树脂吸附回收提金尾液中氰化物的研究

本文通过动态实验研究了在自制的离子交换柱中,GS-1树脂对模拟黄金冶练厂的氰化尾液中氰离子的吸附、解吸过程,分别考查了溶液流速、流动方式、树脂装填量对吸附过程的影响及解吸液体积对解吸的影响.结果表明,当树脂填装量为离子交换柱高度的3/4、溶液的流速为15mL/min时,采用顺流吸附,解吸液/负载树脂（体积比）为20/1可以取得较好的吸附、解吸效果.     

普罗维登斯菌和希瓦氏菌对Pt(IV)的吸附特性

研究了普罗维登斯菌和希瓦氏菌两种微生物对Pt(IV)的吸附特性。pH和离子强度条件优化实验结果表明,pH=2.0时吸附效果较好,吸附量分别为58.62和72.20 mg/g;随着离子强度的增加,普罗维登斯菌对Pt(IV)的吸附量增加而希瓦氏菌却降低;Pt(IV)和Pd(II)共存时,两种微生物吸附剂均优先吸附Pd(II)。动力学和等温吸附实验结果表明,普罗维登斯菌吸附Pt(IV)的过程更符合拟二级动力学模型和Langmuir等温模型,说明化学吸附是该过程的限速步骤,且为单分子层吸附,其理论最大吸附量为136.10 mg/g。因此,以上研究结果表明,普罗维登斯菌和希瓦氏菌可以吸附回收溶液中的Pt(IV)离子。     

壳聚糖固定化枯草芽孢杆菌水溶液中铜离子的吸附(英文)

研究了壳聚糖固定化枯草芽孢杆菌吸附铜离子的性能,分析了pH、吸附剂投加量、温度、铜离子初始浓度和时间对铜离子吸附的影响。结果表明,pH对铜离子的吸附有较大的影响。此外,固定化枯草芽孢杆菌吸附剂比空白吸附剂具有更强的吸附性能。整个吸附过程符合朗缪尔吸附模型(R2=0.994),最大吸附量为100.70mg/L。动力学模型拟合结果表明,实验符合准二级动力学模型,线性相关指数大于0.999。吸附剂能在0.1mol/LNaOH溶液中被成功解吸。     

8-羟基喹哪啶螯合树脂吸附钯(Ⅱ)的性能研究

用静态法研究了8-羟基喹哪啶螯合树脂在酸性溶液中吸附和解吸Pd(II)的性能，分析了吸附等温线和吸附动力学过程。结果表明，在0.6 mol/L HCl的介质中，树脂对Pd(II)的饱和吸附量为99.46 mg/g，吸附率为94.7%，解吸率达到95.6%；吸附过程符合Langmuir和Freundlich等温吸附模型，准二级动力学Lagergren方程更适合描述此吸附过程。     

利用天然二氧化锰吸附铜（英文）

软锰矿的主要成分为MuO2,其可作为一种低成本的吸附剂使用,研究其对废水中铜离子的吸附分离作用。研究Cu(II)离子的初始浓度、溶液初始pH值、吸附剂用量和粒度对吸附过程的影响。结果表明:随着吸附剂的用量增加,吸附铜的比例增大。在不同铜浓度下,溶液的初始pH值为自然状态时的吸附量最大。当初始溶液浓度、初始p H值、接触时间、搅拌速度、粒径大小和吸附剂用量分别为0.0025 mol/L、自然状态、180 min、200 r/min和6 g/L时,软锰矿对铜的吸附率为96.5%。对吸附过程中的等温吸附曲线和动力学进行研究。结果表明:该平衡吸附数据符合Langmuir等温模型,而过程的动力学符合伪二阶动力学模型。     

不同长度金属结合肽对大肠杆菌吸附钯性能的影响

利用微生物吸附法回收铂族金属(PGMs)有较大的应用前景，然而利用基因工程手段改造微生物胞外金属结合基团，进而提升微生物的吸附量与特异性仍是一项挑战。本研究利用微生物表面展示技术，在大肠杆菌(Escherichia coli，简写为E. coli)BL21菌株外膜上展示了不同长度的金属结合肽(EC10、EC20、EC30)，并解析了其对钯(Pd(II))的吸附行为。结果表明，在E.coli BL21表面展示不同长度金属结合肽均能增强其对Pd(II)的吸附量。其中，表面展示了EC20的菌株(简写为E. coli EC20)吸附量最高，为144.25 mg/g，是未进行表面展示菌株的1.14倍；E. coli BL21和E. coli EC20均能够从含多种金属离子的工业废水中选择性吸附Pd(II)和Pt(IV)，两株菌对Pd(II)吸附率分别为96.2%和99.0%。以上研究表明利用表面展示技术增加微生物外膜金属结合基团是一种有效提升微生物吸附能力的手段。     

大肠杆菌对铂(IV)的吸附特性及行为表征

比较了10种菌株对纯溶液中铂(IV)的吸附效果,优选出大肠杆菌作为吸附剂,并对其吸附行为进行了表征和研究。吸附动力学及颗粒内扩散模型表明,大肠杆菌对铂(IV)的吸附过程经历了快速的表面吸附和缓慢吸收2个阶段,并可在60 min内达到吸附平衡;吸附后的SEM、TEM形貌表征显示,大肠杆菌菌体细胞发生形变,皱缩并团聚;XPS结果显示,部分铂(IV)转化为铂(II),表明吸附过程中发生了还原。在25℃、pH=7.0、6 h的条件下,大肠杆菌对初始浓度为100 mg/L的Pt(IV)溶液的吸附率为96.66%。     

S300树脂对汽车失效催化剂浸出液中Pd(Ⅱ)的吸附行为

基于实验室合成的S300树脂对汽车失效催化剂浸出液中Pd^2+吸附过程进行研究,考察温度、溶液体系中HCl浓度、吸附时间等因素对Pd^2+在S300树脂上吸附行为的影响,并对Pd^2+在S300树脂中的动力学特性、交换等温线、复杂体系中的选择性以及解吸过程进行研究,根据表征结果分析在盐酸体系下S300树脂的吸附机理。结果表明:温度对Pd^2+吸附过程影响较小,溶液体系中的HCl浓度在0~1 mol/L范围内,S300树脂的平衡吸附量随HCl浓度升高而显著增加,平衡吸附时间约为30 min。S300树脂吸附过程符合准二级动力学模型与Langmuir等温模型,对汽车失效催化剂浸出液中Pd^2+的吸附分配系数DM=68.66,静态解吸过程中,解吸3 min后,Pd^2+解吸率达到98.79%。研究结果表明,溶液中Pd(Ⅱ)以[PdCl4]2?形式通过离子?偶极作用与S300树脂发生吸附反应。     

壳聚糖-海藻酸钠吸附剂对电镀废水中 Cr( VI) 的吸附性能研究

以天然壳聚糖(CS)和海藻酸钠(SA)为原料,在CaCl2作用下,制备了壳聚糖-海藻酸钠(CS-SA)吸附剂。采用红外光谱仪对CS-SA吸附剂官能团进行表征,表明壳聚糖和海藻酸钠之间产生了静电吸引作用。以含低浓度Cr(Ⅵ)的电镀废水为处理对象,考察了CS-SA用量、吸附时间和pH值对CS-SA吸附性能的影响,同时对吸附动力学进行了研究。结果表明:当pH=6,吸附时间为120 min,CS-SA用量为0.15 g时,离子去除率最高,达到了98.86%;吸附动力学最符合拟二级动力学方程。解吸-再生实验表明,CS-SA吸附剂可以再生使用。     

酯化改性麦糟对Pb(Ⅱ)的吸附特性

以啤酒工业废弃物麦糟为原料,采用一步快速酯化改性法制备高效重金属离子吸附剂酯化改性麦糟。研究酯化改性麦糟对Pb(Ⅱ)的吸附行为、吸附动力学及吸附机制。结果表明:在较宽的pH值范围(4~8)内,酯化改性麦糟表现出对Pb(II)良好的吸附性能。由Langmuir吸附等温线方程计算得到该吸附剂对Pb(Ⅱ)的理论饱和吸附量为393.7 mg/g,高于文献报道的大多数吸附剂的吸附量。吸附反应很快在15 min内达到平衡,吸附符合拟二级动力学方程。活化能的计算表明吸附为活性化学吸附。酯化改性麦糟吸附Pb(Ⅱ)主要是羟基和羧基中C—O基团的氧原子与Pb(Ⅱ)配合的结果。     

利用基因工程菌从贵金属废液中吸附铂和钯

采用表面展示技术将含EC20序列的载体转化至E.coli BL21胞内,制备了高效基因工程菌吸附剂(简称基因工程菌),并利用该工程菌从工业贵金属废液中吸附铂和钯。结果表明,经过表面展示的基因工程菌a对铂和钯的吸附量较E.coli BL21分别提升了1.6倍和1.31倍;当基因工程菌a的添加量为8 g/L,吸附时间为3 h时,工业废水中铂和钯的回收率分别达到90.71%和100%;对比了膜分离与高速离心分离效果,当菌浓度为2 g/L,吸附时间为30 min时,用膜分离的方法所得铂和钯的回收率分别为64.99%和90.09%,是高速离心分离法回收率的2.77倍和1.05倍。     

Application of modified sepiolite as reusable adsorbent for Pd(II) sorption from acidic solutions

The adsorption characteristics and mechanisms of modified sepiolite as an adsorbent to recover Pd(II) from acidic solutions were studied. The Pd(II) adsorption properties were analyzed through isotherm, kinetic and thermodynamic models. In addition, SEM−EDS, TEM and XPS were applied to investigating the Pd(II) adsorption mechanisms onto modified sepiolite. The equilibrium data were well fitted to Langmuir isotherm model with maximum Pd(II) adsorption capacity of 322.58 mg/g at 30 °C. The kinetic data could be satisfactorily simulated by the pseudo- second order model, indicating that the rate-controlling step was chemical adsorption. 99% of Pd(II) could be recovered using 1 g/L modified sepiolite when initial concentration of Pd(II) was 100 mg/L. The results of reusability studies indicated the modified sepiolite had an acceptable stability and reusability. This study indicated that the modified sepiolite might be an efficient and cost-effective material for Pd(II) recovery.     

微生物吸附-化学还原法合成金钯纳米线机理研究

采用微生物吸附-化学还原法,以大肠杆菌(ECCs)为模板、十六烷基三甲基溴化铵(CTAB)为保护剂、抗坏血酸(AA)为还原剂制备金钯纳米线(Au-Pd NWs),考察不同金钯摩尔比对合成金钯纳米材料的影响,并通过SEM、TEM、XRD等技术进行了表征,研究其形成机理。结果表明,吸附还原作用使ECCs在短时间内还原生成了少量Pd(0)和Au(0),大量的钯离子和金离子聚集在ECCs表面周围;还原剂AA的加入使ECCs表面成为优先成核位点,菌体表面基团与晶核相互作用阻止其迁移;在CTAB的作用下,菌体表面的纳米颗粒逐渐形成链状纳米中间结构,中间结构通过Ostwald熟化作用进一步形成Au-Pd纳米线。通过ECCs和CTAB协同作用,有利于一维纳米结构的生长。     

Adsorption properties of Ag（Ⅰ）, Au（Ⅲ）, Pd（Ⅱ） and Pt（Ⅳ） ions on commercial 717 anion-exchange resin

The adsorption properties of the four precious metal ions (Ag(I), Au(II), Pd(III) and Pt(IV)) on the commercial Cl^?-form 717 strongly basic anion-exchange resin were studied in detail. The effects of the contact time, solution acidity, and concentrations of Cl^? and Pb²⁺ ions on the adsorption properties were studied by the batch method. Then, the column method was conducted under the optimized adsorption conditions (pH=3.0). The effects of the sample loading flow rate and the length-to-diameter ratios of the columns were investigated. The precious metal ions adsorbed could not be eluted completely after the saturated adsorption because the precious metal ions were found to be reduced to their metallic states during the adsorption process. So, it is recommended that the commercial Cl^?-form 717 strongly basic anion-exchange resin should be decomposed directly to recovery the precious metals after the saturated adsorption.     

Adsorption behavior of Pd(Ⅱ) from aqueous solutions by D201 resin

The adsorption and desorption behaviors of Pd(Ⅱ) on D201 resin were investigated. The effects of parameters including HCl concentrations, initial metal ion concentrations, contact time, and temperature on the adsorption of Pd(Ⅱ) were studied by batch method. The HCl concentration for studying the effects was set from 0.01 to 2 mol·L-1 and the optimal adsorption condition is in 0.01 mol·L-1 HCl solution. The adsorption isotherm of Pd(Ⅱ) on D201 resin was determined and the equilibrium data fitted the Langmui...     

Synthesis of novel silica-supported chelating resin containing tert-butyl 2-picolyamino-N-acetate and its properties for selective adsorption of copper from simulated nickel electrolyte

A novel silica-supported tert-butyl 2-picolyamino-N-acetate chelating resin (Si-AMPY-1) was successfully synthesized and characterized by elemental analysis, FT-IR, SEM and ¹³C CP/MAS NMR. The adsorption behaviors of the Si-AMPY-1 resin for Cu(II) and Ni(II) were studied with batch and column methods. The batch experiments indicated that the Si-AMPY-1 resin adsorbed Ni(II) mainly via physisorption, while adsorbed Cu(II) via chemisorption. The column dynamic breakthrough curves revealed that the Si-AMPY-1 resin can efficiently separate Cu(II) from the simulated nickel electrolyte before the breakthrough point. Moreover, the concentration of Cu(II) in the column effluent was decreased to be less than 3 mg/L within the first 43 BV (bed volumes), and the mass ratio of Cu/Ni was 21:1 in the saturated resin, which completely satisfied the industrial requirements of the nickel electrorefining process. Therefore, it was concluded that the Si-AMPY-1 resin can be a promising candidate for the deep removal of Cu(II) from the nickel electrolyte.     

A novel recovery technology of trace precious metals from waste water by combining agglomeration and adsorption

A novel and efficient technology for separating and recovering precious metals from waste water containing traces of Pd and Ag was studied by the combination of agglomeration and adsorption. The recovery process and the impacts of operating conditions such as pH value of waste water, adsorption time, additive quantity of the flocculant and adsorbent on the recovery efficiency were studied experimentally. The results show that Freundlich isothermal equation is suitable for describing the behavior of the recovery process, and the apparent first-order adsorption rate constant k at 25℃ is about 0.233 4 h^-1. The optimum technology conditions during the recovery process are that pH value is 8-9; the volume ratio of flocculant to waste water is about 1 ：（2 000-4 000）; the mass ratio of adsorbent to waste water is 1 ：（30-40）; and processing time is 2-4 h. Finally, the field tests were done at the optimum technology conditions, which show that the total concentration of Pd and Ag in the waste water below 11 mg/L can be reduced to be less than 1 mg/L.     

Enhanced Cu(Ⅱ) adsorption by orange peel modified with sodium hydroxide

Copper adsorption by orange peel, which was chemically modified with sodium hydroxide, was investigated. The adsorbent was characterized using surface area analyzer, infrared spectroscopy and scanning electron microscopy. Total negative charge and zeta potentials on the adsorbent surface were determined. Equilibrium isotherms and kinetics were obtained and the effects of solution pH value, adsorbent concentration and temperature were studied in batch experiments. Column experiments were performed to study practical applicability, and breakthrough curves were obtained. Equilibrium is well described by Langmuir and Freundlich isotherms, and kinetics is found to fit pseudo-second order type adsorption kinetics. According to Langmuir equation, the maximum adsorption capacity for Cu(II) is 50.25 mg/g at pH value of 5.3. The results show additional chemical modification of the adsorbent by NaOH and the increased adsorption capacity.