不同热解温度制备的玉米芯生物炭对对硝基苯酚的吸附作用  

Sorption of p-Nitrophenol by Biochars of Corncob Prepared at Different Pyrolysis Temperatures

作　　者：马锋锋[1] 赵保卫[1] 

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070

出　　处：《环境科学》2017年第2期837-844,共8页Environmental Science

基　　金：国家自然科学基金项目(21167007;21467013);高等学校博士学科点专项科研基金项目(20136204110003);兰州交通大学青年科学基金项目(2013015)

摘　　要：以玉米芯为原料,采用限氧热解法制备了不同温度(200~600℃)的玉米芯生物炭,研究玉米芯生物炭对水中对硝基苯酚(PNP)的吸附行为,并对其吸附机制进行了探讨.结果表明,热解温度对生物炭的物理化学性质影响较大,随着热解温度的升高,含氢、氧官能团逐渐消失,生物炭的极性降低,芳香性增强.等温吸附曲线可以被Freundlich模型很好地描述,生物炭的性质对其吸附PNP有着重要影响,Freundlich模型回归参数(n和KF)与玉米芯生物炭的芳香性、亲水性和极性指数[H/C、O/C、(O+N)/C]呈良好的线性关系.定量描述了表面吸附和分配作用的相对贡献,PNP在低温(200℃)制备生物炭上的吸附主要为分配作用,而高温(300~600℃)制备的生物炭对PNP的吸附为π—π电子受体-供体作用和孔填充效应为主的表面吸附机制.Sorption of p-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 （n and KF ） 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.

关 键 词：生物炭 玉米芯 吸附 对硝基苯酚 热解温度 

分 类 号：X131.2[环境科学与工程—环境科学] X712