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叙述将电厂粉煤灰经过处理后所得的改性粉煤灰,对不同浓度 Zn~(2+)和Ag~+的吸附能力进行的研究。改性粉煤灰吸附锌、银离子的能力接近甚至超过了分子筛,这对其用于含银废液的处理和银的回收提供了理论依据。 相似文献
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三聚氰胺对银离子的吸附性能 总被引:2,自引:0,他引:2
三聚氰胺分子中含有三个自由氨基和三个芳香氮原子,具有很大的重金属离子吸附潜力.重点研究了三聚氰胺对银离子的吸附性能,讨论了吸附时间、吸附温度、溶液pH值这三个因素对三聚氰胺吸附性能的影响,揭示出三聚氰胺具有良好的银离子吸附性能.对于30℃下25mL浓度为0.042mol/L的硝酸银溶液,50mg三聚氰胺对其中的银离子吸附容量可达到820mg/g,且表现出了较快的吸附速度,经0.5 h的吸附即可达到饱和吸附容量的91%以上.良好的综合吸附性能和廉价的优势,使得三聚氰胺在银离子废液处理和回收领域具有广阔的潜在应用前景. 相似文献
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本文利用线性电势扫描的方法研究了几种苯并噻唑类化合物及巯基苯基四氮唑在银上的吸附机理。结果表明:2.巯基苯并噻唑和巯基苯基四氮唑以化学吸附方式,通过分子上巯基与银表面的作用形成分子紧密排列的吸附层。25℃下,PMT可以在银表面形成紧密单层。这种吸附在较高吸附温度下可以转化为多层,且完全覆盖银表面。在含Br~-的溶液中,它可以阻碍Br~-与表面的接触。在较大的浓度下,2-甲基苯并噻唑和苯并噻唑也可以在银表面的某些位置,通过杂环上的S原子(或N原子)形成松散的吸附,但这种吸附层不能完全覆盖银表面。电镜实验也表明以上物质在银表面发生了作用。 相似文献
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制备载银活性炭,比较载银活性炭对不同浓度甲基橙溶液和COD的吸附量,可以作为污水处理的吸附剂,用于城市污水的深度处理或是微污染水的二级处理等领域. 相似文献
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废水中的重金属铜离子(Cu(Ⅱ))会污染水体生态环境,并会通过食物链对人体健康造成潜在危害。生物炭可作为废水中Cu(Ⅱ)去除的有效吸附剂。然而,原状生物炭对Cu(Ⅱ)的吸附量有限,需要对生物炭进行定向改性以提升其去除效果。以废水中的Cu(Ⅱ)为对象,重点论述生物炭的改性方法和吸附机制。结果表明,生物炭的主要改性方法包括化学改性(酸、碱、高分子聚合物改性)、物理改性(球磨和气体活化)、金属改性(铁、锰改性)、矿物质改性和高分子聚合物改性等。改性方法对Cu(Ⅱ)去除效果的次序是:纳米羟基磷灰石改性>含氨基有机酸改性>锰改性>铁改性>碱改性。生物炭吸附Cu(Ⅱ)的主要机制包括孔隙扩散、静电作用、沉淀作用、配位作用、阳离子-π机制、离子交换和还原作用,具体的主导机制取决于生物炭的物化性质和溶液的性质。将来的研究方向包括:采取更为有效的改性方法提高对废水中痕量Cu(Ⅱ)的去除效果;利用先进的仪器和模型计算揭示微观机制;开展动态吸附柱或固定床试验。 相似文献
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在银电解生产过程中,电解液中Pd含量升高极易导致电解银粉中Pd含量超标,使产品品级降低,造成较大的经济损失。通过对G-01树脂进行吸附及解吸实验,论证其在生产中应用的可行性,通过实验表明该树脂对电解液中Pd的吸收具有极强的选择性,并且不改变电解液主要成分,对电解银粉生产过程不造成影响,具有较高的生产应用价值。 相似文献
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研究了黑藻对镉离子的吸附作用,考察了溶液pH、镉离子初始浓度、吸附剂用量和吸附时间等因素对吸附的影响.在选定的吸附条件下,即pH为6.0,吸附剂用量为2 g·L-1,吸附时间为120 min时,对于50 mg·L-1的Cd+溶液,黑藻对Cd+的吸附效率为96%,吸附量为24.1 mg·g-1.常温下黑藻对Cd+的吸附作用可用Langmiur、Freundlich和Dubinin-Radushkevich(D-R)等温吸附模型进行拟合,相关系数r2分别达到0.9852、0.9901和0.9982,说明吸附反应符合这三种吸附模型. 相似文献
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Ian Singleton Paul Simmons 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,65(1):21-28
Factors affecting silver biosorption by Saccharomyces cerevisiae biomass, obtained as a waste product from industry, were examined. Maximum removal of silver from solution was achieved within 5 min. Increasing the concentration of biomass in experimental flasks from 1 to 8 mg cm−3 decreased both silver accumulation, from 224·7 to 89·5 μmol Ag g−1 dry wt, and associated H+ ion release, from 109·4 to 31·7 μmol H+ g−1 dry wt. The presence of 1·0 mol dm−3 cadmium or methionine decreased silver biosorption by 40% and 93% respectively. Boiling in 100 mmol dm−3 NaOH or 10 mmol dm−3 sodium dodecyl sulphate decreased silver biosorption by 54% and 25% respectively. A temperature increase from 4°C to 55°C decreased silver biosorption by 9%. The metabolic state of the yeast had no effect on silver biosorption. Decreasing the pH of the silver solution caused a reduction in metal removal by the biomass. 相似文献
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Haoran Zhang Qingbiao Li Yinghua Lu Daohua Sun Xueping Lin Xu Deng Ning He Shuzhen Zheng 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(3):285-290
Corynebacterium strain SH09 separated from a silver mine was used for biosorption and bioreduction of diamine silver complex. The biosorption of the diamine silver complex was better than that of silver ions and the maximum of the former was about 350 (mg Ag) (g dried biomass)?1. After dried cells of SH09 were resuspended in the aqueous solution of diamine silver complex in the dark at 60 °C for more than 72 h, transmission electron microscopy (TEM) observations showed that a large quantity of black particles whose diameter ranged from 10 to 15 nm were formed on the cell wall. The particles were identified as being silver nanoparticles by X‐ray diffraction (XRD) and UV‐vis spectroscopy. Under the same conditions, no bioreduction of silver nitrate was found. According to IR spectra, some functional groups, such as the amide of the proteins, were involved in the processes of biosorption and bioreduction. Copyright © 2004 Society of Chemical Industry 相似文献
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海带中褐藻糖胶的酸提法研究 总被引:1,自引:0,他引:1
采用酸提法从海带中提取褐藻糖胶,分别采用MgCl、乙醇分级沉淀法进行纯化.主要探讨了提取时间、温度、pH等因素对提取率的影响.结果表明,在提取温度70 ℃,pH 2.5,70%乙醇浓度,提取3 h,提取率为7.3%.乙醇分级沉淀法提取率高于MgCl法. 相似文献
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纳米银因其高效、广谱、不易产生耐药性、安全性高等优点,成为当前抗菌材料的研究热点之一,但目前对纳米银的抗菌机理仍有不同的认识.本文首先综述了国内外纳米银抗菌机理的研究进展和主要成果,主要从影响细菌生活环境、破坏细菌的细胞壁和细胞膜、抑制DNA复制、抑制酶呼吸作用和抑制其他酶活性5个方面分析了纳米银的抗菌机理.并且纳米银的抗菌过程受多种因素影响,文中详细阐述了纳米银的尺寸分布、形貌以及稳定剂、活性氧、菌种和培养基等因素对纳米银抗菌性的影响.最后指出纳米银的抗菌过程复杂,进一步研究其具体作用方式和机理以及影响抗菌作用的主要因素都将有助于纳米银抗菌材料的广泛应用. 相似文献
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Li‐Hong Gai Shu‐Guang Wang Wen‐Xin Gong Xian‐Wei Liu Bao‐Yu Gao Hua‐Yong Zhang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(6):806-813
BACKGROUND: To elucidate the process and mechanism of Cu(II) biosorption onto aerobic granules, the influence of pH and ionic strength (IS) on the Cu(II) biosorption capacity and biosorption mechanism was studied. RESULTS: The biosorption of Cu(II) onto aerobic granules under different conditions of pH (3, 4 and 5), IS (0, 0.1 and 0.5 mol L?1) and Cu(II) concentration (25–250 mg L?1) was investigated. The correlation coefficients of the pseudo‐second‐order kinetic model were , while those of the Langmuir and Freundlich models were and respectively. The biosorption of Cu(II) increased with increasing pH, while the effect of IS on the biosorption was complicated, which could be explained by the competition among different metallic ions, colloidal chemistry theory or Derjaguin, Landau, verwey and Overbeek (DLVO) theory. About 70% of the solid phase Cu(II) was exchanged by Na(I), Ca(II) and Mg(II) released from the aerobic granules at pH 4 and 5. The results revealed that ion exchange is the most important biosorption mechanism but that other mechanisms also play a part. CONCLUSION: The sorption performance can be optimised by adjusting the pH and IS. Aerobic granules can be used as an alternative effective, economical and practical biosorbent for heavy metal removal. Copyright © 2008 Society of Chemical Industry 相似文献
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Continuous biosorption process for removal of lead and copper by laboratory scale fixed-bed reactor was carried out using Ca-loadedLaminaria japonica. All biosorption processes were observed as cation exchange such as Pb2+ vs. Ca2+, Cu2+ vs. Ca2+, and Pb2+ vs. Cu2+. The affinity of lead ions towardsL. japonica was stronger than that of copper ions because the initial amount of desorbed Cu2+ in Cu-Pb system was higher than that of eluted Pb2+ in Pb-Cu system. 相似文献
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以海带酸性提取液为原料,采用膜技术除杂纯化褐藻胶。比较了微滤膜和超滤膜的纯化效果,并探讨了淀粉酶酶解提取液对膜处理效果的影响。结果表明,与微滤膜相比,超滤膜纯化褐藻胶的收率更高;优化的诺维信480L型中温淀粉酶酶解条件为:pH值6.0,酶加量0.3‰,酶解温度50℃,酶解时间2h;提取液酶解后,微滤膜和超滤膜的膜通量分别提高了34.3%和27.3%,但对褐藻胶的质量指标影响较小。最终确定的优化方案为:先将提取液中的褐藻淀粉酶解,再采用超滤膜除杂,所得褐藻胶浓缩液质量接近国标规格,褐藻胶损失很少。 相似文献
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Ag3PO4是目前光催化效率最高的可见光光催化剂之一,在降解有机污染物、分解水制氢和CO2还原等领域具有广泛的应用前景。但Ag3PO4光催化性能距离实际应用还存在一定差距,化学性质也不稳定,因此对其性能提升受到了各国研究者的关注。围绕Ag3PO4纳米化、形貌控制、异质结构等提升光催化性能的途径及其增强机制进行阐述,其中与Ag3PO4形成异质结构是目前提升其光催化性能的最主流的方法,Ag3PO4与金属氧化物、卤化物、硫化物、有机半导体、单质金属形成的异质结构均有效改善了其光催化性能,最后还对Ag3PO4基光催化剂未来的发展趋势进行了展望。 相似文献
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本文对醛和其它含醛基化合物在银氨溶液中可能经过的反应历程做了分析,从中找出银镜反应和其它反应的内在联系,对在此条件下,出现某些反应的事实做出解释 相似文献