木质素生物炭磺酸对水中阳离子染料的吸附性能与机制

以木质素磺酸钠(LS)为原料,采用浓硫酸一步氧化碳化的方法在60℃和210℃下分别制备了木质素生物炭磺酸SLBC-60和SLBC-210.SLBC-60磺酸基、羧基和酚羟基含量分别为1.66,1.40,4.41 mmol/g,而SLBC-210磺酸基、羧基和酚羟基含量分别为0.34,3.22,5.41 mmol/g.对...     

木质素生物炭磺酸对水中阳离子染料的吸附性能与机制

以木质素磺酸钠(LS)为原料,采用浓硫酸一步氧化碳化的方法在60℃和210℃下分别制备了木质素生物炭磺酸SLBC-60和SLBC-210。SLBC-60磺酸基、羧基和酚羟基含量分别为1.66,1.40,4.41 mmol/g,而SLBC-210磺酸基、羧基和酚羟基含量分别为0.34,3.22,5.41 mmol/g。对比评价了它们对亚甲基蓝(MB)的吸附效果,结果显示,在pH=1～10溶液中,SLBC-60对MB保持高吸附量(>463.9 mg/g)和高去除率(>91.9%),而SLBC-210对MB吸附量<231.5 mg/g、去除率<45.8%,结合生物炭结构和Zeta电位分析,这可能与SLBC-60富含磺酸基官能团及其在pH=1～10溶液中表面均富集负电荷有关;优化pH、吸附剂加入量、吸附时间等参数,得到SLBC-60对MB、罗丹明B和孔雀石绿饱和吸附量分别为755.1,926.1,1 008.2 mg/g,且吸附性能不受一价金属离子影响。此外,SLBC-60对MB的吸附等温线符合Langmuir模型(R²=0.998 9),吸附动力学符合准二级动力学方程(R2=0.998 9),吸附动力学符合准二级动力学方程(R²=0.999 5),说明该吸附以单层化学吸附为主。因此,改性制备的木质素生物炭磺酸可作为高效的阳离子染料吸附剂,有望应用于印染废水治理。     

二甲基对胺基苯甲酰胺丙基十二烷基二甲胺甲苯磺酸盐在头发表面的吸附

选择二甲基对胺基苯甲酰胺丙基十二烷基二甲胺甲苯磺酸盐（DDABDT）作为探针物质,研究其在头发表面的吸附行为,包括吸附动力学和吸附等温线,并对DDABDT分子在头发表面的团聚结构进行推测。结果表明,DDABDT分子在头发表面的吸附符合二级动力学,吸附等温线符合Freundlich模型。根据对吸附等温线线形分析,推测DDABDT溶液平衡浓度接近1／2cmc时,DDABDT分子在头发表面以单层团聚,溶液平衡浓度大于cmc时以双层团聚。     

凹凸棒石粘土对阳离子染料吸附性能的研究

1 前言 凹凸棒石是一种含水富镁硅酸盐矿物,其理想的化学分子式为Mg_5Si_8O_2。(OH)_2(OH_2)_4·4H_2O。凹凸棒石具有层链状的结构特性,带有与沸石类似的孔道。由于其独特的晶体结构,因而具有很好的吸附脱色性能。本文采用我省皖东地区凹凸棒石粘上,经过高温焙烧活化处理,制成凹凸棒石粘土吸附剂,用于阳离子染料溶液的吸附脱色试验。试验考察了吸附剂的静态吸附容量、阳离子染料溶液的初始浓度、吸附剂颗粒的粒径、吸附剂加入量和吸附温度等因素对吸附过程的影响。     

杏核壳对阳离子染料的吸附研究

本文以杏核壳作为吸附剂,用扫描电镜、红外光谱分析了其表面结构,考察了吸附时间、溶液pH值、染料初始浓度、温度对吸附亚甲基蓝和中性红的影响,并对吸附等温过程和吸附动力学进行了数学模型拟合.结果表明:在染料浓度为50 mg·L-1,吸附剂加入量为6g·L-1,自然pH值,吸附温度25℃,吸附时间为360 min的条件下,杏核壳对亚甲基蓝和中性红有较好的吸附效果,其吸附率都超过90％.Langmuir等温吸附方程能更好地描述杏核壳对两种染料的吸附,准二级动力学模型适合亚甲基蓝的吸附行为,中性红的吸附行为更符合准一级动力学模型.根据红外光谱图及扫描电镜图的分析,可以得出杏核壳对亚甲基蓝和中性红的吸附主要为物理和化学变化共同存在的过程.     

凹凸棒石吸附水溶性染料的热力学研究

通过静态吸附实验,研究凹凸棒石对水溶液中阳离子桃红FG、亚甲基蓝和直接耐酸大红4BS的吸附热力学特性,测定了298～328K范围内的吸附等温线。结果表明：在水溶液中3种染料在凹凸棒石上的吸附均符合Langmuir等温吸附方程。凹凸棒石对水溶液中的阳离子桃红FG和亚甲基蓝的吸附是一个吸热过程,而对直接耐酸大红4BS的吸附是放热过程。根据热力学函数关系计算出阳离子桃红FG、亚甲基蓝和直接耐酸大红4BS在凹凸棒石上的吸附焓变分别为0．49,0．26kJ／mol和-19．68kJ／mol。吸附Gibbs自由能变在-27．48～-31．21kJ／mol之间,表明凹凸棒石对3种水溶性染料的吸附是一自发的过程。凹凸棒石吸附3种水溶性染料均是熵增过程。     

生物炭对阳离子染料的吸附性能研究进展

印染废水是一类重要的难降解工业废水,高效处理印染废水对于保护水生态环境和促进印染行业的可持续发展具有重要的现实意义。生物炭原料来源广泛、比表面积大、孔隙结构发达、制备成本低,对印染废水中的多种污染物均表现出良好的吸附潜能,其中采用生物炭吸附阳离子染料的研究近年来备受关注。概述了可用于制备生物炭的生物质原料选取原则,以及...     

纤维素亲和膜对木瓜蛋白酶的吸附特性

以纤维素滤纸膜为载体,染料汽巴蓝F3GA为配基,制备出一种新型亲和膜色谱介质。分别在277,298,310K的均衡实验条件下,批量法对木瓜蛋白酶进行等温吸附测定。所得的数据用准一级动力学模型和准二级动力学模型进行分析。结果表明:准二级动力学模型具有更好的相关性,纤维素染料亲和膜对木瓜蛋白酶的吸附符合Lang-muir吸附模型,在298K条件下吸附现象的热力学参数:ΔGΘ,ΔHΘ,ΔSΘ分别为-7.71kJ/mol,34.91kJ/mol和0.143kJ/(mol.K),染料纤维素亲和膜对木瓜蛋白酶的吸附是自发的,并且是吸热过程。     

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.     

污泥谷壳吸附剂对两种染料的吸附动力学研究

以脱水污泥和谷壳为原料制备含碳吸附剂,测定了吸附剂对碘和亚甲基蓝的吸附值,研究了其对亚甲基蓝和活性艳红的吸附动力学行为。结果表明:吸附剂对碘和亚甲基蓝的吸附值分别为480 mg/g和69.9 mg/g,说明吸附剂内部孔道丰富,与电镜分析结果吻合,吸附剂对两种染料的平衡吸附量随染料初始浓度和吸附温度的升高而增加,伪二级动力学模型最能描述吸附剂对两种染料的吸附,吸附剂对两种染料吸附的活化能均较小,主要为物理吸附。     

纳米二氧化钛包覆沙对水中有机染料的吸附

以Ti(SO_4)_2和库布齐沙漠沙为原料,制备了纳米二氧化钛包覆沙。以X射线衍射及氮气吸附-脱附分析对样品进行了表征,并测试了合成样品对刚果红的吸附性能。结果表明,制备的样品为二氧化钛与沙子的纳米复合物,其比表面积随二氧化钛含量的升高而增大,最高可达87.1 m²/g。且该纳米复合物对刚果红的吸附性能与溶液酸碱度有关,吸附符合准二级吸附动力学模型以及Langmuir吸附等温式,为单分子层吸附,最大吸附量为246.3 mg/g。     

Adsorption of anionic dyes on a reversibly swelling cationic superabsorbent polymer

A cationic monomer [2‐(methacryloyloxy)ethyl]trimethylammonium chloride was polymerized using N,N′‐methylenebisacrylamide as the crosslinker to obtain a cationic superabsorbent polymer (SAP). This SAP was characterized by Fourier transform‐infrared spectroscopy, and the equilibrium swelling capacity was determined by swelling in water. The SAP was subjected to cyclic swelling/deswelling in water and NaCl solution. The conductivity of the swelling medium was monitored during the swelling/deswelling and was related to the swelling/deswelling characteristics of the SAP. The adsorption of five anionic dyes of different classes on the SAP was carried out and was found to follow the first‐order kinetics. The Langmuir adsorption isotherms were found to fit the equilibrium adsorption data. The dye adsorption capacity of the SAP synthesized in this study was higher than that obtained for other hydrogels reported in the literature. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

山东某硫铁矿烧渣硫酸浸出液制备铁红工艺研究

为了以山东某硫铁矿烧渣硫酸浸出液制备铁红,采用氨水调节溶液pH值,与碳酸氢铵协同沉淀铁离子,沉淀物焙烧制备铁红。结果表明,浓氨水用量为10 mL,碳酸氢铵用量为2 g时,铁离子沉淀率达到97.18%;沉淀物焙烧时间为1.0 h,焙烧温度为800℃,获得铁红Fe_2O_3含量约98.76%,根据氧化铁颜料标准(GB T 1863—2008),为A级铁红,颜料索引号为颜料红101(77491)。     

交联羧甲基纤维素吸附阳离子染料的动力学和热力学特性

以取代度为0.82的羧甲基纤维素钠[CMC(0.82)]为原料,通过固相合成法制备取代度为0.43的交联羧甲基纤维素[CCMC(0.43)],将其应用于对碱性品红(BF)和亚甲基蓝(MB)的吸附,分析吸附动力学和热力学特性。动力学研究结果表明,在CCMC吸附MB(BF)实验中,吸附90 min后,吸附基本达到饱和;吸附过程符合准二级动力学模型。液膜扩散为染料扩散的控速步骤。热力学研究结果表明,Langmuir吸附等温式拟合度更好,CCMC(0.43)对MB(BF)的吸附作用为单分子层吸附,且为优惠吸附,吸附过程是自发进行且为放热过程。用红外光谱(FTIR)和热重(TGA)等手段表征CCMC。     

Evaluation and mechanism of cationic/anionic dyes extraction from water by ionic liquids

Dispersive liquid–liquid micro-extraction (DLLME) using three different imidazolium-based ionic liquid (IL) was applied for extraction of recalcitrant dyes, Eriochrome black T (anionic azo dye), and Crystal Violet (cationic triphenylmethane dye) from aqueous solutions, not previously reported. Effects of process parameters such as initial dye concentration, pH of aqueous phase, amount and type of IL on fraction extracted, and distribution ratio of dyes were studied. Further, dyes interaction with ILs and extraction mechanism were explored. Considering the high cost of ILs, regeneration and reuse study for ILs was also performed using reverse DLLME. The fraction extracted for both the dyes with all the ILs varied significantly with pH change. Maximum dyes fraction extracted were observed nearly at neutral pH (pH =7). However, the fraction extracted were different for different IL.     

Adsorption kinetics and mechanism of cationic methyl violet and methylene blue dyes onto sepiolite

The use of low-cost and ecofriendly adsorbents was investigated as an ideal alternative to the current expensive methods of removing dyes from wastewater. Sepiolite was used as an adsorbent for the removal of methyl violet (MV) and methylene blue (MB) from aqueous solutions. The rate of adsorption was investigated under various parameters such as contact time, stirring speed, ionic strength, pH and temperature for the removal of these dyes. Kinetic study showed that the adsorption of dyes on sepiolite was a gradual process. Quasi-equilibrium reached within 3 h. Adsorption rate increased with the increase in ionic strength, pH and temperature. Pseudo-first-order, the Elvoich equation, pseudo-second-order, mass transfer and intra-particle diffusion models were used to fit the experimental data. The sorption kinetics of MV and MB onto sepiolite was described by the pseudo-second-order kinetic equation. Intra-particle diffusion process was identified as the main mechanism controlling the rate of the dye sorption. The diffusion coefficient, D, was found to increase when the ionic strength, pH and temperature were raised. Thermodynamic activation parameters such as ΔG¹, ΔS¹ and ΔH¹ were also calculated.     

Adsorption of cationic dyes within spherical particles of poly(N-isopropylacrylamide) hydrogel containing smectite

Spherical particle of poly(N-isopropylacrylamide) hydrogel containing smectite clay (a synthetic saponite) was prepared by the polymerization of N-isopropylacrylamide in aqueous clay suspension. The diameter of the gel particle is 800–1300 nm and the clay content is 11 wt.% (clay/poly(N-isopropylacrylamide)). The gel particle was shown to be useful adsorbent of cationic species from water as a result of strong electrostatic interactions between smectites and the cationic species. Due to the fact that the cation adsorption capacity to the present hybrid hydrogel particles is determined by the cation exchange capacity of clay, the hydrogel particles containing clay are a useful scaffold to immobilize various cationic species to construct functional hybrid gel particles.     

Adsorption of cationic dyes from aqueous solution using hydrophilic silica aerogel via ambient pressure drying

In order to remove the organic dyes of textile waste water, the silica aerogel was successfully prepared by using E-40 as a novel precursor and then dried in ambient pressure. The synthesized sample was verified by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). After calcining, the hydrophilic silica aerogel (HSA) was used as adsorbent to remove Methylene Blue (MB), Malachite Green (MG), and Gentian Violet (GV) from aqueous solution. The effects of initial concentration of dyes and adsorbent dosage on the adsorption process were examined. It was found that HSA showed excellent adsorption capacities, the maximum percentage of removal dyes could reach 98%. Herein, the Langmuir, Freundlich and de Boer-Zwikker isotherm modes were employed to discuss the adsorption behavior. The results indicated that the de Boer-Zwikker model can effectively describe the adsorption behavior. Besides, the HSA could be utilized as the recyclable adsorbent in degradation experiment, after five cycles, no obvious loss of adsorption capacity was found. As an efficient, low-cost, environmental friendly and recyclable adsorbent, silica aerogel is expected to be used for dyes removal.