(1. 中南大学 资源加工与生物工程学院，长沙 410083；
2. 中南大学 生物冶金教育部重点实验室，长沙 410083)
摘 要: 在N,N-二甲基甲酰胺中，以次磷酸钠作为催化剂，采用柠檬酸对泡桐皮、芦苇、花生叶3种生物质材料进行化学改性，制备得到生物吸附剂，并研究Cr(Ⅵ)溶液pH值、初始溶液Cr(Ⅵ)浓度、吸附时间等因素对水溶液中Cr(Ⅵ)吸附率的影响。采用红外光谱分析仪对吸附材料的分子结构及其化学键进行表征。结果表明：3种改性生物质材料在pH值为2、Cr(Ⅵ)初始浓度为30 mg/L时，吸附性能较好，吸附平衡时间为120 min。可以用准二级动力学方程很好地描述生物质材料吸附过程。改性后的泡桐皮、芦苇、花生叶对Cr(Ⅵ)的最大吸附率分别为96.78%、91.85%和89.63%，其中改性后泡桐皮具有最大的吸附量。
关键字: 泡桐皮；芦苇；花生叶；Cr(Ⅵ)；化学改性；重金属；生物质吸附
（1. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Biometallurgy, Ministry of Education, Central South University, Changsha 410083, China）
Abstract:Paulownia peel, reed and peanut leaf were chemically modified with citric acid by using sodium hypophosphite monohydrate (NaH2PO2·H2O) as a catalyst in N,N-dimethylformamide (DMF) to obtain biosorbents. The effects of pH of Cr(Ⅵ) solution, initial concentration of Cr(Ⅵ), adsorption time on the adsorption efficiency of Cr(Ⅵ) in aqueous solution were investigated. Fourier transform infrared spectroscopy were used to characterize the molecular structure and its chemical bond of the adsorbent. The results show that, when pH value is 2 and the initial concentration of Cr(Ⅵ) is 30mg/L, three biomass materials have superior adsorptive properties. The adsorption processes achieves equilibrium within 120 min and are found to be well described by the pseudo-second order adsorption kinetics. The maximum adsorption efficiencies of Cr(Ⅵ) by modified paulownia peel, reed and peanut leaf are 96.78%, 91.85% and 89.63%, respectively. Among these biosorbents, the modified paulownia peel has the highest adsorption quantity.
Key words: paulownia peel; reed; peanut leaf; Cr(Ⅵ); chemical modification; heavy metal; biomass adsorption
