活性炭对苯酚的吸附研究

进行了活性炭处理含苯酚废水的应用研究,考察了影响苯酚吸附效果的因素。确定了处理水中苯酚的最佳条件:吸附平衡时间为30 min;最佳pH值为6左右;苯酚初始浓度为10 mg/L;投炭量为20～25 mg/L;苯酚的吸附率高达97.4%;温度对苯酚吸附率的影响不明显。研究了活性炭对苯酚的吸附动力学特性,分别用伪一级动力学方程、伪二级动力学方程、修正伪一级动力学方程和颗粒内扩散模型进行拟合,对于不同浓度的苯酚废水都只有伪二级动力学方程拟合程度比较高,伪二级动力学方程更为真实地反映苯酚在活性炭上的吸附机理。     

Adsorption of diclofenac sodium from aqueous solutions on activated carbon

The kinetics and thermodynamics of the adsorption of diclofenac sodium from aqueous solutions of different concentrations at different temperatures on activated carbon obtained from coconut shell were studied. It was found that the adsorption of diclofenac sodium is described by a pseudo-first-order equation and the adsorption isotherm at its concentration to 750 mg/L in the initial solution is adequately described by the Langmuir equation. It was found that the adsorption of diclofenac sodium is an endothermic process.     

Adsorption of diclofenac sodium from aqueous solutions on expanded graphite

The adsorption of a diclofenac sodium medicine from aqueous solutions of different concentrations on expanded graphite, which was obtained as a result of the thermal treatment of graphite with perchloric acid, was studied. The recovery of diclofenac sodium from aqueous solution on expanded graphite was as high as 98–99%.     

Heavy metals removal from solution by polyaniline/palygorskite composite

Batch adsorption experiments were carried out to remove heavy metal ions such as Cu (II), Ni (II), Cd (II), and Cr (VI) from single‐metal solutions using a polyaniline/palygorskite (PP) composite. Different parameters affecting the adsorption capacity such as contact time and pH of the solution have been investigated. The structural characteristics of the PP composite were studied in this work. Atomic absorption spectroscopy was used for the measurement of heavy metal contents, and the adsorption capacity (q_e) calculated were 114 mg Cu (II) g^?1, 84 mg Ni (II) g^?1, 56 mg Cd (II) g^?1, and 198 mg Cr (VI) g^?1 under optimal conditions. The removal of the metal ions from solutions was assigned to chelation, ionic exchange, and electrostatic attraction. Data from this study proved that the novel organic/inorganic composite presents great potential in the recovery and elimination of noble or heavy metal ions from industrial wastewater. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Removal of phosphate anions from aqueous solutions using polypyrrole‐coated sawdust as a novel sorbent

This work was focused on the removal of phosphate ions using polypyrrole‐coated sawdust as a novel cost‐effective sorbent. The phosphate uptake followed the Langmuir sorption isotherm, and the sorption capacity at 20, 35, and 50°C was found to be 17.33, 23.41, and 30.39 mg/g, respectively; this indicated favorable sorption at higher temperatures. The kinetic uptake data were modeled with the Lagergren equation, first‐order and second‐order kinetic models, and the simple Elovich model. The results indicated that the Lagergren model best described the uptake data. The intraparticle diffusion coefficient, as determined for 250–211‐ and 630–600‐μm sorbent particles at 20°C, was found to be 287.3 × 10^?2 and 228.3 × 10^?2 mg g^?1 min^?1, respectively. The intraparticle diffusion was also confirmed with the Bangham equation. The sorption mean free energy, calculated with the Dubinin–Radushkevich equation, was found to be 10.98 kJ/mol, thus confirming an ion‐exchange regulated sorption process. The positive value of the enthalpy change (i.e., 4.23 kJ/mol) confirmed the endothermic nature of the sorption process. The negative values of the change in the standard free energy were indicative of the spontaneous nature of the sorption process. Finally, the activation energy of the sorption process for 250–212‐μm particles, determined with the Arrhenius equation, was found to be 41.68 J/mol. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Adsorption behaviors of mercury from aqueous solution using sulfur-impregnated adsorbent developed from coal

Adsorption of mercury from aqueous solution on sulfur-impregnated adsorbent has been studied. Raw coal was mixed with K₂S powder, and then heated at 800-1000 °C for 30 min in nitrogen to produce sulfur-impregnated adsorbent. The sulfur content and specific surface area of the adsorbent were determined, and the ability of the adsorbent to adsorb mercury in aqueous solution was examined. With increasing temperature of sulfur-impregnation, specific surface area of the adsorbent increases, while sulfur content of the adsorbent is almost constant. The adsorbent obtained at 900 °C shows the highest and fastest adsorption of mercury from aqueous solution at 25 °C, and the elution extents of adsorbed mercury are negligible in distilled water and 10% in 0.1 M HCl solution, respectively. Adsorption kinetics was tested for pseudo-first order and pseudo-second order reactions, and the rate constants of adsorption for these kinetic models were calculated. Adsorption experiments demonstrate that the adsorption process corresponds to pseudo-second-order kinetic model than pseudo-first-order model. With increasing temperature of aqueous solution, the kinetics of adsorption becomes faster and the amount of mercury adsorbed on the adsorbent increases. The thermodynamic values, ΔG⁰, ΔH⁰ and ΔS⁰, indicated that adsorption was an endothermic and spontaneous process.     

Biosorption of Pb(II) and Cd(II) ions from aqueous solution using polyaniline/chitin composite

In this study, chitin (Ch) was made composite with polyaniline (PANI) and used for the removal of Pb(II) and Cd(II) ions from aqueous solution. Characterization techniques such as Fourier transform infrared spectroscopy, scanning electron microscope, energy-dispersive X-ray analyser and X-ray diffraction were employed to characterize the prepared PANI/Ch composite. Influence of various equilibrium parameters on the adsorption of Pb(II) and Cd(II) ions onto PANI/Ch composite was investigated. The adsorption process followed the Freundlich isotherm model, and the calculated maximum monolayer sorption capacity of PANI/Ch composite for Pb(II) and Cd(II) ions is 7.03 and 6.05 mg g^?1 at 303 K. The kinetic data were well described by the pseudo-second-order model.     

活性碳纤维吸附水溶液中的二价铅离子

对活性碳纤维(ACF)吸附水溶液中的二价铅离子进行研究。分别运用静态和动态方法来考察ACF吸附Pb^2 的性能，测定了吸附等温线，探讨了吸附时间、DH值等因素对吸附的影响，并进行了ACF的再生实验。结果表明，ACF对水中二价铅离子的吸附特性良好，且吸附剂易于再生，可作为去除水中离子态重金属的优良吸附剂。     

Fly ash as a sorbent for boron removal from aqueous solutions: Equilibrium and thermodynamic studies

ABSTRACT

This study presents the application of fly ash from brown coal and biomass burning power plant as a sorbent for the removal of boron ions from an aqueous solution. The adsorption process efficiency depended on the parameters, such as adsorbent dosage, pH, temperature, agitation time and initial boron concentration. The experimental data fitted well with the Freundlich isotherm model and the maximum capacity was found to be 16.14 mg g^?1. The adsorption kinetics followed the pseudo-second-order model. Also, the intra-particle diffusion model parameters were calculated. Thermodynamic parameters such as change in free energy (ΔG°), enthalpy (ΔH°), entropy (ΔS°) revealed on exothermic nature of boron adsorption onto the fly ash.     

Adsorption of glucose into zeolite beta from aqueous solution

Hydrophobic zeolites, including Ti‐ and Sn‐beta, have been found to adsorb and isomerize glucose into fructose. An experimental question has been the significance of the entropic contribution to the free energy of transfer of glucose from solution to zeolite. We here perform Gibbs ensemble Monte Carlo calculations to quantify the enthalpy, entropy, and free energy of transfer of glucose from the aqueous phase to the zeolite phase. We find that the entropic contribution is large and positive, nearly compensating for an unfavorable enthalpy of transfer in all‐silica zeolite beta. A significant component of the positive entropy of transfer from the aqueous phase to zeolite is the unstructuring of first coordination shell waters around glucose as it leaves the solution. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3523–3529, 2013     

Adsorption of alcohols from aqueous solution by ZSM-5

Isotherms have been measured for the adsorption from aqueous solution of water soluble alcohols onto the zeolite ZSM-5. For methanol and ethanol the amount of alcohol adsorbed increases with increasing percentage of Al₂O₃, whereas for n-butanol the amount adsorbed decreases as the amount of Al₂O₃ increases. Adsorption of alcohols is also dependent on the cation form. For the alkali metal ion forms, the amount of alcohol adsorbed decreases as the ionic size increases, the effect being particularly pronounced for Cs⁺. Subsequent alcohol desorption was studied by thermogravimetry and mass spectrometry which showed that the zeolite retained a portion of the alcohol to temperatures (ca 250°C) sufficiently high that catalytic breakdown occurred. This reduces its likely potential for commercial alcohol concentration.     

Water‐soluble chitosan intercalated montmorillonite nanocomposites for removal of basic blue 66 and basic yellow 1 from aqueous solution

Water‐soluble chitosan intercalated montmorillonite (wCTS/MMT) nanocomposites were modified and characterized by using Fourier transform infrared, thermogravimetric analysis, and X‐ray diffractometer techniques. Two types of wCTS, namely, low molecular‐weight chitosan (L‐wCTS) and hydroxyethylacryl chitosan (H‐wCTS) were synthesized and applied. The batch adsorption experiments on these nanocomposites were conducted by using basic dyes, that is, Basic Blue 66 and Basic Yellow 1 (BY1). The adsorption capacities of sodium montmorillonite (Na‐MMT), chitosan, L‐wCTS/MMT, and H‐wCTS/MMT were measured and compared. The results showed that the adsorption capacities of wCTS/MMT nanocomposites were higher than those values of Na‐MMT and chitosan. The adsorption kinetics of wCTS/MMT nanocomposites for BY1 were studied. It was described that the adsorption processes were better fitted by pseudo‐second‐order equation. The Langmuir and the Freundlich models were used to fit the adsorption isotherm. It was indicated that the adsorption isotherms followed the Langmuir model. The values of the maximum adsorption capacity of L‐wCTS/MMT and H‐wCTS/MMT adsorbents were at 188.7 and 294.1 mg/g, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

超声波辅助粉煤灰去除水中亚甲基蓝染料的动力学分析

为了开发更多的粉煤灰用途,采用粉煤灰去除水中的染料污染物,达到以废治废的目的。采用超声波辅助粉煤灰的方法,以亚甲基蓝染料作为模拟污染物,考察此工艺的可行性,讨论亚甲基蓝的去除效果,分析其动力学。研究结果证明,超声波-粉煤灰联合体系（US-FA体系）具有良好的去除染料污染物的能力,超声波的引入能提高粉煤灰对染料污染物的去除率,协同效应非常明显,粉煤灰投加量0.3、0.5、1.0和2.0 g的情况下,协同因子分别达到1.05、1.32、1.55和2.27。在本实验体系内,经过恒温控制后,超声波的热效应可以忽略,主要通过粉煤灰吸附和羟基自由基降解两大主要途径去除污染物,超声波对去除性能的促进作用主要体现在以下几个方面：一是超声波空化作用产生羟基自由基,超声波和粉煤灰表面相互作用产生更多的羟基自由基;二是超声波能促进粉煤灰表面产生更多的活性位,促进了吸附过程的化学反应步骤,由于粉煤灰对亚甲基蓝的吸附过程以化学反应为控制步骤,所以超声波能大为促进粉煤灰的吸附性能;三是超声波的引入加剧了固液混合,促进污染物向固相表面移动,促进更多的污染物进入到吸附剂颗粒内部,改善了传质。     

Adsorption behaviors of crystal violet from aqueous solution using Anatolian black pine (Pinus nigra Arnold.): kinetic and equilibrium studies

ABSTRACT

In this study, Anatolian black pine (ABP, Pinus nigra Arnold.) was evaluated as biosorbent for removal of crystal violet (CV) from aqueous solution. The influence of operational parameters including solution pH, initial CV concentration, biosorbent dosage, contact time, and temperature were studied in batch systems. The adsorption data followed well Langmuir isotherm with a maximum biosorption capacity of 12.36 mg/g. The equilibrium data were better fitted with pseudo-second-order kinetic model (R² ? 0.99). Moreover, the thermodynamic parameters indicated that the CV biosorption was feasible, spontaneous, and endothermic process. This study showed that ABP (Pinus nigra Arnold.) can be used to remove CV from aqueous solutions.     

Adsorption of toluene from aqueous solutions using clay-based nanostructures

In this study, porous clay heterostructures (PCH) are synthesized through gallery template approach and characterized using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Nitrogen adsorption–desorption techniques. Batch adsorption studies are conducted to investigate the effect of parameters such as adsorbent dosage, pH, concentration, and contact time on adsorption of toluene by PCH in aqueous solutions. Equilibrium data were fitted to the Langmuir and Freundlich models. Based on the results, by increasing the PCH dosage from 0.5 g/L to 4 g/L, toluene removal is enhanced from 34% to 88.1%.     

Chitosan/polyaniline hybrid for the removal of cationic and anionic dyes from aqueous solutions

Nanostructured chitosan/polyaniline (CH/PANI) hybrid was synthesized via in situ polymerization of aniline in the presence of chitosan. The CH/PANI hybrid was characterized by FTIR spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The CH/PANI hybrid had a nanofibrous structure with an average diameter of 70 nm. This hybrid was employed as an ecofriendly and efficient adsorbent with high adsorption capacity for the removal of Acid Green 25 (AG) and methylene blue (MB) from aqueous solutions. AG and MB were used as anionic and cationic model dyes, respectively. The CH/PANI adsorbent showed high dependence on the pH of the medium with an excellent adsorption performance and regeneration manner. The kinetics and adsorption isotherms were studied. The CH/PANI hybrid follows the pseudo second-order adsorption kinetics and Temkin isotherm model for the adsorption of both AG and MB dyes. This assumes that the enthalpy of dyes molecules decreases with the adsorption on heterogeneous surface with various kinds of adsorption sites and as well as the ability to form multilayers of the dye. Also, intraparticle diffusion was found to play an important role in the adsorption mechanism. The maximum adsorption capacity was found to be 240.4 mg g⁻¹ of AG at pH 4 and 81.3 mg g⁻¹ of MB at pH 11. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47056.     

氧化改性橡椀单宁对铜离子溶液的吸附性

以橡椀栲胶为原料,通过双氧水氧化降解改性,研究水解类橡椀单宁改性后对铜离子溶液的吸附沉淀以及pH值、金属溶液初始浓度对铜离子吸附沉淀容量的影响和规律。结果表明,氧化橡椀单宁对Cu2+的吸附平衡符合Freundlich方程。改性后吸附沉淀容量受初始浓度影响较大,初始浓度为20 mg/L时基本不发生吸附沉淀,试验最大初始浓度100 mg/L时吸附量达到39.300 mg/g。