淀粉基絮凝剂的制备及其对污水中Pb~(2+)的去除研究

以红薯淀粉、丙烯腈(AN)为主要原料,硝酸铈铵为引发剂,得到腈基淀粉微球,再用N,N-二甲基甲酰胺作为溶剂,在反相溶液中以盐酸羟胺还原,得到拥有大量氨基的改性淀粉絮凝剂。通过对该絮凝剂的红外表征、形貌观察、孔径分布和比表面积测试,可初步判断其吸附的有效官能团—NH_2和—OH是存在的,初步获得吸附所需的孔径分布和比表面积。由此特性,完成以硝酸铅配制模拟吸附溶液,探讨其在不同投入量、pH值及吸附时间等条件下对Pb~(2+)的吸附能力,从而达到最佳的吸附率,确立优化条件,对西安市昆明路和汉城湖污水中的Pb~(2+)进行吸附,其吸附率约在60%左右。     

改性淀粉微球对废水中Cu2+ 、Ni2+吸附性能的研究

改性淀粉表面和内部聚集了大量的活性基团,多孔的特殊结构使其在废水处理、吸附污染物等方面具有较大的应用潜力。以玉米淀粉为原料,通过改性处理得到接枝丙烯酸甲酯的改性淀粉,以改性淀粉为原料在酶的作用下制备了改性淀粉微球。利用扫描电子显微镜对玉米淀粉、改性淀粉、改性淀粉微球进行了分析,研究了改性淀粉微球对废水中重金属的吸附性能。结果表明:改性淀粉微球在酶溶液体积为0.06mL时吸附作用最为明显,对重金属离子有良好的吸附作用,对Cu~(2+)和Ni~(2+)的最高去除率达到74.53%和67.57%。     

淀粉基磁性复合材料的制备及重金属离子的吸附

随着社会和工业化进程的快速发展,水体中的重金属离子对环境以及人类的健康有着严重的危害,人们对含重金属离子废水的处理问题越来越重视。以淀粉为模板,通过共沉淀法和改变反应条件(淀粉-铁离子比例、铁离子-氢氧化钠比例、反应时间和反应温度)制备了多种Fe_3O_4纳米颗粒,并探究了不同吸附条件(吸附时间、pH值、温度和Cu~(2+)的浓度)其对Cu~(2+)的吸附性能的影响。研究结果表明,吸附时间为1 h,pH值为11,温度为50℃,对Cu~(2+)的浓度为0.338 mmol/mL的废水的吸附效果最佳,均达90%。     

改性壳聚糖微球合成及对Cu~(2+)吸附性能的研究

壳聚糖由于其结构特性和表面化学性能,对过渡金属离子有很强的亲和力和良好的选择性。利用二乙胺、三乙胺、聚乙烯亚胺(PEI)对壳聚糖微球进行改性,增加壳聚糖微球的活性中心以强化对二价铜离子(Cu~(2+))的吸附能力。实验结果表明:在Cu~(2+)溶液pH为5,吸附时间为15min,温度为35℃时,制得的改性壳聚糖微球对Cu~(2+)的吸附量达到2.88mmol/g。     

交联淀粉微球的制备及其对Cr(Ⅵ)的吸附性能研究

以可溶性淀粉为主要原料,N,N’-亚甲基双丙烯酰胺(MBAA)为制备反应的交联剂,环己烷为油相,过硫酸钾-亚硫酸氢钠(K_2S_2O_8-Na HSO_3)氧化还原体系为引发剂,Span80、Tween60为乳化剂,采用反向悬浮法制备交联淀粉微球,并利用红外光谱仪对交联淀粉微球的结构进行表征。以交联淀粉微球作为吸附剂,研究了吸附时间、淀粉微球的质量及Cr(Ⅵ)的初始浓度对Cr(Ⅵ)的吸附性能的影响并考察了淀粉微球吸附Cr(Ⅵ)的热力学特性。吸附实验发现,在淀粉微球质量为0.05 g、吸附时间为70 min、初始浓度为50 mg/L时交联淀粉微球对Cr(Ⅵ)的吸附量较高。热力学实验表明,交联淀粉微球对Cr(Ⅵ)吸附行为符合Langmuir热力学方程,相关系数为0.989 0。     

端氨基超支聚合物功能化磁性复合材料对Cu~(2+)和甲基橙的吸附研究

合成端氨基超支聚合物(HBPA)后与"一锅法"合成的氨基修饰磁性纳米微球通过戊二醛交联得到多氨基功能化磁性纳米吸附剂。通过傅里叶红外光谱、XRD光谱和热重分析表明端氨基修饰磁性纳米吸附剂(Fe_3O_4@HBPA)成功制备。探讨了Fe_3O_4@HBPA吸附剂对模拟废水中Cu~(2+)和甲基橙的吸附性能。Fe_3O_4@HBPA对Cu~(2+)和甲基橙的吸附时间为120min,温度30℃,吸附剂用量为10.0mg,pH=5.0时对Cu~(2+)的吸附效果最佳,pH大于5,对甲基橙吸附效果都较佳。Fe_3O_4@HBPA吸附剂对Cu~(2+)和甲基橙吸附速率较快,在10min左右就基本达到吸附平衡,温度对Cu~(2+)和甲基橙的吸附影响不大。结果表明端氨基超支聚合物修饰的磁性纳米吸附剂对Cu~(2+)和甲基橙具有较好的吸附能力。     

基于氧化石墨烯印迹微球的制备及其对Cu~(2+)的选择性吸附研究

以硫脲改性后的壳聚糖(TCS)为印迹单体,氧化石墨烯(GO)为载体,铜离子(Cu~(2+))为模板,在环氧氯丙烷为交联作用下,制备出一种具有Cu~(2+)印迹的GO/TCS微球(IM-GO/TCS)。研究结果表明:当吸附剂IM-GO/TCS用量为0.5g/L,pH=6,温度35℃,Cu~(2+)初始浓度为100mg/L,吸附时间为120min条件下,IM-GO/TCS对Cu~(2+)的吸附量达到146.105mg/g,对Cu~(2+)的选择系数达到9.745,相对分离比达到12.558。     

海藻酸钙-二氧化硅杂化材料的制备及对Cu(Ⅱ)吸附性能

利用海藻酸钠(SA)、正硅酸四乙酯(TEOS)为原料,通过反应制备海藻酸钙/二氧化硅(CA/SiO_2)杂化材料,利用傅里叶变换红外光谱仪(FT-IR)、扫描电子显微镜(SEM)对材料的结构以及表面、断面进行表征,采用原子力发射光谱仪测试杂化材料作为吸附剂对Cu~(2+)吸附性能,并从吸附动力学和热力学角度分析吸附机理。结果表明,红外光谱证实杂化材料制备成功;扫描电子显微镜观察到杂化材料表面趋于平整,断面结构看到材料的内部孔洞较多。吸附实验结果表明,杂化材料对Cu~(2+)去除率较CA提升67.01%,最佳吸附条件为温度为55℃、pH处于中性条件;同时吸附过程符合拟一阶动力学模型及Freundlich等温吸附模型,Langmuir模型计算得到对Cu~(2+)最大吸附容量为129.6 mg/g,Freundlich常数01/n=0.46720.5,吸附过程容易进行;并且材料具备多离子同时吸附能力,重复使用5次仍有优异去除率。     

氮掺杂多孔碳材料的制备及其吸附性能研究

采用细乳液聚合法制备了聚丙烯腈(PAN)微球,以其作为氮掺杂多孔碳材料(NPC)的前驱体,经ZnCl_2溶液浸渍后,分别在450℃、600℃和700℃这3个不同温度下碳化制得多孔碳材料NPC-H450、NPC-H600和NPCH700。采用透射电镜(TEM)、X射线光电子能谱(XPS)和N_2吸附-脱附等方法对样品进行表征。研究了NPC对CO_2和Cu~(2+)的吸附性能。结果表明:所制备的多孔碳材料NPC-H450、NPC-H600和NPC-H700的比表面积大,分别为1114m~2/g、1644m~2/g和931m~2/g;氮含量高,质量分数分别为11.33%、12.12%和13.35%。制备的NPC对CO_2及Cu~(2+)均有良好吸附的性能。在0℃、1atm条件下,NPC-H450对CO_2的吸附量为3.40mmol/g,NPC-H700在常温下对Cu~(2+)24h的吸附量可达62.88mg/g。     

壳聚糖/明胶复合微球的制备及对铬离子的吸附性能

壳聚糖具有较高的吸附性能,明胶高分子链上有氨基、羟基、羧基等活性基团,对六价铬Cr(Ⅵ)具有一定的吸附螯合作用。本工作采用乳化交联法制备壳聚糖/明胶复合微球,以微球对Cr(Ⅵ)的去除率为指标,通过正交实验优化微球制备条件,并利用扫描电镜对微粒形貌进行表征。在研究复合微球对水体中Cr(Ⅵ)的吸附性能时,考察了吸附剂用量、pH值、吸附时间、温度等因素对吸附容量的影响。结果表明,壳聚糖/明胶微球的最佳制备条件为壳聚糖/明胶质量比1∶2,乳化时间40 min,乳化剂span80用量6 mL,水油比1∶7(体积比),乳化温度60℃;最佳吸附条件为:吸附剂用量2 g/L,pH值4,温度35℃,吸附时间120 min,在该条件下微球对Cr(Ⅵ)的去除率为95.5%。     

酰腙功能化MCM-41分子筛吸附铜离子性能研究

利用2-羰基丙酸邻羟基苯甲酰腙对MCM-41分子筛的表面进行功能化,制备得到2-羰基丙酸邻羟基苯甲酰腙功能化MCM-41(简称功能化MCM-41)。采用红外光谱法和热重分析对功能化MCM-41进行表征,研究其对废水中铜离子的吸附性能,并探讨功能化MCM-41对铜离子的吸附机理。结果表明,当吸附时间为30 min,吸附温度为20℃,吸附剂用量为0.08 g,p H为6~7时,功能化MCM-41分子筛对铜离子的吸附效果最佳;在最佳条件下,功能化MCM-41对铜离子的吸附可以达到97.58%。     

Preparation and characterization of polyethyleneglycolmethacrylate (PEGMA)-co-vinylimidazole (VI) microspheres to use in heavy metal removal

Polyethyleneglycolmethacrylate (PEGMA) and vinylimidazole (VI) were used in order to obtain microspheres of PEGMA-VI copolymers that can be used in heavy metal removal applications. The obtained copolymers were characterized and their use as sorbents in heavy metal removal was investigated. In the first part of the study, PEGMA-VI microspheres were prepared by suspension polymerization method. The obtained swellable microspheres with 10-50 microm average diameter did not have permanent porosity according to the morphological and physicochemical determinations. The sizes of microspheres became smaller with increasing VI and cross-linker ethyleneglycoldimethacrylate (EGDMA) contents and increasing agitation rate. The VI content, EGDMA ratio, pH and ionic strength were determined as the effective parameters on the swelling behavior of PEGMA-VI microspheres. In the second part of the study, Cu(II) ions were used as a model species in order to investigate the usability of the obtained PEGMA-VI microspheres in heavy metal removal. Adsorption capacities under optimum conditions were determined. The Cu(II) ion adsorption capacity increased by increasing the initial Cu(II) ion concentration, and it reached the maximum value (i.e., 30 mg Cu(II)/g PEGMA-VI microspheres) at 400 mg Cu(II)/L initial Cu(II) ion concentration under the determined optimum conditions. Microspheres were found to be reusable after desorption for several times.     

氨基功能化P(St-HEMA)磁性微球的制备及对Pb(Ⅱ)的吸附性能

采用分散聚合法制备了P(St-HEMA)磁性微球,利用乙二胺与磁性微球进行反应得到表面含有氨基的[P(St-HEMA)-EDA]磁性微球。通过扫描电镜(SEM)、光学显微镜、傅立叶红外光谱(FT-IR)和样品磁力振荡计(VSM)等对样品进行了表征,并将其应用于对含Pb(Ⅱ)的模拟废水吸附性能研究。考察了pH值、吸附剂用量和吸附时间等因素对吸附量的影响,[P(St-HEMA)-EDA]磁性微球对Pb2+具有较好的吸附能力;在298 K时,[P(St-HEMA)-EDA]磁性微球对Pb^2+的吸附符合准二级动力学模型且为化学吸附过程,在90 min内基本达到吸附平衡,最大吸附量高达87.566 mg/g,Langmuir等温吸附数学模型能比较好地拟合[P(St-HEMA)-EDA]磁性微球对Pb^2+的吸附。     

Recovery of Cu(II) and Cd(II) by a chelating resin containing aspartate groups

A chelating resin, crosslinked poly(glycidyl methacrylate-aspartic acid) (PASP), was synthesized by anchoring sodium aspartate to crosslinked poly(glycidyl methacrylate) for the recovery of Cu2+ and Cd2+ from aqueous solutions. The resin was characterized by Fourier transform infrared spectroscopy, scanning electron microscope and mass balance. In non-competitive conditions, the adsorptions tended toward equilibrium at 60 min and the equilibrium adsorption capacities were 1.40 and 1.28 mmol/gPASP for Cu2+ and Cd2+, respectively. The adsorption isothermals of the metal ions by PASP followed the Freundlich isotherm. Adsorption of Cu2+ was affected slightly in the presence of NaNO3 (0-0.3M) but the uptake of Cd2+ decreased significantly in the same condition. Except pH> or =4.0, the adsorption capacity of each metal ion decreased with lowering of solution pH. The reusability of PASP in adsorptions was investigated for five successive adsorption-desorption operations. When the pH of Cu2+/Cd2+ mixture was 2 or 2.5, the competitive adsorption tests confirmed this resin had good adsorption selectivity for Cu2+ with the coexistence of Cd2+.     

SBA-15介孔分子筛吸附电镀废水中Cu2＋的最佳条件和效果

为了开发新型高效廉价的吸咐材料,利用常压微波辐射法在酸性条件下以三嵌段共聚物（P123）为模板剂,制备了高度有序的SBA．15型介孔分子筛。研究了静态条件下SBA-15对电镀废水中Cu2＋的吸附,探讨了SBA-15用量、废水pH值、吸附时间、吸附温度对去除Cun效果的影响。结果表明：废水pH值为5．0,Cu2＋在0—1...     

Preparation of porous chitosan gel beads for copper(II) ion adsorption

In this paper, chitosan porous beads were prepared by using a phase inversion technique, and then used for the adsorption and removal of copper(II) ions. The porosity, diameter and other characteristics were characterized. With the increase of chitosan and NaOH concentration used to prepare the beads, the amount of adsorbed Cu2+ per gram of the beads decreased. A maximum adsorption amount was observed at a pH value of 6.0 for the cross-linked porous chitosan beads. The amount of the adsorbed Cu2+ increased with the Cu2+ concentration used in the adsorption experiments. By the relationship of the ratio of the equilibrium Cu2+ concentration in the solution (C(e)) to the adsorbed equilibrium amount (P(e)) (C(e)/P(e)) and C(e), we concluded that the adsorption of Cu2+ to the porous chitosan beads was Langmuir adsorption. The Cu2+-loaded porous chitosan beads were stable in water, which is useful for further study on selectively adsorption of IgG. The results suggested that the porous chitosan beads were useful adsorbents for copper ions removal in water treatment, and the Cu2+-loaded beads may be good sorbents for IgG removal in blood purification.     

单宁微球固载α-淀粉酶及其催化性能

以单宁微球为载体,采用戊二醛交联法固定α-淀粉酶。探讨了最佳固定化条件,并考察了温度、pH值和淀粉初始浓度等对固定α-淀粉酶催化淀粉水解的影响。结果表明,单宁微球对α-淀粉酶的吸附率达到了96.99%。最佳固定条件为:戊二醛质量分数0.10%,pH5.5,温度25℃,时间2h。固定α-淀粉酶的重复5次后仍具有较好的催化效果。     

Application of response surface methodology to evaluate the removal efficiency of Mn(II), Ni(II), and Cu(II) by surfactant-modified alumina

Surfactant-modified alumina (SMA) was prepared and used for the removal of Mn(II), Ni(II), and Cu(II) from aqueous environment. Batch studies were conducted to find out optimum pH of the medium, adsorbent dose of SMA, and contact time. They were further optimized using response surface methodology (RSM). In the present study, a three-factor, three-level Box–Behnken experimental design was used to derive a second-order polynomial equation and construct three-dimensional (3D) surface plots and two-dimensional (2D) contour plots to examine the response. The level of significance for each independent variable and their interaction effects were examined by means of analysis of variance (ANOVA), F test, and Student’s t test results. In addition, the percentage effects of the different factors and their interactions on the removal efficacy were also investigated by plotting a Pareto chart. The models were validated for accurate prediction of the percentage (%) removal by performing numerical optimization. The optimum values of three tested variables were determined at pH 6.2, 8.2, and 5.3; adsorbent dose = 20, 5, and 4 g/L; and contact time = 30, 60, and 75 min for the adsorption of Mn(II), Ni(II), and Cu(II) ions, and the corresponding removal efficiency was found to be 77.04, 93.83, and 97.23 %, respectively.     

Self-assembly functionalized membranes with chitosan microsphere/polyacrylic acid layers and its application for metal ion removal

Multilayer composite membranes with high removal capability for metal ion were prepared using electrostatic self-assembly (ESA) technique. Especially, self-assembled multilayer of chitosan microspheres and PAA were formed onto charged surface of polyacrylonitrile (PAN) membranes. It was confirmed that the alternate multilayer of chitosan and PAA were deposited on the base membrane surface. The formation of the ESA layer-by-layer of chitosan/PAA or chitosan microspheres/PAA onto the base membrane surface functionally equipped the membrane with removal capability for Cu²⁺. Especially, membranes with chitosan microspheres/PAA ESA layers on the surface showed relatively higher adsorption capability as compared with membranes with chitosan/PAA ESA layers. Besides, the influence of the pH of metal ion solution on the metal ion adsorption property of ESA modified membrane was investigated. It was proposed that the layer-by-layer self-assembled deposition of chitosan microspheres would be a new approach to functionalize membrane with high adsorption capability for metal ions.     

碳球负载四氧化三铁（Fe3O4／CNs）吸附Cu（Ⅱ）的性能研究米

利用水热法合成碳球（CNs）,原位生长四氧化三铁（Fe3O4）,通过SEM、XRD和FT—IR进行表征,研究碳球负载四氧化三铁（Fe3O4／CNs）对Cu（Ⅱ）的吸附性能,结果表明,当pH=6时,Fe3O4／CNs对Cu（Ⅱ）的去除率最大,吸附符合Langmuir等温方程,最大吸附量为44．08mgg。吸附动力学表明,Fe3O4／CNs对Cu（Ⅱ）的吸附符合准二级动力学方程。