共查询到20条相似文献,搜索用时 15 毫秒
1.
A series of granular pH-sensitive semi-interpenetrating polymer network (semi-IPN) hydrogels based on chitosan (CTS), acrylic acid (AA) and gelatine (GE) were utilized for the adsorption and recycle of Pb(II) from aqueous solutions. The composite hydrogels have been characterized by FT-IR and TGA. The effects of contact time, pH value and initial Pb(II) concentration on the adsorption were investigated. Results indicated that the adsorption capacity of the hydrogel increased with increasing pH value and initial Pb(II) concentration, and a pH-sensitive adsorption characteristic was presented. The adsorption rate of the semi-IPN hydrogels on Pb(II) is fast with an adsorption rate constant of 14.9790 mg/(g·s), and adsorption equilibrium could be reached within 10 min. The adsorption isotherms of the hydrogels for Pb(II) could be described well by the Langmuir equation, rather than the Freundlich equation. The as-prepared hydrogels showed good reusability with 0.05 mol/l HNO3 solutions as the desorbing agent and 0.1 mol/l NaOH solutions as the regeneration agent, respectively. After five consecutive adsorption-desorption processes, the semi-IPN hydrogel with 20 wt% GE may reach 85.26% of its initial adsorption capacity. In addition, the adsorbed Pb(II) can be quantitatively recovered by simply eluting the hydrogel with dilute HNO3 solution, and a recovery ratio of 89.27% was reached for the semi-IPN hydrogel. The satisfactory adsorption amount is mainly derived from the chelating of functional groups (i.e. –COO? and –NH2) with Pb(II) ions. The hydrogel adsorbents exhibited excellent affinity for Pb(II), and can be applied to treat wastewater containing heavy metal ion and simultaneously recover the valuable metal sources. 相似文献
2.
3.
4.
5.
6.
In this work, the amino-functionalized cellulose nanocrystal (ACNC) was prepared using a green route and applied as a biosorbent for adsorption of Cr(VI), Pb2+, and Cu2+ from aqueous solutions. CNC was firstly oxidized by sodium periodate to yield the dialdehyde nanocellulose (DACNC). Then, DACNC reacted with diethylenetriamine (DETA) to obtain amino-functionalized nanocellulose (ACNC) through a Schiff base reaction. The properties of DACNC and ACNC were characterized by using elemental analysis, Fourier transform infrared spectroscopy (FT-IR), Kaiser test, atomic force microscopy (AFM), X-ray diffraction (XRD), and zeta potential measurement. The presence of free amino groups was evidenced by the FT-IR results and Kaiser test. ACNCs exhibited an amphoteric nature with isoelectric points between pH 8 and 9. After the chemical modification, the cellulose I polymorph of nanocellulose remained, while the crystallinity decreased. The adsorption behavior of ACNC was investigated for the removal of Cr(VI), Pb2+, and Cu2+ in aqueous solutions. The maximum adsorption capacities were obtained at pH 2 for Cr(VI) and pH 6 for Cu2+ and Pb2+, respectively. The adsorption all followed pseudo second-order kinetics and Sips adsorption isotherms. The estimated adsorption capacities for Cr(VI), Pb2+, and Cu2+ were 70.503, 54.115, and 49.600 mg/g, respectively. 相似文献
7.
重金属污染是目前最为严峻的环境问题之一,我国的重金属污染问题尤为突出。活性炭、纳米碳管和石墨烯等环境友好型碳质材料由于其比表面积大,吸附能力强等优点而被应用于水中重金属的去除,而进行官能团功能化改性后其吸附效果可以明显提高。本文重点阐述了活性炭、纳米碳管、石墨烯及生物质炭等碳质材料的巯基化(-SH)、氨基化(-NH2)等功能化改性方法及其应用,考察了功能化碳质复合材料对水中重金属离子的去除效果和影响因素,最后展望了功能化碳质复合材料对水中重金属污染物去除研究的发展方向。 相似文献
8.
还原态氧化石墨烯的制备及其对重金属离子的吸附性能 总被引:2,自引:1,他引:1
通过乙二胺(EDA)对氧化石墨烯(GO)进行还原制备了还原态氧化石墨烯(RGO),利用红外光谱、拉曼光谱、热重分析和扫描电子显微镜等技术对制得的RGO进行了表征。 考察了RGO复合材料在静态吸附条件下对Pb(Ⅱ)、Cd(Ⅱ)、Cu(Ⅱ)和Mn(Ⅱ)金属离子的吸附性能。 结果表明,该吸附材料对上述4种重金属离子在25 ℃时的静态饱和吸附量分别为396.6、115.3、54.2和38.6 mg/g。 吸附于RGO上的Pb(Ⅱ)可用0.05 mol/L HCl溶液进行洗脱,再生后的RGO重复使用3次时吸附量能达到首次吸附量的85%。 相似文献
9.
Bernabé L. Rivas Eduardo D. Pereira Pamela Robles Rocío Cid 《Macromolecular Symposia》2006,235(1):152-160
Summary: Water-soluble poly[3-(dimethylamino)propylacrylate] is synthesized by radical polymerization with a yield of 87%. The polymer structure is confirmed by FT-IR and 1H-NMR spectroscopies. The polymer lost only 3% of weight up to 100 °C. The narrowest molecular weight distribution is observed with the fraction between 3,000 and 10,000 Da. P(DAPA) presents a high affinity for the metal ions Pb2+ and Cu2+, while the other metal ions are not significantly retained. By increasing the filtration factor, Z, metal ion affinity decreases, indicating a very weak ligand-metal interaction and the possibility of its destruction when washed with water at the filtration cell's pH. For Z = 10, the retention values of Pb2+ and Cu2+ at pH 5 are 76.5% and 48.5%, respectively, while the values for Cu2+ and Cd2+ at pH 7 are 89.5% and 40.4%, respectively. 相似文献
10.
Bogdan-Constantin Condurache Corneliu Cojocaru Petrisor Samoila Susana Felicia Cosmulescu Georgeta Predeanu Andra-Cristina Enache Valeria Harabagiu 《Molecules (Basel, Switzerland)》2022,27(18)
Nowadays, very coarse wool fibers are considered waste biomass and are discarded at random or burned. Therefore, it is of actual interest to valorize coarse wool fibers as utile products. In this sense, we report herein an environmentally-friendly process for the preparation of a new material based on oxidized wool fibers and designed for efficient adsorption of heavy metals from wastewater. The morphology and the structure of the obtained product were characterized by scanning electron microscopy (SEM) coupled with an X-ray energy-dispersive module (EDX) and by Fourier-transform infrared spectroscopy (FTIR). Likewise, the performances of the oxidized wool fibers for the adsorption of heavy metal cations (Cu2+, Cd2+, Pb2+) from aqueous solutions were tested. The adsorption kinetics data were analyzed by applying the pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The equilibrium of the adsorption process was investigated by using the Freundlich and Langmuir isotherm models. According to the Langmuir isotherms registered at 300 K, the maximum adsorption capacities of the oxidized wool were found to increase from Cu2+ (9.41 mg/g) and Cd2+ (10.42 mg/g) to Pb2+ (30.71 mg/g). Consequently, the removal efficiency of metal ions was found to vary in the range of 96.8–99.7%. The thermodynamic parameters (e.g., enthalpy, entropy, and Gibbs free energy) were calculated and discussed. 相似文献
11.
纳米零价铁去除水中重金属离子的研究进展 总被引:5,自引:0,他引:5
重金属离子危害严重.本文综述了近几年纳米零价铁去除水中重金属离子的研究,总结了纳米零价铁去除水中重金属离子的机理,主要包括:纳米零价铁的表面吸附-配合、还原、吸附-还原,并对纳米零价铁在这一领域的应用进行了展望. 相似文献
12.
壳聚糖的结构中含有大量的—NH2和—OH,因此其对重金属离子有优良的吸附作用。但是作为天然高分子物质,壳聚糖的吸附性能又受到其自身物理形态、原料来源、脱乙酰度及体系pH值的影响,因此,对其进行物理和化学改性是提高壳聚糖吸附性能、扩大应用范围的必要手段。本文综述了壳聚糖的改性方法及其衍生物对重金属离子吸附作用的研究进展,并对其在重金属污染废水处理方面的前景作了展望。 相似文献
13.
Selective separation of heavy metal ions from acidic aqueous solutions is of strong interest for certain industrial processes, such as electroplating, as well as environmental protection, for example battery recycling. Amino-functionalized adsorbents are often discussed as suitable material for this purpose. Herein, two silica-based adsorbents functionalized with 3-aminopropyl- and 3-[2-[2-aminoethylamino]-ethylamino]-propyl-ligands resulting in adsorbents MonoA and TriA, respectively, were investigated regarding their separation behavior with focus on nickel(II) and cobalt(II) in batch as well as continuous flow experiments in acidic aqueous solutions. For both adsorbents, pH shifts into the alkaline range were observed in the process solutions, causing precipitation of metal hydroxides mainly in the particle pores in case of adsorbent MonoA and a combination of precipitation and adsorption regarding adsorbent TriA. Contrary to prior studies, our findings evidence that amino-functionalized adsorbents are not applicable for nickel(II) and cobalt(II) in selective adsorption processes and additionally demonstrate that, besides batch investigations, continuous flow experiments are essential for well-founded adsorbent selections in process development. 相似文献
14.
Youjun Zhang Licong Liu Dixiong Yu Jinglan Liu Lin Zhao Jinpeng Liu Shuo Liu 《Molecules (Basel, Switzerland)》2022,27(11)
A magnetic metal–organic framework nanocomposite (magnetic MIL-68(Ga)) was synthesized through a “one pot” reaction and used for heavy metal ion removal. The morphology and elemental properties of the nanocomposite were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), as well as zeta potential. Moreover, the factors affecting the adsorption capacity of the nanocomposite, including time, pH, metal ion type and concentration, were studied. It was found that the adsorption capacity of magnetic MIL-68(Ga) for Pb2+ and Cu2+ was 220 and 130 mg/g, respectively. Notably, the magnetic adsorbents could be separated easily using an external magnetic field, regenerated by ethylenediaminetetraacetic acid disodium salt (EDTA-Na2) and reused three times, in favor of practical application. This study provides a reference for the rapid separation and purification of heavy metal ions from wastewater. 相似文献
15.
丁二酸酐接枝纤维素纳米纤维膜及其重金属离子吸附 总被引:1,自引:0,他引:1
采用热致相分离(TIPS)法以三醋酸纤维素(TCA)为原料成功制备直径为(110±28)nm TCA多孔纳米纤维膜。将TCA纤维膜通过水解转化为纤维素(Cell)、接枝制备丁二酸酐接枝改性纤维素(Cell-g-SAA)膜。将Cell膜和Cell-g-SAA膜用于吸附水中Cu~(2+)、Pb~(2+),并对膜样品的吸附动力学、等温吸附和吸附热力学进行了研究。结果表明,二级动力学拟合和Langmuir模型更适合于该体系。与Cell膜相比,改性后Cell-g-SAA膜对Cu~(2+)和Pb~(2+)的最大吸附容量分别从51.73和34.29 mg/g增加到116.41和51.73 mg/g。纤维膜对Cu~(2+)、Pb~(2+)的吸附更趋近于单层吸附且化学吸附占主导地位。 相似文献
16.
17.
Amr El‐Hag Ali Hassan A. Abd El‐Rehim H. Kamal Dalia El‐Sayed A. Hegazy 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):628-634
A unique natural polymer based colon specific drug carrier was prepared from carboxymethyl cellulose (CMC) and acrylic acid (AAc) in aqueous solution employing γ‐radiation induced copolymerization and crosslinking. The effect of preparation conditions such as the natural polymer content and irradiation dose on gelation process was investigated. The swelling behavior of the prepared hydrogels was characterized by investigating the time and pH dependent swelling of the (CMC/AAc) hydrogels of different CMC content. The effects of the hydrogel composition and pH of the swelling medium on the swelling indices were estimated. The results show that the increment in the CMC content in the feed solution enhances the gelation process. The results also show the dependence of the swelling indices on both hydrogel composition and pH value of the swelling medium. To evaluate the ability of the prepared hydrogel to be used as a colon‐specific drug carrier, the release profile of theophylline was studied as a function of time at pH 1 and pH 7. 相似文献
18.
聚苯胺及其复合物对重金属离子的高效吸附性能 总被引:5,自引:0,他引:5
基于国外最新文献,系统总结了近年来聚苯胺及其复合物的制备方法及其重金属离子吸附性能,重点分析了吸附性能特征,指出聚苯胺及其复合物具有吸附下限浓度低、达到吸附平衡快以及解吸附性能优异等特点.填充有聚苯胺颗粒的吸附柱在动态处理初始浓度为83 ng/L的汞离子溶液时,经一次吸附与解吸循环操作后,汞离子的富集倍数可达120倍.应用于冷原子吸收光谱的待测样品的浓缩与富集,可以将汞的测试下限拓展到0.05 ng/L.聚苯胺及其复合物在痕量重金属离子的高效富集与灵敏探测等方面展示了广阔的应用前景. 相似文献
19.
聚萘二胺的合成及其对重金属离子的高效反应吸附 总被引:10,自引:0,他引:10
聚萘二胺是继聚苯胺和聚吡咯之后的又一类新型导电高分子,因聚合物中含有活性 的自由胺基和亚胺基而具有新的多功能性.作者根据近期研究工作和国外最新文献,系统论述了聚1,8-、1,5-、2,3-萘二胺的化学氧化合成和电化学氧化合成及其对重金属离子的络合和还原吸附功能,详细比较了两种聚合方法的特点. 指出通过萘二胺的电化学氧化聚合可以方便地获得对重金属离子如Ag+、Pb2+、Hg2+、Cu2+、VO2+敏感的修饰电极,而通过化学 氧化聚合可以高产率地获得对Ag+具有极大的还原吸附容量的聚合物颗粒.聚萘二胺在痕量 金属离子的分析与探测、工业废水中贵金属离子的回收和重金属离子的清除等领域展现了广阔的应用前景. 相似文献
20.
万秋月 《中国无机分析化学》2018,8(4):4-8
建立了香蕉皮快速、高效对重金属离子铅吸附性能的方法。采用分光光度法测定重金属离子铅的浓度,分别研究了7种不同形态的吸附剂对废水中重金属离子铅的吸附性能。在优化的实验条件下,重金属离子铅浓度与吸光度的线性相关系数R=0.999 83,且方法相对标准偏差(RSD)低于3%。结果表明,香蕉皮对废水中的重金属离子铅有良好的吸附效果,吸附率达到91.3%。利用香蕉皮去除废水中的重金属离子,可以变废为宝,且方法吸附率高、准确可靠、精密度高,可用于吸附废水中重金属离子铅。 相似文献