Adsorption Behavior of Methylene Blue from Aqueous Solution by the Hydrogel Composites Based on Attapulgite

A series of carboxymethyl cellulose-g-poly (acrylic acid)/attapulgite hydrogel composites were synthesized for the removal of cationic dye methylene blue. Various factors affecting the uptake behavior were investigated. Adsorption rate of the hydrogel was quite fast, and adsorption equilibrium could be reached within 30 min. Adsorption kinetics well followed the pseudo-second-order equation for all systems. The Langmuir isotherm was found to best represent the data for the dye uptake. Even when 20 wt% attapulgite was introduced into the hydrogel, the corresponding maximum adsorption capacity reached 1979.48 mg/g at 30°C. The as-prepared adsorbents exhibited excellent affinity for the dye, and can be applied to treat wastewater containing basic dyes.     

Sodic and Acidic Crystalline Lamellar Magadiite Adsorbents for the Removal of Methylene Blue from Aqueous Solutions: Kinetic and Equilibrium Studies

The present study reports the feasibility of two synthetic crystalline lamellar nano-silicates, sodic magadiite (Na-mag) and its converted acidic form (H-mag), as alternative adsorbents for the removal of the dye methylene blue (MB) from aqueous solutions. The ability of these adsorbents for removing the dye was explored through the batch adsorption procedure. Effects such as the pH and the adsorbent dosage on the adsorption capacities were explored. Four kinetic models were applied, the adsorption being best fitted to a fractionary-order kinetic model. The kinetic data were also adjusted to an intra-particle diffusion model to give two linear regions, indicating that the kinetics of adsorption follows multiple sorption rates. The equilibrium data were fitted to Langmuir, Freundlich, Sips, and Redlich-Peterson isotherm models. The maxima adsorption capacities for MB of Na-mag and H-mag were 331 and 173 mg g^?1, respectively.     

Preparation of Silk Sericin/Lignin Blend Beads for the Removal of Hexavalent Chromium Ions

In the present study, novel adsorbents having high adsorption capability and reusability were prepared using agricultural by-products: silk sericin and lignin. Silk sericin and lignin blend beads were successfully prepared using simple coagulation methods for the removal of hexavalent chromium (Cr(VI)) from aqueous solution. A 1 M lithium chloride (LiCl)/dimethyl sulfoxide (DMSO) solvent system successfully dissolved both sericin and lignin and had sufficient viscosity for bead preparation. Compared to the conventional sericin bead adsorbent, sericin/lignin blend beads showed higher Cr(VI) adsorption capacity. The amount of lignin added to the adsorbent greatly affected the adsorption capacity of the beads, and a 50:50 sericin/lignin blend ratio was optimal. Adsorption behavior followed the Freundlich isotherm, which means the adsorption of Cr(VI) occurred on the heterogeneous surface. Cr(VI) adsorption capability increased with temperature because of thermodynamic-kinetic effects. In addition, over 90% of Cr(VI) ions were recovered from the Cr(VI) adsorbed sericin/lignin beads in a 1 M NaOH solution. The adsorption-desorption recycling process was stable for more than seven cycles, and the recycling efficiency was 82%. It is expected that the sericin/lignin beads could be successfully applied in wastewater remediation especially for hazardous Cr(VI) ions in industrial wastewater.     

Preparation and Structure of Porous Silk Sericin Materials

Summary: Porous materials of Bombyx mori silk sericin were prepared by freeze-drying. The effects of concentration of the sericin solution and that of freezing temperature on the structure and properties of materials were investigated. The results indicated that porous sericin materials, with average pore radius between 60 and 90 μm and porosity between 75 and 85%, could be prepared by freeze-drying. Thicker solution and lower freezing temperature resulted in smaller pore radius and porosity and moreover, bigger pore density. The condensed structure of interior sericin was mainly amorphous, and contained some crystal structure. Compared to the non-crosslinked porous sericin materials, the content of the β-sheet structure of the sericin materials, cross-linked by poly(ethylene glycol) diglycidyl ether, increased to some extent.

Cross section SEM photograph of the porous sericin material.     

Removal of Methylene Blue from Aqueous Solutions by using Cold Plasma,Microwave Radiation and Formaldehyde Treated Acorn Shell

In this paper, cold plasma (CPTAS), formaldehyde (FTAS), and microwave radiation treated (MTAS) acorn shell obtained from Quercus petraea tree as biosorbent was characterized and its dye removal ability at different dye concentrations was studied. The isoelectric point, functional groups and morphology of acorn shell was investigated as adsorbent surface characteristics. Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and UV–Vis spectrophotometry were used. Methylene blue (MB) was used as model cationic dye. The Langmuir and Freundlich adsorption isotherm models were applied to describe the equilibrium isotherms. The results indicated that the data for adsorption of MB onto treated acorn shell fitted well with the Langmuir isotherm model. Comparison of adsorption capacities of CPTAS with FTAS has shown a significant increase by as much as about 30 mg/g (33.32%) in MB adsorption.The pseudo-first order, pseudo-second order kinetic models were examined to evaluate the kinetic data, and the rate constants were calculated. Adsorption kinetic of dyes followed pseudo-first order kinetics. Thermodynamic parameters such as free energy, enthalpy, and entropy of dye adsorption were obtained. The results indicated that acorn shell could be used as a natural biosorbent for the removal of cationic dyes.     

聚丙烯酸/锂藻土纳米复合水凝胶对亚甲基蓝吸附性能的研究

研究了聚丙烯酸/锂藻土纳米复合水凝胶对染料亚甲基蓝的吸附性能,考察了不同吸附条件,包括凝胶用量、染料浓度、吸附时间及溶液p H条件等对水凝胶吸附效果的影响。实验结果表明,水凝胶对亚甲基蓝的吸附过程在30 min内即能达到平衡,吸附速度快;最大吸附容量高达1 192.9 mg/g,是普通吸附剂吸附容量的几十倍,吸附效果好;凝胶的吸附等温线拟合结果符合Freundlich模型,动力学拟合结果显示,凝胶对亚甲基蓝的吸附过程符合二级动力学模型。     

粉煤灰-聚丙烯酸复合微凝胶对亚甲基蓝的吸附探究

以脱水山梨醇单油酸酯(Span-80)为分散剂,以γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)改性粉煤灰(FA)得到的功能化粉煤灰乳液(org-FA)为单一交联剂,利用反相悬浮聚合法,以过硫酸铵(APS)作引发剂,将丙烯酸(AA)单体成功接枝聚合制备粉煤灰-聚丙烯酸(FA/PAA)复合微凝胶,将其应用于亚甲基蓝(MB)染料废水的处理,从而实现“以废治废”.实验结果表明,FA/PAA复合微凝胶吸附亚甲基蓝的性能优于org-FA.FA/PAA微凝胶最佳制备条件:org-FA乳液与AA质量比1∶4,Span-80占水相质量3％,APS占AA质量1.5％,油水比2∶1,吸附时间90 min,原水pH值,室温下MB脱色率可达90％以上,说明FA/PAA在染料废水治理中有潜在的应用前景.     

环氧氯丙烷改性花生壳对次甲基蓝的吸附研究

以花生壳为原料,环氧氯丙烷为改性剂,对花生壳进行改性制备吸附剂,并对其吸附次甲基蓝的性能作了较系统的研究。结果表明,在 2.0 g 花生壳中分别加入 1.25 mol/L 的NaOH溶液 45 mL 和环氧氯丙烷 25 mL,控制温度 40℃,搅拌反应 30 min,经过滤、水洗干燥后得到改性的花生壳,用此改性的花生壳吸附次甲基蓝的最佳条件为:处理 100 mg/L 的次甲基蓝溶液 50 mL,用 0.2 g 改性花生壳,pH值在6.48,搅拌吸附 60 min,在此条件下吸附率可达 99%,吸附后的花生壳用 0.5 mol/L NaOH溶液再生,重复使用3次对次甲基蓝的吸附率在 96% 以上;未改性花生壳对次甲基蓝的吸附率仅为 82%。     

改性花生壳吸附亚甲基蓝动力学与机理研究

吸附法是去除水中有机污染物的一种重要方式.以农业废弃物花生壳为原料,通过稀酸改性制备对亚甲基蓝吸附性能良好的生物质基吸附材料.FT-IR分析表明改性花生壳表面含有羟基、羧基等有利于吸附的官能团,SEM和孔结构分析结果显示稀硫酸改性花生壳表面形成大量孔结构.亚甲基蓝浓度为100 mg/L时,改性花生壳的去除效率为91.5...     

Easy Preparation of Liposome@PDA Microspheres for Fast and Highly Efficient Removal of Methylene Blue from Water

Mussel-inspired chemistry was usefully exploited here with the aim of developing a high-efficiency, environmentally friendly material for water remediation. A micro-structured material based on polydopamine (PDA) was obtained by using liposomes as templating agents and was used for the first time as an adsorbent material for the removal of methylene blue (MB) dye from aqueous solutions. Phospholipid liposomes were made by extrusion and coated with PDA by self-polymerization of dopamine under simple and mild conditions. The obtained Liposome@PDA microspheres were characterized by DLS and Zeta potential analysis, TEM microscopy, and FTIR spectroscopy. The effects of pH, temperature, MB concentration, amount of Liposome@PDA, and contact time on the adsorption process were investigated. Results showed that the highest adsorption capacity was obtained in weakly alkaline conditions (pH = 8.0) and that it could reach up to 395.4 mg g⁻¹ at 298 K. In addition, adsorption kinetics showed that the adsorption behavior fits a pseudo-second-order kinetic model well. The equilibrium adsorption data, instead, were well described by Langmuir isotherm. Thermodynamic analysis demonstrated that the adsorption process was endothermic and spontaneous (ΔG⁰ = −12.55 kJ mol⁻¹, ΔH⁰ = 13.37 kJ mol⁻¹) in the investigated experimental conditions. Finally, the applicability of Liposome@PDA microspheres to model wastewater and the excellent reusability after regeneration by removing MB were demonstrated.     

鸡蛋壳对废水中亚甲基蓝的吸附性能研究

以废弃的鸡蛋壳为吸附剂,研究了其对亚甲基蓝的吸附作用,利用红外光谱对吸附前后的鸡蛋壳进行了表征。考察了溶液初始浓度、吸附温度、溶液p H、吸附时间对废水中亚甲基蓝吸附性能的影响。由此得出了鸡蛋壳对亚甲基蓝的最佳吸附条件。通过动力学模型、等温线方程对吸附实验数据进行了非线性拟合,结果表明,鸡蛋壳吸附亚甲基蓝等温线能较好较符合拟二级动力学模型,吸附过程为物理吸附;吸附过程较符合Freundlich方程,吸附过程为多层吸附;热力学参数分析结果显示该鸡蛋壳对亚甲基蓝吸附为自发、熵减小、放热过程。     

改性海泡石对亚甲基蓝的吸附性能

对海泡石进行了硫酸改性、高温改性、硫酸/高温改性,以亚甲基蓝为吸附对象,研究了改性方法对海泡石吸附性能的影响,对各改性海泡石进行了孔径、孔体积等表征. 结果表明,3种改性方法中,硫酸/高温改性对海泡石吸附性能的提高效果最好,吸附量比改性前提高47.8%,达41 mg/g,吸附等温线符合Langmuir方程. 硫酸/高温复合改性后的海泡石平均孔径达9.74 nm,孔体积达7.064′10-2 cm3/g,分别提高117%和92.6%. 对改性海泡石对亚甲基兰的吸附机理进行了探讨.     

高岭土尾矿对亚甲基蓝的吸附行为的研究

文章探索了高岭土尾矿对亚甲基蓝溶液的吸附性行为,测定了高岭土尾矿的粒度与用量、亚甲基蓝溶液的pH与浓度、吸附时间及吸附温度等因素对亚甲基蓝吸附性能的影响。结果表明：在碱性条件下,高岭土尾矿对亚甲基蓝溶液有较好的吸附能力,亚甲基蓝浓度增加,高岭土尾矿对其脱色率减小,而随着高岭土尾矿用量的增加,则脱色率不断提高。高岭土尾矿对亚甲基蓝的等温吸附服从Freundlich方程式。高岭土尾矿对亚甲基蓝吸附的随时间的增加、温度的升高而增加。通过对这些参数的探索和测定,高岭土尾矿的吸附能力可以达到98%以上,高岭土尾矿能有效除去溶液中的亚甲基蓝。     

叶蜡石及其改性粉体对亚甲基兰吸附行为的研究

本实验将叶蜡石原矿粉进行改性处理,制备了酸洗粉、球磨粉、酸洗-球磨粉三种改性粉体,从动力学、热力学两个方面系统研究并比较了叶蜡石原矿粉及其改性粉体对水溶液中亚甲基兰(MB)的吸附行为。动力学结果表明,叶蜡石对MB的吸附动力学曲线符合伪二阶反应模型;酸洗-球磨粉快速阶段的吸附反应速率明显大于原矿粉,酸洗-球磨粉的吸附量在反应开始5min时达4.24mg·g-1,而原矿粉为3.71mg·g-1。热力学结果表明,酸洗-球磨粉的平衡吸附容量也较原矿粉明显增大,在MB溶液浓度10~60mg·L-1范围内,酸洗-球磨粉的平衡吸附容量为4.82~10.54mg·g-1,而原矿粉为4.55~9.59mg·g-1;吸附方式均符合Langmuir吸附模型。     

应用美兰吸附法测定纤维素表面积的讨论

以Prism4.0软件包将不同纤维材料吸附美兰的数据拟合Scatchard方程、Klotz-Hunston方程、Langmuir方程的一般形式和单点双曲线吸附方程,据此研究了由美兰等染料分子在纤维基质表面上的吸附从而推算基质的表面积的方法机理和局限性。分析表明Langmuir模型和单点双曲线模型的拟合得到的饱和吸附量为外推值,会导致测量结果失真;而用Sigmoidal dose-response(Variable slope)模型拟合时,则能给出真实吸附量。研究结果还显示,由纤维素分子链自由羟基所介导的美兰吸附不会发挥主导作用,而红外ATR结果和美兰的脱吸附试验表明美兰在纤维素表面上的吸附应为物理吸附,所以根据美兰分子平卧于纤维表面面积162 ?,计算纤维表面积,得到了四种纤维材料的比表面积。但由于真实界面浓度的确定方法仍存在矛盾,也缺少一个直观的检测标准,因此文章中给出的数值仍为一相对的比较值。     

新型炭黑材料对亚甲基蓝吸附性能的研究

研究了XC-72型炭黑材料对亚甲基蓝的吸附。实验结果表明：亚甲基蓝在XC-72上的吸附在3h达到平衡,吸附行为符合拟二级动力学方程和Langmuir方程。当温度为20％,pH为6．5时,最大吸附量为40．11mg·g^-1。溶液pH值的升高有利于提高吸附效果。XC-72对亚甲基蓝的吸附是一个自发熵增的吸热过程。     

磁性埃洛石复合材料的制备及其对亚甲基蓝吸附性能研究

利用简单的化学共沉淀法成功合成了磁性埃洛石复合材料,并用静态批示法对其吸附亚甲基蓝的行为进行研究。采用红外光谱仪( FT-IR)、透射电子显微镜( TEM)、X射线衍射仪( XRD)和振动样品磁强计( VSM)对磁性埃洛石进行表征,考察了埃洛石/FeCl3·6H2 O质量比、吸附剂投入量、亚甲基蓝初始浓度、溶液初始pH值和吸附时间等因素对亚甲基蓝在磁性埃洛石上吸附的影响,并进行了吸附动力学研究。结果表明：Fe3 O4纳米粒子成功地复合到埃洛石的表面;溶液初始pH值对磁性埃洛石吸附亚甲基蓝的影响较大;磁性埃洛石复合材料对亚甲基蓝的吸附行为符合准二级动力学模型。     

二氧化钛纳米管对亚甲基蓝的吸附

采用水热法制备了TiO2纳米管,借助X射线衍射(XRD)、透射电镜(TEM)对产物进行了表征。以亚甲基蓝溶液为体系,考察了TiO2纳米管的吸附性能。结果表明:TiO2纳米管为锐钛矿相,管径小、管形均匀。黑暗条件下TiO2纳米管对亚甲基蓝具有优异的吸附活性,30 min可达到吸附平衡,吸附量达38.3mg/g,最佳吸附质量比为w(MB):w(TiO2)≈0.075。     

球粘土的制备及其吸附亚甲基蓝溶液的研究

以原矿粘土为原料,采用湿选工艺法制备了球粘土粉体,并通过X-射线荧光光谱仪(XRF)、扫描电镜(SEM)和比表面积及孔径分析仅等技术对样品的组成和结构进行表征.考察了球粘土作为吸附剂,在不同投加量下吸附亚甲基蓝(MB)溶液的吸附性能,结果表明,球粘土吸附剂对MB的吸附过程符合准二级吸附动力学模型和Langmuir吸附等温式.     

不同金属卟啉光催化降解亚甲基蓝性能研究

以四苯基卟啉(TPP)为原料,通过金属插入反应,获得FeTPP、ZnTPP、CoTPP、MnTPP,并用UV-Vis对其进行了表征.将合成的金属卟啉用于光催化体系,进行亚甲基蓝溶液的光催化降解及催化剂回收实验.结果发现,以CoTPP为催化剂,在高压汞灯光照3 h后,亚甲基蓝溶液的脱色率可迭100%;不同光源的催化效果为...