共查询到20条相似文献,搜索用时 93 毫秒
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通过Cu2+和Cd2+在改性纳米碳黑(MCB)和钠基膨润土(Na-B)上的吸附-解吸实验,研究了MCB和Na-B对Cu2+和Cd2+的吸附特性和吸附稳定性。研究表明:Cu2+和Cd2+在MCB和Na-B上的吸附动力学能用准二级动力学方程拟合。吸附等温线能用Freundlich方程、Langmuir方程拟合。Freundlich拟合得到的n值均大于1;Langmuir拟合得到MCB对Cu2+和Cd2+的最大吸附量分别为344mmol/kg和222.2 mmol/kg,Na-B对Cu2+和Cd2+的最大吸附量分别为59mmol/kg和45mmol/kg。用0.01mol/L的Ca Cl2对吸附了Cu2+或Cd2+的两种吸附剂进行解吸时,解吸率受p H值影响较大,受温度的影响较小。用不同浓度的Ca Cl2进行解吸时,解吸率变化不大。Cu2+在两种吸附剂上的吸附稳定性均大于Cd2+,MCB对两种重金属的吸附稳定性均大于Na-B。 相似文献
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本文对紫外光度法测定冷却水中苯并三氮唑含量进行了较详细的条件试验,表明酸度变化是干扰的主要来源,确定在pH4~6,波长265nm条件下可消除酸度的影响;用盐酸羟胺可消除NaNO_2的干扰,方法简便快速、准确可靠。 相似文献
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巯基壳聚糖的合成、表征及其对Cu2+的吸附行为 总被引:1,自引:0,他引:1
由简单方法合成巯基壳聚糖,通过FTIR、SEM、XPS、DTA-TG等技术对材料进行表征,实验结果表明,巯基乙酸的羧基分别与壳聚糖的氨基、醇羟基形成酰胺和巯基乙酸甲酯,从而使巯基功能团接枝在壳聚糖表面。吸附实验结果表明,在100 mL,20 mg/L的Cu2+水溶液中,温度为310 K,pH为5,吸附时间为12 min,吸附剂用量为50 mg时,吸附效果最好,去除率达到87%。巯基壳聚糖对Cu2+的吸附动力学可由拟二级反应模型拟合。 相似文献
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介绍用邻硝基氯苯与水合肼为原料合成 1-羟基苯并三氮唑 ,再还原成苯并三氮唑。较好的工艺条件为反应温度为 85℃ ,时间为 4h ,用乙酸乙酯为萃取剂 ,铁粉分次加入。 相似文献
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苯并三氮唑及其衍生物是一类毒性低、稳定性高且应用广泛的紫外吸收材料。文章研究了炭载PdPtCu三金属催化2-硝基-(2’-羟基-5’-甲基苯基)偶氮苯(HAB)加氢合成2-(2’-羟基-5’-甲基苯基)苯并三氮唑(UV-P)的性能,在323 K、0.5 MPa氢气压力条件下反应5 h后HAB转化率为100%、UV-P选择性达92.2%,实现了偶氮化合物加氢高选择性地合成苯并三氮唑紫外吸收剂的目的。利用XRD、TEM及XPS等催化剂表征手段,发现Cu-Pd、Cu-Pt合金相与催化剂表面适量的缺电子态贵金属物种(Mδ )可以有效抑制N-N键断裂与过度加氢副反应,降低了四氢化合物和芳胺类等副产物的生成。 相似文献
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介绍了苯并三氮唑及衍生物的开发,应用,研究进展情况,对合成的10余种可聚合单体在不同方面的应用做了详细阐述,对其开发应用前景做了展望。 相似文献
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废水净化纤维的制备及对Cu^2+的吸附性能 总被引:3,自引:0,他引:3
以环氧基为交联桥,将β-环糊精接枝于纤维素纤维上,制备了废水净化纤维,并获得了适宜的制备工艺参数,同时从动力学角度考察了其静态吸附Cu2+的行为.结果表明,环氧化乃该纤维制备之关键,废水净化纤维对Cu2+吸附量可达6.24
mg/g,吸附能力主要来自废水净化纤维β-环糊精中羟基与Cu2+的络合作用,β-环糊精与Cu2+络合比为47. 相似文献
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采用静态平衡吸附法用柠檬酸纤维素(Cell-CA)吸附废水中Cu2+,考察了溶液的初始浓度、吸附剂颗粒大小、pH值、吸附时间和温度对吸附的影响,分析了吸附过程的热力学、动力学和等温吸附规律.结果表明,在pH值为5.5时Cell-CA对废水中Cu2+的吸附率为92.7%,吸附容量高达18.54mg/g;对不同温度下的吸附等温线采用Freundlich和Langmuir方程进行拟合,结果显示Langmuir方程的拟合效果更好.模拟吸附动力学实验数据符合准一级和准二级动力学模型,Cell-CA对Cu2+的吸附是放热反应. 相似文献
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A.I. Ivanets V. Srivastava M.Yu. Roshchina M. Sillanpää V.G. Prozorovich V.V. Pankov 《Ceramics International》2018,44(8):9097-9104
The aim of this research was to prepare magnesium ferrite (MgFe2O4) magnetic nanoparticles and to investigate their sorption characteristics towards Mn2+, Co2+, Ni2+, Cu2+ ions in aqueous solution. MgFe2O4 was synthesized by glycine-nitrate combustion method and was characterized by low crystallinity with crystallite size of 8.2?nm, particle aggregates of 13–25?nm, BET surface area of 14?m2/g and pore size of 8.0?nm. Sorption properties of MgFe2O4 towards Mn2+, Co2+, Ni2+, Cu2+ ions were studied using one-component model solutions and found to be dependent on metal ions concentration, contact time, pH and conditions of regeneration experiment. The highest sorption capacity of MgFe2O4 was detected towards Co2+ (2.30?mmol?g1) and Mn2+ (1.56?mmol?g?1) and the lowest towards Ni2+ (0.89?mmol?g?1) and Cu2+ (0.46?mmol?g?1). It was observed that sorption equilibrium occurs very quickly within 20–60?min. The pHzpc of sorbent was calculated to be 6.58. At studied pH interval (3.0–7.0) the sorption capacity of MgFe2O4 was not significantly affected. Regeneration study showed that the metal loaded sorbent could be regenerated by aqueous solution of 10?3 M MgCl2 at pH 6.0 within 120?min of contact time. Regeneration test suggested that MgFe2O4 magnetic sorbent can be efficiently used at least for four adsorption-desorption cycles. The high sorption properties and kinetics of toxic metal ion sorption indicates good prospects of developed sorbent in practice for wastewater treatment. 相似文献
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分别采用荧光光谱(FS)、紫外可见吸收光谱(UV-Vis)以及圆二色谱(CD)考察了2种金属离子Cu2+、Zn2+对牛血清白蛋白(BSA)-盐酸小檗碱(BC)结合过程的变构效应,得到表征BSA内源荧光猝灭、BSA-BC复合物稳定性、BC在BSA分子上的结合位点数发生变构的定量变构系数βQ、βA、βn。结果表明,Cu2+/Zn2+对BC猝灭BSA内源荧光呈正变构效应(βQ>1),且变构效应随Cu2+/Zn2+浓度的增大呈现一定的饱和性;而对BSA-BC复合物稳定性以及BC在BSA分子上的结合位点数呈负变构效应(0<βA<1,0<βn<1),且变构效应随Cu2+/Zn2+浓度的增大呈现不同变化趋势;BSA分子构象转变可能是产生变构效应的主要原因。 相似文献
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Jingwei Zhang Lingxin Kong Yao Chen Huijiang Huang Huanhuan Zhang Yaqi Yao Yuxi Xu Yan Xu Shengping Wang Xinbin Ma Yujun Zhao 《Frontiers of Chemical Science and Engineering》2021,15(3):666
As the substitution of common noble catalysts in the hydrogenation of carboxylic acid, a highly effective Cu-Ni/SiO2 catalyst was prepared by a novel stepwise ammonia evaporation method. Its performance in the gas-phase hydrogenation of acetic acid was further examined. With the introduction of Ni dopant, more stable Cuδ+ sites, which can adsorb more acetic acid, were formed due to the electron transfer from Cu to Ni. This makes more Cu0 sites available for hydrogen adsorption, which was suggested as the rate-determining step in acetic acid hydrogenation. A conversion of 99.6% was successfully achieved on this new Cu/SiO2-0.5Ni catalyst, accompanied by the ethanol selectivity of 90%. The incorporation of nickel between copper nanoparticles enhances the synergistic effect between Cu0 and Cu+. It also helps mitigate the aggregation of copper nanoparticles due to the Ostwald ripening effect induced by acetic acid and enhance the stability of copper catalyst in the conversion of carboxylic acid. 相似文献
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用碳纳米管和纳米TiO2混合修饰碳糊电极,用循环伏安法考察了修饰电极测量Cu的优化条件及其电化学稳定性。结果表明,在pH=5.5的HAc-NaAc缓冲溶液中,当Cu2+在修饰电极表面富集200 s、电位扫描速率控制在60 mV/s时,修饰电极在循环伏安图上能出现1个灵敏氧化峰,峰电位为0.141V,利用这个峰可以对Cu进行检测。峰电流与Cu2+的浓度在1.0×10-7~1.0×10-4 mol/L的范围内成良好线性关系,相关系数为0.994 4,检出限为1.43×10-8mol/L。 相似文献