基于Fe(Ⅲ)和邻苯二胺显色反应快速检测硫化物

比较了不同金属离子(Fe²⁺、Fe³⁺、Cu²⁺、Zn²⁺、Al³⁺、Na⁺、Ca²⁺、Mg²⁺、K⁺、Ag⁺、Cr³⁺)对邻苯二胺(OPD)的氧化能力，基于Fe³⁺能直接氧化OPD产生黄色发荧光的产物而构建了Fe³⁺-OPD显色体系。结合硫化物的还原性以及对金属离子较强的亲和性，开发了一种通过比色法选择性检测硫化物的方法。结果表明，在pH 4.0Na Ac-HAc缓冲液中，Fe³⁺-OPD显色体系的吸光度和荧光强度与NaHS的浓度分别在10～200μmol/L和5～150μmol/L范围内呈线性关系，荧光法的检出限可达0.1μmol/L，体系内其他还原性物质及硫醇对Na HS的检测无干扰。将Fe³⁺-OPD显色体系结合纸芯片构建的纸基比色体系蓝色分析色道值(B...     

Mg2+,Al3+和Fe3+对氟磷灰石表面性质的影响(英文)

矿物表面性质是影响其分散聚集和浮选行为的主要因素，通过溶液化学分析计算、浊度、接触角及Zeta-电位测试分析，研究了矿浆中，Mg²⁺,Al³⁺,Fe³⁺等金属离子对氟磷灰石(FAP)表面性质的影响。结果表明：金属离子在溶液中的存在形式随pH值的变化而改变，FAP是亲水性矿物，添加Fe³⁺对FAP的润湿性影响受pH的影响较大，在酸性环境中，Fe³⁺对FAP的亲水起促进作用，在中性及碱性环境下，Fe³⁺能较好地抑制FAP的亲水。Mg²⁺和Al³⁺受pH的影响较小，在中性环境下Mg²⁺,Al³⁺离子均抑制FAP的润湿性。在pH=3～11范围内，Mg²⁺主要以+2价的离子存在，压缩FAP表面双电层；Al³⁺和Fe³⁺主要是通过水解的作用生成氢氧化物沉淀覆盖在FAP表面，并且Mg²⁺,Al     

氯盐体系下阳离子对脱硫石膏晶须水热结晶的影响及其机理

为探索阳离子对水热制备脱硫石膏晶须结晶调控的影响,本文以预处理后的脱硫石膏为原料,NaCl、Cu Cl₂、Al Cl₃为添加剂采用水热法制备脱硫石膏晶须,重点研究Cl^-存在条件下阳离子对脱硫石膏晶须结晶的影响及其作用机理。结果表明,Na⁺、Cu²⁺、Al³⁺对脱硫石膏晶须的显微结构、长径比和品质均有一定的影响,其中Cu²⁺影响最为显著。Cu²⁺可在晶须的(200)、(400)和(020)晶面发生化学吸附形成Cu SO₄膜层,使其径向生长受阻;同时,少量Cu²⁺可取代Ca²⁺,促进Ca²⁺的去溶剂化,使晶须长径比增大至200。Na⁺和Al³⁺均通过物理吸附作用于脱硫石膏晶须(200)、(400)和(020)晶面而阻碍其径向生长。此外,Al³⁺与溶液中的OH     

油田聚合物溶液黏度的影响因素研究

为降低离子对聚合物溶液黏度的影响，研究了K⁺、Na⁺、Ca²⁺、Mg²⁺、Fe²⁺、Fe³⁺、S^2-离子溶液对聚合物黏度的影响规律。研究表明，二价阳离子的影响比一价阳离子的影响大，阳离子中Fe²⁺的影响最大，阴离子中S^2-的影响最大。随着阳离子K⁺、Na⁺、Ca²⁺、Mg²⁺浓度增加聚合物溶液黏度降低，当K⁺、Na⁺、Ca²⁺、Mg²⁺离子质量浓度分别为40,1 000,60,50 mg/L时对母液黏度稳定性影响最大，此时1 500 mg/L聚合物溶液黏度降到110 mP·s。因此，对于油田选用配聚用水时，需要严格控制Fe²⁺和S^2-的出现并保证K⁺、N...     

苯并噻唑基修饰的开链Cu2+比色探针的合成及性能

以N-苯基二乙醇胺和2-巯基苯并噻唑为原料通过亲核取代反应合成了一种新型的苯并噻唑基修饰的开链冠醚类化合物1,并用核磁共振氢谱, 核磁共振碳谱及元素分析方法对合成产物进行了表征。利用紫外光谱仪考察了化合物1与多种金属离子（Mn²⁺、Co²⁺、Cu²⁺、Zn²⁺、Ni²⁺ 、Fe³⁺、 Hg²⁺、Cr³⁺、Al³⁺）在乙腈溶液中的光谱变化,并探究了化合物1处理过的滤纸条在水溶液中对金属离子的识别效果,通过核磁共振氢谱讨论了化合物1与金属离子形成配合物的作用机理。实验发现,化合物1的乙腈溶液中添加Cu²⁺后溶液颜色变为棕色,明显区别于添加其他离子;在水溶液中,特制的滤纸条遇到Cu²⁺会呈现黄色,而遇其他离子均无颜色变化。结果表明,化合物1仅对Cu²⁺具有选择性,且能通过裸眼进行识别,是一种高效、简便的Cu²⁺探针。     

氢氧根对半水硫酸钙晶体形貌的影响机理

以二水硫酸钙为原料在氢氧化钠-水体系中水热合成不同形貌的半水硫酸钙晶体,并通过XRD、XPS和电导率等手段对水热产物进行表征,研究了OH^-对水热产物晶体形貌的影响机理。结果表明,在碱性条件下可获得不同形貌的半水硫酸钙晶体,随着OH^-浓度的增大,纤维状形貌水热产物的含量减小而短柱状形貌的含量增多,且当OH^-浓度为1.0×10^-2 mol/L时水热产物以短柱状形貌为主。OH^-影响半水硫酸钙晶体形貌的原因：OH^-会消耗溶液中的Ca²⁺,从而促进二水硫酸钙的溶解,而Ca²⁺浓度的减少不利于半水硫酸钙晶体的成核生长;同时,OH^-对二水硫酸钙的促溶作用会增加溶液中SO₄^2-的浓度,从而促进半水硫酸钙晶体沿（110）和（200）晶面的生长;此外,OH^-在（002）晶面选择性吸附并与该晶面的Ca²⁺反应生成Ca（OH）⁺和Ca（OH）₂,从而阻碍半水硫酸钙晶体沿该晶面的生长。在以上3种作用下半水硫酸钙晶体形貌由纤维状向短柱状转变。本研究可为碱性条件下生产不同形貌半水硫酸钙晶体提供一定的理论依据。     

Cu2+和Co2+促进芬顿氧化处理垃圾渗滤液的研究

通过在传统芬顿体系中加入Cu²⁺、Co²⁺,研究Cu²⁺/Co²⁺/Fe²⁺/H₂O₂、Cu²⁺/Fe²⁺/H₂O₂、Co²⁺/Fe²⁺/H₂O₂和Fe²⁺/H₂O₂四种芬顿体系对垃圾渗滤液的处理效果,发现当初始pH分别为2、3、4、5、6时,各体系去除CODCr的效果排序为Cu²⁺/Co²⁺/Fe²⁺/H₂O₂>Cu²⁺/Fe²⁺/H₂O₂>Co²⁺/Fe^2...     

席夫碱荧光探针的合成及其对三价金属的识别

Al³⁺、Cr³⁺、Fe³⁺、Ce³⁺对环境和生物体有重要影响，能同时检测这4种三价金属离子的荧光探针较为少见。以2-氨基蒽和对苯基苯甲醛制备了一种席夫碱类荧光探针Ⅰ,通过¹HNMR、HRMS和元素分析对其结构进行了表征。光谱分析实验结果表明，探针Ⅰ在四氢呋喃/水(V(THF)∶V(水)=1∶1)溶液中对三价金属Al³⁺、Cr³⁺、Fe³⁺和Ce³⁺具有较强荧光响应，有较高选择性和快速响应，且不受其他金属离子或阴离子影响，抗干扰能力强，检测的最适pH范围为5～9。结合高分辨质谱检测、紫外测试和理论计算，证实探针与三价金属的作用机理为：探针与三价金属作用后，分解生成2-氨基蒽，发出荧光。进一步将荧光探针负载于试纸条，成功实现对三价金属的试纸检测。     

巯基改性SiO2吸附剂对高氨氮废水中金属离子的去除研究

针对高盐氨氮废水处理过程中,高碱会形成金属铵络合及氨气大量逃逸,造成氨氮去除率低、车间环境恶化等不足。本工作基于金属螯合机理,合成了巯基改性的 SiO₂。考察了改性吸附剂添加对各种金属阳离子(Fe³⁺、Al³⁺、Ca²⁺、Pb²⁺、Mg²⁺)的去除效率。结果表明,当采用混合碱剂+改性吸附剂时,在弱碱(pH=8)时即可实现多种金属离子的去除,去除率达98%以上(除Mg外),实现了高盐高浓度氨氮废水清洁处理。     

红土镍矿硫酸浸出液中和除铁过程Ni2+和Mg2+损失机理及强化分离研究

中和沉淀工艺常用于去除红土镍矿酸浸液中的铁、铝、铬等杂质，这一过程中常伴随镍、镁等金属离子的损失。本工作研究了红土镍矿硫酸浸出液中和除铁过程中Ni²⁺和Mg²⁺的损失，提出了有价金属离子的损失机制。研究表明，固定模拟浸出液Ni²⁺和Mg²⁺浓度条件，随模拟浸出液中Fe³⁺浓度增大，中和沉淀过程中Ni²⁺和Mg²⁺的损失率分别在9.13%～23.23%和9.79%～15.68%左右；固定模拟浸出液Fe³⁺浓度条件，随着模拟浸出液中Ni²⁺和Mg²⁺浓度的提高，二者的损失率逐渐降低。根据溶液化学计算与实验证实，中和沉淀过程中SO₄^2-与Fe(OH)₃胶体形成一元和二元配合物，其中一元配合物中SO₄^2-的孤对电子与Ni²⁺或Mg²⁺     

Ultrafiltration recovery of alginate: Membrane fouling mitigation by multivalent metal ions and properties of recycled materials

Recovery of alginate extracted from aerobic granular sludge (AGS) has given rise to a novel research direction. However, these extracted alginate solutions have a water content of nearly 100%. Alternately, ultrafiltration (UF) is generally used for concentration of polymers. Furthermore, the introduction of multivalent metal ions into alginate may provide a promising method for the development of novel nanomaterials. In this study, membrane fouling mitigation by multivalent metal ions, both individually and in combination, and properties of recycled materials were investigated for UF recovery of sodium alginate (SA). The filtration resistance showed a significantly negative correlation with the concentration of metal ions, arranged in the order of Mg²⁺ < Ca²⁺ < Fe³⁺ < Al³⁺ (filtration resistance mitigation), and the moisture content of recycled filter cake showed a marked decrease. For Ca²⁺, Mg²⁺, Fe³⁺, and Ca²⁺+Fe³⁺, the filtration resistances were almost the same when the total charge concentration was less than 5 mmol·L^-1. However, when the total charge concentration was greater than 5 mmol·L^-1, membrane fouling mitigation increased significantly in the presence of Ca²⁺ or Fe³⁺ and remained constant for Mg²⁺ with the increase of total charge concentration. The filtration resistance mitigation was arranged in the order of Fe³⁺ > Fe³⁺ + Ca²⁺ > Ca²⁺ > Mg²⁺. Three mechanisms were proposed in the presence of Fe³⁺, such as the decrease of SA concentration, change in pH, and production of hydroxide iron colloids from hydrolysis. The properties of recycled materials (filter cake) were investigated via optical microscope observation, dynamic light scattering, Fourier transform infrared, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy. The results provide further insight into UF recoveries of alginate extracted from AGS.     

酸性废水体系中硫酸钙反应结晶过程研究(英文)

The present work focused on the recycle of the sulfate and the metal ions from acidic wastewater dis charged by nonferrous metallurgical industry. The effects of the temperature, the reactant concentration, the stirring speed and the metal ions on the reactive crystallization process of calcium sulfate between sulfuric acid and lime were systematically investigated. The morphology of the precipitated crystals evolved from plateletlike and nee dlelike shape to rodlike shape when the temperature was increased from 25 to 70 ℃. An increase in the agglom.     

镁铝离子共存硅酸体系的聚合行为

通过对镁铝离子共存硅酸体系中硅酸胶凝时间、单硅酸聚合反应速率以及凝胶热性能的研究,得出：在pH<;4的微酸性条件下,硅酸体系的胶凝时间随镁铝离子共存浓度的增大而减小,且铝离子在对硅酸体系的促凝过程中起主要作用。镁铝离子共存硅酸体系的单硅酸反应速率常数比不含金属离子硅酸体系的有所增大,计算得出MA_0.1+0.1硅酸体系的单硅酸平均速率常数为：k₀=7.28×10^-4,k₁=5.62×10^-4。镁铝离子共存硅酸体系凝胶的晶化转变温度与晶型转变温度,相较于不含金属离子硅酸体系的均有所降低,根据热重曲线计算出MA_0.1+0.1硅酸体系水合二氧化硅的化学式为：SiO₂·0.556 H₂O。     

Selective removal of iron(III) from highly salted chloride acidic solutions by solvent extraction using di(2-ethylhexyl) phosphate

Metal ions including Fe³⁺, Ca²⁺, Mg²⁺, Ni²⁺, Co²⁺ and Cu²⁺ are commonly found in the leaching solution of laterite-nickel ores, and the pre-removal of Fe³⁺ is extremely important for the recovery of nickel and cobalt. Di(2-ethylhexyl)phosphate acid (D2EHPA) showed high extraction rate and selectivity of Fe³⁺ over other metal ions. The acidity of the aqueous solution is crucial to the extraction of Fe³⁺, and the stoichiometry ratio between Fe³⁺ and the extractant is 0.86:1.54. The enthalpy for the extraction of Fe³⁺ using D2EHPA was 19.50 kJ/mol. The extraction of Fe³⁺ was ≥99% under the optimized conditions after a three-stage solvent extraction process. The iron stripping effects of different reagents showed an order of H₂C₂O₄>NH₄HCO₃>HCl>NaCl>NaHCO₃>Na₂SO₃. The stripping of Fe was ≥99% under the optimized conditions using H₂C₂O₄ as a stripping reagent.     

Investigation of solution chemistry to enable efficient lithium recovery from low-concentration lithium-containing wastewater

In the production of lithium-ion batteries (LIBs) and recycling of spent LIBs, a large amount of low-concentration lithium-containing wastewater (LCW) is generated. The recovery of Li from this medium has attracted significant global attention from both the environmental and economic perspectives. To achieve effective Li recycling, the features of impurity removal and the interactions among different ions must be understood. However, it is generally difficult to ensure highly efficient removal of impurity ions while retaining Li in the solution for further recovery. In this study, the removal of typical impurity ions from LCW and the interactions between these species were systematically investigated from the thermodynamic and kinetics aspects. It was found that the main impurities (e.g., Fe³⁺, Al³⁺, Ca²⁺, and Mg²⁺) could be efficiently removed with high Li recovery by controlling the ionic strength of the solution. The mechanisms of Fe³⁺, Al³⁺, Ca²⁺, and Mg²⁺ removal were investigated to identify the controlling steps and reaction kinetics. It was found that the precipitates are formed by a zero-order reaction, and the activation energies tend to be low with a sequence of fast chemical reactions that reach equilibrium very quickly. Moreover, this study focused on Li loss during removal of the impurities, and the corresponding removal rates of Fe³⁺, Al³⁺, Ca²⁺, and Mg²⁺ were found to be 99.8%, 99.5%, 99%, and 99.7%, respectively. Consequently, high-purity Li₃PO₄ was obtained via one-step precipitation. Thus, this research demonstrates a potential route for the effective recovery of Li from low-concentration LCW and for the appropriate treatment of acidic LCW.     

不同金属盐破乳对丁基橡胶硫化行为的影响

为考察金属盐凝固剂对丁基橡胶(isobutylene isoprene rubber,IIR)硫化行为的影响,采用流变仪研究了搅拌破乳及11种金属盐破乳后IIR的硫化历程,并分析了其硫化动力学。研究发现金属盐的阳离子及阴离子种类对硫化过程均有显著影响。与传统Ca²⁺凝固剂相比,过渡金属离子Cu²⁺、Zn²⁺破乳会延长焦烧期及正硫化时间,降低硫化表观活化能,硫化膜储能模量较高。与搅拌破乳相比,主族金属离子Ca²、Mg²⁺、Al³⁺破乳对硫化过程影响较小。阴离子Cl^-及NO₃^-有显著的硫化抑制作用,降低硫化表观速率常数,延长正硫化时间;阴离子SO₄^2-和OAc^-对IIR的硫化历程影响较小,相应的IIR硫化胶具有更高的模量。     

反应型荧光探针在检测金属离子中的研究进展

金属离子广泛存在于自然界中,与环境科学、生命科学、医学等领域有着密切的联系。一些金属离子如Hg²⁺、Fe³⁺、Cu²⁺、Zn²⁺、Al³⁺等,在生物体的生理和病理中扮演着重要角色,摄入过量或不足都会导致生理功能的紊乱,引发各种疾病。近几年来,反应型荧光探针因其高选择性和高灵敏性的特点得到了快速的发展。本文主要综述了近五年来反应型荧光探针在检测金属离子中的研究进展,主要介绍了各类探针分子的设计合成、传感机理、检测结果以及其在生物检测中的应用。指出反应型荧光探针的研究发展还处在初级阶段,该领域将会朝着灵敏度更高、反应时间更少、应用范围更广的方向发展,此外,反应型荧光探针在生物检测以及实际应用方面也有望得到进一步的应用发展。     

锂辉石浸出液提锂除杂规律研究

碳酸锂是一种基础锂盐, 不仅广泛应用于传统化工行业, 也是生产锂电池的重要原料, 近年来锂电产业蓬勃发展, 极大推动了原料碳酸锂的提取与制备研究。为了提取锂辉石中的锂来制备碳酸锂, 利用沉淀溶解-平衡理论分析锂浸出液的除杂规律。对锂辉石进行转型焙烧、酸化焙烧、浸取, 锂辉石中98%左右的锂可进入液相, 得到锂浸出液, 然后根据溶解平衡理论确定3步除杂净化条件：1）中和pH至6.5除大部分Al ³⁺和Fe ³⁺;2）加入氧化剂将Fe ²⁺氧化成Fe ³⁺, 调 pH 至8.0除Fe ³⁺;3）调pH至10.0, 加入理论量碳酸钠（以液相Ca ²⁺计）, 最终Al ³⁺、Fe ³⁺、Mg ²⁺ 等浓度低于10 ^-6 mol/L, Ca ²⁺质量分数约为2×10 ^-5。     

Local density functional study on adsorption of Cu and Fe on a Si (100) surface

Using a local density functional calculation, we investigate the adsorption energies, geometries and electronic structures of single Cu²⁺ and Fe²⁺ ions on a Si(100) surface. The adsorption energy results reveal that both ions are stably adsorbed in a hollow site; from this site, Cu²⁺ is located at 0.51 Å and Fe²⁺ is located at 0.41 Å from the surface, respectively. The adsorption energy of Cu²⁺ is about 1.5 times larger than that of Fe²⁺. This means that Cu²⁺ is strongly adsorbed on the silicon surface. From the analysis of spin density, we find that Cu²⁺strongly attracts the electrons of the silicon surface, because spin density is delocalized in the silicon backbone. As a result, the 3d orbital of Cu²⁺ becomes more similar to the closed-shell state compared to that of Fe ²⁺. This means that the core electronic state of Cu²⁺ is closer to the neutral atom, which is qualitatively confirmed by XPS measurements.