利用粉状聚合物吸附剂脱除盐酸溶液中氯仿的研究

为了选择合适的吸附剂来脱除盐酸溶液中的氯仿,本文测定了几种聚合物吸附剂在298.15 K温度下对水溶液和20%盐酸溶液中氯仿的吸附等温线,考察了其吸附能力,并将其吸附能力与活性炭和固体石蜡进行了比较。所研究的吸附剂包括粉末状氯化橡胶,聚丙烯,氯化聚丙烯,聚氯乙烯,活性炭和固体石蜡。结果表明,这些吸附剂的吸附行为服从Langmuir 方程,其吸附能力的次序为活性炭>聚氯乙烯>氯化橡胶>聚丙烯 >氯化聚丙烯 >固体石蜡。该次序基本上与从聚氯乙烯到固体石蜡吸附剂中氯含量逐渐降低的次序相一致。聚氯乙烯与氯化橡胶的吸附能力与活性炭相当,其饱和吸附量大约为1.4g-CHCl3/g-吸附剂。所有吸附剂对氯仿的吸附能力均随着溶液中盐酸浓度的增加而降低。结果表明,工业级的粉状聚氯乙烯或氯化橡胶可以作为一种有效的吸附剂脱除水溶液中的氯仿,且具有成本低,吸附性好和易于通过热再生循环利用的特点。     

Iron Humate as a Novel Adsorbent for p-Arsanilic Acid Removal From Aqueous Solution

In this study, the iron humate (IH) prepared by a coprecipitation procedure with economical and environmentally friendly iron salts and humic acid (HA) was developed as an adsorbent, and its potential for p-arsanilic acid (p-ASA) removal from aqueous solution was then evaluated. The structure, surface morphology, and elemental composition of the synthesized adsorbent were characterized in detail and the adsorption behavior of p-ASA onto IH was investigated by altering the parameters of pH, contact time, adsorbent dosage, p-ASA concentration, ionic strength, competing ions, and temperature. Results showed that IH possessed good adsorption ability to aqueous p-ASA. The amount of p-ASA adsorbed increased with increasing adsorbent dosage and temperature, but decreased as the pH increased. The adsorption process of p-ASA obeyed pseudo-second-order kinetics. Equilibrium data were best described by the Langmuir model, and the estimated maximum adsorption capacity of IH was 188.68 mg/g at 308 K, displaying higher efficiency for p-ASA removal than previously reported adsorbents. The FTIR analysis further verified that p-ASA adsorption over the adsorbent could be attributed to the Fe–O–As complexation on IH surfaces. This work, therefore, suggests that IH could be used as a promising adsorbent in the enrichment of p-ASA from water, which is needed in environmental pollution cleanup.     

Study of Removal of Cationic Dye from Waste Aqua Using Chromatographic Grade Silica as Adsorbent

The adsorption of cationic dye, Basic Red 13 from aqueous solution onto silica has been studied. The time growth adsorption as a function of the amount of adsorbent, pH, initial dye concentration as well as the temperature was measured of the system. Adsorption was found to follow a first-order process. Various isotherm and thermodynamic parameters for the adsorption of dye have been calculated. Isotherms were used to identify formation of either monolayer or multilayer formation whereas thermodynamic and other parameter indicated that the dye adsorption process was physisoption as well as spontaneous and exothermic in nature.     

Trichloroacetic Acid Removal by a Reductive Spherical Cellulose Adsorbent

A novel spherical cellulose adsorbent with amide and sulphinate groups was used for a first reduction of trichloroacetic acid(TCAA) and a subsequent adsorption of generated species, haloacetic acids. The removal mechanism involved TCAA reduction by sulphinate groups and the adsorption of the haloacetic acids through electrostatic interaction with amide group. Investigation of product formation and subsequent disappearance reveals that the reduction reactions proceed via sequential hydrogenolysis, and transform to acetate ultimately. Adsorption of haloacetic acids was ascertained by low chloride mass balances(89.3%) and carbon mass balances(75.1%) in solution. The pseudo-first-order rate constant for TCAA degradation was (0.93±0.12) h^-1. Batch experiments were conducted to investigate the effect of pH value on the reduction and adsorption process. The results show that the reduction of TCAA by sulphinate groups requires higher pH values while the electrostatic attraction of haloacetic acids by amino group is favorable in more acidic media.     

双网络凝胶吸附剂的构建及其去除水中污染物的应用

近年来,随着工业的迅速发展,水污染危机是世界面临的主要威胁之一,开发新型环境功能材料和技术,实现水体污染物的高效去除是目前研究热点。双网络水凝胶(Double Network hydrogels)是具有三维网络结构的高分子聚合物,其机械性能优越,具备较高的强度,可以承受高水平的拉伸和压缩变形。低溶胀率使水凝胶可以容纳大量水并保持稳定的形态和网络结构。此外,由于其独特的交联方式,它还具有快速的自修复性能和显著的抗疲劳性能。具备众多优点的双网络水凝胶是一种有着巨大潜力的吸附材料,在水处理领域引起广泛关注。本文综述了双网络凝胶吸附剂的物化特性及其分类,以及近年来双网络凝胶吸附剂去除水体中重金属、抗生素和染料等污染物的应用进展。通过该综述,为双网络凝胶吸附剂的深入开发以及在水质净化中的工程应用提供新思路、新方法和新技术。     

The Amine Functionalized Sugarcane Bagasse Biocomposites as Magnetically Adsorbent for Contaminants Removal in Aqueous Solution

The method of solvothermal by one-step operation has been performed to synthesize of magnetic amine-functionalized sugarcane bagasse biocomposites (SB-MH). The obtained SB-MH contains 62.34% of Fe, 17.8 mmol/g of amine, and a magnetic property of 19.46 emu/g. The biocomposite surface area increased significantly from 1.617 to 25.789 m²/g after amine functionalization. The optimum condition of SB-MH used for Pb(II) ion removal was achieved at pH 5 for 360 min with adsorption capacity of 203.522 mg/g. The pseudo 2nd order was well-fitted to the model of Pb(II) ion adsorption. Meanwhile, other contaminant parameters number of Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), and dye in wastewater were also remarkably reduced by about 74.4%, 88.0%, and 96.7%, respectively. The reusability of SB-MH with 4th repetitions showed only a slight decrease in performance of 5%. Therefore, the proposed magnetic amine-functionalized sugarcane bagasse biocomposites lead to a very potential adsorbent implemented in high scale due to high surface area, easy separation, stable materials and capability to adsorb contaminants from aqueous solution.     

高分子溶液为连续相的悬浮液的粘弹性

综述了高分子架桥导致絮凝的悬浮液的粘弹性，及描述这种悬浮体系的逾渗方法。     

纳米二氧化钛富集-分光光度法测定水体中痕量5-磺基水杨酸

采用纳米TiO2化学吸附法富集水样中痕量5-磺基水杨酸。5-磺基水杨酸含有酚羟基(OH)和羧基(COOH)可与TiO2表面上的羟基(OH)发生酯化反应,形成稳定的六元环结构。纳米TiO2对5-磺基水杨酸的吸附量≤18.47mg/g,在pH2.5、吸附时间20min、吸附剂用量1.80g/L的条件下,纳米TiO2对试样中5-磺基水杨酸的吸附率达到99.0%,以5mL2mol/L NaOH为洗脱液,洗脱率达99.8%,对试样中5-磺基水杨酸的富集倍数达50倍,检出限(3σ,n=11)为26.7μg/L。本法操作简便,直接用于九龙江和海水中痕量5-磺基水杨酸的测定,结果准确,回收率达到95.5%～98.5%。     

Rationally Designing Molecularly Imprinted Polymer Toward a High Specific Adsorbent by Using Metal as Assembled Pivot

This article presents an original work aimed at rationally designing molecularly imprinted polymer (MIP) toward a high specific adsorbent. Assembling with cobalt as the pivot, the MIP was prepared by coordinating polymerizable monomers around an inducible template. The use of pivot obviously plays a positive role on increasing the specificity of MIP, so as to adsorb more for the template and less for its analogue. Related studies indicate that these may be a result of increasing specific interaction, which makes the MIP capable of recognizing the imprint species. Further information from thermodynamic analysis reveals that the increasing specific interaction, in logic, can be due to a higher fidelity of imprint, which specifically allures the template to bind.     

Evaluating the Removal of the Antibiotic Cephalexin from Aqueous Solutions Using an Adsorbent Obtained from Palm Oil Fiber

This study aimed to understand the adsorption process of cephalexin (CPX) from aqueous solution by a biochar produced from the fiber residue of palm oil. Scanning electron microscopy, Fourier transform infrared spectroscopy, Boehm titration, and the point of zero charge were used to characterize the morphology and surface functional groups of the adsorbent. Batch tests were carried out to evaluate the effects of the solution pH, temperature, and antibiotic structure. The adsorption behavior followed the Langmuir model and pseudo-second-order model with a maximum CPX adsorption capacity of 57.47 mg g⁻¹. Tests on the thermodynamic behavior suggested that chemisorption occurs with an activation energy of 91.6 kJ mol⁻¹ through a spontaneous endothermic process. Electrostatic interactions and hydrogen bonding represent the most likely adsorption mechanisms, although π–π interactions also appear to contribute. Finally, the CPX removal efficiency of the adsorbent was evaluated for synthetic matrices of municipal wastewater and urine. Promising results were obtained, indicating that this adsorbent can potentially be applied to purifying wastewater that contains trace antibiotics.     

天然高分子壳聚糖作为吸附剂的吸附特性研究

甲壳素经化学改性制得的壳聚糖吸附Cu²⁺、Ni²⁺、Zn²⁺、Ca²⁺、Rb⁺、Cs⁺、Cd²⁺、Pb²⁺等离子的研究已有报道^[1],但吸附Pd²⁺等贵金属离子的研究尚不多见.本文报道了壳聚糖及其交联产物的造粒方法,并测定了该糖吸附Hg²⁺、Cu²⁺、Ag⁺、Pd²⁺等离子的特性.结果表明,化学交联后的颗粒(作吸附剂)在酸性条件下仍保持相当好的刚性,对Pd²⁺离子的吸附容量较大,在Pd²⁺、Cu²⁺共存时可选择性吸附Pd²⁺.     

Synthesis of Molecularly Imprinted Polymer for Removal of Effective Impurity (Benzhydrol) from Diphenhydramine Hydrochloride Drug

The present study describes the synthesis and preliminary testing of molecularly imprinted polymers (MIPs) as scavenger resins for removal of the genotoxic impurities (GTI) benzhydrol from active pharmaceutical ingredients (API). A new molecularly imprinted polymer was synthesized using benzhydrol (template molecule), methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross‐linker), 2,2′‐azobisisobutironitril (intiator) and chloroform (porogenic solvent). To compare the performance of this polymer, a control polymer or non‐imprinted polymer (NIP) was prepared under the same conditions without the use of template molecule. The synthesized polymers were characterized by FT‐IR spectroscopy. Selectivity of the molecularly imprinted polymer for absorption benzhydrol impurities through adsorption experiments reviews and the results were compared with the adsorption of impurities by NIP. Various parameters were optimized such as time, pH, type of eluent for elution of impurities from polymer, concentration of sample and saturation of polymer. The proposed method was applied for removal of benzhydrol from Diphenhydramine hydrochloride syrup and passing it through the MIPs led to the quantitative removal of benzhydrol.     

Removal of Safranine from Aqueous Solution by Using Adsorptive Bubble Separation Techniques

Safranine, a cationic dye, was removed from synthetic wastewater by ion flotation. Over 98% of safranine was removed from the solution in 10 min. A stoichiometric amount of surfactant (1 mol of surfactant to 1 mol of dye) was found to be most effective for safranine removal. The separation efficiency of safranine decreased with increasing concentration of NaNO3. Safranine was also removed by adsorbing colloid flotation technique using Fe(OH)3 as the coagulant. Sodium lauryl sulfate was used as the collector, and over 97% of safranine was removed in 5 min. The separation efficiency decreased with increasing ionic strength of the solution. The deleterious effect of neutral salt was compensated somewhat with the aid of Al^3 as the activator. Both ion flotation and adsorbing colloid flotation may be applicable in the removal of safranine from wastewater.     

Oxidized Biomass and Its Usage as Adsorbent for Removal of Heavy Metal Ions from Aqueous Solutions

Nowadays, very coarse wool fibers are considered waste biomass and are discarded at random or burned. Therefore, it is of actual interest to valorize coarse wool fibers as utile products. In this sense, we report herein an environmentally-friendly process for the preparation of a new material based on oxidized wool fibers and designed for efficient adsorption of heavy metals from wastewater. The morphology and the structure of the obtained product were characterized by scanning electron microscopy (SEM) coupled with an X-ray energy-dispersive module (EDX) and by Fourier-transform infrared spectroscopy (FTIR). Likewise, the performances of the oxidized wool fibers for the adsorption of heavy metal cations (Cu²⁺, Cd²⁺, Pb²⁺) from aqueous solutions were tested. The adsorption kinetics data were analyzed by applying the pseudo-first-order (PFO) and pseudo-second-order (PSO) kinetic models. The equilibrium of the adsorption process was investigated by using the Freundlich and Langmuir isotherm models. According to the Langmuir isotherms registered at 300 K, the maximum adsorption capacities of the oxidized wool were found to increase from Cu²⁺ (9.41 mg/g) and Cd²⁺ (10.42 mg/g) to Pb²⁺ (30.71 mg/g). Consequently, the removal efficiency of metal ions was found to vary in the range of 96.8–99.7%. The thermodynamic parameters (e.g., enthalpy, entropy, and Gibbs free energy) were calculated and discussed.     

Recognition of Sialic Acid Using Molecularly Imprinted Polymer

Abstract

The molecular imprinting technique was applied for the preparation of a polymer selective for sialic acid. To evaluate its binding ability the molecularly imprinted polymer obtained was used as a stationary phase in liquid chromatography. The polymer showed pH-dependent characteristics for binding: an optimum specificity to sialic acid at pH 8.1 and a higher affinity with group selectivity for cis-diol containing sugars at higher pH.     

Dyes Removal from Aqueous Solution Using Wood Activated Charcoal of Bombax Cieba Tree

Thermodynamic and kinetics of adsorption of basic dyes (methylene blue and basic blue 3) on wood charcoal activated at 800 °C, prepared from Bombax Cieba (M78D) was investigated. Equilibrium data was obtained using batch method at temperatures of 10 °C to 50 °C. It was found that adsorption increase with increase in temperature. The Langmuir isotherm model describe the equilibrium of adsorption. Thermodynamic parameters such as ΔS°, ΔH° and ΔG° were calculated. From the values of ΔH° and ΔG°, it was concluded that the adsorption process is endothermic and spontaneous in nature. To determine kinetics parameter Lagergren equation was applied, and it was found that the reaction proceed through first order kinetic mechanism.     

Concentration with Selective Acid Removal from Americium Solutions Using Ion Exchange Membranes

Donnan dialysis and diffusion dialysis techniques are investigated for deacidification and possible concentration of actinide bearing acidic streams. Cation and anion exchange membranes are used in a two compartment dialysis cell to selectively remove acid from americium solutions. Acid concentrations, as high as 8.0M HNO₃ are used and the stability of membranes are ascertained. Possibility of simultaneous deacidification and concentration of acidic americium solutions are indicated by combining simple osmosis with diffusion dialysis. All the experiments are carried out under non stirring conditions at room temperature.     

Removal of Malachite Green Dye from Aqueous Solution by Catalytic Wet Oxidation Technique Using Ni/Kaolin as Catalyst

In this study, natural Algerian kaolin was used as a support and impregnated with nickel at different loading amounts (2 wt.%, 5 wt.%, and 7 wt.%) in order to prepare a supported catalyst. The wet impregnation technique was used in this preparation; nickel oxide (NiO) was the active phase precursor of the catalyst, and the catalysts were designated as follows: 2%, 5%, and 7% Ni/kaolin. These catalysts were put to the test in catalytic wet peroxide oxidation (CWPO) for degrading the organic contaminant malachite green dye (MG). Analytical techniques such as FTIR spectroscopy, X-ray diffraction, BET, and X-fluorescence were used to examine the structure, morphology, and chemical composition of the support and the produced catalysts. Several parameters, including temperature, catalytic dose, metal loading, hydrogen peroxide volume, and kinetic model were systematically investigated. The combination of improved parameters resulted in a significant increase in the catalytic activity, achieving a high removal rate of MG dye of 98.87%.