Template synthesis and adsorption properties of chitosan salicylal Schiff bases

To improve the adsorption properties of chemically modified chitosan, the chelating resin of salicylal chitosan Schiff bases was prepared by the template cross-linking method using Cu(Ⅱ) as template ion and ethylene glycol bisglycidyl ether as cross-linking agent in microwave, and was characterized by IR. The adsorption capacity and selectivity coefficient of the chemically modified chitosan for Cu(Ⅱ), Fe(Ⅲ) and Zn(Ⅱ) were investigated, respectively. The results show that the adsorption capacity of the resin 2.73 mmol/g for Cu(Ⅱ) is bigger than that for other two metal ions, 0.22 mmol/g for Fe(Ⅲ), and 0.42 mmol/g for Zn(Ⅱ), and the selectivity coefficients are as follows: KCu(Ⅱ)/Fe(Ⅲ)=12.4, KCu(Ⅱ)/Zn(Ⅱ)=6.5.     

Synthesis and extractive properties of bisthiophosphorylimines

Novel transition metal complexes of bis（diarylsubstitutedthiophosphoryl）imines ligand derived from O,O-di（p-methoxylphenyl）thiophosphoryl chloride and O,O-di-（p-methoxylphenyl）thiophosphoryl amine with Cu（Ⅱ ）,Co（ Ⅱ） ,Ni（ Ⅱ） ,Fe（Ⅱ ） and Mn（ Ⅱ ） were synthesized. The formation mechanism of complexes and their stereochemistry structures were investigated according to elemental analysis,infrared spectra and 31P-nuclear magnetic resonance spectra. The extractions of the ligand for different divalent metal ions,such as Zn（Ⅱ ）,Cd（ Ⅱ） ,Cu（ Ⅱ） ,Ni（ Ⅱ ）,Fe（ Ⅱ） ,Sn（ Ⅱ） ,Mn（ Ⅱ） ,Pd（ Ⅱ） ,Hg（ Ⅱ） and Fe（Ⅲ）,were investigated in sulphate solution,respectively. The results show the metal atom is coordinated by 4 sulfur atoms in a square-planar fashion,and the titled compound has not only powerful ability to coordinate with cadmium from aqueous solution with a high extractive rate about 61.20% and a relatively weak complexation for other divalent metals with the extractive rate from 2.46% to 36.66%,but also a good selectivity to Fe（Ⅲ ）.     

十二烷基苯磺酸钠对磁性多壁碳纳米管吸附水中重金属离子的影响

通过水溶液中磁性多壁碳纳米管(MWCNTs)对Cd(II)、Zn(II)、Cu(II)三种重金属离子的吸附实验,探讨了十二烷基苯磺酸钠(SDBS)表面活性剂的添加量对吸附效率的促进与抑制效应,以及溶液pH值和碱金属离子强度对磁性MWCNTs吸附重金属离子的影响.实验结果表明:溶液的酸性或强碱性对磁性MWCNTs吸附重金属离子有较强的负面影响;而溶液呈中性偏碱性时(pH值在7~10)吸附效果较好,其最大值达90%以上;水中存在SDBS时,磁性MWCNTs吸附重金属离子的效果受溶液酸碱性的影响很小,但SDBS剂量较大时,吸附效果则会受影响;添加Na+、K+改变水溶液中的离子强度,吸附效果几乎不受影响.吸附动力学研究发现,准二级方程能够真实地拟合重金属离子在磁性MWCNTs上的吸附过程.     

磁性多壁碳纳米管吸附水中重金属离子的动力学与热力学

采用湿式化学法合成了磁性多壁碳纳米管(MWCNTs),用透射电镜、X-射线衍射、傅里叶变换红外光谱、比表面积分析仪对磁性MWCNTs的表面特性进行了表征.考察了溶液pH值、吸附时间等因素对水中镉(II)、铜(II)和锌(II)吸附过程的影响.结果表明:金属离子的吸附过程强烈依赖于pH值,金属离子的去除率随着溶液pH值的增大而增大,当溶液pH值达到一定值时,去除率达到最大,然后保持不变;吸附动力学分析与等温线拟合表明,准二级模型准确地反映了吸附过程的动力学,Freundlich等温线更好地说明了升高温度有利于吸附的事实.对热力学参数(ΔH0,ΔS0和ΔG0)的计算结果揭示了吸附过程具有自发且吸热的性质.     

树脂001×7填充PES膜吸附水中重金属离子的研究

以聚醚砜(PES)为膜基质材料,以粉末状强酸性苯乙烯系阳离子交换树脂001×7为功能颗粒,采用溶剂相分离法制备了膜吸附剂,并系统研究了膜吸附剂对水中重金属离子的吸附性能,考察了树脂含量、吸附时间对膜吸附剂吸附容量的影响,同时研究了膜吸附剂对水中铜离子的动态吸附及脱附效果.研究结果表明:膜吸附剂的吸附容量随着树脂填充量的增加而增大;当树脂质量分数达到65%时,膜吸附剂对重金属离子Hg2+、Pb2+和Cu2+的吸附容量分别可达255.31 mg/g、255.35 mg/g和80.76 mg/g;动态吸附试验表明,该膜吸附剂对水中铜离子有持续的吸附去除效果,膜吸附剂的脱附率可达94.67%;该膜吸附剂吸附过程符合Langmuir等温吸附方程,吸附速度较快,吸附容量较高;与传统工艺相比,膜吸附剂对水中重金属离子去除效果明显,有较好的应用价值.     

环庚酮双缩硫代对称二氨基脲Cu(Ⅰ)、Zn(Ⅱ)、Fe(Ⅱ)配合物的直接电化学合成

用电化学金属阳极氧化法在非水溶剂中合成了环庚酮双缩硫代对称二氨基脲 (HL)与Cu(Ⅰ )、Zn(Ⅱ )、Fe(Ⅱ )的配合物 ,通过元素分析、红外光谱、紫外光谱、磁化率、摩尔电导等对配合物进行了表征     

STUDY ON MAGNETIC CHELATING RESIN Ⅰ.PREPARATI0N OF PEI2 AND ITS ADSORPTION PROPERTIES TO METAL IONS

Magnetic polyethyleneimine chelating resin(PEI2) was prepared. Its average diameter was 0. 44mm and it contained magneticparticles over 11% of the microcapsules after it had been treated with 8%hot HCl. The results showed that tbe reaction media had significant effecton Physical forms,magnetic particles content and stability in acid of themicrocapsules.PEI2 bad very high adsorption capacity to Au~(3+),Pb~(2+) andHg~(2+),and little one towards Mg~(2+),Pb~(2+) and Cu~(2+).It was discoveredthat PEI2 could reduce Au~(3+) into elemental gold.     

膨润土对底泥重金属的抑制效果及机制探讨

采用底泥原地稳定化处理技术中的帽封方法,考察膨润土对苏州河底泥中Cu2＋、Pb2＋和Zn2＋3种重金属离子释放的抑制效果。结果表明：钙基膨润土对Cu2＋、Pb2＋和Zn2＋的最大吸附容量分别为273.4 mg.g-1、473.6mg.g-1和263 mg.g-1;均具有较强的吸附性能;且在溶液pH值升高时,其对Cu2＋、Pb2＋和Zn2＋的吸附效果增强。在Zn-Pb混合体系下,钙基膨润土对Pb2＋吸附效果增强,Zn2＋的吸附效果不明显;而在Zn-Cu混合体系下,钙基膨润土对Cu2＋效果增强,对Zn2＋的吸附效果减弱。     

新型螯合树脂聚苯乙烯负载葡糖胺对Pd(II)吸附性能的研究

合成了新型螯合树脂聚苯乙烯负载葡糖胺(PS-GA),并研究了所合成树脂对Pd(II)的吸附容量、吸附动力学、等温吸附等静态吸附性能及影响吸附的因素。结果表明:该树脂对Pd(II)的吸附量较高;树脂对Pd(II)的吸附为液膜扩散控制,吸附的活化能为59.76 kJ/mol;在实验浓度范围内,对Pd(II)的等温吸附符合弗伦德利希方程;较高温度有利于吸附;树脂可用2%的硫脲-0.1 mol/L HNO3清洗再生,再生后仍保持良好的吸附能力。     

纳米磁性壳聚糖对腐殖酸和重金属离子混合吸附研究

研究了纳米磁性壳聚糖吸附剂对腐殖酸的吸附性能和重复使用性能,分析了腐殖酸存在的条件下对Cu2+、Pb2+、Cd2+三种重金属离子吸附的影响及机理.实验结果表明:该吸附剂对腐殖酸吸附的最佳pH值为11,饱和吸附量为292mg/g;吸附速度快,15min可达吸附平衡;经5次吸附后,保留了初次吸附量的60%,具有一定的可再生性和重复使用性.同时,该吸附剂吸附腐殖酸后仍可对Cu2+、Pb2+、Cd2+产生吸附作用,较单独吸附时Cu2+、Pb2+的吸附量有所降低,而Cd2+的吸附量则有大幅提高.     

Synthesis and adsorption properties for Au（Ⅲ） of alkoxycarbonyl thiourea resin

A novel alkoxycarbonyl thiourea resin（ATR） was synthesized by monomer polymerization of oxydiethane-2,1-diyl dicarbonisothiocyanatidate and polyethylene polyamine, and characterized by FT-IR. The adsorption properties of ATR were investigated by batch test. The adsorption capacities for Au（Ⅲ）, Ag（Ⅰ）, Cu（Ⅱ）, Zn（Ⅱ, Fe（Ⅲ）, Ca（ Ⅱ ） and Mg（ Ⅱ ） are 4.65, 4.40, 0.40, 0.90, 0.86, 0.0080 and 0.016 mmol/g, respectively, when the adsorption condition is as follows： contact time 24 h, temperature 30 ℃, initial concentration of Au（Ⅲ） 5.08 mmol/L and that of other metals 0.10 mol/L, and concentration of acid 1.0 mol/L. The adsorption capacity for Au（Ⅲ） increases with the increase of contact time, temperature and initial concentration of Au（Ⅲ）. The capacity after five adsorption-desorption cycles remains 90% that of the first time, and the separation factors of ATR for binary metal ion solutions are larger than 995, indicating that ATR is of good regeneration property and selectivity. XPS results show that the functional atoms of ATR supply electrons for Au and coordinate with Au during the adsorption.     

Thermochemical Studies of the Toxic Action of Heavy MetalIons on Escherichia coli by Microcalorimetry

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金属改性介孔炭吸附脱硫性能研究

以介孔炭(MC)为载体,采用浸渍法制备4种不同金属改性的介孔炭Ag+/MC、Zn2+/MC、Cu2+/MC和Fe3+/MC,考察负载量、金属类别等因素对脱硫效果的影响。结果表明,介孔炭表面负载适当的Ag+、Zn2+、Cu2+、Fe3+可以提高其对二苯并噻吩(DBT)的吸附能力,对不同金属改性介孔炭最佳吸附效果进行比较,得出吸附DBT能力大小顺序是：Ag+/MC>Zn2+/MC>Cu2+/MC>Fe3+/MC。其中以Ag+负载量为10%处理介孔炭吸附效果最佳。同比未处理介孔炭的饱和硫容量增加了1.11 mg/g,透过硫容量也同比增加了1.93 mg/g。     

徐州城市表层土壤中重金属元素的富积特征与来源识别

根据对21个土壤样品中30种元素的测试结果，研究了徐州城市表层土壤中重金属元素的富积特征和来源．结果表明：与我国土壤元素背景值相比，研究区表层土壤中Zn，cd，As，Hg，Sb，Sn，Ag等的富集程度相对较高，而Fe，Se，Sc，Ba，Bi，Pb，Cu，Ni，Cr，Mn，Mo，Be，Ti，A1．Ga，Li，Co等的富集程度相对较低；样品中30种元素可被分为4个类剐，即自然因子类剐（Al，Ti，Ga，Li，V，Co，Mn，Be，Pt）、交通因子类别（Ag，Se，Sc，Pb，Cu，Zn，Cd，Br，S，Mo，Au）、燃煤因子类别（Bi，Cr，Hg，As，Sb，Pd）和混合源类别（Fe，Sn，Ba）．     

重金属Cu(Ⅱ)在球黏土中的吸附特性

通过批式吸附试验,考察球黏土对Cu(Ⅱ)的吸附效果,重点分析吸附时间、吸附剂用量、pH值以及初始质量浓度的影响。结果表明,Cu(Ⅱ)在球黏土上的吸附是一个先快速而后缓慢的过程,在60 min基本达到吸附平衡,且吸附量和吸附率随球黏土用量和Cu(Ⅱ)初始质量浓度的升高而提高。pH值对球黏土的吸附量有较大的影响,当pH值为6时,球黏土的吸附量可达97.93 mg/g。球黏土对Cu(Ⅱ)的吸附符合Langmiur等温吸附模型,拟合得到的最大吸附量为202.383 mg/g,准二阶动力学模型更适合描述球黏土对Cu(Ⅱ)的吸附过程,说明控制吸附速率的主要是化学吸附。与其他常见的黏土吸附剂材料相比,球黏土对Cu(Ⅱ)具有良好的吸附性能,可以作为天然矿物吸附剂来处理含Cu(Ⅱ)废水。     

二氧化硅纳米粒子荧光探针对Cu2+的探测

铜离子是造成环境污染的重金属之一,如何检测出超低浓度的铜离子是人们一直关心的课题。合成了一种新型的纳米粒子荧光探针,利用荧光光谱法比较了Cd2＋、Co2＋、Ni2＋、Pb2＋、Mg2＋、Zn2＋、Ca2＋、Cu2＋对该纳米粒子荧光探针的荧光淬灭效应。结果表明,该纳米粒子荧光探针对Cu2＋具有很敏感的检测作用,其检测浓度达到1.0×10-11mol/L。     

携三唑硫酮功能基螯合纤维的研制

以腈纶纤维(PAN)为起始原料,经二乙烯三胺(DETA)预交联后,以N,N-二甲基甲酰胺(DMF)作溶剂,加入少量金属钠作为催化剂,与硫代氨基脲反应,合成了一种携三唑硫酮功能基的螯合功能纤维。利用红外光谱、热稳定分析、重量分析等手段表征了该螯合纤维的结构,研究了纤维对金属离子的吸附性能。结果表明:纤维对Au3 、Pd2 等贵金属离子具有良好的吸附性,对Au3 、Pd2 的吸附量分别为437.1mg/(g干纤维)和203.7mg/(g干纤维)。     

吸附材料处理含Zn~（2＋）重金属废水的影响因素

考察了废水初始pH值、不同阳离子、阴离子、有机物、共存重金属离子、极端条件等因素对吸附Zn2＋的影响.结果表明,8 h后吸附接近饱和,废水初始pH=6时处理效果最好,Zn2＋吸附容量为3.98 mg/g,去除率为79.6%;Na＋、K＋、Mg2＋、Ca2＋均会抑制Zn2＋的吸附,影响顺序从小到大为Na＋〈K＋〈Mg2＋〈Ca2＋;Cl-、SO24-对吸附Zn2＋抑制作用很小,且Cl-的抑制作用小于SO42-;COD对吸附Zn2＋有促进作用;Pb2＋、Cu2＋共存时,对Zn2＋的吸附有抑制作用,影响顺序为Pb2＋单元体系〈Cu2＋单元体系〈Pb2＋、Cu2＋二元体系;高盐和强酸对Zn2＋的吸附有较大影响,但高温基本无影响.饱和吸附材料的后处理试验表明,在550℃马弗炉中热处理6.5 h,烧失率为75.4%,烧渣中Zn2＋含量为1.75%,与热处理前相比,富集倍数为4.1倍.本文研究成果为吸附法处理含锌重金属废水并回收废水中的重金属提供了重要依据.     

Adsorption of copper（ Ⅱ ） and chromium（Ⅵ） on diaspore

The adsorption of Cu（ Ⅱ ） and Cr（Ⅵ） on diaspore was studied with the help of X-ray diffraction analysis, BET measurement, zeta potential measurement and atomic adsorption spectrometry. The adsorption equilibrium almost reaches within 60 min. The adsorption isotherms of Cu（ Ⅱ ） and Cr（Ⅵ） could be well described by the Langmuir equation. The adsorption capacities of Cu（Ⅱ） and Cr（Ⅵ） are 1.944 and 1.292 mg/g, respectively. The adsorption percentage of Cr（Ⅱ ） increases with the increment of solution pH, but the adsorption percentage of Cr（Ⅵ） decreases. This could be explained by zeta potential theoretical and electrostatic attraction between metal ions and diaspore surface.     

Electrochemical Sensing of Heavy Metal Ions based on Monodisperse Single-crystal Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> Microspheres

Single-crystal Fe₃O₄ with monodisperse microspheres structure has been used for individual electrochemical detection of heavy metal ions. Morphology and structure of the as-prepared Fe₃O₄ microspheres were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). Meanwhile the electrochemical properties of the Fe₃O₄ microspheres modified glass carbon electrodes (GCE) were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and the enhanced electrochemical response in stripping voltammetry for individual detection of Pb(II), Hg(II), Cu(II), and Cd(II) was evaluated using square wave anodic stripping voltammetry (SWASV). With high specific surface area and excellent catalytic activity toward heavy metal ions, the as-prepared monodisperse and single-crystal Fe₃O₄ microspheres show a preferable sensing sensitivity (22.2 μA/μM) and limit of detection (0.0699 μM) toward Pb(II). Furthermore, the electrochemical sensor of Fe₃O₄ microspheres exhibits excellent stability and it also offers potential practical applicability for the determination of heavy metal ions in real water samples. This study provides a potential simple and low cost iron oxide for the construction of sensitive electrochemical sensors applied to monitor and control the pollution of toxic metal ions.