Yan Jieru, Zuo Xiaoxue, Yang Shengjiong, Chen Rongzhi, Cai Tianming, Ding Dahu
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China.
Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
J Hazard Mater. 2022 Feb 15;424(Pt B):127435. doi: 10.1016/j.jhazmat.2021.127435. Epub 2021 Oct 7.
Combined pollution caused by organic pollutants and heavy metals pose a significant challenge to the adsorption process. In this study, iron-modified biochar (Fe-BC) was prepared by using ferrate (KFeO) and wheat stalk as the precursors for the adsorption of copper (Cu) and sulfadiazine (SDZ), especially under combined pollution scenarios. Iron modification not only enlarged the surface area but also loaded iron oxide nanoparticles on biochar surface. Accordingly, Fe-BC exhibited better adsorption capability of Cu and SDZ than the pristine biochar (BC). The corresponding maximum adsorption capacities of Fe-BC were 46.85 mg g and 45.43 mg g towards Cu and SDZ, respectively. Interestingly, the adsorption was elevated in binary-pollutants system, suggesting a synergistic effect, which was probably attributed to the mutual bridging effects and complexation between Cu and SDZ. The loaded iron oxide particles could serve as a physical barrier to separate the adsorptions of Cu and SDZ and thus inhibited the competitive adsorption. Meanwhile, theoretical calculation demonstrated that sulfonamide group was the most probable binding site. Columns packed with Fe-BC showed better performances for Cu and SDZ removal in binary system (635.73 BV for Cu and 4846.26 BV for SDZ) than in single systems (571.60 BV for Cu and 3572.06 BV for SDZ), which was consistent with batch adsorption experiments. These results demonstrated the potential application of Fe-BC for simultaneous adsorption of Cu and SDZ and provided a cost-effective way for the remediation of organic and inorganic pollutants.
有机污染物和重金属造成的复合污染给吸附过程带来了重大挑战。在本研究中，以高铁酸钾（KFeO）和小麦秸秆为前驱体制备了铁改性生物炭（Fe-BC），用于吸附铜（Cu）和磺胺嘧啶（SDZ），特别是在复合污染场景下。铁改性不仅增大了表面积，还在生物炭表面负载了氧化铁纳米颗粒。因此，Fe-BC对Cu和SDZ的吸附能力比原始生物炭（BC）更好。Fe-BC对Cu和SDZ的相应最大吸附容量分别为46.85 mg/g和45.43 mg/g。有趣的是，在二元污染物体系中吸附量有所提高，表明存在协同效应，这可能归因于Cu和SDZ之间的相互桥连作用和络合作用。负载的氧化铁颗粒可作为物理屏障，分离Cu和SDZ的吸附，从而抑制竞争吸附。同时，理论计算表明磺胺基团是最可能的结合位点。填充Fe-BC的柱子在二元体系中对Cu和SDZ的去除性能（Cu为635.73床体积，SDZ为4846.26床体积）优于单一体系（Cu为571.60床体积，SDZ为3572.06床体积），这与批量吸附实验结果一致。这些结果证明了Fe-BC在同时吸附Cu和SDZ方面的潜在应用，并为有机和无机污染物的修复提供了一种经济有效的方法。
