Ferric ion-triggered surface oxidation of galena for efficient chalcopyrite-galena separation

The efficient separation of chalcopyrite(CuFeS2)and galena(PbS)is essential for optimal resource utilization.However,find-ing a selective depressant that is environmentally friendly and cost effective remains a challenge.Through various techniques,such as mi-croflotation tests,Fourier transform infrared spectroscopy,scanning electron microscopy(SEM)observation,X-ray photoelectron spec-troscopy(XPS),and Raman spectroscopy measurements,this study explored the use of ferric ions(Fe^(3+))as a selective depressant for ga-lena.The results of flotation tests revealed the impressive selective inhibition capabilities of Fe^(3+)when used alone.Surface analysis showed that Fe^(3+)significantly reduced the adsorption of isopropyl ethyl thionocarbamate(IPETC)on the galena surface while having a minimal impact on chalcopyrite.Further analysis using SEM,XPS,and Raman spectra revealed that Fe^(3+)can oxidize lead sulfide to form compact lead sulfate nanoparticles on the galena surface,effectively depressing IPETC adsorption and increasing surface hydrophilicity.These findings provide a promising solution for the efficient and environmentally responsible separation of chalcopyrite and galena.

Mechanism of influence of ferric ion on electrogenerative leaching of sulfide minerals with FeCl_3

A dual cell system was used to study the influence of ferric ion on the electrogenerative leaching of sulfide minerals. Reaction mechanisms for the ferric chloride electrogenerative leaching of a series of sulfide minerals were proposed based on the data collected from the dual cell experiments. The influences of ferric ion on the electrogenerative leaching of sulfide minerals are similar. Ferric ion plays an important role on limiting the electrogenerative leaching rate at a relatively low concentration of FeCl3 (about less than 0.15 mol/L). The mathematical models based on the Butler-Volmer relation were delineated, and kinetic equations with respect to ferric ions for each sulfide mineral were obtained. The kinetic equations show that when the concentration of ferric ion is relatively low, the electrogenerative leaching rates are predicted to be proportional to 6/7, 4/5, 2/3 and 2/3 order of ferric ion for nickel concentrate, chalcopyrite concentrate, sphalerite and galena respectively. As the concentration of ferric ion increase, the correlative dependence between electrogenerative leaching rate and concentration of ferric ion becomes weak. The above conclusions are in agreement with the experimental results.

Ferric ion-ascorbic acid complex catalyzed calcium peroxide for organic wastewater treatment:Optimized by response surface method

Hydrogen peroxide(H_(2)O_(2))disproportionation,iron precipitation,and narrow pH range are the drawbacks of traditional Fenton process.To surmount these barriers,we proposed a ferric ion(Fe^(3+))-ascorbic acid(AA)complex catalyzed calcium peroxide(CaO_(2))Fenton-like system to remove organic dyes in water.This collaborative Fe^(3+)/AA/CaO_(2)system presented an obvious improvement in the methyl orange(MO)decolorization,and also effectively eliminated other dyes.Response surface method was employed to optimize the running parameters for this coupling process.Under the optimized arguments(2.76 mmol/L Fe^(3+),0.68 mmol/L AA,and 4 mmol/L CaO_(2)),the MO removal achieved 98.90%after 15 min at pH 6.50,which was close to the computed outcome of 99.30%.Furthermore,this Fenton-like system could perform well in a wide range of pH(3-11),and enhance the H_(2)O_(2)decomposition and Fe ions recycle.The scavenger experiment result indicated that hydroxyl radical,superoxide anion free radical,and singlet oxygen were acted on the dye elimination.Moreover,electron spin resonance analysis corroborated that the existences of these active species in the Fe^(3+)/AA/CaO_(2)system.This study could advance the development of Fenton-like technique in organic effluent disposal.

Anomalous enhancement of fluorescence of carbon dots through lanthanum doping and potential application in intracellular imaging of ferric ion

An anomalous enhancement of fluorescence of carbon dots （CDs） was observed via lanthanum （La） doping. La-doped CDs （La-CDs） were prepared through microwave pyrolysis within 4 min. With La^3＋ doping, the emission band shifted from blue to green although LaB＋ is non-fluorescent. The quantum yield and fluorescence lifetime improved by about 20% and 35%, respectively. All experiment results indicate that La^3＋ doping is an effective way to tune fluorescence and improve the performance of CDs. Another unique attribute of La-CDs is high sensitivity to Fe^3＋. The La-CD-based fluorescence probe was established and used for sensitive and selective detection of Fe^3＋ with a limit of detection of 91 nmol/L. The proposed fluorescence probe also was successfully employed to visualize intracellular Fe^3＋ in live HeLa cells through cell imaging. It was also shown that yttrium exhibited the same fluorescence enhancement effect as La. The results may provide a new route for preparing CDs with special properties.

Photochemical decomposition of 1H,1H,2H,2H-perfluorooctane sulfonate(6:2FTS)induced by ferric ions

Perfluorooctane sulfonate（PFOS） had wide applications,such as in the electroplating industry,but its use was restricted in 2009 by the Stockholm Convention,due to its environmental persistence and potential hazards.As the most common PFOS alternative,lH,lH,2H,2H-perfluorooctane sulfonic acid（6：2FTS） and its salts have been increasingly used.However,little is known about its photochemical decomposition.This paper reports the ferric ion-induced efficient decomposition and defluorination of 6：2FTS under 254 nm ultraviolet（UV） irradiation;the underlying mechanisms were also investigated.In the presence of 100 ｜imol/L ferric ion and at pH 3.0,the first-order decomposition rate constant of 6：2FTS（10 mg/L） was 1.59/hr,which was 6 times higher than for direct UV photolysis.The effects of the ferric ion concentration and the solution pH on the 6：2FTS photodecomposition were investigated and the optimal reaction conditions were determined.In addition to fluoride and sulfate ions,shorter-chain PFCAs（C2-C7） were detected as major intermediates.The addition of hydrogen peroxide or oxalic acid accelerated the decomposition of 6：2FTS under UV irradiation,but not its defluorination,indicating that hydroxyl radicals can directly react with 6：2FTS but not with the shorter-chain PFCAs.Accordingly,a mechanism for 6：2FTS photochemical decomposition in the presence of ferric ion was proposed,which comprises two reaction pathways.First,hydroxyl radicals can directly attack 6：2FTS,leading to C- C bond cleavage.Alternatively,6：2FTS coordinates with ferric ion to form Fe（III）-6：2FTS complexes,which can undergo ligand-to-metal charge transfer under UV irradiation,causing C-S bond cleavage.

Facile and large-scale synthesis of green-emitting carbon nanodots from aspartame and the applications for ferric ions sensing and cell imaging

A facile,economical and green strategy to prepare green-fluorescent nitrogen-doped carbon nanodots(NCDs)with a quantum yield(QY)of approximately 31.91%has been built up,while aspartame was employed as the carbon–nitrogen source for the first time.The prepared N-CDs exhibited ultrahigh brightness,favorable strong photostability and negligible cytotoxicity.The outstanding optical properties are mainly derived from the their robost composition and steric distribution of the doped nitrogen atoms,which have been characterized detailedly.The obtained N-CDs showed highly selective and sensitive response toward ferric ions(Fe^(3+))through a fluorescence static quenching process in a wide linear range of 0.005–60 mmol/L.The detection limit was as low as 1.43 nmol/L,allowing the analysis of Fe^(3+)in a very simple method.The excitation-dependent luminescent behavior of the obtained N-CDs guaranteed the multicolor emissive property when they were used in cell imaging.And the application for intracellular Fe^(3+)sensing further verified this novel N-CDs may open more opportunities in biosensor,bioimaging and biological assay.

离子液体热合成法制备钒酸铁及其电化学性能

以离子液体1-丁基-3-甲基咪唑酸溴盐([Bmim]Br)为反应溶剂,采用离子液体热合成法制备了钒酸铁前驱体,通过煅烧和后处理成功地合成了粒径均一、排布密集的FeVO_(4)纳米颗粒。采用SEM、XRD、XPS、TEM、N_(2)吸附-脱附对材料的结构和形貌进行了表征。以FeVO_(4)纳米颗粒为负极材料构建了锂离子电池,采用恒流充电放电测试、循环伏安法(CV)和电化学阻抗对电池进行了电化学性能评价。结果表明,Fe VO_(4)电极作为锂离子电池负极材料在高电流密度下表现出优异的循环性能和电化学性能,其在300 mA/g电流密度下的初始放电比容量为1471.58 mA·h/g,在300 mA/g下循环100次后,仍获得783.00 mA·h/g的高比容量,其优异的电化学性能可能归因于电极材料的纳米级尺寸。

铁自噬介导铁死亡机制和检测方法的研究进展

1铁死亡发生机制在多细胞生物组织稳态的正常发育和维持过程中,以及消除受损、感染或衰老的细胞过程中依赖于程序性细胞死亡(programmed cell death, PCD)信号事件的严密调控。PCD主要包括细胞凋亡、坏死性凋亡、细胞焦亡、铁死亡以及自噬等死亡方式[1]。

Study on Catalytic Wet Oxidation of H_2S into Sulfur on Fe/Cu Catalyst

A wet catalytic oxidation at room temperature was investigated with solution containing ferric, ferrous and cupric ions for H2S removal. The experiments were carried out in a two step process, and the results obtained show that the removal efficiency of H2S can always reach 100% in a 300 mm scrubbing column with four sieve plates, and the regeneration of ferric ions in 200 mm bubble column can match the consumed ferric species in absorption. Removal of H2S, production of elemental sulfur and regeneration of ferric, cupric ions can all be accomplished at the same time. No raw material is consumed except O2 in flue gas or air, the process has no secondary pollution and no problem of catalyst degradation and congestion.

盐酸中Ca^(2+)、Mg^(2+)、Fe^(3+)含量超标的原因及处理

介绍了盐酸中Ca^(2+)、Mg^(2+)、Fe^(3+)含量超标原因的快速排查及处理措施。

植酸在浓香型白酒中去除铁离子的应用研究

阐述了植酸在浓香型白酒中去除铁离子的工艺过程,对比分析了植酸处理前后的基酒质量,分析了植酸处理后的基酒在贮存过程中的坍塌效应,以及植酸在酒脚串蒸中的催化作用。

A Novel Enhancer for Fe^(2+)-Catalyzed Light Emission Reaction of Luminol and Dissolved Oxygen

用ＥＤＴＡ可增强Ｆｅ２＋催化鲁米诺与溶解氧的发光反应，将ＥＤＴＡ加入鲁米诺溶液中可使流动注射分析测亚铁的检出限降低约１６０倍。在流动注射分析的试样分流路中使用新型的锌镀铜微还原柱，可同时测定Ｆｅ２＋和Ｆｅ３＋。该微还原柱可至少测定３０００个试样。测定Ｆｅ２＋和Ｆｅ３＋的线性范围是１×１０９～１×１０５ｍｏｌ·Ｌ１，检出限分别为２．７×１０１０和３．５×１０１０ｍｏｌ·Ｌ１，测定试样的速率为６０ｈ１。Ｃｒ３＋和Ｃｏ２＋有干扰。测定混合物中的Ｆｅ２＋和Ｆｅ３＋获得满意结果，测试样的结果同标准的分光光度法结果一致。实验表明，ＥＤＴＡ起增强剂的作用，Ｆｅ２＋是催化剂，而溶解氧是氧化剂。对反应机理进行了讨论。

Hollow Bio-derived Polymer Nanospheres with Ordered Mesopores for Sodium-Ion Battery

Bio-inspired hierarchical self-assembly provides elegant and powerful bottom-up strategies for the creation of complex materials.However,the current self-assembly approaches for natural bio-compounds often result in materials with limited diversity and complexity in architecture as well as microstructure.Here,we develop a novel coordination polymerization-driven hierarchical assembly of micelle strategy,using phytic acid-based natural compounds as an example,for the spatially controlled fabrication of metal coordination bio-derived polymers.The resultant ferric phytate polymer nanospheres feature hollow architecture,ordered meso-channels of^12 nm,high surface area of 401 m2 g−1,and large pore volume of 0.53 cm3 g−1.As an advanced anode material,this bio-derivative polymer delivers a remarkable reversible capacity of 540 mAh g−1 at 50 mA g−1,good rate capability,and cycling stability for sodium-ion batteries.This study holds great potential of the design of new complex bio-materials with supramolecular chemistry.

Chemical Dosimetry during Alpha Irradiation: A Specific System for UV-Vis <i>in Situ</i>Measurement

This paper is devoted to the study of the potentiality of the Fricke dosimeter for the characterization of the highly energetic (62.1 MeV) α particles beams generated by a new cyclotron facility, namely ARRONAX started in 2009. Such for this high energetic α beam, in situ dosimetry is performed in order to avoid radiation safety inconvenience and to earn run time of irradiation. Therefore, an in situ Fricke dosimetry protocol is developed and its reliability is checked by comparison with other experiments carried out by using the traditional method (ex situ Fricke dosimetry) within another cyclotron facility (CEMHTI) and by comparison with literature data. To author’s knowledge, it is the first time that Fricke dosimetry is performed during the α irradiation experiment. The results of these in situ dosimetry experiments show that the value of ferric ions radiolytic yield (G(Fe3+) = (11.7 ± 1.2) 10–7 mol?J–1) extrapolated from literature data can be used for this higher energy of α particles (Eα = 62.1 MeV).

复合水凝胶SA/AAm-Lgs的制备及其对Fe^(3+)的静/动态吸附

将木质素磺酸钠(Lgs)引入到以海藻酸钠(SA)和丙烯酰胺(AAm)为基体的溶液中,通过自由基聚合法制备得到多孔三维的复合水凝胶(SA/AAm-Lgs),使用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FT-IR)和力学性能测试仪等对其结构和性能进行分析,并将其应用于去除废水中的Fe^(3+)。研究结果表明:实验成功制备了多孔三维网状结构的复合水凝胶SA/AAm-Lgs。当Lgs用量增加时,水凝胶的断裂伸长率和抗拉强度相应增加,溶胀性能也有一定程度提高。SA/AAm-Lgs(含Lgs 7 mg)静态吸附Fe^(3+)的较佳工艺为:水凝胶用量0.5 g、温度25℃、Fe^(3+)初始质量浓度2 g/L,该条件下水凝胶对Fe^(3+)的吸附量可以达到143 mg/g,吸附性良好且具有循环使用性能。吸附动力学和吸附等温线模拟结果表明该水凝胶对Fe^(3+)的吸附过程符合准二级动力学和Langmuir模型。此外,通过固定床工艺对Fe^(3+)进行动态吸附实验证明了SA/AAm-Lgs具有良好的工业价值。对固定床高度、Fe^(3+)进水质量浓度和流速对突破曲线的影响进行探讨,结果表明:随着固定床高度的增加,突破时间延长;随着Fe^(3+)进水质量浓度增大和流速增加,突破时间急剧缩短。BDST模型能准确预测不同流速或浓度下的突破时间,理论突破时间和实际突破时间的平均误差均小于15%。

LO-CAT硫回收工艺铁离子流失研究

为了增强煤气化硫回收系统LO-CAT溶液稳定性,提高硫化氢排放的达标率,进而加强对环境的保护,以IGCC电厂实际生产为例,进行了相应的机理分析及试验论证,对LO-CAT硫回收工艺应用中铁离子流失的原因进行了分析研究,思考了如何将该技术更加科学有效地加以应用,并提出了具体的方法和措施。

一种镉基金属有机骨架材料对丙酮和Fe^(3+)的荧光检测

以1,3,5-三(4-羧基苯基)苯(H_(3)BTB)为配体,通过溶剂热法得到一种三维四重穿插结构的镉基金属有机骨架材料:(Me_(2)NH_(2))[Cd(BTB)(DMF)]·DMF·H_(2)O(Cd-MOF)。通过单晶X射线衍射、粉末X射线衍射、红外分析、元素分析和热重分析表征了其组成和结构。荧光研究结果表明:Cd-MOF在含有丙酮或Fe^(3+)离子的溶液中均表现出荧光猝灭现象,其检测限(体积分数和浓度)分别为0.6%和0.89μmol·L^(-1),线性检测范围分别为2.0%~2.8%和0~0.05 mmol·L^(-1)。时间响应实验和可循环利用实验显示Cd-MOF可长时间、稳定且高效地检测丙酮和Fe^(3+)离子。

Fe^(3+)-EDTA催化CaO_(2)类Fenton体系降解苯酚的机制及效果

基于CaO_(2)的类Fenton体系具有缓释H2O_(2)、高效降解污染物、有效作用周期长等优点,在环境修复领域得到广泛应用.但目前研究主要针对Fe^(2+);CaO_(2)体系,关于Fe^(3+);CaO_(2)的研究较少,而如何提高Fe^(3+)活化CaO_(2)的能力,是铁离子高效循环利用、污染物持续降解的关键.本研究有针对性地建立了Fe^(3+);EDTA;CaO_(2)体系,对其降解能力、作用机制、关键因素进行了深入分析,结果表明,Fe^(3+);EDTA;CaO_(2)体系在中性条件下对苯酚的降解率在95%以上,EDTA的加入可以明显增加铁离子在中性环境中的溶解度,而且EDTA可以桥接CaO_(2)和Fe^(3+),加快二者之间的电子转移速率,促进Fe^(3+);Fe^(2+)循环,改善苯酚的降解效果;活性自由基测定的实验表明,降解苯酚起主要作用的活性自由基是羟基自由基(·OH),·O_(2)^(-)起到还原Fe^(3+)的作用,促进Fe^(3+);Fe^(2+)循环.本研究对CaO_(2)类Fenton体系的应用具有一定的理论意义.

可食用植物来源外泌样纳米颗粒体外抗氧化能力及其对过氧化氢诱导PC12细胞氧化损伤的保护作用

目的:探讨生姜、青椒、大蒜、蘑菇、柠檬、山药、葡萄、番茄、西兰花和洋葱10种可食用植物来源外泌样纳米颗粒(ELNs)的体外抗氧化能力及其对过氧化氢诱导PC12细胞氧化损伤的保护作用,为深入研究ELNs提供依据。方法:将PC12细胞分为对照组、外泌体组、过氧化氢组和过氧化氢+ELNs组。高速差速离心法分离提取10种ELNs,采用二苯基苦基苯肼(DPPH)自由基清除体系、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二按盐(ABTS)阳离子自由基体系和铁离子总还原能力(FRAP)体系检测10种ELNs的体外抗氧化能力,MTT法检测各组PC12细胞活力。结果:10种ELNs对DPPH自由基的清除能力从高到低依次为蘑菇、洋葱、生姜、柠檬、葡萄、番茄、青椒、西兰花、山药和大蒜。10种ELNs对ABTS阳离子自由基的清除能力从高到低依次为生姜、蘑菇、洋葱、柠檬、山药、葡萄、青椒、大蒜、番茄和西兰花。10种ELNs对FRAP体系的总抗氧化能力从高到低依次为生姜、青椒、洋葱、蘑菇、柠檬、西兰花、葡萄、山药、番茄和大蒜,其中抗氧化能力相对较强的5种ELNs对DPPH自由基、ABTS阳离子自由基的清除能力以及FRAP随着ELNs浓度升高而增大,半数抑制浓度(IC50)值分别为洋葱73.15、 123.02和83.00 g·L^(-1),生姜124.07、 91.24和91.24g·L^(-1),蘑菇310.44、 518.04和237.10g·L^(-1),青椒969.06、 847.32和237.10 g·L^(-1),柠檬1 718.94、 544.38和962.12 g·L^(-1);与对照组比较,600μmol·L^(-1)过氧化氢组PC12细胞活力下降约30%。与过氧化氢组比较,过氧化氢+ELNs组(青椒、柠檬、山药和西兰花)PC12细胞活力明显提高21.08%、26.2%、11.72%和15.15%。结论:生姜、蘑菇、柠檬和洋葱来源ELNs外泌体在DPPH自由基清除体系、ABTS阳离子自由基体系和FRAP体系中均表现出较强的抗氧化能力。青椒、柠檬、山药和西兰花来源ELNs对过氧化氢诱导的PC12细胞氧化损伤具有保护作用。

试钛灵-铁(Ⅲ)配合物褪色分光光度法测定安乃近片剂含量

基于安乃近可将三价铁离子还原为二价铁离子,剩余三价铁离子再与试钛灵(钛铁试剂)发生配位反应形成绿色配合物,提出试钛灵-铁(Ⅲ)配合物褪色分光光度法测定安乃近含量的新方法。在测定波长660 nm,安乃近浓度的线性范围在2.5~40.0 mg·L^(-1)。本方法成功地测定了安乃近片剂的含量,与碘量法所测结果一致。