Ghezeljeh nanoclay as a new natural adsorbent for the removal of copper and mercury ions:Equilibrium,kinetics and thermodynamics studies

Heavy metal determination was carried out by applying the solid phase extraction (SPE) method in batch mode followed by atomic absorption spectroscopy (AAS) and inductively coupled plasma atomic emission spectrosco-py (ICP-AES) from aqueous solutions using Ghezeljeh montmoril onite nanoclay as a new natural adsorbent. The Ghezeljeh clay is characterized by using Fourier Transform Infrared (FT-IR) Spectroscopy, Scanning Electron Mi-croscopy–Energy Dispersive Spectrometry (SEM–EDS) and X-ray Diffractometry (XRD) and X-ray Fluorescence (XRF). The results of XRD and FT-IR of nanoclay confirm that montmoril onite is the dominant mineral phase. Based on SEM images of Ghezeljeh clay, it can be seen that the distance between the plates is Nano. The effects of varying parameters such as initial concentration of metal ions, pH and type of buffer solutions, amount of ad-sorbent, contact time, and temperature on the adsorption process were examined. The effect of various interfer-ing ions was studied. The adsorption data correlated with Freundlich, Langmuir, Dubinin–Radushkevich (D–R), and Temkin isotherms. The Langmuir and Freundlich isotherms showed the best fit to the equilibrium data for Hg(I ), but the equilibrium nature of Cu(II) adsorption has been described by the Langmuir isotherm. The kinetic data were described with pseudo-first-order, pseudo-second-order and double-exponential models. The adsorp-tion process follows a pseudo-second-order reaction scheme. Calculation ofΔG0,ΔH0 andΔS0 showed that the nature of Hg(II) ion sorption onto the Ghezeljeh nanoclay was endothermic and was favored at higher temper-ature, and the nature of Cu(II) ion sorption was exothermic and was favored at lower temperature.     

Removal of Cd（II） by Nanometer AIO（OH） Loaded on Fiberglass with Activated Carbon Fiber Felt as Carrier

A new nanometer material, nanometer AlO（OH） loaded on the fiberglass with activated carbon fibers felt（ACF） as the carrier, was prepared by hydrolytic reaction for the removal of Cd（II） from aqueous solution using column adsorption experiment. As was confirmed by XRD determination, the hydrolysis production loaded on fiberglass was similar to the orthorhombic phase AlO（OH）. SEM images showed that AlO（OH） particles were in the form of small aggregated clusters. The Thomas model was applied for estimating the kinetic parameters and the saturated adsorption ability of Cd（II） adsorption on the new adsorbent. The results showed that the maximum adsorption capacity of Cd（II） was 128.50 mg·g^-1 and 117.86 mg·g^-1 for the adsorbent mass of 0.3289 g and the adsorbent mass of 0.2867 g, respectively. The elution experiment result indicated that the adsorbed Cd ions was easily desorbed from the material with 0.1 mol·L^-1 HCl solution. Adsorption-desorption cycles showed the feasibility of repealed uses of the composited material. The adsorption capacities were influenced by pH and the initial Cd（II） concentration. The amount adsorbed was greatest at pH 6.5 and the initial Cd（II） concentration of 0.07 mg·L^-1, respectively. Nanometer AlO（OH） played a major role in the adsorption process, whereas the fiberglass and ACF were assistants in the process of removing Cd（II）. In addition, the adsorption capacities for Cd（II） were obviously reduced from 128.50 mg·L^-1 to 64.28 mg·L^-1 when Pb ions were present because Pb ions took up more adsorption sites.     

交联壳聚糖磁性颗粒吸附去除水溶液中的铜

The performance of cross-linked magnetic chitosan, coated with magnetic fluids and cross-linked with epichlorohydrin, was investigated for the adsorption of copper (II) from aqueous solutions. Infrared spectra of chitosan before and after modification showed that the coating and cross-linking are effective. Experiments were performed at different pH of solution and contact time, and appropriate conditions for the adsorption of Cu(II) were determined. Experimental equilibrium data were correlated with Langmuir and Freundlich isotherms for determination of the adsorption potential. The results showed that the Langmuir isotherm was better compared with the Freundlich isotherm, and the uptake of Cu(II) was 78.13 mg•g－1. The kinetics of adsorption corresponded with the first-order Langergren rate equation, and Langergren rate constants were determined.     

Static magnetic field-assisted synthesis of Fe_3O_4 nanoparticles and their adsorption of Mn(Ⅱ) in aqueous solution

A facile method for synthesis of the magnetic Fe_3O_4 nanoparticles was introduced.Magnetic nanoparticles were prepared via co-precipitation method with(PMF) and without(AMF) 0.15 T static magnetic field.The effects of magnetic field on the properties of magnetic nanoparticles were studied by XRD,TEM,SEM,VSM and BET.The results showed that the magnetic field in the co-precipitation reaction process did not result in the phase change of the Fe_3O_4 nanoparticles but improved the crystallinity.The morphology of Fe_3O_4 nanoparticles was varied from random spherical particles to rod-like cluster structure.The VSM results indicated that the saturation magnetization value of the Fe_3O_4 nanoparticles was significantly improved by the magnetic field.The BET of Fe_3O_4nanoparticles prepared with the magnetic field was larger than the control by 23.5%.The batch adsorption experiments of Mn(Ⅱ) on the PMF and AMF Fe_3O_4 nanoparticles showed that the Mn(II) equilibrium capacity was increased with the pH value increased.At pH 8,the Mn(Ⅱ) adsorption capacity for the PMF and AMF Fe_3O_4 was reached at 36.81 and 28.36 mg·g~(-1),respectively.The pseudo-second-order model fitted better the kinetic models and the Freundlich model fitted isotherm model well for both PMF and AMF Fe_3O_4.The results suggested that magnetic nanoparticles prepared by the magnetic field presented a fairly good potential as an adsorbent for an efficient removal of Mn(Ⅱ) from aqueous solution.     

Adsorptive potential of Acacia nilotica based adsorbent for chromium(Ⅵ) from an aqueous phase

The objective of this research was to enhance adsorption capacity of Acacia nilotica(keekar) sawdust for the abatement of chromium bearing wastewater and to investigate the effect of process parameters on adsorption capacity. The sawdust was activated by acid wash and functionalized subsequently with formaldehyde.Functionalization of activated sawdust raised its chromium removal efficiency of almost 10% as compared to its adsorption removal efficiency of HCl treated sawdust in a batch adsorption study. Adsorption kinetic data provided better fitting with pseudo second order model. Maximum adsorption capacity calculated through the best fitting Langmuir model was 6.34 mg·g~(-1) and 8.2 mg·g~(-1) for HCl treated and formaldehyde functionalized sawdust adsorbents, respectively. The adsorption of Cr(Ⅵ) was endothermic when studied by varying temperature from 20 °C to 50 °C for both activated and functionalized adsorbents.     

Efficient adsorption to hexavalent chromium by iron oxalate modified D301:Characterization,performance and mechanisms

Chromium is a common harmful pollutant with high toxicity and low bearing capacity of soil and water. Excellent salinity resistance, a wide p H range, and high regeneration capacity were essential for qualified adsorbents used in removing hexavalent chromium(Cr(VI)) from polluted water. Herein, iron oxalate modified weak basic resin(IO@D301) for the removal of Cr(VI) was prepared by the impregnation method. The IO@D301 was characterized by scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FTIR), X-Ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS). Owing to abundant amine, carboxyl groups and iron ions existing on the surface, IO@D301 possesses high adsorption and salinity resistance capacity for Cr(VI). The maximum adsorption capacity of IO301 towards Cr(VI) reached 201.30 mg·g~(-1) at 293 K and a p H of 5. The adsorption equilibrium was well fitted by the Freundlich model, and the adsorption process was described by the pseudofirst-order kinetics model as spontaneous and exothermic. The mechanism may be identified as electrostatic attraction, coordination, and reduction, which was confirmed by FT-IR and X-ray photoelectron spectroscopy.     

D72树脂对镨(Ⅲ)的吸附性能(英文)

In this work, the feasibility of using a macroporous strong acid ion exchange resin (D72) as an adsorbent for praseodymium (Ⅲ) was examined. The adsorption behavior and mechanism were investigated with various chemical methods and IR spectrometry. The results showed that the loading of Pr (III) ions was strongly dependent on pH of the medium and the optimal adsorption condition is in HAc-NaAc medium with pH value of 3.0. Adsorption kinetics of Pr (III) ions onto D72 resin could be best described by pseudo-second-order model. The maximum adsorption capacity of D72 for Pr (Ⅲ) was evaluated to be 294 mg·g 1 for the Langmuir model at 298K. The apparent activation energy, E a , was 14.71 kJ·mol 1 . The calculated data of thermodynamic parameters, ΔSΘ value of 100 J·mol 1 ·K 1 and ΔHΘ value of 8.89 kJ·mol 1 , indicate the endothermic nature of the adsorption process, while a decrease of ΔGΘ with increasing temperature indicates the spontaneous nature of the adsorption process. Finally, Pr (Ⅲ) can be eluted by using 1.00 mol·L 1 HCl-0.50 mol·L 1 NaCl solution and the D72 resin can be regenerated and reused. Thomas model was successfully applied to experimental data to predict the breakthrough curves and to determine the characteristic parameters of the column useful for process design. The characterization before and after adsorption of Pr (Ⅲ) ions on D72 resin was conformed by IR.     

交联氧化铝-壳聚糖新杂化吸附剂的制备及去除废水中Cu(Ⅱ)(英文)

A novel biosorbent was developed by coating chitosan,a naturally and abundantly available biopolymer,on to activated alumina based on oil shale ash via crosslinking.The adsorbent was characterized by various techniques,such as Fourier transform infrared spectroscopy,scanning electron microscopy,thermogravimetric-differential thermal analysis,and X-ray photoelectron spectroscope.Batch isothermal equilibrium adsorption experiments were condcted to evaluate the adsorbent for the removal of Cu(Ⅱ) from wastewater.The effect of pH and agitation time on the adsorption capacity was also investigated,indicating that the optimum pH was 6.0.The equilibrium adsorp-tion data were correlated with Langmuir and Freundlich models.The maximum monolayer adsorption capacity of chitosan coated alumina sorbent as obtained from Langmuir adsorption isotherm was found to be 315.46 mg·g-1 for Cu(Ⅱ).The adsorbent loaded with Cu(Ⅱ) was readily regenerated using 0.1 mol?L?1 sodium hydroxide solution.All these indicated that chitosan coated alumina adsorbent not only have high adsorption activity,but also had good stability in the wastewater treatment process.     

Adsorption equilibrium of citric acid from supercritical carbon dioxide/ethanol on cyano column

Supercritical adsorption equilibrium has a significant role in defining supercritical adsorption behavior. In this paper, the adsorption equilibrium of citric acid from supercritical CO2/ethanol on a cyano column was systemat-ical y investigated with the elution by characteristic point method. Equilibrium loading was obtained at 313.15 K and 321.15 K with supercritical CO2/ethanol densities varying from 0.7068 g·cm?3 to 0.8019 g·cm?3. The exper-imental results showed that the adsorption capacity of citric acid decreased with increasing temperature and in-creasing density of the supercritical CO2/ethanol mobile phase. The adsorption equilibrium data were fitted wel by the Quadratic Hill isotherm model and the isotherms showed anti-Langmuir behavior. The monolayer satura-tion adsorption capacity of citric acid is in the range of 44.54 mg·cm?3 to 64.66 mg·cm?3 with an average value of 56.86 mg·cm?3.     

Hydrous cerium oxides coated glass fiber for efficient and long-lasting arsenic removal from drinking water

A novel arsenic adsorbent with hydrous cerium oxides coated on glass fiber cloth(HCO/GFC)was synthesized.The HCO/GFC adsorbents were rolled into a cartridge for arsenic removal test.Due to the large pores between the glass fibers,the arsenic polluted water can flow through easily.The arsenic removal performance was evaluated by testing the equilibrium adsorption isotherm,adsorption kinetics,and packed-bed operation.The pH effects on arsenic removal were conducted.The test results show that HCO/GFC filter has high As(Ⅴ)and As(Ⅲ)removal capacity even at low equilibrium concentration.The more toxic As(Ⅲ)in water can be easily removed within a wide range of solution p H without pre-treatment.Arsenic contaminated ground-water from Yangzong Lake(China)was used in the column test.At typical breakthrough conditions(the empty bed contact time,EBCT=2 min),arsenic researched breakthrough at over 24,000 bed volumes(World Health Organization(WHO)suggested that the maximum contaminant level(MCL)for arsenic in drinking water is 10 mg/L).The Ce content in the treated water was lower than 5 ppb during the column test,which showed that cerium did not leach from the HCO/GFC material into the treated water.The relationship between dosage of adsorbents and the adsorption kinetic model was also clarified,which suggested that the pseudo second order model could fit the kinetic experimental data better when the adsorbent loading was relatively low,and the pseudo first order model could fit the kinetic experimental data better when the adsorbent loading amount was relatively high.     

阴离子交换纤维对草酸根离子吸附性能的研究

以含偕胺肟基团的螯合纤维为原料,分别经Hg（NO3）2、Pb（NO3）2等溶液化学处理,制得五种不同类型的阴离子交换纤维。研究了时间、温度、pH值和离子浓度等因素对阴离子交换纤维吸附草酸根离子性能的影响。实验结果表明,汞阴离子交换纤维、铅阴离子交换纤维和铜阴离子交换纤维可以吸附草酸根离子,且汞阴离子交换纤维吸附性能最好。汞阴离子交换纤维在反应时间为90min、温度为40℃、pH值为9、草酸根离子浓度为0．05mol/L时,最高吸附量可达1．65mmol/g.     

Investigation on selective adsorption of Hg(II) ions using 4‐vinyl pyridine grafted poly(ethylene terephthalate) fiber

In the work, poly(ethylene terephthalate) (PET) fibers were grafted with 4‐vinyl pyridine (4‐VP) monomer using benzoyl peroxide (Bz₂O₂) as initiator in aqueous media. The removal of Hg(II) ions from aqueous solution by the reactive fiber was examined by batch equilibration technique. Effects of various parameters such as pH, graft yield, adsorption time, initial ion concentration, and adsorption temperature on the adsorption amount of metal ions onto reactive fibers were investigated. The optimum pH of Hg(II) was found 3. The maximum adsorption capacity was found as 137.18 mg g^?1. Moreover such parameters as the adsorption kinetics, the adsorption isotherm, desorption time and the selectivity of the reactive fiber were studied. The adsorption kinetics is in better agreement with pseudo‐first order kinetics, and the adsorption data are good fit with Freundlich isotherms. The grafted fiber is more selective for Hg(II) ions in the mixed solution of Hg(II)‐Ni(II), Hg(II)‐Zn(II), and Hg(II)‐Ni(II)‐Zn(II) at pH 3. Adsorbed Hg(II) ions were easily desorbed by treating with 1M HNO₃ at room temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Removal of nickel(II) from aqueous solutions using iminodiacetic acid functionalized polyglycidyl methacrylate grafted-carbon fibers☆

Iminodiacetic acid functionalized polyglycidyl methacrylate grafted-carbon fibers (PGMA-IDA/CFs) were prepared for Ni(II) removal from aqueous solutions. The effects of solution pH value, temperature and adsorption time were investigated. The maximum adsorption capacity of Ni(II) on PGMA-IDA/CFs is 0.923 mmol·L?1 · g?1 at pH 5.2 and 50 °C. Kinetic data indicate that the adsorption process matches the pseudo-second-order model and Elovich kinetic model. Thermodynamic data suggest that the adsorption process is endothermic spontaneous reaction.     

Studies on uptake behavior of Hg(II) and Pb(II) by amine modified glycidyl methacrylate–styrene–N,N′-methylenebisacrylamide terpolymer

The removal of mercury and lead ions from aqueous solutions investigated by ethylenediamine, diethylenetriamine and tetraethylenepentamine functionalized polymeric adsorbent. The adsorbent was prepared by amination of terpolymer synthesized from glycidylmethacrylate, styrene and N,N′-methylenebisacrylamide. In the single metal species system (only mercury or lead ions are present) poly(glycidylmethacrylate–ethylenediamine) (PGMA–EDA), poly(glycidylmethacrylate–diethylenetriamine) (PGMA–DETA), and poly(glycidylmethacrylate–tetraethylenepentamine) (PGMA–TEPA) were found to adsorb lead or mercury ions with a slightly higher adsorption uptake capacity for lead than mercury ions. Among the three functionalized polymers poly(glycidylmethacrylate–diethylenetriamine) (PGMA–DETA) shows faster and higher adsorption capacity than poly(glycidylmethacrylate–ethylenediamine) (PGMA–EDA), poly(glycidylmethacrylate–tetraethylenepentamine) (PGMA–TEPA). The natural pH of both the metal ions was found to be most suitable for uptake. The uptake of Hg(II) and Pb(II) ions was investigated by using batch technique. The maximum adsorption capacities of Pb ions were predicted to be 4.74, 4.76 and 4.73 mmol/g and the maximum Hg(II) ion uptakes were found to be 4.76, 4.80 and 4.21 mmol/g respectively for PGMA–EDA, PGMA–DETA and PGMA–TEPA resins at their natural pH. The uptakes of Hg(II) and Pb(II) ions on the resins were found to follow Langmuir adsorption isotherm and pseudosecond order kinetics.     

Sulfated katira gum‐graft‐poly(N‐vinyl imidazole): A useful scavenger of mercury(II) ions

Katira gum-graft-poly(N-vinyl imidazole) was synthesized in a water medium with potassium perdisulfate as the free-radical initiator at 70 ± 1 °C. The graft copolymer was sulfated by chlorosulfonic acid in the presence of pyridine and formamide. Various characterization techniques, including Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy, were used to characterize both the unsulfated and sulfated graft copolymers. The sulfated graft copolymer was used for the adsorption of Hg(II) ions from its aqueous solution. The operating variables affecting the Hg(II) adsorption, including the solution pH, amount of sulfated graft copolymer, contact time, and concentration of Hg(II), were investigated extensively. The sulfated graft copolymer was also used for competitive metal-ion removal with Pb(II), Cd(II), Cu(II), and Zn(II). Metal complexation was studied with FTIR spectroscopy, ultraviolet–visible (UV–vis) spectroscopy, and cyclic voltammetry analysis. The Hg(II) adsorption data of the sulfated graft copolymer were described well by the pseudo-second-order rate equation. The Langmuir adsorption isotherm provided the best correlation for the adsorption data. Various thermodynamic parameters for the adsorption were calculated. FTIR and UV–vis spectroscopy and cyclic voltammetry analysis before and after the adsorption of Hg(II) on the sulfated graft copolymer showed that columbic attraction was mainly responsible for the binding of the Hg(II) ions with the  groups present in the sulfated graft copolymer. The sulfated graft copolymer showed a better adsorption performance than the graft copolymer itself under optimized conditions. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44565.     

Response surface approach for optimization of Hg(II) adsorption by 3-mercaptopropyl trimethoxysilane-modified kaolin minerals from aqueous solution

The optimization of Hg(II) adsorption conditions from aqueous solutions with 3-mercaptopropyl trimethoxysilane-modified kaolin (MMK) used as a new adsorbent was analyzed by response surface methodology (RSM) approach. The MMK adsorbent was characterized by means of energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). According to the quadratic model obtained from central composite design (CCD) in RSM, the optimal conditions for adsorption were found to be 30.83 mg/L, 0.1 g, 7.44 and 31.41 °C for C _o , adsorbent dosage, initial pH, and T (°C), respectively. With the obtained model, the maximum amount of adsorbed Hg(II) and %Hg(II) removed was calculated to be 30.10 mg/g and 98.01%, respectively. Langmuir and Dubinin-Radushkevich isotherms fitted well the experimental results. Thermodynamic studies revealed that the adsorption was physical, exothermic, spontaneous. The results indicate that MMK a new adsorbent has great potential for the removal of Hg(II) from aqueous media.     

Removal of Cd(II), Hg(II), and Pb(II) ions from aqueous solution using p(HEMA/chitosan) membranes

An interpenetration network (IPN) was synthesized from 2‐hydroxyethyl methacrylate (HEMA) and chitosan, p(HEMA/chitosan) via UV‐initiated photo‐polymerization. The selectivity to different heavy metal ions viz Cd(II), Pb(II), and Hg(II) to the IPN membrane has been investigated from aqueous solution using bare pHEMA membrane as a control system. Removal efficiency of metal ions from aqueous solution using the IPN membranes increased with increasing chitosan content and initial metal ions concentrations, and the equilibrium time was reached within 60 min. Adsorption of all the tested heavy metal ions on the IPN membranes was found to be pH dependent and maximum adsorption was obtained at pH 5.0. The maximum adsorption capacities of the IPN membrane for Cd(II), Pb(II), and Hg(II) were 0.063, 0.179, and 0.197 mmol/g membrane, respectively. The adsorption of the Cd(II), Hg(II), and Pb(II) metal ions on the bare pHEMA membrane was not significant. When the heavy metal ions were in competition, the amounts of adsorbed metal ions were found to be 0.035 mmol/g for Cd(II), 0.074 mmol/g for Hg(II), and 0.153 mmol/g for Pb(II), the IPN membrane is significantly selective for Pb(II) ions. The stability constants of IPN membrane–metal ions complexes were calculated by the method of Ruzic. The results obtained from the kinetics and isotherm studies showed that the experimental data for the removal of heavy metal ions were well described with the second‐order kinetic equations and the Langmuir isotherm model. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Efficient Removal of Hg(II) by Polymer-Supported Hydrated Metal Oxides from Aqueous Solution

Chelating PS-EDTA resins modified by metal (Fe, Al, and Zr) oxides were used as adsorbents to remove Hg(II) from aqueous solutions. The modified resins were characterized by BET, FTIR, and XPS. The amino, carboxylate, and the metal oxides on resins exhibited a synergistic effect for Hg(II) removal. It was observed that the modification of PS-EDTA resin not only increased the adsorption of Hg(II) but also accelerated the adsorption rate of Hg(II). The equilibrium data of Hg(II) were best described by the Freundlich isotherm, and the kinetics were found to follow the pseudo-second-order kinetic model. Also, thermodynamic parameters showed that Hg(II) adsorption was endothermic and spontaneous in nature. The increasing the concentration (0.1–2.0 g/L) of NaNO₃ in Hg(II) solution did not affect the adsorption of Hg(II). Moreover, the competitive adsorption indicated that the modified resins had higher selectivity towards Hg(II) over Cd(II), Pb(II), Zn(II), or Cu(II) in a binary system. All of the above results indicated that the modified resin was an efficient and reusable adsorbent for Hg(II) removal due to its simple preparation, high adsorption capacity, fast adsorption rate, ionic strength independence, high selectivity, and good reusability. These properties are of potential application in the fixed-bed continuous-flow column for Hg(II) removal from wastewaters.     

Investigation of adsorption of lead,mercury and nickel from aqueous solutions onto carbon aerogel

Recently a new form of activated carbon has appeared: carbon aerogel (CA). Its use for the removal of inorganic (and especially metal ions) has not been studied. In the present study, the adsorption of three metal ions, Hg(II), Pb(II) and Ni(II), onto carbon aerogel has been investigated. Batch experiments were carried out to assess adsorption equilibria and kinetic behaviour of heavy metal ions by varying parameters such as agitation time, metal ions' concentration, adsorbent dose and pH. They facilitated the computation of kinetic parameters and maximum metal ion adsorption capacities. Increasing the initial solution pH (2–10) and carbon concentration (50–500 mg per 50 cm³) increases the removal of all three metal ions. A decrease of equilibrium pH with an increase of metal ion concentration led us to propose an adsorption mechanism by ion exchange between metal cations and H⁺ at the carbon aerogel surface. Carboxylic groups are especially involved in this adsorption mechanism. Langmuir and Freundlich isotherm models were used to analyse the experimental data of carbon aerogel. The thermodynamics of the metal adsorption was also investigated for the practical implementation of the adsorbent. The sorption showed significant increase with increase of temperature. Kinetics models describing the adsorption of Hg(II), Pb(II) and Ni(II) ions onto carbon aerogel have been compared. Kinetics models evaluated include the pseudo‐first order and second order model. The parameters of the adsorption rate constants have been determined and the effectiveness of each model assessed. The result obtained showed that the pseudo‐second order kinetic model correlated well with the experimental data and better than the pseudo‐first order model examined in the study. Mass transfer coefficients obtained can be useful in designing wastewater treatment systems or in the development of environmental technologies. Copyright © 2005 Society of Chemical Industry