其老化后与双酚A的相互作用。结果表明,经过为期7 d的氧化,H_2O_2的氧化使200℃下制备的生物炭结构片段流失,其吸附性能降低以及生物炭总量减少;而500℃下制备的生物炭虽然碳损失率较低,但由于其极性增强和芳香性减弱导致其吸附性能减弱。2种生物炭在土壤中长期暴露后都可能导致其吸附双酚A能力下降,相对于200℃下制备的生物炭,500℃下制备的生物炭老化后吸附双酚A的能力下降程度更大。
In this study, biochars were oxidized by H_2O_2 to simulate their environmental aging process. The surface properties and adsorption capacities of the oxidized and unoxidized biochars were compared to evaluate their stabilities and the sorption properties for bisphenol A(BPA) after aging. The results showed that the sorption capacities for BPA of biochars produced at 200 ℃ were decreased because of the loss of biochar mass after oxidation for 7 days.Although the mass loss of the biochars produced at 500 ℃ was negligible, the adsorption to BPA by the oxidized biochars were decreased due to the decreased aromaticity and the increased polarity. The immobilization ability of these two biochars for BPA was reduced after H_2O_2 treatment, most likely the same after exposed in environmental conditions. Comparing to the oxidized biochars produced at 200 ℃, the immobilization of the oxidized biochars produced at 500 ℃ for BPA decreased more greatly.