酚类化合物在2-羧基苯甲酰基修饰的超高交联树脂上的吸附

合成了一种用来吸附和去除水溶液中酚类化合物的 2 羧基苯甲酰基修饰的超高交联吸附树脂 (ZH 0 1) ,并从动力学和吸附容量角度比较了XAD 4、AM 1和ZH 0 1分别吸附浓度为 80 0mg/L苯酚的情况。实验结果表明 ,ZH 0 1吸附剂有利于吸附苯酚、对甲苯酚和对硝基苯酚之类的酚类化合物。动力学和热力学研究都得到了相同的结果 :ZH 0 1对苯酚和对甲苯酚吸附是化学吸附的过渡状态 ,而对对硝基苯酚的吸附是一种物理吸附过程 ,并且显示了ZH 0 1表面均孔特性。苯酚在ZH 0 1上的小柱吸附研究表明了吸附穿透容量和总吸附量分别为 2 .38mmol/g和 3.0 5mmol/g ,溶剂甲醇对吸附在ZH 0 1上苯酚的脱附效果较好。     

Adsorption of phenol by bentonite

The potential of bentonite for phenol adsorption from aqueous solutions was studied. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, initial concentration, pH, presence of solvent, and the desorption characteristics of bentonite. The adsorption of phenol increases with increasing initial phenol concentration and decreases with increasing the solution pH value. The adsorption process was significantly influenced by the solvent type in which phenol was dissolved. The affinity of phenol to bentonite in the presence of cyclohexane was greater than that in water and was lowest in the presence of methanol. Methanol was used to extract phenol from bentonite. The degree of extraction was dependent on the amount of phenol adsorbed by bentonite. X-ray diffraction analysis showed that the crystalline structure of bentonite was destroyed when cyclohexane was used. The ability of bentonite to adsorb phenol from cyclohexane decreased as the water to cyclohexane ratio was increased. Furthermore, hysteresis was observed in phenol desorption from bentonite in aqueous solutions. The equilibrium data in aqueous solutions was well represented by the Langmuir and Freundlich isotherm models. The removal of phenol from aqueous solutions was observed without surface modification.     

Influence of air humidity on sampling efficiency of some solid adsorbents used for sampling organics from work-room air

The influence of air humidity on the sampling efficiency of Amberlite XAD porous polymers and activated charcoal was studied by determining the recovery of various organics at 20% and 85% relative humidity. The sampling efficiency of XAD-7 was found to decrease with increasing relative humidity, while the sampling efficiency of XAD-2 and activated charcoal was relatively unaffected for the compounds studied. Activated charcoal had a greater capacity than Amberlite XAD for several types of compounds, however.     

Equilibrium and kinetic studies on the adsorption of aniline compounds from aqueous phase onto bifunctional polymeric adsorbent with sulfonic groups

In the present study, a hydrophilic bifunctional polymeric resin (LS-2) with sulfonic groups was synthesized, and the adsorption performance of three aniline compounds, aniline, 4-methylaniline, and 4-nitroaniline onto LS-2 was compared with that on the commercial Amberlite XAD-4. The uptake of the aniline compounds on LS-2 is a procedure of coexistence of physisorption and chemisorption and obeys the pseudo-second order rate equation, while the uptake of the compounds on XAD-4 is merely a physical adsorption and follows the pseudo-first order rate equation. All the isothermal data fit well with the Freundlich model, and the values of K(F) of the compounds adsorbing on LS-2 are much higher than those on XAD-4 suggesting the higher adsorbing capacities on LS-2 than those on XAD-4, which may be attributed to the microporous structure and the polar groups on the network of LS-2 resin. Dynamic adsorption and desorption studies for aniline on LS-2 show that the breakthrough adsorption capacity and the total adsorption capacity are 0.96 and 1.24 mmol per milliliter resin, respectively. Nearly 100% regeneration efficiency for the adsorbent was achieved by 5% hydrochloric acid.     

Selective removal of some polyhydric phenols from aqueous solution by ferric antimonate

Ferric antimonate, a cation-exchanger, has been investigated as an adsorbent for the removal of phenol and polyhydric phenols from aqueous solution. It has been found that ferric antimonate in H+ form selectively adsorbs polyhydric phenols having hydroxyl groups on adjacent positions. While phenol, resorcinol, and quinol did not show any appreciable adsorption, catechol, pyrogallol, and gallic acid having hydroxyl groups on adjacent positions exhibited considerable adsorption on ferric antimonate. Batch equilibrium experiments were carried out to study the effect of contact time, initial concentration of phenolic compounds, and temperature on the adsorption of phenolic compounds on ferric antimonate. The equilibrium time was found to be 1.5 hours for gallic acid and pyrogallol and 2 hours for catechol and salicylic acid. The adsorption data of the phenols at temperatures of 30 degrees, 40 degrees, and 50 degrees C have been described by Langmuir and Freundlich isotherm models. The best fit was obtained with the Langmuir model in the whole range of concentrations studied at all temperatures, indicating a monolayer adsorption onto a homogeneous adsorption surface. On the basis of the Langmuir isotherm, the maximum adsorption capacity of ferric antimonate for gallic acid, pyrogallol, catechol, and salicylic acid was found to be 3.915, 3.734, 2.397, and 2.758 mg/g, respectively at 30 degrees C. The maximum sorption capacity of ferric antimonate for the phenolic compounds studied is in the following order: gallic acid > pyrogallol > salicylic acid > catechol. The adsorption of phenolic compounds was found to decrease with an increase in temperature. Thermodynamic parameters like free energy, enthalpy, and entropy changes were calculated and discussed. The adsorption of polyhydric phenols on ferric antimonate is exothermic and spontaneous in nature.     

季铵化木屑纤维素的制备及其对水中苯酚的吸附性能研究

以3-氯-2-羟丙基三甲基氯化铵(CTA)为醚化剂，对木屑纤维素进行了改性。探讨了改性木屑纤维素用量、pH值、吸附温度、吸附时间和苯酚初始浓度等因素对静态吸附效果的影响。结果表明，木屑纤维素经改性后，对水中的苯酚的吸附过程存在化学吸附，对水中的苯酚的吸附容量得到明显提高。     

Removal and pre-concentration of phenolic species onto beta-cyclodextrin modified poly(hydroxyethylmethacrylate-ethyleneglycoldimethacrylate) microbeads

Poly(Hydroxyethylmethacrylate-Ethyleneglycoldimethacrylate), poly(HEMA-EGDMA), microbeads with 150-200 microm in size, was prepared by suspension polymerization. Beta-cyclodextrin was modified onto the polymeric microbeads using glutaraldahyde activation in an acidic medium at pH=2.5. FT-IR and TGA were used for the characterization of modified polymers and the determination of the nature of the interaction between phenolic compounds and the modified polymeric microbeads. Plain and beta-cyclodextrin modified microbeads were used in adsorption-desorption studies of phenolic species in single solution. Adsorption capacities of the phenolic species onto the plain microbeads were found to be 28.2, 17.0, 14.3, 9.8, and 1.92 mg/g polymer for o-chloro phenol, p-nitro phenol, p-chloro phenol, o-nitro phenol, and phenol, respectively. However, for beta-cyclodextrin modified microbeads, adsorption capacity of phenolic species was determined as 274, 365, 128, 182, and 87 mg/g for phenol, o-nitro phenol, p-nitro phenol, o-chloro phenol, and p-chloro phenol, respectively. Desorption ratio for the phenolic species was more than 90%, except for o-nitro phenol. Detection limits of the phenolic species were improved at least 500-fold for UV-Vis spectrophotometric detection, after the pre-concentration of all phenolic species used in this study. Adsorption time for the phenolic species onto beta-cyclodextrin-modified poly(HEMA-EGDMA) microbeads was found to be reasonable short (10-60 min) and suitable for the applications. Also, synthesized microbeads were useful for the repeated use for the removal and pre-concentration of phenolic species.     

Adsorption of phenolic compounds by activated carbon--a critical review

Adsorption of phenol and its derivatives on activated carbons is considered based on numerous papers related to this issue. Special attention is paid to the effects of carbon surface functionalities, pH of solution and heterogeneity effects that accompany adsorption of phenolic compounds. Moreover, in this paper the most important aspects are overviewed referring to irreversible adsorption of phenols and impact of different substituents of phenolic compounds on their uptake by activated carbons is considered. Finally, some remarks pertaining to applications of novel adsorbents for phenol adsorption are discussed and illustrated by means of a few examples.     

Comparison of the removal of 2,4-dichlorophenol and phenol from polluted water, by peroxidases from tomato hairy roots, and protective effect of polyethylene glycol

Multiple efforts have been directed towards optimized processes in which enzymes, like peroxidases, are used to remove phenolic compounds from polluted wastewater. Here we describe the use of peroxidase isoenzymes from tomato hairy roots, which were able to oxidise 2,4-dichlorophenol (2,4-DCP) and phenol from aqueous solutions. This could be an interesting alternative for the removal of these compounds from contaminated sites. We used different enzyme fractions: total peroxidases (TP), ionically bound to cell wall peroxidases (IBP), basic (BP) and acidic peroxidases (AP). We analyzed the optimum conditions of removal, the effect of Polyethyleneglycol (PEG-3350) on the process and on the enzyme activities, to obtain the maximum efficiency. The optimal H2O2 concentrations for 2,4-DCP and phenol removal were 1 and 0.1mM, respectively. TP, IBP and BP showed better removal efficiencies than AP, for both contaminants. The addition of different concentrations (10-100mg l(-1)) of PEG-3350 to solutions containing 2,4-DCP showed no effect on the removal efficiencies of the isoenzymes. However, PEG (100mg l(-1)) increased the removal efficiency of phenol by BP and IBP fractions. On the other hand, peroxidase activities from BP and IBP fractions were 3 and 13 times higher, respectively, than those detected for the same fractions in phenol treated solutions without PEG. The protective effect of PEG, which depends on the contaminant as well as of the enzyme fraction used, would be important to improve the removal efficiency of phenol by some peroxidase isoenzymes.     

Biosorption of copper(II) from aqueous solutions by pre-treated biomass of marine algae Padina sp

Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions. The biomass of marine algae has been reported to have high uptake capacities for a number of heavy metal ions. In this paper, the adsorption properties of a pre-treated biomass of marine algae Padina sp. for copper(II) were investigated. Equilibrium isotherms and kinetics were obtained from batch adsorption experiments. The biosorption capacities were solution pH dependent and the maximum capacity obtained was 0.80 mmol/g at a solution pH of about 5. The biosorption kinetics was found to be fast, with 90% of adsorption within 15 min and equilibrium reached at 30 min. The effects of light metal ions on copper(II) uptake were studied and the presence of light metal ions did not affect copper(II) uptake significantly. Fixed-bed breakthrough curves for copper(II) removal were also obtained. This study demonstrated that the pre-treated biomass of Padina sp. could be used as an effective biosorbent for the treatment of copper(II) containing wastewater streams.     

Electrochemical and FTIR studies of the mutual influence of lead(II) or iron(III) and phenol on their adsorption from aqueous acid solution by modified activated carbons

Cyclic voltammetry and spectral FTIR studies of the influence of activated carbon surface modification on the co-adsorption of metal cation (lead or iron) and phenol from aqueous acidic solution were carried out. The diversity in surface chemical structure was achieved by applying different procedures of inorganic matter removal and by modifying the carbon samples in various ways: heating under vacuum, aminoxidation in an ammonia-oxygen atmosphere, oxidation with concentrated nitric acid. The quantities of adsorbed metal ions (Pb(2+) or Fe(3+)) and phenol from solutions containing cation or phenol separately or in a mixture were determined. The adsorption capacity from acidic aqueous acidic solution depends on the chemical properties of the activated carbon surface (e.g., decrease in phenol adsorption with relative lower basicity of the adsorbent). The electrochemical parameters of electrodes made from the carbon samples were estimated, and some possible electrochemical reactions were determined from voltammograms recorded in acid electrolyte solution containing adsorbed species (separately or as a mixture). Relationships were found between metal ion adsorption and electrochemical behavior of Pb(2+)/Pb(4+) and Fe(3+)/Fe(2+) couples on the one hand, and the presence of phenol in the solutions tested and the influence of surface chemistry of the carbon electrodes on electrochemical processes on the other. The changes in adsorption capacity with respect to the adsorbates used and the changes in FTIR spectra of the carbons as a result of adsorption and/or coupling phenol molecules are discussed.     

颗粒活性炭去除水中甲基叔丁基醚的可行性研究

随着甲基叔丁基醚（MTBE）作为汽油添加剂被持续大量使用，其已成为一种地下水中常见的有机污染物。本文通过纯净水、自来水和地下水中MTBE的平衡吸附容量和微型快速穿透实验（MCRB），比较了5种不同种类活性炭对MTBE的吸附性能。结果显示，苯酚值可准确预测活性炭样品对MTBE的平衡吸附容量大小次序，而丹宁酸值则可大致估计活性炭在实际处理应用时的吸附速度和吸附容量利用率。水样中共存的有机成分降低了活性炭对纯净水中MTBE的吸附容量，在背景TOC较低的去离子水中，活性炭对于MTBE的吸附性能反而比在地下水中降低得更多。穿透实验数据显示双柱串联的处理方式是高效应用活性炭吸附水中MTBE的优选工艺。使用环境友好的竹质活性炭去除地下水中MTBE具有良好的可行性和较高的性价比。     

氧化树脂的制备及其对水溶液中2,4-二氯苯酚的吸附研究

用H₂O₂或HNO₃氧化的方法制备了新型吸附树脂ZH-07和ZH-08,同时研究了它们对不同温度下水溶液中2,4-二氯苯酚的静态吸附和脱附特征,并对其吸附机理进行了探讨。结果表明,经氧化后的树脂ZH-07和ZH-08对水溶液中2,4-二氯苯酚的吸附过程存在化学吸附作用,可以提高它们对水溶液中2,4-二氯苯酚的吸附容量。     

固定化改性蒙脱土对苯酚吸附性能的研究

利用十六烷基三甲基溴化铵对天然蒙脱土进行改性,并用聚乙烯醇对改性蒙脱土进行固定化处理,然后进行柱状吸附和振荡条件的吸附试验。研究结果表明,HDTMA改性蒙脱土固定化后能有效吸附苯酚,不同环境条件对苯酚的柱状吸附能力产生不同的影响。在pH4~8的范围内,固定化改性蒙脱土对苯酚的吸附效果无显著性差异,pH在10以上,其吸附能力明显下降;温度对吸附效果影响不大;进水苯酚浓度越高,改性蒙脱土对苯酚的吸附量越大,但出水苯酚浓度也高;苯酚的流速越小,吸附容量越高,吸附效果越好。     

Experimental design methodology for the preparation of carbonaceous sorbents from sewage sludge by chemical activation--application to air and water treatments

The objective of this study is to optimize experimental conditions of sorbent preparation from sewage sludge using experimental design methodology. Series of carbonaceous sorbents have been prepared by chemical activation with sulfuric acid. The sorbents produced were characterized, and their properties (surface chemistry, porous and adsorptive properties) were analyzed as a function of the experimental conditions (impregnation ratio, activation temperature and time). Carbonaceous sorbents developed from sludge allow copper ion, phenol and dyes (Acid Red 18 and Basic Violet 4) to be removed from aqueous solution as well as VOC from gas phase. Indeed, according to experimental conditions, copper adsorption capacity varies from 77 to 83 mg g(-1), phenol adsorption capacity varies between 41 and 53 mg g(-1) and VOC adsorption capacities (acetone and toluene) range from 12 to 54 mg g(-1). Each response has been described by a second-order model that was found to be appropriate to predict most of the responses in every experimental region. The most influential factors on each experimental design response have been identified. Regions in which optimum values of each factor were achieved for preparation of activated carbons suitable for use in wastewater and gas treatments have been determined using response surfaces methodology. In order to have a high mass yield and to minimize the energetic cost of the process, the following optimal conditions, 1.5 g of H2SO4 g(-1) of sludge, 700 degrees C and 145 min are more appropriate for use of activated carbon from sludge in water and gas treatments.     

改性钢渣吸附氨氮和磷的特性研究

利用钢渣与氢氧化铝以4∶3质量配比混合,在700℃下进行2 h煅烧,得到改性钢渣。通过批次吸附实验,研究了改性钢渣在不同初始pH值、振荡时间和温度下对水溶液中氨氮和磷酸根的吸附情况,进而分析了改性钢渣对氨氮和磷酸根的吸附等温线、热力学和动力学特性。结果表明,改性钢渣脱氮除磷能力比原钢渣显著增强,且最适pH值为4～8。改性沸石对氨氮和磷酸盐的吸附均符合Langmuir等温吸附方程,氨氮(以N计)最大吸附量在10、20和30℃下分别为1.67、2.59和3.24 mg/g,磷酸根(以P计)的最大吸附量在10、20和30℃下分别为1.02、1.19和1.37 mg/g。热力学参数ΔG0、ΔH0和ΔS0表明,该吸附是一个自发、吸热、熵增型反应过程,且磷的吸附是化学吸附为主,氨氮的吸附是以离子交换吸附和物理吸附为主。改性钢渣对磷和氨氮的吸附动力学符合伪二级方程(R2>0.999)。     

Kinetic and equilibrium studies of adsorptive removal of phenol onto eggshell waste

The aim of the present research is to develop economic, fast, and versatile method for the removal of toxic organic pollutant phenol from wastewater using eggshell. The batch experiments are conducted to evaluate the effect of pH, phenol concentration, dosage of adsorbent, and contact time on the removal of phenol. The paper includes in-depth kinetic studies of the ongoing adsorption process. Attempts have also been made to verify Langmuir and Freundlich adsorption isotherms. The morphology and characteristics of eggshell have also been studied using scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray fluorescence analysis. At ambient temperature, the maximum adsorption of phenol onto eggshells has been achieved at pH 9 and the contact time, 90 min. The experimental data give best-fitted straight lines for pseudo-first-order as well as pseudo-second-order kinetic models. Furthermore, the adsorption process verifies Freundlich and Langmuir adsorption isotherms, and on the basis of mathematical expressions of these models, various necessary adsorption constants have been calculated. Using adsorption data, various thermodynamic parameters like change in enthalpy (?H ⁰), change in entropy (?S ⁰), and change in free energy ?G ⁰ have also been evaluated. Results clearly reveal that the solid waste material eggshell acts as an effective adsorbent for the removal of phenol from aqueous solutions.     

Preparation of a porous clay heterostructure and study of its adsorption capacity of phenol and chlorinated phenols from aqueous solutions.

A porous clay heterostructure (PCH) from a Mexican clay was prepared and characterized, and its aqueous phenol and dichlorophenols (DCPs) adsorption capacities were studied using a batch equilibrium technique. The PCH displayed a surface area of 305.5 m2/g, 37.2 A average porous diameter, and a basal space of 23.2 A. The adsorption capacity shown by the PCH for both phenol and DCPs from water (14.5 mg/g for phenol; 48.7 mg/g for 3,4-DCP; and 45.5 mg/g for 2,5-DCP) suggests that the PCH has both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PCH. The values of maximal adsorption capacity for dichlorophenols were higher than those reported for aluminum pillared clays and some inorgano-organo clays and comparable with some ionic exchange resins.     

Irrigation model of bleached Kraft mill wastewater through volcanic soil as a pollutants attenuation process

An irrigation process through volcanic soil columns was evaluated for bleached Kraft mill effluent pollutants retention. The system was designed to remove color and phenolic compounds and a simple kinetic model for determining the global mass transfer coefficient and the adsorption rate constant was used. The results clearly indicate that the global mass transfer coefficient values (K(c)a) and the adsorption rate constants are higher for the irrigation processes onto acidified soil. This means that the pretreatment of washing the volcanic soil with an acid solution has a positive effect on the adsorption rate for both pollutant groups. The enhanced adsorption capacity is partially explained by the activation of the metal oxides present in the soil matrix during the acid washing process. Increasing the flow rate from 1.5 to 2.5 ml/min yielded higher (K(c)a) values and adsorption rate constants for both pollutant groups. For instance, regarding color adsorption onto acidified soil, there is an increment of 43% in the (K(c)a) value for the experiment with a flow rate of 2.5 ml/min. Increasing the porosity of the column from 0.55 to 0.59, yielded a decrease in the (K(c)a) values for color and phenolic compounds adsorption processes. Onto natural soil for example, these decreases reached 21% and 24%, respectively. Therefore, the (K(c)a) value is dependent on both the liquid-phase velocity (external resistance) and the soil fraction in the column (internal resistance); making forced convection and diffusion to be the main transport mechanisms involved in the adsorption process. Analyzing the adsorption rate constants (K(c)a)/m, phenolic compounds and color adsorption rates onto acidified soil of 2.25 x 10(-6) and 2.62 x 10(-6) l/mg min were achieved for experiment 1. These adsorption rates are comparable with other adsorption systems and adsorbent materials.     

ZH-02树脂对水中腐殖酸的吸附去除研究

通过几种吸附树脂ZH 0 0、ZH 0 1、ZH 0 2、ZH 0 3、颗粒活性炭 (GAC)和AmberliteXAD 4对腐殖酸的静态吸附试验的筛选结果 ,发现大孔树脂ZH 0 2对腐殖酸具有较好的吸附效果。利用颗粒活性炭作为参照 ,探讨了ZH 0 2的动态吸附去除效果和脱附再生条件 ,发现常温下醇碱溶液效果较好。