Kinetics and equilibrium adsorption of copper(II) and nickel(II) ions from

使用乙二胺改性的木屑黄原酸盐对水溶液中的Cu(II)、Ni(II)离子进行吸附。在单离子体系中,考虑影响因素(温度、投加量)对Cu(II)、Ni(II)单离子吸附等温线的影响;并计算Cu(II)、Ni(II)离子吸附的热力学参数:吸附吉布斯自由能(?GΘ)、吸附过程的焓变(?HΘ)以及熵变(?SΘ),表明此吸附是一个放热自发的过程。在Cu(II)和Ni(II)双离子体系中,采用修正后的拓展Langmuir模型对体系的吸附情况可以进行很好的预测。在单离子体系和双离子体系中,吸附过程的数据均可通过准二级动力学模型进行描述;计算得到其对Cu(II)和Ni(II)单离子的吸附活化能分别为59.12和55.92 kJ/mol。结果表明,金属离子在改性木屑表面的吸附效果会受到另一离子存在的影响。Abstract: Sawdust xanthate modified with ethanediamine was used for the removal of Cu(II) and Ni(II) from aqueous solution. The influence of various operating parameters such temperature and adsorbent dosage on the adsorption isotherms of modified sawdust was investigated. Thermodynamic parameters, namely Gibbs free energy (ΔGΘ), enthalpy (ΔHΘ) and entropy (ΔSΘ) of Cu(II) and Ni(II) adsorption process were calculated, showing that the adsorption is a spontaneous and exothermic process. The modified extended Langmuir equation approaches provide excellent prediction of the binary adsorption. In single and binary systems, the overall adsorption data were best described by the pseudo-second order kinetic model, then the calculated values of activation energy of Cu(II) and Ni(II) adsorption process were 59.12 and 55.92 kJ/mol respectively. The results show that the affinity of each metal ion onto the modified sawdust surface is influenced by the presence of the other one.Project(41061044)supported by the National Natural Science Foundation of China;Projects(2010GXNSFD013016,2012GXNSFAA053017)supported by the Natural Science Foundation of Guangxi,Chin

Kinetic and Equilibrium Adsorption of Cu~（2＋）,Ni~（2＋） and Cd~（2＋） Ions on Chelating Sawdust Xanthate

采用丙烯酸甲酯、乙二胺对碱化木屑进行接枝反应,然后用二硫化碳黄化,合成了具有酰胺基和氨基的木屑黄原酸盐;并研究了其对重金属离子Cu2+、Ni2+和Cd2+的吸附行为。结果表明,螯合木屑黄原酸盐对Cu2+、Ni2+和Cd2+的平衡吸附量次序为:Cd2+>Cu2+>Ni2+,其值分别是32.873 mg/g、17.328 mg/g和32.982 mg/g。等温吸附过程符合Langmuir方程,说明吸附可能属于单分子层吸附;动力学吸附过程符合准二级动力学模型,吸附过程可能属于化学吸附反应。The containing acylamino and amino chelating sawdust xanthate synthesized by the grafting reaction of sawdust,methyl acrylate,epichlorohydrin and carbon disulfide was used to investigate the adsorptions of Cu2＋,Ni2＋ and Cd2＋ ions.The results showed that the order of the equilibrium adsorption capacity for three metal ions was as follows： Cd2＋ Cu2＋ Ni2＋,the value was calculated to be 32.873 mg/g,17.328 mg/g and 32.982 mg/g respectively.The Langmuir isotherm model could explain the isotherm data,and indicated the process was possible monolayer adsorption.The pseudo second-order rate equation could explain the kinetic experimental data,this suggested the adsorption process is possible chemical adsorption reaction.国家自然科学基金项目(41061044);广西自然科学基金重点项目(2010GXNSFD013016);广西自然科学基金面上项目(2012GXNSFAA053017)资

Optimal Preparation of Dithioamino Starch Xanthogenate and Its Characterization

以可溶淀粉和原乙酸三甲酯进行缩醛反应生成淀粉环酯,在氨水中交联、接枝共聚、磺化合成出以氮为中心的交联接枝共聚淀粉黄原酸盐(dithioamino starch xanthogenate,DSX)。通过正交试验设计方法优化制备条件,结果表明:原料淀粉10g、交联剂(环氧氯丙烷)1.77g、引发剂(过硫酸铵)0.053g、接枝单体(丙烯酰胺)3.37g和二硫化碳6.30g,合成的产物(DSX)对模拟废水中Cu2+的去除率达到98.5%。采用红外图谱、元素分析、核磁、热分析、扫描电镜等多种手段对产物进行表征。In order to synthesize a novel dithioamino starch xanthogenate（DSX）,the acetalization reaction between soluble starch and trimethyl orthoacetate was carried out to form starch acetal-3,6 ring ester,followed by cross-linking in aqueous ammonia,graft copolymerization with acrylamide and sulfonation.Using orthogonal array design,the optimal reaction system was determined to consist of： 10 g of starch,1.77 g of cross-linking reagent,0.053 g of initiator,3.37 g of graft monomer and 6.30 g of carbon disulfide.The synthesized product could remove 98.5% Cu2＋ from simulated wastewater.Further,its structure was characterized by FT-IR,elemental analysis,nuclear magnetic resonance（13C-NMR and H-NMR）,thermogravimetric analysis（TG） and scanning electron microscope（SEM）.国家自然科学基金项目(41061044);广西自然科学基金重点项目(2010GXNSFD013016);广西教育厅“广西高校优秀人才资助计划”项目(桂教人[2007]70号

Visible photocatalytic degradation of wastewater from eosin Y solution using nitrogen-doped TiO2 catalyst

采用溶胶凝胶法制备了氮掺杂二氧化钛光催化剂,用XRD、SEM、FTIR和粒度分析仪对催化剂进行了表征,并且在可见光作用下对曙红Y溶液进行了光催化降解实验。研究了催化剂的投加量、曙红Y的初始浓度、光照时间和pH对曙红Y溶液的光降解效果。结果表明,以可见光作光源,催化剂的投入量为0.4 g,曙红Y溶液的初始浓度为20 mg/L,光照时间为50 min,pH=4条件下,曙红Y溶液的降解率达98.87%。Nitrogen-doped TiO2 were prepared by sol-gel method, and charactered by means of XRD, SEM, IR and particles size analysis. Photoeatalytie degradation of wastewater from eosin solution was also studied by using nitrogen-doped TiO2 as catalyst and visible light as light source. The influences of the dosage of catalyst, concentration of eosin Y, photocatalytic reaction time and pH were investigated. The optimum conditions are found ： the proper dosage of nitrogedoped TiO2 catalyst is 0. 4 g, concentration of eosin Y solution is 20 mg/L, the photocatalytie reaction time is 45 min,pH =4, decolorization rate of eosinY solution is 98.87 %.国家自然科学基金资助项目(41061044);广西自然科学基金重点项目(2010GXNSFD013016);广西自然科学基金面上项目(2012GXNSFAA053017

Adsorption of Cu2 + and Ni2 + in dual ion system

利用木屑制备木屑黄原酸盐吸附剂,对其进行FTIR、XRD和BET分析,并考察了对双离子体系中铜镍离子的吸附情况,重点研究了木屑黄原酸盐吸附量的预测和吸附初始速率的计算。结果表明,在铜镍双离子体系中,利用扩展的Langmuir模型能很好地预测木屑黄原酸盐对铜镍离子的吸附;吸附之初,吸附速率很快,并且随着干扰离子的浓度增大,所考察离子的初始速率逐渐减小。吸附情况说明,木屑黄原酸盐是一种具有良好吸附性能的吸附材料。Abstract Sawdust xanthate was prepared from sawdust． And it was characterized by FTIＲ，XＲD and BET． The adsorption of Cu2 + and Ni2 + on sawdust xanthate for the dual ion system，especially adsorption capacity of the adsorbent and the initial adsorbing rate，was investigated． The results showed that extended Langmuir model could predict the adsorption behavior for the Cu-Ni dual ion system． The adsorption rate was very high at the beginning，while the rate decreased with the increase of the concentration of interference ions． The results demonstrated that sawdust xanthate has good affinity for metal ions．国家自然科学基金资助项目(41061044);广西自然科学基金重点资助项目(2010GXNSFD013016);广西自然科学基金面上项目(2012GXNSFAA053017