榴莲壳生物炭对磺胺嘧啶的吸附性能

以榴莲壳为原材料，制备了榴莲壳生物炭（biochar，BC），以磷酸为活化剂，在碳化温度为350℃、浸渍比为2.5∶1（磷酸∶生物质，质量比）的条件下，制备了活化榴莲壳生物炭（activated durian shell biochar，DBC），并探究二者对磺胺嘧啶（sulfadiazine，SDZ）的吸附作用。通过单因素实验探究了DBC投加量、溶液pH、初始浓度、吸附温度对水中SDZ的去除影响，并用正交实验确定了DBC对SDZ吸附的最优条件。在生物炭的投加量为1.2g/L、SDZ初始浓度为10mg/L、溶液pH为4时，SDZ最大去除率最高。利用吸附等温模型（Langmuir、Freundlich）和吸附动力学模型（准一级动力学、准二级动力学），探究DBC对SDZ的吸附特性，并进行了比表面积及孔径分析、扫描电镜（SEM）、傅里叶红外光谱（FTIR）的表征分析。结果表明，与BC相比，DBC有丰富的微孔结构，比表面积达1224.635m²/g，含氧官能团数量增加，为SDZ的吸附提供了更多的吸附位点，同时Langmuir吸附等温模型可以较好地描述DBC对SDZ的吸附等温过程，吸附动力学过程更符合准二级动力学方程。因此，磷酸活化榴莲壳生物炭可以作为一种高效的吸附剂去除水中的磺胺嘧啶。

Adsorption characteristics of biochar prepared by durian shell on sulfadiazine

Durian shell biochar (BC) and activated durian shell biochar (DBC) were prepared using durian shell for removal of sulfadiazine (SDZ). DBC was pyrolyzed with the impregnation ratio of 2.5∶1 (mass ratio of phosphoric acid to biomass) at 350℃. The effects of the amount of adsorbent, the pH of solution, the initial concentration of SDZ on the removal of SDZ were investigated by single factor experiments. The orthogonal experiments were used to determine the optimal conditions of SDZ adsorption by DBC. At the condition of the initial concentration of SDZ 10mg/L, the amount of adsorbent 1.2g/L and the initial pH 4, the maximum adsorption amount of SDZ by DBC could reach the highest. The adsorption isotherm models (Langmuir model and Freundlich model) and adsorption kinetics models (the pseudo first-order kinetic model and the pseudo second-order kinetic model) were used to explore the adsorption characteristics of SDZ by DBC. Meanwhile, the biochars were characterized by Bruner-Emmet-Teller, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results indicated that the experimental data could be well fitted by Langmuir model, and the pseudo second-order kinetic model could be used to describe the adsorption behaviors of SDZ by DBC. DBC had a rich porous structure, and its specific surface area was up to 1224.635m²/g which provided enough adsorption sites for SDZ adsorption. Compared with BC, the oxygen-containing functional groups of DBC increased. Therefore, phosphoric acid-activated durian shell biochar could be a promising adsorbent for the removal of SDZ from aqueous solution.