Ma Feng-Feng, Zhao Bao-Wei
School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
Huan Jing Ke Xue. 2017 Feb 8;38(2):837-844. doi: 10.13227/j.hjkx.201608101.
Sorption of -nitrophenol (PNP) on biochars prepared from pyrolysis of corncob in the temperature range of 200-600℃ (CC200-CC600) was investigated. Sorption mechanisms were discussed. Pyrolysis temperature showed a pronounced effect on properties of biochars. Decreases in molar H/C, O/C and (O+N)/C ratios were resulted from removal of H- and O-containing functional groups with increasing pyrolysis temperature, and produced biochars with low polarity and high aromaticity. The isotherms data were well described by the Freundlich model. Batch sorption experiments showed that the PNP sorption was strongly dependent on the properties of biochars. A linear relationship was observed between sorption parameters ( and ) and properties of biochars such as molar elemental ratios[H/C, O/C, and (O+N)/C]. The sorption and partition fractions were quantified by isotherm separation method. PNP sorption on biochar produced at 200℃ was linear due to partition on uncarbonized organic matter in biochar, while PNP sorption on biochars produced at 300-600℃ was nonlinear and adsorption-dominant for all the biochars via π-π electron donor-acceptor interaction and pore-filling.
研究了200-600℃温度范围内玉米芯热解制备的生物炭（CC200-CC600）对对硝基苯酚（PNP）的吸附情况，并探讨了吸附机制。热解温度对生物炭的性质有显著影响。随着热解温度升高，含氢和含氧官能团的去除导致摩尔H/C、O/C和（O+N）/C比值降低，从而产生了低极性和高芳香性的生物炭。等温线数据能用Freundlich模型很好地描述。批量吸附实验表明，PNP的吸附强烈依赖于生物炭的性质。吸附参数（和）与生物炭的性质如摩尔元素比[H/C、O/C和（O+N）/C]之间存在线性关系。通过等温线分离法对吸附和分配分数进行了量化。由于PNP在200℃制备的生物炭中的未碳化有机物上的分配，其吸附呈线性，而在300-600℃制备的生物炭上，PNP的吸附是非线性的，且通过π-π电子供体-受体相互作用和孔隙填充，对所有生物炭而言吸附占主导地位。
