摘要
以咖啡渣为原料,采用正交试验法,通过磷酸活化制备咖啡渣基质活性炭(CGAC),研究了活化温度、活化时间和磷酸质量浓度对活性炭吸附性能及炭化得率的影响。利用比表面积(BET)、N_2吸附-脱附及孔径分析、扫描电镜(SEM)、X射线衍射(XRD)、红外光谱(FTIR)等对其理化性能进行表征。结果表明:以10%磷酸为活化剂,600℃高温活化1.5 h,制得CGAC-1.5 h-600℃-10%H_3PO_4,对水中Cr(Ⅵ)去除率可达98.76%,炭化得率为45.54%。CGAC芳构化程度高,形成了类石墨微晶碳结构,其表面呈现网孔状疏松结构,比表面积可达1 058.75 m^2/g,平均孔径为1.80 nm,是一种微孔型活性炭。经红外图谱分析,活性炭表面的-OH、C=O、C-H等含氧、含氢官能团及芳香环提供的π电子对吸附溶液中Cr(Ⅵ)有重要贡献。
According to orthogonal test method, the high adsorption performance activated carbons were prepared from coffee grounds by phosphoric acid activation. The influence of activated temperature, activation time and concentration of phosphoric acid on the adsorption properties and recovery rate of the samples were evaluated. The structure and properties of the obtained activated carbons were characterized by BET, N2 adsorption-desorption, pore size distribution, SEM, XRD and FTIR. The results showed that the optimal pretreatment and activation conditions were as follows: 10% of phosphoric acid, 600 ℃ activated temperature and 1.5 h activation time. Under these conditions, the recovery rate of the obtained activated carbons was 45.54% and the removal rate on Cr(Ⅵ) could reach 98.76 %. XRD analyses showed that CGAC-1.5 h-600 ℃-10%H3PO4 had better aromatization of carbon atoms and graphite-like crystallite structure was formed. The activated carbons shared a lot of micropores, while the average pore size of the adsorbent was 1.80 nm and the surface area reached to 1 058.75 m2/g. FTIR demonstrated that oxygen- and hydrogen- containing functional groups including -OH, C=O, C-H and π-electrons of aromatic ring were important for Cr(Ⅵ) sorption onto activated carbons.
作者
邵俊
沈丽
张志众
郭丰艳
冯保磊
Shao Jun;Shen Li;Zhang Zhizhong;Guo Fengyan;Feng Baolei(Department of Environmental and Chemical Engineering, Tangshan University, Tangshan, Hebei 063000)
出处
《非金属矿》
CAS
CSCD
北大核心
2019年第3期92-95,共4页
Non-Metallic Mines
基金
河北省教育厅指导项目(Z2017055)
唐山市科技计划项目(17130253a)
唐山学院2018年大学生创新创业训练计划项目
关键词
磷酸
咖啡渣
活性炭
吸附
phosphoric acid
coffee grounds
activated carbon
adsorption
