改性竹炭对4-硝基苯酚的吸附行为研究

采用硝酸对竹炭进行改性,考察了改性竹炭对水溶液中4-硝基苯酚的吸附热力学和动力学特性。结果表明,与原竹炭相比,硝酸改性竹炭的比表面积、孔容及对4-硝基苯酚的吸附量显著提高。在实验条件下,动力学过程用二级吸附动力学模拟具有很好的线性相关性,通过二级吸附模型计算出的平衡吸附量与实验值相符。改性竹炭对4-硝基苯酚的吸附行为可用Langmuir和Freundlich等温式进行描述,相关性都较好,但更符合Langmuir公式。求得热力学参数ΔH=28.36 kJ/mol,ΔS=168.88 J/(K.mol),ΔG分别为-19.41(10℃)、-22.86(30℃)、-26.16(50℃)kJ/mol,表明改性竹炭对4-硝基苯酚的吸附是吸热、自发的过程,以物理吸附为主。     

磁性竹炭对酸性红B吸附性能的研究

通过化学共沉淀法制备了MnFe₂O₄-竹炭复合物(MnFe₂O₄-BC)和CuFe₂O₄-竹炭复合物(CuFe₂O₄-BC),并研究了该复合物对酸性红B的吸附性能。结果表明:MnFe₂O₄-BC和CuFe₂O₄-BC具有磁性;CuFe₂O₄-BC对酸性红B具有较强的吸附能力,CuFe₂O₄-BC的用量为每升溶液2 g的样品对初始质量浓度为150 mg/L的酸性红B溶液进行吸附,吸附速度较快,在前30 min时,酸性红B的去除率就达81%,当吸附时间为20 h时,吸附基本达到饱和,其饱和吸附量为33 mg/g;在酸性红B溶液pH值为4.5左右时,最有利于CuFe₂O₄-BC对酸性红B的吸附;酸性红B在CuFe₂O₄-BC上的吸附行为较好地符合Langmuir等温式和Freundlich等温式。     

磁性复合材料对染料吸附性能的研究

采用两性聚合物对钠基蒙脱土进行有机化改性,通过共沉淀法制备了Fe_3O_4/MMT剥离型磁性复合材料,对阳离子染料进行吸附性能的研究,显示出对阳离子染料的高效吸附效率。随着染料溶液初始浓度的增大,Fe_3O_4/MMT复合材料的吸附容量也随之增大。Fe_3O_4/MMT复合材料吸附再生性能优异,可多次循环吸附,而吸附效率未明显下降。     

硅藻土复合磁性壳聚糖对铬（VI）离子吸附性能研究

以硅藻土、壳聚糖和四氧化三铁为原料,而硅藻土相比于其他吸附材料较廉价,制备硅藻土复合磁性壳聚糖材料,研究了对铬(VI)离子的吸附性能,同时考虑了影响吸附的主要因素,并研究了动力学、热力学和等温模型。实验结果表明,低温有利于吸附,溶液pH为3,温度为15C,达到吸附平衡时,吸附量为47.8mg/g;对等温模型进行拟合,更符合Langmuir模型,动力学符合准二级动力学模型,热力学分析表明,此吸附为放热反应。在吸附材料吸附饱和后,可以采用氢氧化钠进行再生利用。     

磁性壳聚糖微球对酸性嫩黄G吸附行为的研究

随着我国工业化进程的快速推进,大量印染废水随之产生。印染废水具有色度高、有机物含量高、难降解等特点,且存在致畸、致癌等健康风险,对环境和人类健康造成极大危害。本研究采用反相乳液法制备了磁性壳聚糖微球（MCPs）,并系统研究了其对酸性嫩黄G染料的吸附行为。结果表明,MCPs对酸性嫩黄G的平衡吸附量（qe）随染料初始浓度的增大而增大,随pH的减小而增大。在MCPs添加量为0.05 g、染料初始质量浓度为1 000 mg/L、溶液体积为50 mL、pH为3.5、吸附时间为24 h的条件下,MCPs对酸性嫩黄G的吸附量达到272.86 mg/g。在时间尺度上,前200 min内MCPs对酸性嫩黄G的吸附量随时间延长迅速增加,200～480 min时吸附速率逐渐降低,480 min后吸附基本达到平衡。吸附动力学表明,MCPs对酸性嫩黄G的吸附过程符合准二级动力学模型,属于化学吸附。Langmuir模型相关系数高达0.924 9,表明MCPs吸附酸性嫩黄G的过程为单分子层吸附。本研究可为MCPs在印染废水处置领域的基础及应用研究提供一定思路。     

聚苯胺磁性壳聚糖对Cr(Ⅵ)离子吸附性能研究

以Fe3O4、壳聚糖和苯胺为原料,采用化学氧化聚合法制备聚苯胺磁性壳聚糖复合材料,通过傅里叶变换红外光谱和X射线衍射对其进行表征,考察了 Cr(Ⅵ)离子初始质量浓度、吸附时间和pH值对水中重金属Cr(Ⅵ)离子吸附性能的影响,探讨了聚苯胺磁性壳聚糖对Cr(Ⅵ)离子的吸附动力学.结果表明:Fe3O4促进了聚苯胺壳聚糖的分散...     

竹炭对水体中重金属离子的吸附规律研究

在竹炭对重金属汞(Ⅱ)、铅(Ⅱ)、锌(Ⅱ)、镉(Ⅱ)、铬(Ⅵ)吸附性能研究的基础上,探讨了竹炭对水体中重金属离子的吸附规律.研究了离子形态、重金属离子的初始浓度、竹炭量、温度对吸附的影响,以及竹炭的粒径及性质对吸附的影响.为竹炭在重金属废水处理中的应用提供了科学依据.     

竹炭对苯酚吸附的热力学及动力学参数的研究

研究了竹炭对水相中苯酚吸附的动力学和热力学参数。动力学实验表明:竹炭对苯酚的吸附拟用准一级动力学处理。并测定不同粒径、不同温度下竹炭对苯酚吸附的表观速率常数及活化能。热力学研究表明:竹炭对苯酚的吸附符合 Langmuir 等温吸附方程。测得吸附热ΔH=-14.0 kJ/mol,说明竹炭对苯酚的吸附过程为放热过程,且ΔH<40 kJ/mol,表明吸附过程主要为物理吸附。同时测得吉布斯自由能ΔG<0,且受温度的影响不大,表明吸附质从溶液到吸附剂表面的吸附过程是自发过程。     

竹炭壳聚糖吸附剂的制备及对Cr(Ⅵ)的吸附性能

采用竹炭与壳聚糖复配的方法,并以海藻酸钠作为交联剂制备竹炭壳聚糖吸附剂,考察了制备过程中的交联剂种类、原料配比、操作条件及吸附过程中的吸附时间、溶液酸度等对Cr(Ⅵ)吸附性能的影响。结果表明,竹炭壳聚糖比活性炭壳聚糖具有更好的吸附性能;壳聚糖的交联剂对吸附性能的影响不大;当m(竹炭)∶m(壳聚糖)为1∶2,吸附t为30 min,溶液pH为5~7时,竹炭壳聚糖吸附剂对Cr(Ⅵ)有较好的吸附性能。     

胺化羧甲基改性磁性壳聚糖的制备及吸附性能研究

采用交联法制备了磁性壳聚糖,并在此基础上使用柠檬酸及二乙烯三胺对其进行化学改性,得到了磁性能良好、颗粒分布均匀、平均孔径为4.37 nm的胺化羧甲基改性磁性壳聚糖。将其用于模拟废水中进行静态吸附实验。结果表明,改性后的磁性壳聚糖在保证机械强度与回收率的基础上,提高了磁性壳聚糖的吸附性能,在最适pH=6的条件下,对Cu~(2+)、Cd~(2+)、Ni~(2+)的吸附容量分别达到76.82、54.15、62.64 mg/g。     

水凝胶吸附法去除水中重金属离子研究综述

水凝胶是一种具有三维网络结构的高分子材料,因其具有吸附性能强、环境友好、可具备特定功能等诸多优点而倍受环保研究人员的青睐。近年来水凝胶作为一种新型重金属吸附材料在水处理领域中得到了特别的重视,并取得了显著进展。对壳聚糖类、丙烯酰胺类、天然高分子接枝类三类代表性水凝胶的制备及吸附处理重金属废水的研究成果进行了较系统的梳理和总结,并对目前国内外的研究进展进行了分析和讨论,进一步指出了今后的研究重点和方向。     

Preparation of a porous,magnetic, quaternary chitosan salt by preadsorption and desorption for azo dye adsorption from water

A porous magnetic quaternary chitosan salt (pre‐CS/EPTAC/Fe₃O₄) was successfully prepared via a kind of novel method of preadsorption and desorption. The physicochemical properties of pre‐CS/EPTAC/Fe₃O₄ were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometry. The adsorption of pre‐CS/EPTAC/Fe₃O₄ for methyl orange (MO) showed much higher dye uptakes compared with Npre‐CS/EPTAC/Fe₃O₄ without the preadsorption and desorption of MO, and the maximum adsorption capability for MO was 486.1 mg/g. Adsorption isotherms and adsorption kinetics were well fitted by the Freundlich isotherm model and the pseudo‐second order model, respectively. Thermodynamic parameters, such as the standard free energy change, enthalpy change, and entropy change, were also calculated; this indicated that the adsorption was spontaneous and exothermic. The introduction of MO preadsorption and desorption into the process of preparation improved not only the adsorption of MO but also the adsorption of acid red 1 and orange G. Furthermore, pre‐CS/EPTAC/Fe₃O₄ particles could be easily regenerated and remained almost constant (98.5%) for six cycles of adsorption and desorption. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43448     

甲醇酯化改性花生壳吸附水溶液中铬蓝黑

以花生壳为原料,甲醇为改性剂,制备了酯化改性花生壳吸附剂,并以其吸附水溶液中的铬蓝黑,考察了铬蓝黑的初始质量浓度、吸附时间、吸附剂粒径、温度等因素对改性花生壳吸附铬蓝黑过程的影响。分别采用拟一级和拟二级动力学模型和Langmuir,Freundlich等温式对吸附动力学和等温线进行分析。结果表明:酯化改性花生壳对铬蓝黑的吸附过程符合拟二级动力学方程,吸附平衡符合Freundlich等温方程,吸附焓变ΔH>0,反应吉布斯自由能ΔG<0,表明该吸附过程为自发进行的吸热过程。甲醇酯化改性花生壳对去除水溶液中铬蓝黑效果好,是一种具有发展潜力的吸附剂。     

双波长K系数分光光度法同时测定日落黄与柠檬黄

采用双波长K系数分光光度法同时测定饮料中的日落黄和柠檬黄,其中日落黄的回归方程为A1/A2=0.9083+2·604×10~(-2)c/A2,r_日=0.9998,线性范围为5～60μg/mL,柠檬黄的回归方程为A1/A2=0.9105+3.204×10~(-2)c/A2,r_柠=0.9999,线性范围为10～55μg/mL。对实际样品的测定表明,日落黄的加标回收率为99.72％,柠檬黄的加标回收率为94.76％,比双波长法更符合要求。     

Effect of nickel coating on carbon for adsorption of cadmium from aqueous solutions

Nickel was coated on carbon and it was characterized by SEM and XRD. Sorption of Cd(II) ions onto carbon and nickel‐coated carbon (Ni/C), effect of acids, pH, shaking time, loading capacity, and adsorbent weight has been investigated. Acids reduce sorption and maximum sorption takes place from deionized water and R_d values for carbon and Ni/C in deionized water are 212.9 ± 0.9 and 232.5 ± 2.5. The sorption data followed the Freundlich, Dubinin–Radushkevich (D–R), isotherms and different parameters have been calculated. Sorption free energy values have been calculated and are 12.56 ± 0.19 and 14.84 ± 0.196 for carbon and Ni/C and indicate that adsorption process is chemisorption. Increase in adsorption shows the increase in catalytic activity of the adsorbent. The variation of sorption with temperature has been used to calculate the values of ΔH, ΔS, and ΔG for Cd(II) sorption. These values show that adsorption of Cd(II) ions on the adsorbents is endothermic, spontaneous, and entropy driven. Coating of carbon with nickel has improved its adsorption properties. Adsorption behaviour provides useful information for the catalytic activity of catalysts.     

Preparation and adsorption performances of mesopore-enriched bamboo activated carbon

Activated carbon with high specific surface area and considerable mesopores was prepared from bamboo scraps by phosphoric acid activation. The effect of activation conditions was studied. Under the conditions of impregnating bamboo with 80% H₃PO₄ at 80°C for 9 days and activation at 500°C for 4 h, the prepared activated carbon had the highest mesopore volume of 0.67 cm³/g, a specific surface area of 1567 m²/g, and the mesopore ratio reached 47.18%. The study on adsorption isotherms of CH₄, CO₂, N₂ and O₂ on the activated carbon were carried out at 298 K. The considerable difference in the adsorption capacity between CO₂ and the other gases was observed, which would be of interest for the adsorptive separation/purification of gaseous CO₂ from its mixtures, especially from mixtures with N₂ and/or O₂. __________ Translated from Journal of Functional Materials, 2008, 39(3): 420–423 [译自: 功能材料]     

NaHCO处理胶乳生产污泥制备吸附剂对阳离子染料的吸附

以胶乳生产厂脱水污泥为原料、1.40mol/L的NaHCO₃作膨胀剂,60℃浸渍并超声处理30min,污泥烘干后再经高温炭化制备吸附剂,将其用于吸附阳离子兰X-GRRL染料溶液,考察炭化温度、炭化时间、吸附剂粒径、吸附剂投加量、吸附时间及溶液pH对吸附效果的影响,并对其吸附动力学和吸附等温线类型进行了探讨。结果表明：污泥在炭化温度700℃、炭化时间120min的条件下,制备的吸附剂（粒径<0.75mm）的比表面积为118.95m²/g,孔隙结构较为发达,对染料溶液吸附效果最佳;在振荡频率150r/min、吸附温度为25℃±0.10℃、初始染料质量浓度为250mg/L、吸附剂投加量为1.20g/L、溶液pH为5.47、吸附时间为300min时,溶液脱色率可达98.30%,染料吸附量为204.80mg/g;其吸附动力学可用准二级动力学方程进行描述;符合Langmuir型吸附等温线,属于单分子层吸附;吸附剂浸出液及吸附处理后的染料溶液的COD值分别为4.00mg/L和20.00mg/L,不会对水体造成二次污染。     

CuO/腐植酸复合材料的制备及其吸附性能

采用水热法合成了CuO-腐植酸（HA）纳米复合材料,研究了其对亚甲基蓝的初始吸附性能及再生吸附性能。运用扫描电镜/能谱仪（SEM/EDS）、傅里叶变换红外光谱仪（FTIR）、X射线粉末衍射仪（XRD）、激光粒度分析仪和比表面积测定仪（BET）对其结构进行了表征。研究了pH、亚甲基蓝初始浓度和反应温度等因素对CuO/HA吸附亚甲基蓝的影响,采用多种模型研究了CuO/HA复合材料对亚甲基蓝的吸附动力学和热力学行为。结果表明：合成的CuO/HA平均粒径约为135.0nm,比表面积为188.15m²/g。CuO/HA对亚甲基蓝（MB）的吸附动力学行为符合拟一级动力学模型,在60min内达到吸附平衡,较好地符合Frendlich吸附模型。在室温下pH=7时,CuO/HA复合材料初始饱和吸附量达172.01mg/g;循环使用8次,可保持初始吸附能力的89.27%,表明有较好的吸附性能,可作为一种有效除去水体中亚甲基蓝污染物的高容量吸附材料。     

Preparation of magnetic zeolite/chitosan composite using silane as modifier for adsorption of Cr(VI) from aqueous solutions

This study aimed to prepare an efficient, cost-effective, and separable magnetic zeolite/chitosan composite (MZFA/CS) adsorbent from solid waste to deal with the water pollution of Cr(VI). The MZFA/CS was characterized by X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM) techniques. Then, the effect of pH, temperature, initial concentration of Cr(VI) ions, and contact time was considered in the study. For a sorbent dose of 0.1 g in 50 mL of a Cr(VI) solution, at a contact time of 30 min, temperature of 30°C, and a pH of 3, an adsorption capacity (q_e) of 16.96 mg g⁻¹ was achieved. Adsorption kinetics and isotherm data obtained for all adsorption systems were well-fitted by pseudo-second-order and Langmuir models, respectively. The thermodynamic study suggested that the adsorption process is spontaneous and endothermic in nature. In summary, the adsorbent with better separability (Ms = 16.83 emu g⁻¹) and adsorbability was successfully fabricated.