盐酸改性松针生物炭对磺胺甲噁唑的吸附性能

Adsorption performance of hydrochloric acid-modified pine needle biochar on sulfamethoxazolef

以松针为原料,使用盐酸活化制备获得松针生物炭(PBC),将其用于吸附去除水体中的磺胺甲噁唑(SMX)。分别考察了投加量、pH、吸附时间、阴离子浓度等因素对PBC吸附性能的影响,采用吸附动力学模型和吸附等温模型对吸附过程进行了拟合分析。FT-IR、SEM和BET表征结果证明,经盐酸活化后的松针生物炭表面疏松多孔,含有羧基和羟基等含氧官能团。吸附实验结果表明:当PBC投加量为0.4 g·L-1时,吸附60 min后SMX去除率可达97.1%;当pH为4.0~8.0时,随着pH升高,PBC对SMX的去除率下降;CO32-和HCO3-对吸附反应起抑制作用,CO32-抑制作用更强,SO42-对吸附过程影响较小;PBC对SMX的吸附可用准二级动力学方程来描述,与Freundlich等温方程式拟合度更好(R2>0.98);热力学数据表明PBC对SMX的吸附过程是自发的吸热反应;5次实验后PBC对SMX的去除率仍在40%以上。考虑到PBC吸附效果好,可重复利用,说明PBC具有良好的应用前景,研究可为水污染治理的应用提供参考。

The pine needle biochar(PBC) was prepared with resource of pine needles and activation agent of hydrochloric acid, and was used to adsorb and remove sulfamethoxazole(SMX). The effects of dosage, pH value, initial pH, adsorption time and concentration of coexistence anions on the adsorption performance of PBC were investigated. The adsorption kinetics model and adsorption isotherm model were used to conduct the fitting analysis. The characterization results of scanning electron microscopy(SEM), Surface area analysis(BET) and Fourier transform infrared spectroscopy(FT-IR) demonstrated that the pine needle biochar activated by hydrochloric acid had loose and porous surface and contained oxygen functional groups such as carboxyl groups and hydroxyl groups. The removal rate of SMX reached 97.1% after 60 min adsorption at PBC dosage of 0.4 g·L-1. Within the pH range from 4.0 to 8.0, SMX removal rate by PBC decreased as pH increased. Both CO32- adsorption process. The SMX adsorption by PBC could be described by quasi-second-order kinetic equation,and be better fitted by Freundlich isotherm equation(R2>0.98). The thermodynamic parameters indicated that the adsorption process of PBC to SMX was a spontaneous endothermic reaction. The SMX removal rate by PBC was still above 40% after five recycles. Considering the good adsorption and recycle effects, PBC has a good application prospect. This study can provide reference for its application in water pollution control.