荆树皮栲胶/纤维素-聚乙烯亚胺气凝胶吸附阿散酸的研究

Study on Adsorption of p-Arsanilic Acid by Wattle Extract/Cellulose-Polyethylenimine Aerogel

以纤维素为原料,采用NaOH/尿素/水混合溶液溶解纤维素,通过溶胶-凝胶法将荆树皮栲胶(BWT)和聚乙烯亚胺(PEI)接枝到纤维素上以制备荆树皮栲胶/纤维素-聚乙烯亚胺气凝胶((Cell/BWT)@PEI),通过扫描电子显微镜(SEM)、比表面积(BET)分析、热分析(TG-DTG)等手段对其进行结构表征和性能分析,并且研究了其对阿散酸(p-ASA)的吸附性能。结果表明,(Cell/BWT)@PEI比表面积为190.5 m^(2)/g,孔径为15.2 nm,具有较好的热稳定性;当p-ASA初始质量浓度为100 mg/L、溶液pH值为5.0、吸附时间为360 min、吸附温度为25℃、(Cell/BWT)@PEI投加量为0.4 g/L时,(Cell/BWT)@PEI对p-ASA的平衡吸附容量(Qe)为163.3 mg/g,去除率为65.3%;(Cell/BWT)@PEI对p-ASA的吸附为化学吸附,Freundlich等温吸附方程更适于描述(Cell/BWT)@PEI对p-ASA的吸附,且吸附过程自发进行;吸附再生实验结果表明,循环再生5次后,(Cell/BWT)@PEI对p-ASA的Qe为107.2 mg/g、去除率为42.9%。

A novel functionalized cellulose aerogel was successfully prepared by sol-gel method to graft wattle extract(BWT)and polyethylenimine(PEI)on cellulose using NaOH/urea/water as solvent.Scanning electron microscopy(SEM),specific surface area(BET)analysis,thermal analysis(TG-DTG),etc.were used to characterize the structure and properties of the as-prepared wattle extract/cellulose-PEI aerogel((Cell/BWT)@PEI)and its adsorption performance on p-arsanilic acid(p-ASA)was studied as well.The results showed that the specific surface area of(Cell/BWT)@PEI was 190.6 m^(2)/g,the pore diameter 15.2 nm,and it had good thermal stability.The equilibrium adsorption capacity(Qe)of(Cell/BWT)@PEI for p-ASA was 163.3 mg/g and the removal rate was 65.3%when the initial mass concentration of p-ASA was 100 mg/L,pH value of solution 5.0,adsorption time 360 min,adsorption temperature 25℃,and dosage of(Cell/BWT)@PEI 0.4 g/L.Moreover,the adsorption of p-ASA by(Cell/BWT)@PEI was a chemical and spontaneous process,conforming more to the Freundlich isothermal adsorption equation.The results of adsorption regeneration experiments showed that after 5 cycles of regeneration,the Qe of(Cell/BWT)@PEI for p-ASA was 107.2 mg/g and the removal rate was 42.9%.