葡萄糖酸钠派生多孔碳对刚果红的吸附特性研究  

Study on Adsorption Characteristics of Congo Red Using Sodium Gluconate-Derived Porous Carbon

作　　者：陈锋 马路路 朱思嘉 李冰倩 王书文 刘欣欣 CHEN Feng;MA Lulu;ZHU Sijia;LI Bingqian;WANG Shuwen;LIU Xinxin(School of Environmental and Biological Engineering,Henan University of Engineering,Zhengzhou 451191,China;School of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]河南工程学院环境与生物工程学院,河南郑州451191 [2]昆明理工大学环境科学与工程学院,云南昆明650500

出　　处：《水处理技术》2023年第10期41-46,63,共7页Technology of Water Treatment

基　　金：国家自然科学基金面上项目(42172189);河南省自然科学基金青年基金项目(222300420134);河南省高等学校重点科研项目(21A610002);河南工程学院2021年度科研培育基金项目(PYXM202105)。

摘　　要：论文以葡萄糖酸钠为碳源,采用惰性气氛条件下的一步碳化法制备葡萄糖酸钠派生多孔碳(SGPC),对其进行物理性能表征,并探究SGPC吸附废水中刚果红(Congo red,CR)的影响因素和特性。研究表明,SGPC为片状结构无定型碳,直径几微米到几十微米不等,厚度为纳米级,无序化程度较高,表面含有一定的缺陷和丰富的含氧官能团(O元素含量为3.87wt%),可以提供更多的活性吸附位点,有利于提升对废水中CR的吸附效果。在CR吸附实验中,吸附量、吸附率与SGPC投加量分别呈负相关和正相关;pH=6时SGPC对CR的吸附效果最好;SGPC对CR的吸附量随着CR初始质量浓度的增大而增大,温度升高有利于吸附的进行;720 min时,SGPC对CR的吸附基本达到平衡。相对于Freundlich吸附等温线模型,Langmuir吸附等温线模型能较好的描述SGPC对CR的吸附过程,在25、35和45℃下的最大吸附量qm分别为74.63、87.72和102.04 mg/g,属于单分子层吸附;热力学研究中,ΔG=-5.35 kJ/mol(25℃)、-7.29 kJ/mol(35℃)和-8.65 kJ/mol(45℃),ΔH=15.91 kJ/mol,ΔS=0.059 J/(mol·K),说明SGPC对CR的吸附过程吸热、熵增且可以自发进行。准二级动力学模型可以更好描述CR的吸附过程(R2为0.9931),吸附过程主要受化学吸附控制;颗粒内扩散和Boyd模型说明液膜在前期控制吸附速率,在后续阶段内扩散控制吸附速率。In this paper,sodium gluconate-derived porous carbon(SGPC)was prepared by one-step carbonization method under inert atmosphere using sodium gluconate as the carbon source,and its physical properties were characterized.The influencing factors and characteristics of Congo red(CR)adsorption in wastewater by SGPC were then investigated.Studies have shown that SGPC was amorphous carbon with lamellar structure,a few microns to tens of microns in diameter,the thickness was nanoscale and the disorder degree was relatively high,and the surface has some defects and rich in oxygen-containing functional groups(O element content was 3.87wt%),which could provide more active adsorption sites,and be conducive to improving the adsorption effect of CR in wastewater.In the CR adsorption experiments,the adsorption capacity and adsorption rate were negatively and positively correlated with SGPC dosage,respectively.SGPC has the best adsorption effect on CR when pH value was 6.The adsorption capacity of CR by SGPC increased with increasing of the initial concentration of CR,and increasing temperature was conducive to the adsorption.The adsorption of CR by SGPC reached equilibrium at 720 min.Compared with Freundlich adsorption isotherm model,Langmuir adsorption isotherm model could better describe the CR adsorption process by SGPC.The maximum adsorption capacities(qm)were 74.63,87.72 and 102.04 mg/g at 25,35 and 45℃,respectively,and the adsorption belonged to monolayer adsorption.In the thermodynamic study,ΔG equaled to-5.35,-7.29 and-8.65 kJ/mol at 25,35 and 45℃,respectively,ΔH equaled to 15.91 kJ/mol,andΔS equaled to 0.059 J/(mol·K),which indicated that the CR adsorptive process by SGPC was endothermic,entropic and spontaneous.The quasi-second-order kinetic model could better describe the CR adsorption process(R2 was 0.9931),which was mainly controlled by chemisorption.The intra-particle diffusion and Boyd models indicated that the liquid film controlled the adsorption rate in the early stage and diffusion controlled the adsor

关 键 词：多孔碳 葡萄糖酸钠 刚果红 吸附 机理 

分 类 号：X52[环境科学与工程—环境工程]