Effect of high-energy Ne ions irradiation on mechanical properties difference between Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5)metallic glass and crystalline W

In this paper,high-energy Ne ions were used to irradiate Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) metallic glass(MG)and crystalline W to investigate their difference in mechanical response after irradiation.The results showed that with the irradiation dose increased,the tensile micro-strain increased,nano-hardness increased from 7.11 GPa to 7.90 GPa and 8.62 GPa,Young’s modulus increased,and H3/E2 increased which indicating that the plastic deformability decreased in crystalline W.Under the same irradiation conditions,the Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG still maintained the amorphous structure and became more disordered despite the longer range and stronger displacement damage of Ne ions in Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG than in crystalline W.Unlike the irradiation hardening and embrittlement behavior of crystalline W,Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG showed the gradual decrease in hardness from 6.02 GPa to 5.89 GPa and 5.50 GPa,the decrease in modulus and the increase in plastic deformability with the increasing dose.Possibly,the irradiation softening and toughening phenomenon of Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG could provide new ideas for the design of nuclear materials.

Sorption Characteristics for Multiple Adsorption of Heavy Metal Ions Using Activated Carbon from Nigerian Bamboo

Sorption characteristics of multiple adsorption of six heavy metal ions often found in refinery waste waters using activated carbon from Nigerian bamboo was investigated. The bamboo was cut, washed and dried. It was carbonized between 350℃ - 500℃, and activated at 800℃ using nitric acid. Simultaneous batch adsorption of different heavy metal ions (Cd2+, Ni2+, Pb2+, Cr3+, Cu2+ and Zn2+) in same aqueous solution using activated carbon from Nigerian bamboo was carried out. The adsorption process had a better fit for the Freundlich, Temkin isotherm and Dubinin-Radushke-vich (DRK) isotherm models but could not fit well into Langmuir isotherm. Adsorption isotherms showed that there is competition among various metals for adsorption sites on Nigerian bamboo. The DRK model was used to determine the nature of the sorption process and was found to be physical and chemical, with sorption energy of metal ions ranging from (7 - 10 kJ/mol). The adsorption of Cd2+, Zn2+, Pb2+ and Ni2+ ions was chemisorptions and that of Cu2+ and Cr3+ ions was cooperative adsorption. Therefore, this study revealed that Nigerian bamboo can serve as a good source of activated carbon with multiple and simultaneous metalions—removing potentials and may serve as a better replacement for commercial activated carbons in applications that warrant their use.

Comparative adsorption of heavy metal ions in wastewater on monolayer molybdenum disulfide

To maximize the potential of monolayer molybdenum disulfide(MoS2)sheet in the disposal of heavy metal ions in wastewater,we compared the adsorption of several common heavy metal ions(including Cr^(3+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),and Pb^(2+))in wastewater on the monolayer MoS2 sheet through first-principles calculation.Our simulation results show that the monolayer MoS2 sheet is a potential heavy metal adsorption material because of the attractive interaction between them.The most negative adsorption energy determines that the TMo site is the most stable adsorption site for the heavy metal ions.The attractive interaction is considered as chemical adsorption,and it is closely related to charge transfer.The orbital hybridization between S p and heavy metal ions p and d states electrons contributes to the adsorption,except the orbital hybridization between S p and Pb p states electrons contributes to the Pb^(2+) adsorption.All the results show that the monolayer MoS2 sheet is most suitable for removing Ni^(2+) and Cr^(3+) ions from wastewater,followed by Cu^(2+) and Pb^(2+).For the ions Cd^(2+),Zn^(2+),and Hg^(2+),its adsorption strength remains to be improved.

Binding and Adsorption Energies of Heavy Metal Ions with Hapli-Udic Argosol and Ferri-Udic Argosol Particles

Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles.The distribution of Gibbs free adsorption energies could not be determined experimentally before the development of Wien effect measurements in dilute soil suspensions.In the current study,energy relationships between heavy metal ions and particles of Hapli-Udic Argosol(Alfisol)and Ferri-Udic Argosol were inferred from Wien effect measurements in dilute suspensions of homoionic soil particles(<2μm)of the two soils,which were saturated with ions of five heavy metals,in deionized water.The mean Gibbs free binding energies of the heavy metal ions with Hapli-Udic Argosol and Ferri-Udic Argosol particles diminished in the order of Pb^(2+)>Cd^(2+)>Cu^(2+)>Zn^(2+)>Cr^(3+),where the range of binding energies for Hapli-Udic Argosol(7.25-9.32 kJ mol^(-1))was similar to that for Ferri-Udic Argosol(7.43-9.35 kJ mol^(-1)).The electrical field-dependent mean Gibbs free adsorption energies of these heavy metal ions for Hapli-Udic Argosol and for Ferri-Udic Argosol descended in the order:Cu^(2+)≥Cd^(2+)≥Pb^(2+)>Zn^(2+)>Cr^(3+), and Cd^(2+)>Cu^(2+)>Pb^(2+)>Zn^(2+)>Cr^(3+),respectively.The mean Gibbs free adsorption energies of Cu^(2+),Zn^(2+),Cd^(2+), Pb^(2+),and Cr^(3+)at a field strength of 200 kV cm^(-1),for example,were in the range of 0.8-3.2 kJ mol^(-1)for the two soils.

Adsorption of Ammonium and Heavy Metal Ions on Industrial Vermiculite from the Yuli Mine in Xinjiang, China

The present work discusses the mineralogy, saturated adsorption of ammonium and adsorption of heavy metal ions （Cu^2＋, Pb^2＋ and Zn^2＋） on industrial vermiculite samples from the Yuli Mine in Xinjiang Autonomous Region. The saturated adsorption capacity of ammonium and the affection factors of adsorption of Cu^2＋, Pb^2＋ and Zn^2＋ are discussed on the basis of the mineralogical characteristics of the industrial vermiculite samples. The saturated adsorption capacities of ammonium are between 56.02 and 98.42 mmol/100g. The time of adsorption equilibrium is about 30-60 min, and the pH values and concentration of the ion solution significantly affect the adsorption capacities of the heavy metal ions. The adsorption capabilities of the heavy metal ions on industrial vermiculite are almost the same in the low ion concentration solutions, characterized by a sequence of Zn^2＋〉Pb^2＋〉Cu^2＋ for adsorption capacity in solutions with relatively high ion concentration. The results have practical significance for the application of the industrial vermiculite to treating wastewater containing ammonium or heavy metal ions.

Comments on“Adsorption behavior of heavy metal ions by carbon nanotubes grown on microsized Al_2O_3 particles”

Recently, Hsieh and Horng [1] published the paper entitled as above. In section 3 results and discussion, the authors mentioned the first and the second order kinetic models without any quotations. In fact these two kinetic models have been published [2-5]. In order to distinguish a kinetics model based on the ad- sorption capacity of a solid from the one based on the concentration of a solution, Lagergren＇s first-order rate equation has been called pseudo-first-order [6-7]. The Lagergren＇s equation has been widely cited, but there are far more mistakes made in the quotation and in the reference section of papers, including the title, the author＇s name, journal title, year of publishing, volume, and page number [3]. In addition, the second order kinetic expression for the adsorption systems of divalent metal ions using sphagnum moss peat has been reported by Ho [8].

Robust Waterborne Polyurethane/Wool Keratin/Silk Sericin Freeze-Drying Composite Membrane for Heavy Metal Ions Adsorption

Wool keratin(WK)and silk sericin(SS)have the ability to interact with metal ions.In order to take advantage of this potential,a novel environmentally friendly waterborne polyurethane(WPU)/WK/SS membrane named as WPU&WK&SS membrane with crosslinked structure was constructed by freeze-drying via self-assembly style.Surface morphology and chemical structure characterization were investigated by scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FT-IR).In addition,the adsorption experiments of Cu2+and Cr6+were performed to evaluate the adsorption of WPU&WK&SS membrane,including adsorption kinetics,adsorption isotherm models and various factors affecting adsorption.Further investigation indicates that the maximum adsorption capacity of Cu2+and Cr6+can reach 54.21 mg·g-1and 85.21 mg·g-1,respectively,which are higher than most of the reported adsorbents.Through adsorption kinetics and thermodynamic analysis,it is find that the pseudo-second-order kinetic equation and the Langmuir adsorption isotherm model are more suitable for the static adsorption of Cu2+and Cr6+by WPU&WK&SS membrane.

Experimental Study on Surface Reactions of Heavy Metal Ions With Quartz—Aqueous Ion Concentration Dependence

Adsorption of divalent metal ions, including Cu\+\{2+\}, Pb\+\{2+\}, Zn\+\{2+\}, Cd\+\{2+\} and Ni\+\{2+\}, on quartz surface was measured as a function of metal ion concentration at 30℃ under conditions of solution pH=6.5 and ion strength I=0.1mol/L. Results of the experimental measurements can be described very well by adsorption isotherm equations of Freudlich. The correlation coefficients (r) of adsorption isotherm lines are >0.96. Moreover, the experimental data were interpreted on the basis of surface complexation model. The experimental results showed that the monodentate coordinated metal ion surface complex species (SOM\++) are predominant over the bidentate coordinated metal ion surface complex species \ formed only by the ions Cu\+\{2+\}, Zn\+\{2+\} and Ni\+\{2+\}. And the relevant apparent surface complexation constants are lgK\-M=2.2-3.3 in order of K\-\{Cd\}≥K\-\{Pb\}>K\-\{Zn\}>K\-\{Ni\}≥K\-\{Cu\}, and lgβ\-M=5.9-6.8 in order of β\-\{Ni\}>β\-\{Zn\}>β\-\{Cu\}. Therefore, the reactive ability of the ions onto mineral surface of quartz follows the order of Cd>Pb>Zn>Ni>Cu under the above mentioned solution conditions. The apparent surface complexation constants, influenced by the surface potential, surface species and hydrolysis of metal ions, depend mainly on the Born solvation coefficient of the metal ions.

Characterization of the Optical Properties of Heavy Metal Ions Using Surface Plasmon Resonance Technique

The aim of this research is to characterize the optical properties of heavy metal ions (Hg2+, Cu2+, Pb2+ and Zn2+) using surface plasmon resonance (SPR) technique. Glass cover slips, used as substrates were coated with a 50 nm gold film using sputter coater. The measurement was carried out at room temperature using Kretchmann SPR technique. When the air medium outside the gold film is changed to heavy metal ions solution, the resonance angle shifted to the higher value for all samples of heavy metal ions solution. By our developed fitting program (using Matlab software), the experimental SPR curves were fitted to obtain the refractive index of Hg2+, Cu2+, Pb2+ and Zn2+ ions solution with different concentrations. Both the real and imaginary part of refractive index of the heavy metal ions solution increased with the concentration. The results give the basic idea such that the SPR technique could be used as an alternative optical sensor for detecting heavy metal ions in solution.

Spectroscopic Properties and Judd-Ofelt Theory Analysis of Er^(3+)-Doped Heavy Metal Oxyfluoride Silicate Glass

Er^(3+)-doped heavy metal oxyfluoride silicate glass was fabricated and characterized, and the absorption spectrum and fluorescence spectrum of the glass were studied. The Judd-Ofelt intensity parameters Ω_t (t =2, 4, 6), spontaneous transition probability, fluorescence branching ratio and radiative lifetime of each energy levels for Er^(3+) were calculated by Judd-Ofelt theory, and stimulated emission cross-section of (()~4I_(13/2))→(()~4I_(15/2)) transition was calculated by McCumber theory. The results show that fluorescence full width at half maximum and stimulated emission cross-section of Er^(3+)-doped heavy metal oxyfluoride silicate glass are broad and large, respectively. Compared with other host glasses, the gain bandwidth property of Er^(3+)-doped heavy metal oxyfluoride silicate glass is close to those of tellurite and bismuth glasses, and has advantage over those of silicate, phosphate and germante glasses.

Adsorption Properties and Cost of Dicarboxylic Nanocellulose on Copper Ions for Wastewater Treatment

The accumulation of Cu^(2+)in water is a potential threat to human health and environment.Dicarboxylic nano-cellulose(DNC)with rich carboxyl groups was prepared through the NaIO_(4)–NaClO_(2) sequential oxidation meth-od to efficiently remove copper ions,and the Cu 2+adsorption properties and cost were studied.The maximum adsorption capacity reached 184.2 mg/g at pH 6 and an adsorbent dose of 5 g/L.Theoretically,the maximum adsorption capacities of monocarboxylic nanocellulose(MNC),DNC,and tricarboxylic nanocellulose(TNC)with carboxyl groups as the main adsorption sites were calculated to be 228.7,261.3,and 148.1 mg/g,respectively.The Cu^(2+)adsorption costs of MNC,DNC,and TNC were calculated and compared with those of powdered activated carbon(PAC).The Cu^(2+)adsorption capacity of DNC is higher than that of PAC,and the adsorption cost is close to or lower than that of PAC,demonstrating that the DNC prepared by sequential oxidation of NaIO_(4)–NaClO_(2) has competitive adsorption capacity and cost in the treatment of wastewater containing Cu^(2+).

SYNTHESES AND ADSORPTION PROPERTIES OF PHENOL-FORMALDEHYDE-TYPE CHELATING RESINS BEARING THE FUNCTIONAL GROUP OFTAR TARIC ACID

Several kinds of novel chelating resins bearing the functional group of tartaric acid (TTA-FQ-12, TTA-FQ-23, and TTA-FQ-34) were synthesized by reacting epoxy maleic anhydride, which was prepared through the oxidization reaction of maleic anhydride by hydrogen peroxide, with phenol-formaldehyde resin containing polyamine (FQ resins series). The effects of such factors as reaction time, reaction temperature and pH value on the loading capacity of TTA in resins were investigated. The results showed that the optimum reaction conditions are as follows: time 9-12 h; temperature 90-105'C; pH value 6-10. The loading capacities of TTA can reach 0.15, 0.14, and 0.11 mmol/g-1 when the functional group of FQ resin was - OCH2CH2NHC2H4NH2, - O(CH2CH2NH)2C2H4NH2 and - O(CH2CH2NH)3C2H4NH2), respectively. The structures of resins were characterized by FTIR spectra. The primary study on the adsorption properties of the resins for metal ions showed that there are two kinds of adsorption mechanisms i.e. ion exchange and chelate in the adsorption process. TTA-FQ resins have much higher adsorption selectivity for Pb2+and Zn2+ than for Cu2+ and Ni2+. These resins can probably be used for separating Pb2+ or Zn2+ in the mixture of metal ions or for treating wastewater containing heavy metal ions.

Adsorption of Cu(II), Ni(II), Zn(II), Cd(II) and Pb(II) onto Kaolin/Zeolite Based- Geopolymers

This work deals with geopolymers based on local Jordanian resources, namely, kaolin and zeoltitic (phillipsite) tuff. The geopolymers were prepared from these two materials by a reaction with an alkali solution at 80oC. The research group of the present work has demonstrated in previous work that addition of zeolitic tuff to kaolin based-geopolymers increases the adsorption capacity toward Cu(II) metal ion compared to zeolite-free geopolymers, while retaining high mechanical strength. The aim of the present work is to extend our work and to study the effect of changing geopolymers components (zeolitic tuff and kaolin) on their adsorption properties toward Cu(II), Ni(II), Zn(II), Cd(II) and Pb(II) metal ions. Both isothermal and kinetic studies revealed that increasing the zeolitic tuff: kaolin ratio improves the adsorption capacity of geopolymer toward metal ions. The adsorption capacity of the geopolymers of 150: 50 zeolites: kaolin content was found to be higher than that of the raw materials themselves. The rate of adsorption of geopolymers was found to be lower than that of raw materials due to kinetic limitations imposed by the formation of geopolymerization network. The selectivity of geopolymers toward adsorption of? metal ions was found to be distinct from raw zeolite and kaolin where the adsorption onto geopolymers was found to be more preferential for small size metal ions (Cu(II), Ni(II), Zn(II)) than for large size metal ions (Pb(II), Cd(II)). The adsorption of Cu(II) and Pb(II) onto geopolymers did not decrease with competition with other metal ions, which indicates cooperative adsorption. The adsorption process of metal ions onto geopolymers was found to be reversible that indicates that metal ions are bound by physical cation exchange to the exchangeable sites of unreacted phillipsite and new amorphous geopolymer sites. Leaching of metal ions from raw kaolin was much more effective than geopolymers and zeolite because of compact structure of geopolymers.

Studies on Heavy Metal Pollution in Soil-Plant System:A Review

Heavy metal pollution in soil-plant system is of major environmental concern on a world scale and in China in particular with the rapid development of industry. The heavy metal pollution status in soil-plant system in China, the research progress on the bioavailability of heavy metals (affecting factors, extraction methods, free-ion activity model, adsorption model, multivariate regression model, Q-I relationship, and compound pollution), and soil remediation are reviewed in the paper. Future research and monitoring is also discussed.

ADSORPTION OF HUMIC SUBSTANCES BY MACRO WEAKLY BASIC IONEXCHANGE RESIN AND THEIR EFFECTS ON REMOVAL OF Cu^(2+) AND Pb^(2+)

Adsorption of humic, tannic and gallic acids by a macro weakly basic ion-exchange resin JN-01 was studied. The adsorption capacity of this resin for gallic and tannic acids is much higher than that for humic acid, which can be explained on the basis of both their molecular size and ionization degree. Furthermore, humic acid is separated into different components with molecular weight in the range from 2000 Da to 100000 Da by ultra-filter, and their adsorption isotherms on resin JN-01 indicate that humic acid＇s molecular weight is an important factor which makes significant influence on adsorption. Finally, changes in the amount of Cu^2＋ and Pb^2＋ adsorbed on resin JN-01 as a function of the concentration of each of these three acids were studied. A large increase in the heavy metal ions uptake is observed in the presence of humic substance, such advantages are due to the interactions between the heavy metal ions and the unbound functional groups of the adsorbed organic acids.

Characterization and Application of Adsorption Material with Hematite and Polystyrene

In this study, a three-dimensional ordered macroporous hematite was prepared using the polystyrene colloid crystal templates and characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, and nitrogen adsorption isotherm. The as-prepared hematite shows a porous structure consisting of the macropores about 200 nm in diameter and the walls about 20 nm in thickness. The adsorption of Pb2+ and Cd2+ ions in aqueous solution by this hematite was also evaluated. At room temperature, each gram hematite adsorbs 12.5 mg of Pb2+ ions and 7.0 mg of Cd2+ ions. The results suggest that the obtained hematite should be a promising adsorbent to remove Pb2+ and Cd2+ ions, and other heavy metal ions from aqueous solution.

壳聚糖复合水凝胶的制备方法及在水处理中的应用

壳聚糖由于来源广、吸附性能强和可自然降解等优点成为备受关注的天然吸附剂。壳聚糖复合水凝胶(CCH)材料是以壳聚糖为主要原料,通过化学、物理等方法改性后得到的新型复合材料。介绍了化学交联、物理交联以及互穿网络等合成壳聚糖复合水凝胶的主要方法。综述了近年来使用CCH对工业废水中常见染料、重金属离子和其他常见污染物的吸附机理和处理效果,讨论了当前利用CCH在处理工业废水中各种污染物时存在的问题及解决方法。最后对CCH在合成方法、选择性吸附、回收利用和智能改性等方面进行了展望,为深入研究提高CCH材料性能及拓宽其在工业废水处理中的应用范围提供了思路。

淀粉基水凝胶St/CMC-g-PAA对Cu^(2+)的吸附性能研究

以玉米淀粉(St)、羧甲基纤维素钠(CMC)为原料,丙烯酸(AA)为接枝单体,通过接枝和交联反应合成了淀粉基水凝胶St/CMC-g-PAA。考察了投药量、pH、Cu^(2+)初始浓度(ρ0)、吸附时间对吸附效果的影响。结果表明,当ρ0=40 mg/L,投药量为300 mg/L,pH=5.2时,Cu^(2+)的去除率可达92.7%。实验数据拟合结果表明,水凝胶对Cu^(2+)的吸附过程符合Langmuir吸附模型和准二级动力学模型,属于单分子层的化学吸附过程。在25℃时,水凝胶对Cu^(2+)的饱和吸附容量qm=142.86 mg/g。水凝胶再生性能较好,经过4次吸附-脱附循环后,Cu^(2+)去除率仍可达到82.1%。

Ti_(3)C_(2)T_(x)超薄纳米片高效率去除废水中重金属的研究

通过刻蚀剥离法制备了Ti_(3)C_(2)T_(x)超薄纳米片,探究了其对废水中重金属离子的吸附特性。通过SEM、XRD、AFM、FT-IR、Raman对Ti_(3)C_(2)T_(x)超薄纳米片的形貌和结构进行了表征,通过ICP-MS对处理前后水体中重金属离子的含量进行了测试。结果表明剥离的Ti_(3)C_(2)T_(x)超薄纳米片表面含有结构缺陷和羟基,当水体中Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)初始浓度为50 mg/L时,47.5 mg Ti_(3)C_(2)T_(x)超薄纳米片对其的去除效率高达90%以上,尤其是对Pb(Ⅱ)的去除效率达到了98.81%,吸附性能远高于大孔树脂、硅藻土和活性炭等常见吸附试剂。在Na(Ⅰ)、Cu(Ⅱ)、Pb(Ⅱ)、Cr(Ⅵ)4种离子共存溶液中,Ti_(3)C_(2)T_(x)超薄纳米片对于Pb(Ⅱ)和Cr(Ⅵ)的去除依然可以达到92%以上。通过动力学和吸附等温拟合,Ti_(3)C_(2)T_(x)纳米片对Pb(Ⅱ)的吸附符合拟二级动力学模型和Langmuir等温模型,对Pb(Ⅱ)的最大吸附量和最低检出限分别为81.7 mg/g和0.0094 mg/L。Ti_(3)C_(2)T_(x)超薄纳米片对重金属离子的吸附特性在化学工业、食品加工的废水处理中具有良好的应用前景。

多离子印迹膜的制备及其吸附性能研究

以Zn^(2+)、Co^(2+)、Cr^(3+)和Pb^(2+)为混合模板,双硫腙为螯合剂,APTES为功能单体,TEOS为交联剂,PVDF为基膜,采用凝胶溶胶法成功合成了对模板离子有高吸附量和良好特异性识别能力的多离子印迹膜(MIIM)。采用SEM对材料的形貌进行了表征,并以多离子印迹聚合物(MIIP)为对比评价了MIIM的吸附性能。结果表明,MIIM对Zn^(2+)、Co^(2+)、Cr^(3+)和Pb^(2+)的吸附量分别是MIIP的1.71、1.43、1.60和9.03倍,最大吸附量分别为21.32、11.21、12.72和25.97 mg·g^(-1)。在竞争离子(Cu^(2+)、Ni^(2+)、Fe^(2+))存在的情况下具有良好的吸附选择性,MIIM的4种模板离子对Ni^(2+)和Fe^(2+)的特异性因子(SP)值在4.86~8.34之间,对Cu^(2+)的SP值在3.58~3.92之间。同时,MIIM可以多次再生,而不会明显降低吸附能力,在废水处理和样品前处理领域具有很好的应用前景。