交联淀粉微球对Cr^3＋的吸附研究

以淀粉为原料,N,N',-亚甲基双丙烯酰胺为交联剂,采用反相悬浮聚合得到了一种交联淀粉微球(CSM),利用红外光谱仪、SEM以及XRD对其结构进行表征.同时研究了CSM对Cr3+的吸附行为,研究了pH和时间对吸附性能的影响,并根据吸附等温线拟合出Langmiur方程和Freundlich方程.结果表明,淀粉微球表面粗糙多孔,交联后淀粉微球结晶性下降,吸附Cr3+后其结晶性进一步下降,淀粉微球对Cr3+的吸附行为很好地符合Langmiur方程和Freundlich方程,其相关系数分别为0.9949和0.9967.     

交联淀粉微球对Ni~(2+)的吸附性能研究

以可溶性淀粉为原料,N,N'-亚甲基双丙烯酰胺为交联剂,采用反相悬浮聚合得到了一种交联淀粉微球(CSM利用扫描电镜、红外光谱仪和X射线衍射仪对其结构进行表征.研究了在不同温度下CSM对Ni2+的静态吸附行为,并根据吸附等温线研究了吸附热力学性质,结果表明:在308～328K和研究的浓度范围内,CSM对Ni2+吸附行为符合Freundlich方程;CSM吸附Ni2+的吸附焓变△H、吸附自由能变△G、吸附熵变△S均为负值,表明吸附是一个自发的、放热的熵减小过程,适当降低温度有利于吸附.热力学性质分析结果表明CSM主要通过物理吸附方式吸附Ni2+.     

交联淀粉微球对对羟基苯甲醚的吸附行为及机理的探讨

以可溶性淀粉为原料,通过反相悬浮聚合法,合成了一种交联淀粉微球（CSM）。研究了CSM对羟基苯甲醚的吸附行为,分析了其吸附动力学特性和热力学性质,并利用扫描电子显微镜（SEM）、傅里叶红外光谱仪（FTIR）和X射线衍射仪对淀粉微球及其吸附产物进行了表征,探讨其吸附机理。结果表明：在研究范围内,CSM对对羟基苯甲醚的吸附行为同时符合Langmuir和Freundlich等温吸附方程;在不同温度下,CSM吸附对羟基苯甲醚的吸附焓变（ΔH）、吸附熵变（ΔS）、吸附自由能变（ΔG）均为负值,吸附是一个自发、放热过程。     

交联淀粉微球对Co~(2+)的吸附行为及机理研究

研究了交联淀粉微球(CSM)对Co2+的静态吸附行为,并根据吸附等温线研究了吸附热力学性质,利用红外光谱仪、X射线衍射仪对吸附产物进行了结构表征,探讨了吸附机理。结果表明:在研究的浓度范围内,CSM对Co2+吸附等温线同时符合Langmu ir等温方程和Freund lich等温方程,不同温度下,CSM吸附Co2+的吸附焓变ΔH、吸附自由能变ΔG、吸附熵变ΔS均为负值,表明吸附是一个自发的、放热的过程,降低温度有利于吸附;CSM通过物理吸附、配位吸附方式吸附Co2+,并导致CSM结晶结构被进一步破坏。     

淀粉微球对Pb^2＋的吸附及动力学研究

以淀粉微球(CSM)为载体,研究了微球吸附Pb2+时pH,温度、溶液浓度对吸附量的影响及对Pb2+的吸附动力学特性,利用红外(FT-IR)、SEM和X射线衍射仪(XRD)对微球进行表征.结果表明,其吸附最适pH为5～6,在一定的温度范围内,随吸附温度的升高,吸附量增大;微球对Pb2+吸附行为符合Langmiur方程和Freundlich方程;且求得吸附表现活化能为Ea=2.210 kJ·mol-1.     

新型淀粉基吸附材料对Cr~(3+)吸附性能的研究

以可溶性淀粉为原料,N,N’-亚甲基双丙烯酰胺为预交联剂,环氧氯丙烷为交联剂,采用反相悬浮聚合得到了一种新型淀粉基吸附材料-淀粉微球,研究了微球对Cr3+的吸附行为。结果表明,微球对Cr3+吸附行为符合Langmiur方程和Freundlich方程;吸附Cr3+使微球的结晶结构被进一步破坏,结晶度下降。     

木薯羧甲基淀粉对Cu(Ⅱ)的吸附行为和机理

以机械活化60 min的木薯淀粉为原料,采用干法工艺合成羧甲基淀粉。研究了羧甲基淀粉对Cu(Ⅱ)的静态吸附行为和吸附热力学、吸附动力学性质,表征了产物结构,对吸附机理进行了探讨。结果表明,在考察条件下,羧甲基淀粉对Cu(Ⅱ)的吸附符合Freundlich方程和Langmuir方程;在303、313、323 K 3种温度下,羧甲基淀粉对Cu(Ⅱ)的吸附焓变ΔH、吸附自由能变ΔG、吸附熵变ΔS均为负值;CMS60对Cu(Ⅱ)的吸附是以颗粒内扩散为控制步骤。吸附机理是物理吸附、离子交换和配位综合作用的结果。     

煤基Fe/AC去除废水中苯胺和吡啶的吸附行为和模型优化

通过浸渍法制备煤基活性炭Fe系吸附剂(Fe/AC),并采用扫描电镜、N_2吸附、元素分析和Boehm滴定法表征其结构及表面官能团。以批处理方式调变吸附条件(时间、初始质量浓度和温度)研究吸附剂对苯胺和吡啶的吸附行为,并分别采用Langmuir,Freundlich和Temkin模型拟合实验数据,同时用准一级、准二级和Elovich动力学方程分析吸附动力学行为,研究吸附剂吸附苯胺和吡啶的热力学行为。结果表明:当吸附100 mg/L的苯胺和吡啶时,硝酸铁处理对吸附剂的吸附量无显著影响,而当吸附2 500 mg/L的苯胺和吡啶时,活性炭(AC),Fe3/AC(载铁活性炭,铁负载量为3%)和Fe5/AC(载铁活性炭,铁负载量为5%)的苯胺吸附量略有差别,分别为167 mg/g,166 mg/g和164 mg/g,AC,Fe3/AC和Fe5/AC的吡啶吸附量则分别为122 mg/g,102 mg/g和100 mg/g,说明硝酸铁处理可以降低吸附剂对苯胺和吡啶吸附量(吸附剂对吡啶吸附量降低得更为显著),这是由酸性含氧官能团的增加和吸附质亲水性叠加作用所致;吸附剂的吸附量随着温度升高而略下降;负载Fe具有催化氧化苯胺活性;Freundlich模型较好描述了AC和载铁活性炭(Fe/AC)对苯胺及吡啶吸附过程;准二级方程较好描述了Fe/AC对吡啶和低质量浓度苯胺吸附过程,Evolich动力学方程适用于高质量浓度苯胺吸附;吸附苯胺和吡啶是自发的和放热的。载铁活性炭适用于处理低质量浓度苯胺和吡啶废水。     

磁性淀粉微球对Ni(Ⅱ)吸附性能的研究

研究了磁性淀粉微球对Ni(Ⅱ)的吸附性能。考查了在常温条件下,反应时间、Ni(Ⅱ)的初始浓度、磁性淀粉微球的用量等对吸附性能的影响。探讨了磁性淀粉微球对Ni(Ⅱ)的吸附热力学和吸附动力学行为。结果表明:Ni(Ⅱ)为80mg/L,磁性淀粉微球用量为30mg时,在常温下经过80min的振荡吸附,磁性淀粉微球对Ni(Ⅱ)饱和吸附量达到11.69mg/g;吸附热力学表明磁性淀粉微球对Ni(Ⅱ)的吸附行为符合Freundlich方程;磁性淀粉微球对Ni(Ⅱ)离子的吸附过程可用准一级和准二级动力学模型进行模拟,但更符合二级动力学方程。     

木薯羧甲基淀粉对Cu（Ⅱ）的吸附行为和机理研究

以机械活化60 min的木薯淀粉为原料,采用干法工艺合成羧甲基淀粉。研究了羧甲基淀粉对Cu（Ⅱ）的静态吸附行为和吸附热力学,吸附动力学性质,表征了产物结构,对吸附机理进行了探讨。结果表明,在考察条件下,羧甲基淀粉对Cu（Ⅱ）的吸附符合Freundlich方程和Langmuir方程;在303K、313K、323K三种温度下,羧甲基淀粉对Cu（Ⅱ）的吸附焓变△H、吸附自由能变△G、吸附熵变△S 均为负值;CMS60对Cu(Ⅱ)的吸附是以颗粒内扩散为控制步骤。吸附机理是物理吸附,离子交换和配位作用综合作用的结果。     

Novel crosslinked starch microspheres as adsorbents of Cu2+

A novel adsorbent, a crosslinked starch microsphere (CSM), was prepared from soluble starch and N,N′‐methylenebisacrylamide. The microporous structure of the CSM was determined with scanning electron microscopy. The diameter distribution of the CSMs was quite uniform, and the average diameter of the microparticles was estimated to be 50 μm. Cu²⁺ was introduced into the CSM. The successful adsorption of Cu²⁺ in the CSM was confirmed with Fourier transform infrared spectroscopy. The crystal structure of the CSM was destroyed after the incorporation of Cu²⁺. This was proven with X‐ray diffraction. The thermal stability of the CSM was weakened with the introduction of Cu²⁺ during simultaneous thermal analysis. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Simultaneous adsorption of aniline and Cr(VI) ion by activated carbon/chitosan composite

Activated carbon/chitosan composite has been used as an adsorbent to remove aniline and Cr(VI) ions from aqueous solutions simultaneously. The effects of preparation conditions such as the ratio of activated carbon to chitosan, crosslinking reagents, crosslinking time, and adsorption conditions including adsorbent dosage, pH value of solution, and contact time on simultaneous adsorption of aniline and Cr(VI) ion were investigated. Experimental results showed that epichlorohydrin was the proper crosslinking reagent, and the ratio of activated carbon to chitosan was kept at 1. When the adsorbent dosage was 4.0 g/L, and the concentrations of aniline and Cr(VI) were lower than 50 and 100 mg/L, respectively, both aniline and Cr(VI) were simultaneously removed at natural pH with high removals (>95%). The presence of Cr(VI) enhanced the adsorption of aniline, while the presence of aniline almost had no influence on the adsorption of Cr(VI). The adsorption processes of both aniline and Cr(VI) followed the pseudo‐second‐order kinetics model, but the sorption of Cr(VI) was preferential to that of aniline by this composite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39903.     

阴离子淀粉微球对Cr~(3+)的吸附及动力学研究

以阴离子淀粉微球为载体,研究了微球对Cr3+的吸附行为,考察了pH、时间、温度、初始浓度等因素对其去除率的影响及对Cr3+的吸附动力学特性,结果表明,其吸附最适pH值为7~9,在吸附作用的前60 m in对Cr3+的吸附速率较快,在一定的温度范围内,随吸附温度的升高,吸附量及去除率增大,初始浓度越小去除率越大;且求得吸附表观活化能为Ea=2.213 kJ/mol。     

Electrochemically enhanced adsorption of aniline on activated carbon fibers

For adsorptive separation processes, the adsorption rate and capacity are two important factors affecting the costs. This study describes the anodic polarization of activated carbon fibers (ACFs), which can enhance the adsorption rate and capacity of aniline. The electrosorption kinetics and the affecting factors (bias potential, electrolyte, and pH) of isotherms for aniline on ACFs were investigated. The adsorption/electrosorption of aniline on ACFs follow pseudo-first-order adsorption kinetics, and the adsorption rate improves with increasing bias potential. The electrosorption isotherms, which exhibit a variety of responses depending on bias potential, electrolyte and pH, follow the two classical models of Langmuir and Freundlich. With electrosorption of aniline from aqueous solution, a two-fold enhancement of adsorption capacity is achievable. The initial and saturated ACFs were characterized using scanning electron micrograph (SEM) and Fourier transform infrared spectroscopy (FT-IR). The SEM micrographs show that the surface of ACFs is not oxidized, which is also verified by cyclic voltammetry results. The FT-IR spectroscopy suggests that the interaction between aniline and ACFs is main weak physisorption instead of chemisorption. These experimental results suggest that the electrochemical polarization of ACFs can effectively improve the adsorption rate and capacity of aniline, which may be due to the enhanced affinity between aniline and ACFs instead of the oxidation on the surface of ACFs or in the solution.     

木薯淀粉磁性微球的结构表征及其对溶菌酶的吸附性能

磁性微球是高分子材料与磁性物质通过一定作用复合而成的一类具有特殊功能的磁性高分子微球。以木薯淀粉为原材料,复合共沉淀法制备的改性磁流体Fe₃O₄,采用两步法(化学交联法)制备木薯淀粉磁性微球。利用傅里叶变换红外光谱仪、X射线衍射仪、同步热分析仪、扫描电镜、激光粒度仪、磁天平等对其性能及结构进行表征并研究其对溶菌酶的吸附行为。通过单因素法考察磁性微球用量、溶液pH值、吸附温度、吸附时间对吸附率的影响,并采用准一级动力学模型和准二级动力学模型研究其吸附动力学。结果表明:制备的木薯淀粉磁性微球Fe₃O₄含量为19.71%,D₅₀(中位径)为15.40μm,磁化率为1.571×10^-3cm³/g,形貌规整;在微球用量为1.25g,溶液pH=10,吸附温度为25℃,吸附时间为80min时,微球对溶菌酶的吸附率最高,达到84.67%。以相关系数R²为参考,准二级动力学模型(R²=0.99993)较准一级动力学模型(R²=0.99174)、颗粒内扩散模型(R²=0.69996)能更好描述木薯淀粉磁性微球对溶菌酶的吸附行为。     

改性活性碳纤维对苯胺吸附特性分析

开展了等离子体改性活性碳纤维对苯胺吸附性能的理论和实验研究。通过改变等离子体改性功率和改性时间,探寻最佳改性条件;采用BET、XPS、FTIR、热重测试对改性前后活性碳纤维理化特性进行了表征分析。结果表明,在等离子改性功率为22W,时间为3min时为最佳改性条件;改性后的活性碳纤维对水溶液中苯胺的去除率可达79.3%,去除率提高了8%。微观上等离子体改性使得活性碳纤维表面含氧官能团含量增加,增强对溶液中苯胺的吸附效果。吸附实验结果表明,改性前后活性碳纤维对苯胺的吸附在溶液pH为6时,吸附效果最佳;但达到同一去除率时改性活性碳纤维的速度更快,并且平衡吸附容量也更大。采用准一级和准二级动力学模型对该吸附过程进行描述,其改性前后均用准二级动力学拟合效果更好,表明活性碳纤维结构的特殊性使其对苯胺的吸附以化学吸附为主。活性碳纤维的等离子体改性提高了其对水溶液中苯胺的吸附速度和容量,增强去除效果降低了苯胺对环境的危害。