改性海泡石对废水中Pb2+、Hg2+、Cd2+ 吸附性能的研究

用盐酸溶液对海泡石进行处理和在450℃灼烧,制备出改性海泡石。在动态条件下,研究了改性海泡石对重金属离子Pb2+、Hg2+、Cd2+的吸附效果及吸附条件。同时探讨了改性海泡石对重金属离子Pb2+、Hg2+、Cd2+的吸附机理。含Pb2+、Hg2+、Cd2+的冶金废水经改性海泡石吸附后,重金属离子含量显著低于国家排放标准。     

改性海泡石对废水中Pb2^＋、Hg2^＋、Cd2^＋1吸附性能的研究

用盐酸溶液对海泡石进行处理和在450C灼烧，制备出改性海泡石。在动态条件下，研究了改性海泡石对重金属离子Pb2^ 、Hg2^ 、Cd2^ 的吸附效果及吸附条件。同时探讨了改性海泡石对重金属离子Pb2^ 、Hg2^ 、Cd2^ 的吸附机理。合Pb2^ 、Hg2^ 、Cd2^ 的冶金废水经改性海泡石吸附后，重金属离子含量显著低于国家排放标准。     

微波改性的稻壳对Pb(Ⅱ)、Cd(Ⅱ)吸附性能的研究

以稻壳为原料,采用微波处理制备出改性的吸附材料,用于吸附Pb2+、Cd2+的实验,探讨了溶液p H、搅拌时间及金属离子初始浓度等对吸附平衡的影响,利用扫描电镜和红外光谱(FTIR)分析,探讨微波处理后的稻壳吸附Pb2+、Cd2+等金属离子的吸附机理。结果表明:微波处理后的稻壳对Pb2+的最佳吸附p H=5,在60 min内建立吸附平衡,对Pb2+的最大吸附量为0.232 4 mmol/g;在相同条件下对Cd2+的最大吸附量为0.185 2 mmol/g。     

改性聚丙烯腈纤维对铅镉汞离子的吸附性能研究

以改性聚丙腈纤维(简称改性纤维,用L表示)为吸附剂,对水溶液中的重金属离子Pb2+、Cd2+、Hg2+进行螯合吸附.实验证明,L对它们有很强的吸附能力,通过实验确定出L对各离子吸附的最佳条件参数:温度、时间、pH值、离子浓度等;并发现L对Pb2+、Hg2+有累积吸附作用;吸附后的纤维可以反复再生使用,并找出再生的最佳条件.而且,在一定的浓度范围内三种离子的吸附都能符合Freundlich型等温方程式.     

高岭土-MBT复合体对某些重金属离子吸附性能的研究

通过对高岭土进行表面改性制备了高岭土 MBT复合体 ,并考察了其对水溶液中某些重金属离子的吸附性能。结果表明 :高岭土 MBT复合体对水中Pb2 +、Hg2 +、Zn2 +的吸附能力明显优于纯高岭土和仅经过表面处理的高岭土 ,其对Pb2 +、Hg2 +、Zn2 +的最大吸附量分别为 16 91μmol·g- 1、2 0 5 2 μmol·g- 1和 10 80 μmol·g- 1。     

柠檬酸改性花生壳对水中重金属Cu、Pb、Cd和Cr的吸附特性研究

用柠檬酸对粒状花生壳进行改性,考察了改性粒状花生壳的投加量、吸附反应时间、重金属初始浓度等对水中Cu、Pb、Cd和Cr吸附量的影响,探讨了改性粒状花生壳的等温吸附及吸附动力学特性。结果表明,准二级吸附动力学方程可较好地模拟Cu、Pb、Cd和Cr等4种重金属在改性粒状花生壳上的吸附动力学行为;Langmuir模型能相对更好地拟合改性粒状花生壳对4种重金属的等温吸附过程,Cu、Pb、Cd和Cr的理论最大吸附量分别为11.88,20.70,7.82,7.35 mg/g。改性粒状花生壳与Pb的结合力最强,对Pb的吸附容量远大于其它3种重金属。     

柠檬酸改性花生壳对水中重金属Cu、Pb、Cd和Cr的吸附特性研究

用柠檬酸对粒状花生壳进行改性,考察了改性粒状花生壳的投加量、吸附反应时间、重金属初始浓度等对水中Cu、Pb、Cd和Cr吸附量的影响,探讨了改性粒状花生壳的等温吸附及吸附动力学特性。结果表明,准二级吸附动力学方程可较好地模拟Cu、Pb、Cd和Cr等4种重金属在改性粒状花生壳上的吸附动力学行为;Langmuir模型能相对更好地拟合改性粒状花生壳对4种重金属的等温吸附过程,Cu、Pb、Cd和Cr的理论最大吸附量分别为11.88,20.70,7.82,7.35 mg/g。改性粒状花生壳与Pb的结合力最强,对Pb的吸附容量远大于其它3种重金属。     

氨基和羧基功能化磁性微球去除水溶液中Cd(Ⅱ)和Pb(Ⅱ)

以甲基丙烯酸和丙烯酰胺为功能单体,通过悬浮聚合法制备了氨基和羧基双功能化的磁性复合微球(Fe3 O4@SiO2-NH2/COOH),并探讨了其对水溶液中Cd(Ⅱ)和Pb(Ⅱ)的吸附性能.X-射线衍射(XRD)分析表明,制备的磁性吸附剂内核为Fe3 O4.红外光谱(FT-IR)和扫描电镜(SEM)测试表明,氨基和羧基对Fe3 O4@SiO2表面改性成功.吸附试验显示,Fe3O4@SiO2-NH2/COOH吸附Cd(Ⅱ)和Pb(Ⅱ)的最优pH值分别为5.0和5.5,吸附过程均符合动力学准二级模型和Langmuir吸附等温模型,吸附剂对Cd(Ⅱ)和Pb(Ⅱ)最大吸附量分别为207.807 mg/g和168.995 mg/g.实际饮用水样中Cd(Ⅱ)和Pb(Ⅱ)的吸附表明,去除率分别可达97.74％和91.44％.该磁性吸附剂对两种重金属离子吸附量大、去除率高,具有良好的实际应用潜力.     

废弃溴代环氧树脂制备螯合材料及其对Cu2+的吸附性能

以废弃印刷电路板固体废料中的溴代环氧树脂为高分子母体材料,经酸碱预处理后先用乙二胺进行胺化改性,然后再用氯乙酸进行功能化反应,制备了一种含有氨基乙酸基团的新型螯合树脂。通过傅立叶变换红外光谱仪(FTIR)以及13C NMR对其改性前后的树脂结构进行了表征,并测定了改性前后材料对Cu2+的吸附效果,数据表明:改性制备的胺基乙酸螯合树脂对Cu2+具有良好的吸附效果。此外,通过考察氯乙酸功能化反应过程中反应温度、反应时间以及氯乙酸的用量对改性产物吸附Cu2+的性能影响,确定了改性制备该螯合树脂的最佳工艺参数。结果表明:当树脂用量与氯乙酸的用量比为1∶1时,在60℃下反应8h,改性所得的螯合树脂对Cu2+的吸附效果最佳,最大的吸附容量达到4.727mg/g。     

红壤和褐壤对F-、Cr2O42-、和Pb2+的吸附特性对比

对比了红壤和褐壤对F-、Cr2O2-4和Pb2+等离子的静态和动态吸附特性。结果表明,土壤对其中阴离子的吸附容量为600~3000 mg/kg,符合单层吸附,而对阳离子吸附随溶液浓度升高而上升,在300 mg/L的Pb2+溶液内吸附容量达16000 mg/kg,红壤对F-的吸附性比褐壤强,而对Cr2O2-4和Pb2+则相反;土壤对F-的动态吸附速率最快,容量为338~800 mg/kg,Pb2+次之,容量为228~293 mg/kg,而Cr2O2-4几乎不吸附。     

鸡蛋壳废料和磷酸改性粉末活性炭及去除生活饮用水中的重金属

从鸡蛋壳废弃物中提取钙溶液,被用来作为一种低成本的活化剂,以提高活性炭的吸附性能。并研究了这种吸附剂在自来水中对As3+、Cd2+、Pb2+、Cr6+的吸附效果。实验表明:在室温26℃,pH值为7的自来水中,鸡蛋壳废料改性的粉末活性炭用量是1 g/L,可一次去除《生活饮用水卫生标准》[1]中As3+、Cd2+、Pb2+、Cr6+限值的2.5倍量,并且自来水中原有Cu2+、Zn2+、Al3+含量均有所降低。     

香豆素基吡啶盐选择性识别Cu2＋

【摘要】设计合成了新型禽吡啶盐结构的褥驻素类Cu2＋荧光分子探针CCu。在中性缓冲溶液中,CCu在常见碱金属离子（K＋,Na＋）、碱土金属离子（Ca2＋,Mg2＋）、过渡金属离子（Cd2＋,Ag＋,Fe3＋,Pb2＋,Hg2＋,Cr3＋,Co2＋,Ni2＋,Cu2＋,Zn2＋）中能够专一性的识别Cu2＋。滴加Cu2＋后引起吸收光嘴蓝移27nm,溶液颜色由黄色变为淡绿色,荧光光谱蓝移18nm,荧光增强8．3倍。     

Implications of the structure of cementitious wastes containing Pb(II), Cd(II), As(V), and Cr(VI) on the leaching of metals

Cement stabilisation has been widely applied for the immobilisation of heavy metal ions before their disposal in landfills. This paper investigated the microstructure of cementitious wastes containing Pb, Cd, As, and Cr using an electron probe microanalyser and examined the implications of the microstructure on the leaching of the metal ions. From the microstructure analysis, it was proposed that Pb, As, and Cr ions were homogeneously dispersed in the calcium silicate hydrate (C-S-H) matrix by adsorption or precipitation with calcium or silicate compounds present in the cement. However, Cd formed discrete Cd(OH)₂ precipitates believed to be contained within the cement pores or adsorbed on the C-S-H matrix. The leaching of metals in the pH region of 6 to 8 decreased in the following order: Cr(VI)>Cd(II)>Pb(II)>As(V). This leaching trend was found to be influenced by the manner in which the metal ions were incorporated into the cement matrix.     

Removal of Cd(II), Hg(II), and Pb(II) ions from aqueous solution using p(HEMA/chitosan) membranes

An interpenetration network (IPN) was synthesized from 2‐hydroxyethyl methacrylate (HEMA) and chitosan, p(HEMA/chitosan) via UV‐initiated photo‐polymerization. The selectivity to different heavy metal ions viz Cd(II), Pb(II), and Hg(II) to the IPN membrane has been investigated from aqueous solution using bare pHEMA membrane as a control system. Removal efficiency of metal ions from aqueous solution using the IPN membranes increased with increasing chitosan content and initial metal ions concentrations, and the equilibrium time was reached within 60 min. Adsorption of all the tested heavy metal ions on the IPN membranes was found to be pH dependent and maximum adsorption was obtained at pH 5.0. The maximum adsorption capacities of the IPN membrane for Cd(II), Pb(II), and Hg(II) were 0.063, 0.179, and 0.197 mmol/g membrane, respectively. The adsorption of the Cd(II), Hg(II), and Pb(II) metal ions on the bare pHEMA membrane was not significant. When the heavy metal ions were in competition, the amounts of adsorbed metal ions were found to be 0.035 mmol/g for Cd(II), 0.074 mmol/g for Hg(II), and 0.153 mmol/g for Pb(II), the IPN membrane is significantly selective for Pb(II) ions. The stability constants of IPN membrane–metal ions complexes were calculated by the method of Ruzic. The results obtained from the kinetics and isotherm studies showed that the experimental data for the removal of heavy metal ions were well described with the second‐order kinetic equations and the Langmuir isotherm model. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

火焰原子吸收法测定废水中Hg(Ⅱ)、Ni(Ⅱ)和Cr(Ⅵ)

采用了壳聚糖装柱法对金属离子进行吸附,研究了壳聚糖对Hg(Ⅱ)、Ni(Ⅱ)、Cr(Ⅵ)离子的吸附以及吸附时间、pH值和流速等对壳聚糖吸附的影响。通过最佳条件实验,用火焰原子吸收法测得重金属的含量并应用于工业废水的测定。     

Poly(4-sodium styrene sulfonate-co-4-acryloylmorpholine). Synthesis,Characterization, and Metal Ion Retention Properties

Abstract

A novel resin poly(sodium 4-styrene sulfonate-co-4-acryloyl morpholine) was synthesized through a radical solution polymerization in solution and studied as an adsorbent under uncompetitive and competitive conditions by batch and column equilibrium procedures for the following divalent metal ions Cd(II), Zn(II), Pb(II), and Hg(II), and trivalent Cr(III). For all metal ions, the adsorption was strongly influenced by the pH. The maximum retention capacity, 3.29 mmol of metal ion/g, was obtained for Zn(II) at pH 5 by batch equilibrium procedure. For both the batch and column procedures, the retention behavior was similar for Cd(II), Cr(III), Zn(II), and Pb(II).     

榆林学院校区生活饮用水中重金属污染物的健康风险评估

对榆林学院校区生活饮用水水源和管网末梢水中Cr6+、Cd、As、Pb、Hg、Cu、Zn和Fe 8种重金属进行了测定,其浓度均低于《生活饮用水卫生标准》(GB 5749—2006)。并根据美国国家环保局推荐的健康风险评估模型对其通过饮用水途径所引起的健康风险做了初步评估,数据显示,致癌物质(Cr6+、Cd和As)所引起的健康风险远大于非致癌物质(Pb、Hg、Cu、Zn和Fe)所引起的健康风险,其优先控制顺序为Cr6+CdAsZnCuPbHgFe。结果表明,榆林学院校区生活饮用水中重金属污染物对人体健康产生的个人年总风险均已超过国际防辐射委员会规定的可接受健康风险水平5×10-5/a,主要贡献者是Cr6+,应引起相关部门的重视,也是优先治理的指标。     

Preparation and characterization of magnetic polymethylmethacrylate microbeads carrying ethylene diamine for removal of Cu(II), Cd(II), Pb(II), and Hg(II) from aqueous solutions

Magnetic polymethylmethacrylate (mPMMA) microbeads carrying ethylene diamine (EDA) were prepared for the removal of heavy metal ions (i.e., copper, lead, cadmium, and mercury) from aqueous solutions containing different amount of these ions (5–700 mg/L) and at different pH values (2.0–8.0). Adsorption of heavy metal ions on the unmodified mPMMA microbeads was very low (3.6 μmol/g for Cu(II), 4.2 μmol/g for Pb(II), 4.6 μmol/g for Cd(II), and 2.9 μmol/g for Hg(II)). EDA‐incorporation significantly increased the heavy metal adsorption (201 μmol/g for Cu(II), 186 μmol/g for Pb(II), 162 μmol/g for Cd(II), and 150 μmol/g for Hg(II)). Competitive adsorption capacities (in the case of adsorption from mixture) were determined to be 79.8 μmol/g for Cu(II), 58.7 μmol/g for Pb(II), 52.4 μmol/g for Cd(II), and 45.3 μmol/g for Hg(II). The observed affinity order in adsorption was found to be Cu(II) > Pb(II) > Cd(II) > Hg(II) for both under noncompetitive and competitive conditions. The adsorption of heavy metal ions increased with increasing pH and reached a plateau value at around pH 5.0. The optimal pH range for heavy‐metal removal was shown to be from 5.0 to 8.0. Desorption of heavy‐metal ions was achieved using 0.1 M HNO₃. The maximum elution value was as high as 98%. These microbeads are suitable for repeated use for more than five adsorption‐desorption cycles without considerable loss of adsorption capacity. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 81–89, 2000     

用主成分回归法同时测定Zn~(2+)、Cd~(2+)、Pb~(2+)和Cu~(2+)的研究

使用聚类分析对不同缓冲体系下Zn2+、Cd2+、Pb2+、Cu2+的吸光度光谱数据分析,通过数量化的方法确定pH值=6.0的最佳缓冲体系。通过单因素实验分析确定缓冲溶液用量为5.0ml、显色剂用量为3.0ml、环糊精用量为2.0ml及最佳显色时间10min。绘制Zn2+、Cd2+、Pb2+、Cu2+的标准曲线,结果表明其具有良好的线性范围和线性加和性。应用主成分回归法计算含有干扰离子的待测水样中Zn2+、Cd2+、Pb2+、Cu2+的浓度,并计算出平均回收率为109.64%、92.77%、98.18%、102.28%,相对标准偏差为11.48%、11.12%、6.34%、4.72%。     

Metal‐chelating properties of poly(2‐hydroxyethyl methacrylate–methacryloylamidohistidine) membranes

Metal‐chelating membranes have advantages as adsorbents in comparison with conventional beads because they are not compressible and they eliminate internal diffusion limitations. The aim of this study was to explore in detail the performance of poly(2‐hydroxyethyl methacrylate–methacryloylamidohistidine) [poly(HEMA–MAH)] membranes for the removal of three toxic heavy‐metal ions—Cd(II), Pb(II), and Hg(II)—from aquatic systems. The poly(HEMA–MAH) membranes were characterized with scanning electron microscopy and ¹H‐NMR spectroscopy. The adsorption capacity of the poly(HEMA–MAH) membranes for the selected heavy‐metal ions from aqueous media containing different amounts of these ions (30–500 mg/L) and at different pH values (3.0–7.0) was investigated. The adsorption capacity of the membranes increased with time during the first 60 min and then leveled off toward the equilibrium adsorption. The maximum amounts of the heavy‐metal ions adsorbed were 8.2, 31.5, and 23.2 mg/g for Cd(II), Pb(II), and Hg(II), respectively. The competitive adsorption of the metal ions was also studied. When the metal ions competed, the adsorbed amounts were 2.9 mg of Cd(II)/g, 14.8 mg of Pb(II)/g, and 9.4 mg of Hg(II)/g. The poly(HEMA–MAH) membranes could be regenerated via washing with a solution of nitric acid (0.01M). The desorption ratio was as high as 97%. These membranes were suitable for repeated use for more than three adsorption/desorption cycles with negligible loss in the adsorption capacity. The stability constants for the metal‐ion/2‐methacryloylamidohistidine complexes were calculated to be 3.47 × 10⁶, 7.75 × 10⁷, and 2.01 × 10⁷ L/mol for Cd(II), Pb(II), and Hg(II) ions, respectively, with the Ruzic method. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1213–1219, 2005