王秀娟,雷育涛,曾经文,赵涛,林晓君,蔡倩怡,周志洪,丘锦荣.生物炭对三氯生的吸附热动力学研究[J].环境科学学报,2019,39(6):1790-1800
生物炭对三氯生的吸附热动力学研究
- Adsorption thermodynamics of triclosan by biochar
- 基金项目：2017年度广东省水利科技创新项目（No.2017-29）
- 王秀娟
- 生态环境部华南环境科学研究所, 广州 510655
- 雷育涛
- 生态环境部华南环境科学研究所, 广州 510655
- 曾经文
- 生态环境部华南环境科学研究所, 广州 510655
- 林晓君
- 生态环境部华南环境科学研究所, 广州 510655
- 蔡倩怡
- 生态环境部华南环境科学研究所, 广州 510655
- 丘锦荣
- 生态环境部华南环境科学研究所, 广州 510655
- 摘要：以玉米秸秆、皇竹草和花生壳为原料制备成玉米秸秆生物炭（BCcs）、皇竹草生物炭（BCn）、花生壳生物炭（BCps），采用CEC、等电点滴定，表面官能团分析，元素分析、FT-IR、扫描电镜等方法对3种生物炭进行表征，采用单因素静态吸附实验方法考察了生物炭吸附三氯生的主要影响因素.结果表明：CEC和表面官能团数量排序为BCcs > BCn > BCps，BCcs极性和亲水性更强，孔结构发育更加完善，其次是BCn，BCps的极性和亲水性最弱，孔隙极少.3种生物炭对三氯生的吸附去除率均随着三氯生初始浓度的升高而升高，随着温度的升高而降低，酸性更有利于吸附实验的进行.低离子强度有利于BCcs和BCn吸附三氯生，BCps则相反.在10、25、40℃ 3种温度下，3种生物炭对三氯生的吸附均更符合准二级反应动力学，Freundilich等温方程和Langmuir等温方程都能描述这3种生物炭对三氯生的吸附行为，吸附反应属于自发、放热反应.吸附机制主要为物理吸附，生物炭与三氯生之间无化学键、配位基交换等强作用力.
- Abstract：The biochars were produced from Corn Stalks, Napier and Peanut shells, and were characterized by CEC, isoelectric point analysis, then manifested by elemental analysis, FT-IR and electron microscope scanning. The adsorption capability of biochars for triclosan were investigated by Single-factor batch experiments. The results show that the amount of CEC and surface functional groups are BCcs > BCn > BCps, and in turn, The strength of polarity and hydrophilicity are BCcs > BCn > BCps, according to their pore structure development. the removal rate of triclosan increased as the increasing concentration of triclosan, and decreased with the increasing of temperature. What's more, acidic environment is more conducive to the adsorption to triclosan, and low ionic strength is conducive to the adsorption by BCcs and BCn. under the temperatures of 10, 25 and 40℃, BCcs's triclosan adsorption conforms better with pseudo-second reaction kinetics. Results of adsorption Thermodynamics analysis show that Freundilich and Langmuir isotherm equation can well describe the adsorption behavior of Corn stalks biochar, and the adsorption behavior belongs to spontaneous and exothermic reaction. The main mechanism was physical adsorption. Furthermore,there was no acting force like chemical bond, ligand exchanges between biochars and triclosan.
