Equilibrium and kinetics of copper(Ⅱ) biosorption by Myriophyllum spicatum L.

The potential use of Myriophyllum spicatum L. biomass as a biosorbent for the removal of copper（ Ⅱ ） from aqueous solution was investigated in laboratory condition. The sorption experiments were undertaken to obtain copper（ Ⅱ ） biosorption properties of M. spicatum L., i.e. equilibrium time, the maximum capacity, and rate constants. Copper（ Ⅱ ） biosorption was fast and equilibrium was attained within 35 min at initial copper（ Ⅱ ） concentration of 6 mg/L. Different isotherm models including the Langmuir, Freundlich, Temkin and Redlich-Peterson model, were used to investigate the sorption capacity and isotherm. These models showed an excellent match with the experimental data except for the Freundlich model. According to the Langmuir coefficients, the maximum sorption capacity of copper onto M. spicatum L. was 10.80 mg/g. The kinetics of copper（ Ⅱ ） sorption was also analysed and rate constants were derived. It was found that the overall sorption process was best described by the pseudo second-order equation, and that intraparticle diffusion was not the rate determining step. The results of this study showed that M. spicatum L. can be considered as useful vehicles for the removal and recovery of copper（ Ⅱ ） from aqueous solutions.

Characteristics of copper removal and ion release during copper biosorption by Stenotrophomonas maltophilia in presence of benzo[a]pyrene

The ability of Stenotrophomonas maltophilia was demonstrated to selectively remove Cu2+from Cu(NO3)2 solution under the circumstance that 1 mg/L benzo[a]pyrene(BaP) was either present or not. The removal ratios of 2 and 10 mg/L Cu2+by 0.25 g/L biosorbent are up to 80% and 49% at 10 min, respectively. The biosorption includes ion exchange, NO3 reduction, ion release, and cell oxidation by Cu2+. BaP does not significantly affect Cu2+removal and ion release. Although 2 mg/L Cu2+increases the release of PO4 3, K+, NH4 +and Ca2+, 10 mg/L Cu2+has strong oxidation on cell, and then decreases NO3 reduction and hinders the release of K+, NH4 +and Ca2+. Exogenous cations inhibit the Cu2+biosorption, while additional anions increase the removal ratios of 10 mg/L Cu2+from 52% to 88%.

Characteristics of Zn^(2+) Biosorption by Saccharomyces cerevisiae

Objective To investigate the characteristics of Zn^2＋ biosorption and the release of cations during the process of Zn^2＋ biosorption by intact cells of Saccharomyces cerevisiae. Methods The batch adsorption test was used to study the biosorption equilibrium and isotherm. Zn^2＋ concentration was measured with atomic adsorption spectrophotometer （AAS） AAS 6.Vario. Results When the initial concentration of Zn^2＋ ranged between 0.08 and 0.8 retool/L, the initial pH was natural （about 5.65）, the sorbent concentration was about 1 g/L and the capacity ofZn〉 biosorption was from 74.8 to 654.8 μmol/g. The pH value increased by 0.55-1.28 and the intracellular cations （K^＋, Mg^2＋, Na^＋, Ca〉） of the cells were re/eased during the process of Zn〉 biosorption. Conclusion Ion exchange was one of the mechanisms for Zn^2＋ biosorption. The biomass of Saccharomyces cerevisiae is a potential biosorbent for the removal of Zn^2＋ from aqueous solution. More work needs to be done before putting it into practical application.

Kinetic and thermodynamic studies on biosorption of Cu(Ⅱ) by chemically modified orange peel

Cu(Ⅱ)biosorption by orange peel that was chemically modified with sodium hydroxide and calcium chloride was investigated.The effects of temperature,contact time,initial concentration of metal ions and pH on the biosorption of Cu(Ⅱ)ions were assessed.Thermodynamic parameters including change of free energy),(Θ-G enthalpy)( Θ -H and entropy(-S Θ)during the biosorption were determined.The results show that the biosorption process of Cu(Ⅱ)ions by chemically treated orange peel is feasible,spontaneous and exothermic under studied conditions.Equilibrium is well described by Langmuir equation with the maximum biosorption capacity(qm)for Cu(Ⅱ)as 72.73 mg/g and kinetics is found to fit pseudo-second order type biosorption kinetics.As the temperature increases from 16℃to 60℃,copper biosorption decreases.The loaded biosorbent is regenerated using HCl solution for repeatedly use for five times with little loss of biosorption capacity.

Tolerance and biosorption of copper (Cu) and lead (Pb) by filamentous fungi isolated from a freshwater ecosystem

Filamentous fungi are able to accumulate significant amount of metals from their environment. The potential of fungal biomass as agents for biosorption of heavy metals from contaminated sediments is currently receiving attention. In the present study, a total of 41 isolates of filamentous fungi obtained from the sediment of the Langat River, Selangor, Malaysia were screened for their tolerance and uptake capability of copper （Cu） and lead （Pb）. The isolates were identified as Aspergillus niger, A. fumigatus, Trichoderma asperellum, Penicillium simplicissimurn and P. janthinellum. A. niger and P. simplicissimum, were able to survive at 1000 mg/L of Cu（Ⅱ） concentration on Potato Dextrose Agar （PDA） while for Pb, only A. niger survived at 5000 mg/L concentration. The results showed that A. niger, P. simplicissimum and T. asperellum have a better uptake capacity for Pb compared to Cu and the findings indicated promising biosorption of Cu and Pb by these filamentous fungi from aqueous solution. The present study was also determined the maximum removal of Cu（Ⅱ） and Pb（Ⅱ） that was performed by A. niger. The metal removal which occurred at Cu（Ⅱ） 200 mg/L was （20.910 ＋ 0.581） mg/g and at 250 mg/L of PbⅡ） was （54.046 ± 0.328） mg/g.

Biosorption of copper and zinc by immobilised and free algal biomass,and the effects of metal biosorption on the growth and cellular structure of Chlorella sp.and Chlamydomonas sp.isolated from rivers in Penang,Malaysia

In this study, the biosorption of copper and zinc ions by Chlorella sp. and Chlamydomonas sp. isolated from local environments in Malaysia was investigated in a batch system and by microscopic analyses. Under optimal biosorption conditions, the biosorption capacity of Chlorella sp. for copper and zinc ions was 33.4 and 28.5 mg/g, respectively, after 6 hr of biosorption in an immobilised system. Batch experiments showed that the biosorption capacity of algal biomass immobilised in the form of sodium alginate beads was higher than that of the free biomass. Scanning electron microscopy and energy-dispersive X-ray spectroscopy analyses revealed that copper and zinc were mainly sorbed at the cell surface during biosorption. Exposure to 5 mg/L of copper and zinc affected both the chlorophyll content and cell count of the algal cells after the first 12 hr of contact time.

Biosorption effects of copper ions on Candida utilis under negative pressure cavitation

Under the optimal condition of copper ions adsorption on yeast,we found some different effects among static adsorption, shaking adsorption and negative pressure cavitation adsorption, and the methods of yeast with different pretreatments also affect adsorption of copper ions. At the same time, the change of intercellular pH before and after adsorption of copper with BCECF was studied. The copper distribution was located by using PhenGreen （dipotassium salt and diacetate）, and the surface of yeast was observed by an atomic force microscope. The results showed that negative pressure cavitation can improve bioadsorption capacity of copper ions on yeast. However, the yeasts＇ pretreatment has a higher effect on bioadsorption. It indicates that heavy metal bioadsorption on yeast has much relation with its cellular molecule basis. With the adsorping, the intercellular pH of yeast increased gradually and changed from acidity to alkalescence. These results may suggest that negative pressure cavitation can compel heavy metals to transfer from the cell surface into inside cell and make the surface of yeast coarse.

Effects of anions on the biosorption of microelement cations by macroalga Enteromorpha prolifera in single-and multi-metal systems

The results of research on the effects of anions on the biosorption of microelement cations by the edible marine macroalga Enteromorpha prolifera in singleand multi-metal systems are discussed in this paper. It was shown that the maximum biosorption capacity (qmax) in a single-metal system of Co(II) ions decreased in the following sequence: Cl- (46.0 mg g-1) > SO42- (42.8 mg g-1) > NO3- (41.9 mg g-1). In multi-metal systems, in which the ratios of Cl-, NO3-, and SO42- were 0:0:4, 1:1:2, 3:0:1, and 4:0:0, there were clear differences among the biosorption capacities. In all the examined systems (other than the 0:0:4 system), inhibition of the binding of microelement cations by the macroalga was observed. In all the systems, the highest value of qmax was obtained for Cu(II) cations; the value ranged from 31.9 mg g-1 in 0:0:4 (SO42- only) to 18.2 mg g-1 in 4:0:0 (Cl-only).

Sorption Kinetic Analysis for the Removal of Copper(Ⅱ) by Using Biofilm

The biosorption of copper(R) ions onto biofilm was studied in a batch system with respect to the temperature, initial pH value and biofilm sorbent mass. The biomass exhibited the highest copper(R) sorption capacity under the conditions of room temperature, initial pH value of 6.0 and the sorbent mass 8 g. The experimental data were analyzed using four sorption kinetic models, the pseudo-first order, the Ritchie second order, the modified second order and the Elovich equations to determine the best-fit equation for the sorption of metal ions onto biofilm.Comparing with the sum of squared-errors, the results show that both the Ritchie second order and modified second order equations can fit the experimental data very well.

Removal of copper from aqueous solutions by bentonites and the factors affecting it

In order to study the ability of bentonites to remove heavy metal ions from waste water and its factors affecting it,batch sorption experiments of Cu2+ were conducted on Ca-bentonite and Na-bentonite under various conditions.The results show that the adsorption process of bentonite accorded with the Freundlich isotherm model and that the sorption results of Na-bentonite are better than those of Ca-bentonite.Adsorption behavior of both bentonites was strongly depending on pH,initial concentration and additional amounts of bentonites.There are three kinds of adsorption mechanism at different ranges of pH values:the competition adsorption between Cu2+ and H+(pH<3),ion-exchange adsorption(pH=3～7) and precipitation adsorption of copper hydroxyl compounds(pH>8.3).The removal rate of bentonite decreases with an increase in the initial metal ion concentration.The maximum adsorption capacity of Na-bentonite was 26 mg/g and that of Ca-bentonite 12 mg/g.The removal rate of Cu2+ was practically 100% at the initial concentration of 40 mg/L,when 4 g/L of Na-bentonite and 14 g/L of Ca-bentonite were added to the solution.

Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro

AIM: To study the effect of copper transporting P-type ATPase in copper metabolism of hepatocyte and pathogenesis of Wilson disease (WD).METHODS: WD copper transporting properties in some organelles of the cultured hepatocytes were studied from WD patients and normal controls. These cultured hepatocytes were incubated in the media of copper 15mg.L-1 only, copper 15 mg. L-1 with vincristine (agonist of P-type ArPase) 0.5mg. L-1, or copper 15 mg. L-1 withvanadate (antagonist of P-type ATPase) 18.39 mg. L-1separately. Microsome (endoplasmic reticulum and Golgi apparatus), lysosome, mitochondria, and cytosol were isolated by differential centrifugation. Copper contents in these organelles were measured with atomic absorption spectrophotometer, and the influence in copper transportion of these organelles by vanadate and vincristine were comparatively analyzed between WD patients and controls.WD copper transporting P-type ATPase was detected by SDS-PAGE in conjunction with Western blot in liver samples of WD patients and controls.RESULTS: The specific WD proteins (Mr155 000 lanes) were expressed in human hepatocytes, including the control and WD patients. After incubation with medium containing copper for 2 h or 24 h, the microsome copper concentration in WD patients was obviously lower than that of controls,and the addtion of vanadate or vincristine would change the copper transporting of microsomes obviously. When incubated with vincristine, levels of copper in microsome were significantly increased, while incubated with vanadate,the copper concentrations in microsome were obviously decreased. The results indicated that there were Wdproteins, the copper transportion P-type ATPase in the microsome of hepatocytes. WD patients possessed abnormal copper transporting function of WD protein in the microsome, and the agonist might correct the defect of copper transportion by promoting the activity of copper transportion P-type ATPase.CONCLUSION: Copper transportion P-type ATPase plays an important role in hepatocytic copper metabolism.Dysfunction of hepatocytic WD protein copper transportion might be one of the most important factors for WD.

重金属抗性菌及其去除CMP废水中Cu2+的研究进展

环境中重金属主要来源于工业废水的排放,如何经济有效地去除工业废水中的重金属是水处理领域的难点。重金属抗性菌比通常微生物具有更高的重金属抵抗能力,可以在重金属胁迫的情况下生长,这为重金属废水的微生物处理提供了新的思路。但是,目前人们对重金属抗性微生物的特性和应用仍然知之甚少。基于此,综述了重金属抗性菌的发现过程及其分离状况,对重金属抗性菌抗性能力的评价方法进行了介绍,着重分析了重金属抗性菌抗性机制中可作为去除重金属离子理论基础的胞外吸附与胞内累积机制,并以集成电路板生产关键工艺,即化学机械研磨(CMP)过程产生的低浓度含铜废水为处理对象,总结了重金属抗性菌对铜离子的去除原理及其在CMP废水处理中的应用,最后对今后的研究方向进行了展望,以期为应用重金属抗性菌生物膜处理含铜废水的研究提供参考。

中空硫化铜纳米酶脂质复合载体的制备及其联合激光杀伤黑色素瘤B16-F10细胞

目的:构建中空硫化铜纳米酶脂质复合载体CuS@LIP并探讨其联合激光照射杀伤黑色素瘤B6-F10细胞的效果与机制。方法:构建(2,3-二油酰基-丙基)-三甲胺-丙烷(氯盐)(DOTAP)阳离子脂质体包被硫化铜纳米载体CuS@LIP,研究不同质量浓度的CuS与CuS@LIP在1 064 nm激光照射下的光热性能和热稳定性,通过H_(2)O_(2)与3,3',5,5'-四甲基联苯胺(TMB)催化活性检测体系检测CuS@LIP的类过氧化物活性;用系列质量浓度梯度的CuS、CuS@LIP在有/无激光条件下分别处理B16-F10细胞,CCK-8法检测细胞的存活率,Calcein-AM/PI染色法、AnnexinⅤ-FITC/PI染色法结合流式细胞仪分别检测20μg/mL CuS或CuS@LIP在激光照射或非激光照射条件下对B16-F10细胞活力和凋亡的影响。结果:成功制备的CuS@LIP的平均粒径为(178.23±6.46)nm,平均Zeta电位为(20.47±0.93)mV;在激光照射下,80μg/mL CuS@LIP最高温度可达65.4℃,比单纯CuS的63.4℃更高;经3个激光开关周期测试,CuS@LIP终点温度基本保持不变;此外,CuS@LIP与CuS具有相同的类过氧化物酶催化活性。低于20μg/mL的CuS@LIP在体外对B16-F10细胞的增殖活性没有明显影响(P>0.05),但联合激光照射后细胞存活率明显降低(29.76±3.60)%vs(87.95±8.18)%,P<0.000 1,细胞凋亡率显著升高[(19.34±4.41)%vs(13.36±0.86)%,P<0.01]。结论:制备的CuS@LIP具有符合设计要求的理化性质、良好的光热性能和优异的类过氧化物酶催化活性,其与激光照射联合后显示出更优异的杀伤B16-F10细胞的效果。

阴阳离子在铜、铅、锌氧化矿硫化浮选中的强化作用研究现状及展望

硫化浮选法是回收铜、铅、锌氧化矿常用的浮选工艺。为获得更高的回收率,研究人员常使用一些阴阳离子对硫化过程进行强化。文章通过对近些年铜、铅、锌氧化矿强化硫化浮选相关研究成果的梳理,阐述了铜、铅、锌氧化矿硫化浮选机制,讨论了铵根离子、铅离子、铜离子、锌离子、氟离子、氯离子、碳酸根离子等阴阳离子的强化机理,综述了其强化硫化基础理论研究的进展,并对未来发展方向进行了展望,以期对铜、铅、锌氧化矿强化硫化浮选的研究提供一定的帮助。

硫酸改性玉米秸秆对铜离子的吸附性能研究

以农业大量废弃物玉米秸秆为原料,采用硫酸对玉米秸秆进行改性处理,通过单因素实验研究玉米秸秆改性吸附剂在不同实验条件下对溶液中Cu^(2+)去除率的影响,通过正交实验研究了最优去除率时的反应条件。实验结果表明,改性后的玉米秸秆具有非常强的吸附能力,当初始ρ(Cu^(2+))=20 mg/L、溶液pH为4、硫酸改性玉米秸秆吸附剂0.6 g(溶液50 mL)、吸附温度20℃、振荡速度为150 r/min,振荡吸附90 min,此时溶液中Cu^(2+)去除率可以达到86.7%。如果不考虑成本和效率,最优去除率可达91.1%。

使用膜技术对刚果(金)某铜钴矿湿法冶金废液进行浓缩分离研究初探

刚果(金)现行铜钴湿法冶金普遍采用浓密机洗涤技术,存在严重的酸膨胀和水膨胀现象,几乎每个湿法冶金工厂都要花费巨额资金建设尾矿库和废液池,造成巨大资源浪费的同时还面临着严重的环境隐患。刚果(金)某矿业公司拟对湿法冶金过程中产生的尾矿库废水、洗涤液等低含量料液,采用特种阳离子分离膜,让分子水平上不同粒径的混合物在通过半透膜时实现选择性分离,铜、钴、硫酸根离子可以得到成倍数的富集,从而使尾矿库废水中的硫酸和铜钴金属离子可再回收利用,产生的透析液可作为尾矿输送用水和浓密机洗涤用水,加上自然蒸发,整个系统可实现废水零排放,从而消除水膨胀造成的环境隐患,有较强的工业化应用推广价值。

产朊假丝酵母生物吸附Cu^(2+)影响因素及吸附机理的研究

选取产朊假丝酵母作为生物吸附材料,在确立Cu2+最佳吸附条件的基础上,通过细胞内pH值荧光探测剂测定酵母吸附重金属前后的pH值变化,以及运用phengreen细胞内外重金属荧光探测剂进行重金属分布定位,对酵母生物吸附的机理进行了初步的探讨.实验结果表明,最佳吸附条件为pH4.49~5.04,[酵母]∶[Cu2+]为60∶1;酵母细胞内pH值随吸附时间的增加而有所升高,并由酸性变为弱碱性,与此同时酵母死亡率也随吸附时间的增加而迅速增加;生物吸附主要集中在细胞壁的结合位点上,在细胞内部基本没有;生物吸附过程分为2个步骤,首先是一个快速过程,然后是一个慢速过程,但吸附中出现的慢速过程并不一定代表重金属由细胞外进入细胞内.

甘蓝皮生物吸附去除水中的阳离子染料

研究了低值的地产甘蓝皮生物吸附去除水中阳离子染料的可行性,选用了亚甲蓝、中性红、吖啶橙3种染料,研究了各种操作条件对吸附的影响,如吸附剂量、染料浓度、吸附剂粒径、pH值、吸附时间等,确定了最佳吸附条件.结果表明,初始pH值大于4,3种染料去除率高.吸附在12h达到平衡.吸附等温线符合Langmuir或Freundlich模式,吸附过程符合Langergren准一级动力学方程.由此表明甘蓝皮是一种优良的处理阳离子染料废水的生物材料.

谷壳的差热红外扫描电镜分析及对铜铅离子的生物吸附研究

用差热分析(DTGDTA)、红外光谱(FTIR)、扫描电镜(SEM/EDS)等方法对谷壳的质量随温度上升而变化的情况、表面的官能团、表面形态及主要元素构成等进行了分析,并研究了谷壳对水溶液中Cu2+、Pb2+的生物吸附作用.加热170℃时谷壳质量损失约6%,至170～290℃时质量损失约45%,至500℃时质量仅余约11%.在320℃、440℃分别有2个放热峰.谷壳的红外吸收光谱图主要由碳水化合物如木质素、纤维素等的吸收带组成.红外光谱分析表明,1735cm-1和1615cm-1处的吸收峰为不同CO的伸缩振动峰;1515cm-1处为苯环的骨架振动峰,而1243cm-1处是苯羟基中C—O的伸缩振动峰.1456cm-1处的吸收峰为CH3—和CH2—的弯曲振动峰,1374cm-1处是甲基的弯曲振动峰.SEM/EDS分析表明,谷壳表面粗糙,且主要由碳氧硅铝元素构成.结果表明,吸附时间、溶液pH、吸附剂用量、金属离子初始浓度及Na+和Ca2+离子对吸附均有影响.谷壳对Cu2+、Pb2+的吸附在30min基本达到平衡,在pH为5左右吸附效果较好,Ca2+对吸附的影响比Na+严重.随初始浓度的增加,吸附量增大,且吸附可用Langmuir方程描述.在本实验条件下,谷壳对Cu2+、Pb2+的最大吸附量分别为3.46mg·L-1、12.5mg·L-1.一种金属离子的存在能显著降低谷壳对另一种金属离子的吸附,且Pb2+对Cu2+的影响较Cu2+对Pb2+的影响更严重.单一体系和混合体系的实验结果表明,谷壳对单一体系中Cu2+、Pb2+的吸附能力分别大于对混合溶液中Cu2+、Pb2+的吸附能力.

黑藻吸附Cd^2＋和Cu^2＋的拓展Langmuir模型研究

运用沉水植物修复低浓度重金属污染是一种廉价和清洁的技术。采用摇床振荡试验方法,研究了不同pH条件下,沉水植物——轮叶黑藻鲜样对重金属镉和铜的吸附特征。结果表明,pH值对吸附结果影响较大,黑藻对镉和铜的吸附,最适宜的pH值分别为7.0和5.0。在选用的3个拓展Langmuir模型中,模型A拟合效果最好,模型B大大低估了黑藻对重金属镉和铜的吸附能力,模型C则略偏高,表明沉水植物黑藻对重金属镉和铜的吸附与离子所带电荷关系不大,且没有产生吸附剂-重金属-H+的复合式吸附产物(BMH)。运用模型A的回归参数,绘制的三维吸附网格图清晰阐明了不同H+浓度下,黑藻对重金属镉和铜的吸附曲面特征。拓展Langmuir模型A的计算值与实测值的对比表明:24mg·L-1≤C0≤72mg·L-1时,78%的镉吸附量计算值与实测值偏差控制在22%以内,90%的铜吸附量计算值与实测值偏差控制在10%以内。研究不同pH条件下黑藻对镉和铜的生物吸附特征,将有助于对沉水植物修复低浓度重金属污染技术的理解和规范。