Biosorptive Flotation in Metal Ions Recovery

Abstract

Heavy metals can be removed from dilute aqueous solutions in many ways. Among the innovative ones may be classified a process consisting of biosorption followed by flotation. A metal cation, cadmium, was examined; the metal was abstracted by microorganisms belonging to the Actinomycetes, i.e., Streptomyces clavuligerus and Streptomyces griseus, which have a filamentous morphology, and hence present a flocculent character. Dissolved-air flotation was the technique applied on a laboratory scale without the addition of any flotation surfactant. The parameters investigated in the batch mode were contact time, recycle ratio, solution pH, Cd concentration, biomass addition, and use of a frother (ethanol). Promising results were obtained; in certain cases an almost quantitative cadmium abstraction, followed by higher than 90% biomass recovery, was found.     

铜离子和镍离子对绿泥石的抑制作用及机理

通过浮选实验、动电位测量、ICP离子浓度测试及溶液化学计算,研究铜离子和镍离子对绿泥石浮选的影响,并考察其作用机理.结果表明,绿泥石具有一定的天然可浮性,一定pH值条件下铜离子和镍离子能够水解生成亲水的氢氧化物沉淀,通过静电作用吸附在绿泥石表面,抑制绿泥石的浮选;在较高pH条件下,生成的氢氧化物沉淀与绿泥石表面电性相同,吸附量较少,抑制效果较弱.     

杯芳烃衍生物与碱金属离子、碱土金属离子配合的研究进展

杯芳烃衍生物作为"第三代超分子",对金属离子有着优异的结合力和选择性,已广泛用于金属离子的萃取、离子色谱、催化、跨膜运输、离子通道以及自组装分子层等领域。综述了近年来杯芳烃及其衍生物与金属离子,主要是碱金属、碱土金属阳离子配合的最新进展。     

The Effect of the Nature of Inorganic Ions on Hydrocarbon Flotation

Abstract

The liquid hydrocarbons hexadecane and pseudocumene (1,2,4-trimethyl-benzene) were removed from their O/W-type emulsions by flotation. The effect of different inorganic salts (NaCl, Na₂SO₄, Na₃PO₄) on the removal efficiency was investigated. It was shown that the inorganic salt effect on flotation efficiency is connected with their influence on the double-layer thickness and on the adsorption of surface-active ions.     

磷化液中金属离子的分析

0 引言 磷化作为金属涂装前处理工艺,已经得到广泛的应用.磷化工艺以前主要以锌系、钙系、锰系或锌-钙、锌-锰系二元磷化体系为主.随着涂装对表面处理质量要求的提高,三元磷化开始在阴极电泳中广泛应用.它能显著提高涂层的附着力,改善磷化膜质量,增强涂层的耐蚀性能.     

金属离子对厌氧消化的影响

金属离子对微生物的生长具有重要作用,是生物厌氧消化反应器稳定运行的重要影响因素。从轻金属离子和重金属离子两个方面对厌氧消化的影响进行了总结。     

Biosorption of Metal Ions from Aqueous Solutions

Abstract

Copper biosorption from aqueous solutions by calcium alginate is reported in this paper. The experimental section includes potentiometric titrations of biosorbents, batch equilibrium and kinetic studies of copper biosorption, as well as fixed-bed biosorption experiments. The potentiometric titration results show that the surface charge increases with decreasing pH. The biosorption of copper strongly depends on solution pH; the metal ion binding increases from 0 to 90 percent in pH ranging from 1.5 to 5.0. In addition, a decrease in ionic strength results in an increase of copper ion removal. Kinetic studies indicate that mass transfer plays an important role in the biosorption rate. Furthermore, a fixed-bed biosorption experiment shows that calcium alginate has a significant capacity for copper ion removal. The two-pK Basic Stern model successfully represents the surface charge and equilibrium biosorption experimental data. The calculation results demonstrate that the copper removal may result from the binding of free copper and its hydroxide with surface functional groups of the biosorbents.     

ICP-MS测定液晶中金属离子及溴离子和碘离子含量

建立了用电感耦合等离子体质谱法(ICP-MS)测定液晶中14种金属离子及溴离子和碘离子含量的方法.采用NMP作为溶剂,直接进样法建立校准曲线进行测定,结果表明:回收率为87％～117％,RSD在1.2％～3.7％,检测限为0.00049～0.02907 ng·mL-1.     

Recovery of Co2+ Ions from Aqueous Solutions by Froth Flotation

ABSTRACT

The recovery of Co(II) ions from aqueous solutions under acidic conditions (pH 5) was investigated in flotation columns with inside diameters of 4.0 and 8.0 cm. Three surfactants, dodecylamine, cetyl pyridinium chloride, and sodium dodecyl sulfate, were used as collectors. Sodium dodecyl sulfate was found to be the most efficient; all three, however, produced hydrated froths, leading to rather low recoveries and separation efficiencies. The volumetric gas flow rate was found to affect the process in relation to the amount of surfactant added and the column diameter. The scale-up of the column should be done in terms of the same superficial gas velocity in order to maintain similar levels of metal ion recovery.     

粉煤灰用于土壤聚合物固化重金属离子的研究

为了使土壤聚合物固化重金属离子比较理想效果,同时减少成本,本实验在土壤聚合物中掺加30%的粉煤灰固化重金属离子,结果表明:掺加 30% 粉煤灰的土壤聚合物对不同重金属离子有各自的理想固化量;综合抗压强度和浸出毒性两个方面,Cu2+、Zn2+ 和 Pb2+ 的理想固化量分别为2.O%、1.3%和1.4%;固化体具有良好的后期稳定性和抗酸性,可以满足我国酸雨比较严重的南方地区建材应用要求.总之,掺加 30% 粉煤灰的土壤聚合物固化重金属离子具有良好的经济效益和环境效益.     

离子液体萃取金属离子的研究进展

室温离子液体具有低蒸汽压、低熔点、宽电化学窗口、良好离子导电性、导热性及高热稳定性等特点,故近年来在各种金属离子液／液萃取领域的应用日益受到关注。本文系统的评述了离子液体萃取金属离子特点,并展望了该分离方法在环境分析化学领域的应用前景。     

羧甲基壳聚糖对金属离子吸附的研究进展

羧甲基壳聚糖及其改性产品的吸附性能主要体现在对各种金属离子的的吸附上.为了有选择性地吸附某些金属离子,人们通过修饰、交联、接技等方法对羧甲基壳聚糖进行了各种改性研究.文章综述了1992年以来羧甲基壳聚糖及其衍生物在金属离子吸附方面的研究进展.展望了吸附剂存重金属离子废水处理过程中的巨大优势和良好的发展前景.     

重金属离子吸附材料的研究进展

综述了以无机吸附材料（碳质类、矿物类和金属氧化类）、高分子吸附材料（人工合成高分子材料和天然高分子材料）和复合型吸附材料（有机/有机型、有机/无机型和无机/无机型）为代表的重金属离子吸附材料的结构特征和吸附性能。重点介绍了离子选择性吸附材料（螯合型吸附材料和离子印迹型吸附材料）和可降解生物质基离子吸附材料（纤维素、壳聚糖、木质素和农林废弃物）等新型重金属离子吸附材料的研究进展,同时展望了重金属离子吸附材料的发展方向。     

玉米芯重金属离子吸附材料的研究进展

水体中的重金属是环境的危险污染物之一,寻找经济、高效的废水中微量重金属离子的去除方法是水处理研究的热点问题。低成本玉米芯吸附剂具有操作简单、去除重金属离子效果好的特点,对当前低成玉米芯吸附材料在含重金属废水处理中的吸附机理进行了概括,对于玉米芯吸附剂的改性研究以及处理含重金属废水的影响因素进行了探讨,并指出了目前研究中存在的问题以及发展趋势。     

胞外聚合物对重金属离子的吸附

胞外聚合物(Extacellular Polymeric Substances,EPS)是微生物分泌于细胞外的多种有机物的总称,它是环境工程中微生物聚集体的主要成分,其主要由蛋白质、多糖、腐殖质、脂肪、核酸以及无机物质组成,对重金属具有良好的吸附效果。文章综述了EPS对重金属离子的吸附机理、影响吸附的因素,探讨了烟曲霉EPS对Pb2+的吸附特性,研究讨论了活性污泥胞外聚合物对多种混合金属离子的吸附,最后比较了不同EPS对Cu2+的吸附特性。     

不同重金属离子对硅酸盐水泥熟料烧成的影响

1引言高胶凝性硅酸盐水泥熟料是制备高性能水泥的关键组分。它除发挥强度之外,还对水泥混合材活性的激发起重要作用,C3S是最主要的胶凝相,C3S含量和活性     

Absorption Spectra of First-Row Transition Metal Ions in Glasses

Certain optical transitions were calculated for the first-row transition metal ions Ti³⁺, V³⁺, Cr³⁺, Fe²⁺ Co²⁺, and Ni²⁺ in a silicate matrix. The calculations were performed at 7 inter-ionic distances for each ion because the metal-ion-to-oxygen interionic distances are unknown; the silicate oxygen charge was varied from 1.00 to 2.00 in each case because the true charge on silicate oxygens is also unknown. Integrals used in the calculations were calculated using Slater and self-consistent field wave functions, and computer programs were used to evaluate all integrals. Equations were derived for calculating all optical transitions for these ions in octahedral fields; the extension to fields of other symmetry is trivial. Several optical transitions were computed to obtain the calculated orders of magnitude for the optical transition. The results for self-consistent field wave functions are lower than expected; they indicate that the transition metal ion in glasses is situated in fields near the size of aquo complexes.     

Reverse Osmosis Separation of Metal Ions in Acid Mine-Water

Abstract

Cellulose acetate membranes obtained from Osmonics Inc. were characterized in terms of pure water permeability constant, solute transport parameter, and mass transfer coefficient with the reference system of aqueous sodium chloride solution. Reverse osmosis separation behavior of Ca, Mg, Zn, Mn, Cu, Al, and Fe as nitrate, chloride, and sulfate salts was studied. The effect of the addition of sodium sulfate to Mg(ClO₄)₂ and Mn(NO₃)₂ solutions on solute separation was also investigated. Acid mine-water obtained from New Brunswick was subjected to reverse osmosis, and separation of metal ions in the range of 95 to 99 % was obtained along with the recovery of product water of suitable quality for use in recycle operations.     

镉离子表面印迹微球吸附性能研究

以三羟甲基丙烷三甲基丙烯酸酯(TRIM)作为交联剂,镉离子作为印迹分子,1,12-十二烷二醇-O,O'-二苯基磷酸(DDDPA)为功能单体,采用油包水,水包油(W/O/W)多重乳液聚合制备得到镉离子印迹微球。扫描电镜显示大约85%~95%Cd(III)的分子印迹微球颗粒的直径分布在20~40μm,平均直径约35μm。印迹微球膨胀率为25%,这说明了TRIM和DDDPA的组合导致识别位点规则的排布在聚合物表面。为了评价表面印迹技术的有效性,考察了这种镉离子印迹聚合物对镉离子和铜离子吸附性能。此外,将金属离子印迹微球应用于柱操作,通过填充有镉离子表面印迹微球的色谱柱进行金属离子分离和回收。与具有相似的磷酸基团商业螯合树脂相比,镉(II)印迹聚合物对镉离子显示出高选择性。     

基于纳米探针的压电重金属离子检测

文章通过在QCM（Quartz Crystal Microbalance,石英晶体微天平）表面形成纳米复合物引起质量变化来检测溶液中的痕量重金属离子。先让金属离子在羧基修饰的QCM表面进行络合吸附,然后加入羧基修饰的金纳米粒子,使之与QCM表面吸附的重金属离子结合,在QCM表面形成一层三明治结构的纳米复合物,引起QCM谐振频率明显下降。该方法大大提高了QCM检测重金属离子的灵敏度,且具有重现性好、传感器易再生等特点。