(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 資源加工與生物工程學(xué)院，長(zhǎng)沙 410083；
3. 中南大學(xué) 國(guó)家重金屬污染防治工程技術(shù)研究中心，長(zhǎng)沙 410083)
摘 要: 采用巰基化改性麥糟去除廢水中的鋅離子，研究溶液pH值、反應(yīng)時(shí)間和溫度以及Zn(Ⅱ)初始溶度對(duì)巰基化改性麥糟吸附效果的影響；借助吸附平衡等溫線及吸附動(dòng)力學(xué)模型擬合，結(jié)合傅立葉變換紅外光譜(FTIR)分析闡明吸附機(jī)制。結(jié)果表明：在較寬的pH值范圍(6~9)內(nèi)，巰基化改性麥糟表現(xiàn)出對(duì)Zn(Ⅱ)良好的吸附性能。由Langmuir吸附等溫線方程計(jì)算得到該吸附劑對(duì)Zn(Ⅱ)的理論飽和吸附量為353.36 mg/g，高于改性木質(zhì)纖維素類(lèi)吸附劑的吸附量(17.88~156 mg/g)。巰基化改性麥糟對(duì)Zn(Ⅱ)的吸附動(dòng)力學(xué)特性表明吸附反應(yīng)很快在30 min 內(nèi)達(dá)到平衡，吸附符合擬二級(jí)動(dòng)力學(xué)方程，活化能的計(jì)算結(jié)果表明吸附為活性化學(xué)吸附。FTIR分析可知：由巰基化改性麥糟吸附Zn(Ⅱ)主要是羥基和巰基中S—H基團(tuán)的硫原子與Zn(Ⅱ)配合的結(jié)果。
關(guān)鍵字: 巰基化改性麥糟; 吸附; Zn(Ⅱ); 動(dòng)力學(xué); 吸附特性
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China;
3. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution,
Central South University, Changsha 410083, China）
Abstract:The thiol-functionalized spent grain (TSG) was used to remove Zn(Ⅱ) from wastewater. The effects of solution pH, reaction time and temperature and initial Zn(Ⅱ) concentration on the adsorption were investigated. The adsorption mechanism was clarified by the adsorption equilibrium isotherm and adsorption kinetics model fitting combined with Fourier transform infrared spectroscopy (FTIR) analysis. The results show that the thiol-functionalized spent grain exhibits good adsorption performance over the wide pH range of 6-9. The maximum theoretical Zn(Ⅱ) adsorption capacity of TSG calculated from Langmuir isotherm is 353.36 mg/g, which is higher than those of other modified lingocellulosic adsorbents reported (17.88-156 mg/g). In addition, the results of Zn(Ⅱ) sorption kinetics by TSG indicate that the sorption process is fast and the equilibrium is established in 30 min. The sorption kinetics is well described by the pseudo-second order kinetic model. The calculated activation energy (Ea) implies that the adsorption of Zn(Ⅱ) on TSG is a chemical adsorption. FTIR analysis demonstrates that the hydroxyl groups and sulphur atoms of thiol groups (S—H) of TSG complexing with the zinc ion leads to the adsorption.
Key words: thiol-functionalized spent grain; adsorption; Zn(Ⅱ); kinetics; adsorption characteristic
