天然水凝胶材料在水体中重金属离子处理的研究进展

水凝胶材料由于其良好的金属离子吸附性能,从而在废水处理和环境保护等领域起到了重要作用。本文综述了天然水凝胶材料的开发及其在水处理(重金属离子去除方面)应用上的研究进展。详细讨论了天然水凝胶类型及其不同结构对重金属离子处理性能的影响。最后,对废水处理的水凝胶材料进行了展望。     

碱性染料分子结构对水凝胶吸附的影响

研究碱性染料分子结构对水凝胶吸附的影响,考察了不同吸附条件,包括染料浓度、吸附时间及溶液温度等条件对水凝胶吸附效果的影响。实验结果表明,当孔雀绿和结晶紫的初始浓度分别为80 mg/L时,吸附容量分别达到100.3和192.6 mg/g。在实验浓度下,吸附过程可符合Langmuir和Freundlich等温线。动力学研究表明,实验数据符合准二级扩散模型。对于碱性染料孔雀绿和结晶紫来说,在318 K时,吸附容量达到最大值。     

坡缕石/聚乙二醇/丙烯酸水凝胶的表征及其对阳离子染料的吸附性能

采用红外光谱、X射线衍射和扫描电镜对辉光放电电解等离子体引发制备的坡缕石/聚乙二醇/丙烯酸(PGS/PEG/AA)水凝胶的结构和形貌进行了表征.研究了其对阳离子型染料亚甲基蓝、结晶紫、孔雀石绿和罗丹明B的吸附行为,考察了pH值、吸附时间对吸附性能的影响,同时探讨了可能的吸附机理.结果表明,PGS、PEG和AA发生接枝共聚形成水凝胶,组分间相容性好,表面呈现褶皱和深浅不均匀的孔洞;吸附的最佳pH值为6.2左右,吸附时间为3h,吸附动力学符合准二级模型,阳离子染料在PGS/PEG/AA上的吸附是由离子交换、氢键、范德华力等共同作用的物理化学过程.     

双网络水凝胶的研究进展

双网络水凝胶在保持高吸水性等性能的基础上改善了传统水凝胶机械性能差、不稳定等缺点.重点介绍了双网络水凝胶及其在组织工程、伤口敷料、离子吸附、农林业等方面的应用.当在组织工程、导电和伤口敷料等医学领域应用时,水凝胶的生物相容性及力学性能成为研究重点;当应用在林业和吸附染料、离子方面时,水凝胶的溶胀性能较为重要.     

互穿网络聚合物水凝胶的制备及其吸附研究进展

互穿网络聚合物(IPN)水凝胶在分离技术领域具有广泛的应用前景,这些年受到人们广泛关注.本文介绍了聚多糖基(壳聚糖、海藻酸、淀粉和其他聚多糖)、蛋白质基(明胶、胶原蛋白、丝纤蛋白和大豆蛋白)和合成聚合物基(非离子型和离子型)IPN水凝胶的制备方法,主要包括同步-IPN、分步-IPN和半-IPN的制备方法.为了提高聚合物水凝胶的生物相容性、溶胀率和机械强度,采用天然高分子与合成高分子共混制备IPN水凝胶.与单网络水凝胶相比,IPN水凝胶对染料和重金属离子的吸附速率快、吸附容量大.为了达到选择性吸附和提高水凝胶的比表面积,制备离子印迹IPN水凝胶和多孔IPN复合冷冻凝胶,是未来研究高效吸附IPN水凝胶的发展方向之一.     

新型聚合物网络水凝胶制备及其吸附性能研究

为同步吸附复合污水中的重金属离子及含酚化合物,利用半胱氨酸接枝改性β-环糊精(β-CD)得到巯基接枝β-环糊精(β-CD-Cys),氧化偶合反应巯基得到二硫键交联型新型聚合物网络水凝胶。通过红外光谱(IR)、核磁共振谱(~1H NMR)结合扫描电镜(SEM)表征其中间及最终产物,考察新型水凝胶热稳定性能和溶胀性能,并测试其分子-离子同步识别性能。结果表明,设计的反应路线合理,成功制得新型聚合物网络水凝胶,该新型水凝胶具有良好的热稳定性、溶胀性。同步去除重金属离子和含酚污染物的性能较优,对Cu~(2+)、Pb~(2+)、Cr~(3+)、Zn~(2+)和苯酚的最大吸附量分别为172.16、465.56、65.98、187.55、46.55mg×g~(-1)。新型聚合物网络水凝胶对重金属离子及苯酚的吸附符合准二级动力学模型,吸附等温线符合Langmuir吸附等温线。     

废水中重金属离子吸附材料的研究进展

自然界中的重金属离子会在生物体中富集和迁移,不会被降解,对人体和环境构成了严重危害.因操作方便、选择性高等优点,吸附法处理重金属离子的应用非常广泛,吸附材料是目前的研究热点.本文综述了天然高分子吸附材料、多孔吸附材料、生物吸附材料等新型吸附材料的研究进展,对其发展前景和研究方向做了展望.     

重金属螯合吸附材料的研究进展

重金属的污染问题一直是环保领域的研究重点.本文综述了高分子螯合吸附材料以及重金属螯合吸附材料的研究动态,分析了天然高分子螯合材料、合成高分子螯合材料、以N、S、O基团为代表的重金属螯合吸附材料的国内外研究现状及存在的问题,对下一步重金属螯合吸附材料的研究方向做了一些设想.     

生物吸附法处理重金属废水研究进展

现代工业排放的重金属废水对环境有严重的负面影响.生物吸附法作为新兴的重金属去除技术,有着广阔的应用前景.本文阐述了生物吸附的机理,介绍了现今国内外生物吸附的研究现状,并对其发展前景作了展望.     

活性污泥吸附重金属离子的研究进展

从处理含重金属离子废水的现状出发,简述了活性污泥吸附重金属离子过程中的表面有机络合、离子交换及其它机理;讨论了温度、时间、pH值、污泥种类、预处理、重金属离子浓度等因素对活性污泥吸附重金属离子的影响,并对解吸方式进行了论述;综述了目前国内外有关活性污泥吸附重金属离子的最新研究成果,指明了进一步加强吸附机理和固定化技术以提高活性污泥应用性的研究是今后的方向。     

重金属离子吸附用微凝胶研究新进展

微凝胶聚合物网络中易于引入能够与重金属离子螯合或络合的功能基团,且比表面积大,对重金属离子具有较快的吸附速率,因此,微凝胶在重金属离子的去除方面具有广阔的应用前景。本文介绍了重金属离子吸附用微凝胶研究新进展,重点回顾了基于羧基、氨基、磺酸基、羟基及巯基等多官能团化合物与重金属离子通过静电相互作用形成稳定络合物的微凝胶用于重金属离子的吸附,离子印迹型微凝胶用于重金属离子的吸附,以及基于冠醚环（苯并-18-冠-6醚）与Pb²⁺离子通过超分子主-客体识别作用形成稳定络合物的微凝胶用于重金属离子的吸附;描述了这三类微凝胶对重金属离子的吸附性能、优点、用途等;指出了这三类微凝胶适用于不同场合下重金属离子的吸附。     

Synthesis of sulfhydryl chitin and its adsorption properties for heavy metal ions

This article discusses the preparation of the water‐insoluble adsorbent sulfhydryl chitin (s‐chitin), by treatment of the chitin with sulfhydryl acetic acid in the presence of sulfuric acid as a catalyst. Its structure was confirmed by elemental analysis, FTIR spectra analysis and near‐IR spectra analysis. We also investigated the adsorption properties of sulfhydryl chitin for Cu^II, Cd^II, Pb^II, Cr^III, and Ni^II. Based on the research results of adsorption capacity, the effect of pH value on adsorption, adsorption kinetics experiments, and selective adsorption experiments were observed. It has been shown that the s‐chitin has much better adsorption for Pb^II, Cu^II, and Cd^II than chitin itself. The adsorption capacities of s‐chitin for Pb^II, Cu^II, and Cd^II were 108.3, 94.7, and 57.1 mg/g, respectively. It also had good adsorption properties for heavy metal ions. The adsorption capacities were also affected by the acidity of medium. The adsorbed Cu^II, Cd^II, and Pb^II could be eluted by diluted chlorhydric acid. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 151–155, 2000     

Amidinothiourea-linked covalent organic framework for the adsorption of heavy metal ions

For the first time, a novel amidinothiourea-linked covalent organic framework (COF) (TpAt) has been successfully synthesized by the condensation between 1,3,5-triformylphloroglucinol and amidinothiourea via vacuum solvothermal reaction, and was further utilized for the adsorption of metal ions from aqueous solution. The effects of initial concentration, pH and contact time on the adsorption process were investigated. As a result, the TpAt COF showed maximum binding capacities as high as 95.44, 100.76 and 99.08 mg g^–1 for Cr(III), Cd(II) and Cu(II) within 180 min at the initial concentration of 100 mg L^–1, respectively. The isotherms of metal ions onto TpAt could be described by the Freundlich isotherm equation, and the adsorption kinetics followed the pseudo-second-order model. The TpAt could be reused for more than five adsorption–elution cycles, whilst basically maintaining its original adsorption performance and the structural integrity of the COF layers. The robust adsorption efficiency can be attributed to the coordination between metal ions and N, O and S atoms in the TpAt framework. The TpAt COF represents an ideal candidate for the removal of heavy metal ions in environmental pollution treatment. © 2021 Society of Industrial Chemistry.     

风化煤对水中重金属离子的吸附

以甘肃景泰风化煤作吸附剂,常温下对水溶液Pb^2＋、Cu^2＋、Zn^2＋进行了吸附实验研究,探讨了吸附动力学、吸附平衡、介质酸度的影响及吸附机理。结果表明,风化煤对几种重金属离子的吸附具有pseudo-second-order Lagergren模型的特征,吸附平衡基本符合Langmuir模型,介质酸度对吸附效果有显著的影响,pH大于5时吸附率均可接近90％。     

生物膜吸附重金属离子的模型及影响因素的研究

重金属是对生态环境危害极大的一类污染物。去除废水中的重金属元素,生物膜法是一种有效的净化工艺。为了寻找生物膜去除重金属离子的最优操作条件,考察了各种影响因素pH值、温度、吸附时间、生物膜量、共存离子对吸附的影响。从实验结果可知,Cu2+的最优操作条件是pH值为6,温度在30℃左右,吸附时间为15min,生物膜量为12g,吸附率可达到65%;Cr3+的最优操作条件是pH值为3～7,温度在25℃左右,吸附时间为5min,生物膜量为10g,吸附率可达到87%。共存离子的竞争吸附会对吸附能力弱的Cu2+产生很大的影响,Cr3+没有表现出受到抑制或促进作用的影响,对单一Cu2+或Cr3+吸附体系,可以用经典的吸附模型进行拟合。     

Polymer brushes on graphene oxide for efficient adsorption of heavy metal ions from water

The pollution of heavy metal ions in water poses a serious threat to human being and ecosystems. Here, we report polyamidoxime (PAO) brush grafted graphene oxide (GO) as a highly efficient adsorbent for extraction of toxic metal cations from water. Surface-initiated atom transfer radical polymerization was used to grow polyacrylonitrile (PAN) brushes on GO, followed by conversion of the nitrile groups in PAN into amidoxime groups, which had high binding affinity toward heavy metal cations. The PAO brush grafted GO demonstrated significantly fast adsorption kinetics and large adsorption capacity. At optimal pH 5, the PAO brush grafted GO can achieve maximum adsorption capacities of 116.7 mg g⁻¹ for Pb(II), 258.6 mg g⁻¹ for Ag(I), 192.2 mg g⁻¹ for Cu(II), and 167.9 mg g⁻¹ for Fe(III), which were significantly larger than those of small molecule functionalized GO. Mechanism analysis suggested that the enhanced adsorption performance was due to the myriads of functional groups in PAO brushes that were easily accessible to metal ions because of the swelling of the polymer brushes in water. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48156.     

赤泥吸附重金属离子性能及其机理研究进展

赤泥（RM）是铝土矿提取氧化铝时排放的工业废渣,对其进行改性后可作为一种低成本吸附剂有效吸附废水中的重金属离子。本文从赤泥的性质和组成进行讨论,分析赤泥吸附重金属离子的优势,总结酸改性、焙烧改性和复合改性对赤泥结构及重金属吸附性能的影响。在此基础上,阐述了赤泥吸附重金属离子的机理,列举了吸附热力学及吸附动力学模型。指出赤泥作为一种大宗工业废弃物,用作吸附剂吸附废水中的重金属离子,具有成本低、来源广泛等优点,同时可达到以废治废的目的,具有良好的应用前景。     

新型合成聚合物重金属离子吸附剂及其吸附性能

阐述了新型聚合物重金属离子吸附剂的合成与改性及其对水溶液中Cd(Ⅱ)、Pb(Ⅱ)、Cu(Ⅱ)、Hg(Ⅱ)等重金属离子的吸附性能。这些聚合物重金属离子吸附剂对低浓度的重金属离子表现出了较好的吸附能力，其中聚合物吸附剂PGHyFeO—COOH对mg／L级的Pb(Ⅱ)、Cd(Ⅱ)、Hg(Ⅱ)的最大吸附量分别为211．4mg／g、155．0mg／g、147．2mg／g。这些吸附剂的吸附速度也较快，平衡吸附时间一般在60min左右，有的甚至只有几分钟。新型聚合物重金属离子吸附剂在水处理工业中具有广阔的应用前景。     

New sorbent hydrogels for removal of acidic dyes and metal ions from aqueous solutions

Summary Poly(N-hydroxymethylacrylamide), PHMA, hydrogels were prepared by using N-hydroxymethylacrylamide, HMA, monomer and polyethyleneglycol(400)diacrylate as a crosslinking agent in aqueous medium and then amine groups were incorporated onto PHMA hydrogels by amination reaction with different diamines. The obtained hydrogels were characterized by determination of amine value, hydroxymethyl group content and FTIR spectra. The amine value of hydrogels changed from 2.23 to 4.64 mmol/g by depending on the amine compounds used in amination reaction. Their swelling degree increased at acidic pH values and they showed pH dependent swelling behaviour. They were used as sorbent for removal of indigo carmine and Cu(II) ion, as a model dye molecule and metal ion, respectively, from aqueous solutions. The adsorption properties of the hydrogels were investigated by depending on pH, time and initial indigo carmine or Cu(II) ion concentration. It was seen that the amine group incorporated hydrogels have quite high adsorption rate and adsorption capacity, and their adsorption capacities changed with pH of the solution. Langmuir isotherm model was the best fit for adsorption of both indigo carmine and Cu (II) ion.