Zhao Nan, Zhao Chuanfang, Lv Yizhong, Zhang Weifang, Du Yuguo, Hao Zhengping, Zhang Jing
Department of Environmental Nano-materials, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; School of Environmental Science and Engineering, Guangdong Provincial Key Lab of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510275, PR China.
School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, PR China.
Chemosphere. 2017 Nov;186:422-429. doi: 10.1016/j.chemosphere.2017.08.016. Epub 2017 Aug 7.
The study of simultaneous removal of heavy metals and organic contaminants has practical applications due to the coexistence of complex pollutants in the wastewater or soil. In this work, biochar was prepared to study the removal efficiencies of Cr(VI), naphthalene (NAP) and bisphenol A (BPA) in the single or mixed systems. HPO-treated biochar presented a much higher adsorption capacity of the pollutants than the untreated biochar and also showed a high resistance to coexisting salts. The maximum adsorption capacities for Cr(VI) and BPA were 116.28 mg g and 476.19 mg g, respectively. Coadsorption experiments revealed that the presence of organic pollutants caused a limited decrease (∼10%) of removal efficiency of Cr(VI) and no further decrease was observed with higher concentrations of organic pollutants, while the presence of Cr(VI) had little impact on the removal of NAP. Infrared spectra and molecular simulation demonstrated that Cr(VI) was mainly adsorbed on the biochar via chemical complexation, while the organic pollutants through π-π interaction. Unexpectedly, the addition of Cr(VI) increased the removal efficiency of BPA, probably due to the increased H-bond interactions between BPA and the biochar through bridge bonds of oxygenic groups from CrO.
由于废水中或土壤中复杂污染物共存，同时去除重金属和有机污染物的研究具有实际应用价值。在本研究中，制备了生物炭以研究其在单一或混合体系中对Cr(VI)、萘（NAP）和双酚A（BPA）的去除效率。经HPO处理的生物炭对污染物的吸附能力远高于未处理的生物炭，且对共存盐具有较高的抗性。Cr(VI)和BPA的最大吸附容量分别为116.28 mg/g和476.19 mg/g。共吸附实验表明，有机污染物的存在导致Cr(VI)去除效率有限下降（约10%），且随着有机污染物浓度升高未观察到进一步下降，而Cr(VI)的存在对NAP的去除影响不大。红外光谱和分子模拟表明，Cr(VI)主要通过化学络合吸附在生物炭上，而有机污染物则通过π-π相互作用吸附。出乎意料的是，Cr(VI)的加入提高了BPA的去除效率，这可能是由于CrO中含氧基团的桥键增加了BPA与生物炭之间的氢键相互作用。
