Freundlich Isotherm Equation Research Articles

Efficient removal of Eriochrome black-T from aqueous solution using NiFe2O4 magnetic nanoparticles.

The magnetic NiFe2O4 nanoparticles have been synthesized and used as adsorbents for removal of an azo dye, Eriochrome black-T (EBT) from aqueous solution. The NiFe2O4 nanoparticles were characterized by scanning electron microscope (SEM), Transmission electron microscope (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectra (FTIR). The adsorption studies were carried out under various parameters, such as pH, adsorbent dosage, contact time and initial dye concentration. The experimental results show that the percentage of adsorption increases with an increase in the adsorbent dosage. The maximum adsorption occurred at the pH value of 6.0. The equilibrium uptake was increased with an increase in the initial dye concentration in solution. Adsorption kinetic data were properly fitted with the pseudo-second-order kinetic model. The experimental isotherms data were analyzed using Langmuir and Freundlich isotherm equations. The best fit was obtained by the Langmuir model with high correlation coefficients (R2 = 0.9733) with a maximum monolayer adsorption capacity of 47.0 m g/g.

Study of the performance of Esparto grass fibers as adsorbent of dyes from aqueous solutions

In this work, the sorption behavior of two basic dyes, Toluidine blue and Crystal violet (CV), on Esparto grass fibers Stipa tenacissima L., an abundant semi-arid region biomass was investigated. The surface properties of this new adsorbent were analyzed using various techniques such as FT-IR, BET, Differential scanning calorimetric, Boehm titration, and pHPZC determination. Batch experiments were carried out to analyze the sorption kinetics and isotherms. The effect of operational parameters such as adsorbent dosage, dye concentration, ionic strength, pH, and temperature onto dye removal was studied. Under optimum conditions (25°C, pH 7.0, contact time of 150 min, and 2 g L−1 adsorbent dose), the monolayer sorption capacities were about 40.00 mg g−1 for TB and 43.47 mg g−1 for CV. Equilibrium data were fitted to the Langmuir, Freundlich, and Temkin isotherm equations, and these data were found to be well represented by the Langmuir isotherm. The adsorption kinetics is represented by second-order kinetic model. Evaluated ΔG and ΔH specify the spontaneous and endothermic nature of the adsorption. The adsorption takes place with an increase in entropy (ΔS is positive). FT-IR spectrum was also taken to investigate the functional groups involved in the biosorption of cationic dyes. The obtained results indicated that Stipa tenacissima L. could be used to treat dye containing effluents.

Kinetics and equilibrium modeling of uranium(VI) sorption by bituminous shale from aqueous solution

Sorption of U(VI) onto a bituminous shale (BS) from a nuclear power plant project site in Black Sea region was investigated for potential risk assessment when it releases into the environment with contaminated ground and surface water. The sorption characteristics of the BS for U(VI) recovery were evaluated as a function of contact time, adsorbent dosage, initial concentration, pH and temperature. Kinetic results fit better with pseudo-second-order model rather than pseudo-first-order. The possibility of diffusion process was analyzed based on Weber–Morris intra-particle diffusion model. The McKay equation assuming film- and intraparticle diffusion better predicted the data than the Vermeulen approximation presuming surface diffusion. Equilibrium sorption data were modeled according to the Langmuir, Dubinin–Radushkevich (D–R) and Freundlich isotherm equations. Sorption capacity increased from 0.10 to 0.15mmolg−1 in 298–318K temperature range. FT-IR analysis and pH dependent sorption studies conducted in hydroxide and carbonate media revealed that U(VI) species were sorbed in uranyl and its hydroxo forms on the BS. Desorption studies showed that U(VI) leaching with Black Sea water was negligible from the loaded BS. The activation parameters (Ea, ΔH∗ and ΔG∗) estimated from diffusion coefficients indicated the presence of an energy barrier in the sorption system. However, thermodynamic functions derived from sorption equilibrium constants showed that overall sorption process was spontaneous in nature and entropy controlled.

Adsorption of sulfamonomethoxine antibiotics to cucurbit[6]uril-anchored silica gel: effect of aqueous solution chemistry

Cucurbit[6]uril-anchored silica gel (ACB[6]-SG) was used to adsorb sulfamonomethoxine (SMM) from aqueous solution. The performance of SMM adsorption onto ACB[6]-SG at 278, 288, 298, 308, and 318 K and the effects of various solution conditions were evaluated. The adsorption capacity of SMM on ACB[6]-SG increased as the cucurbit[6]uril content of ACB[6]-SG increased. The experimental isotherm data were analyzed using non-linear Freundlich and Henry isotherm equations with five error functions, namely the sum of the squares of the errors, the sum of the absolute errors, the average relative error, the hybrid fractional error function, and Marquardt’s percent standard deviation. The error analysis showed that Freundlich model and Henry model described well the SMM adsorption data. Our thermodynamic investigation indicated that the adsorption of SMM onto ACB[6]-SG was a spontaneous and exothermic process. The adsorption was favorable in the pH range of 3.0–4.0. The adsorption affinity of SMM onto ACB[6]-SG increased after adding ions (in the form of NaCl, KCl, CaCl2, or MgCl2), suggesting the predominant role of the hydrophobic force.

Biosorption of Phenolic Compounds from Aqueous Solutions using Pine (Pinus densiflora Sieb) Bark Powder

The present study describes the development of a new bioadsorbent from lignocellulosic wastes of agricultural origin. The biosorption capacity of an agricultural solid waste, pine bark (Pinus densiflora Sieb.), to remove phenolic compounds (phenol, 2-chlorophenol (2-CPh), and 4- chlorophenol (4-CPh)) from aqueous solutions under batch equilibrium conditions was investigated. The morphological characteristics of the biosorbent were evaluated by BET surface area analysis, Fourier transform infrared spectroscopy (FTIR), elemental analysis, an X-ray diffractometer (XRD), and a scanning electron microscope (SEM). Batch experiments were conducted to investigate the effect of initial pH (2 to 10), contact time, initial concentration of adsorbate (50 to 200 mg/L), and biosorbent dosage. The biosorption of phenolic compounds decreased with increasing pH, and the highest biosorption capacity was achieved at a pH of 6.0. Biosorption equilibrium was established in 120 min. The biosorption equilibrium data were fitted and analyzed with Langmuir, Freundlich, and Dubinin-Radushkevich isotherm equations, as well as four adsorption kinetic models. The kinetics data fitted well into the pseudo-second-order kinetic model, with a correlation coefficient greater than 0.993. The maximum monolayer biosorption capacity of pine bark for phenol, 2-CPh, and 4-CPh was found to be 142.85, 204.08, and 263.15 mg/g, respectively, as calculated by the Langmuir model at 30 ± 1 °C. Pine bark could be used as a new effective, low-cost biosorbent material with good uptake capacity and rapid kinetics for the removal of phenolic compounds from aqueous media.

Equilibrium isotherms and adsorption heats analysis for ternary mixture of methane, ethane, and propane on 4A zeolite

Equilibrium isotherms were obtained experimentally and theoretically for adsorption of methane, ethane, and propane mixtures on 4A zeolite at 301 K. The experimental data were measured using constant volume method and analyzed by extended Langmuir, modified extended Langmuir, and extended Freundlich isotherm models. The best correlation was achieved with the extended Freundlich isotherm equation and the negative values for heats of adsorption indicate exothermic adsorption nature for these gases on 4A zeolite. The selectivity of 4A zeolite to adsorb gases was also studied with the observation that ethane was more selectively adsorbed than methane on 4A zeolite, while propane was less selectively adsorbed on this zeolite at the studied temperature. Also, it was found that an increase in initial partial pressure of ethane decreases the adsorbed amount of methane, while the increase in partial pressure of methane had no effect on adsorbed amount of ethane.

Heterogeneity of multiwalled carbon nanotubes based on adsorption of simple aromatic compounds from aqueous solutions

The surface heterogeneity of multiwalled carbon nanotubes (MWCNTs) is studied on the basis of adsorption isotherms from dilute aqueous phenol and dopamine solutions at various pH values. The generalized Langmuir–Freundlich isotherm equation was applied to investigate the cooperative effect of the surface heterogeneity and the lateral interactions between the adsorbates. The theoretical isosteric heats of adsorption were obtained assuming that the heat of adsorption profile reveals both the energetic heterogeneity of the adsorption system and the strength of the interactions between the neighboring molecules. The adsorption energy distribution functions were calculated by using algorithm based on a regularization method. The great advantage of this method is that the regularization makes no assumption about the shape of the obtained energy distribution functions. Analysis of the isosteric heats of adsorption for MWCNTs showed that the influence of the surface heterogeneity is much stronger than the role of the lateral interactions. The most typical adsorption heat is 20–22 kJ/mol for both phenol and dopamine. After purification of nanotubes, heat value for phenol dropped to 16–17 kJ/mol. The range of the energy distribution is only slightly influenced by the surface chemistry of the nanotubes in the aqueous conditions.

Biogenic derived binary metal oxide as a reactive material for remediation of pyrophosphate contaminated aqua system

Owing to the recent discovery about the potentials of pyrophosphate (PP) as a contributor to eutrophication, the ability of a binary metal oxide (BMO) as an adsorbent for PP removal from aqua system was investigated. The choice of a BMO was based on the synergy of the constituent metal oxides in sequestrating ionic species. The binary metal oxide (BMO) of Ca and Fe, synthesized using a Gastropod shell, as precursor, exhibited high removal efficiency (>99%) for pyrophosphate (PP), irrespective of initial PP concentration studied (25–300mg/L). The pseudo second order kinetic model had the best (r2−1.00) fitting to the time-concentration profile data. The determination of the saturation index (SI) value of calcium pyrophosphate and application of the principle of constant solubility product affirmed the role of precipitation as a paramount factor in the PP removal process by BMO, in addition to the complex formation between any of the ionic species (i.e. Ca and Fe) in the system. The XRD analysis of the derived sludge revealed the formation of amorphous calcium pyrophosphate. Process variables optimization revealed that initial solution pH, organic load, and ionic strength had no negative impact on the PP removal efficiency. The results of the equilibrium isotherm analysis showed that the Freundlich isotherm equation gave the best description of the sorption process (r2=0.9109) and the Langmuir monolayer sorption capacity (qm, mg/g) value of 120.48 was obtained.

Biosorption of Cu<sup>2+</sup> by Anaerobic Granular Sludge

In order to investigate the biosorption of Cu2+ by anaerobic granular sludge, the effect of equilibrium time, pH, sludge dosage, biosorption kinetics, biosorption thermodynamics and biosorption isotherms had been studied. Results showed that pseudo second-order kinetic model was useful to describe the biosorption process of Cu2+. Both Langmuir and Freundlich isotherm equations could well describe the desorption process at 15-55 °C. Thermodynamic studies showed that the biosorption process was spontaneous and endothermic in nature. When the solution temperature maintained at 35 °C, pH of 6~7, a good biosorption process could be obtained.

Adsorption of Malachite Green from Aqueous Solution using Activated Ntezi Clay: Optimization, Isotherm and Kinetic Studies

The adsorption of malachite green from aqueous solution using a local low cost adsorbent, acid activated Ntezi clay, was investigated. The low cost adsorbent was activated with different concentrations of sulphuric acid and the physicochemical properties of the adsorbent were determined and the structural properties were analyzed using XRF and XRD. The adsorption process was studied as a function of different process parameters such as temperature, adsorbent dosage, contact time, particle size and stirring speed. These process parameters were optimized using response surface methodology (RSM). The significance of the different process parameters and their combined effect on the adsorption efficiency has been established through a full factorial central composite design. The equilibrium modeling was analyzed using Langmuir, Freundlich, Dubini-Radushkevich and Temkin isotherm equation and the results of the experimental data follows the Langmuir adsorption isotherm. Adsorption kinetics follows the pseudo-second order with intra-particle diffusion as the rate-determining step. This investigation has shown that local clay mineral can be modified and used as a good adsorbent in the removal of impurities from contaminated water.

Removal of Mercury(II) Ions from Aqueous Solutions using Chemically Modified Banana Stem: Kinetic and Equilibrium Modeling

In this study, removal of mercury(II) ions from aqueous solutions under different experimental conditions using formaldehyde polymerized banana stem (FPBS) has been investigated. Formaldehyde treatment favored the stabilization of the organic substances of banana stem (BS). The adsorbent was characterized using IR, SEM, TG, and potentiometric titration methods. The adsorption efficiency of FPBS was compared with BS and the result showed that FPBS was found to be 1.8 times more effective than BS for mercury(II) removal. The maximum removal of 99.3 and 99.1%, respectively, for 10 and 25 mg/L in 50 mL initial concentrations was obtained at pH 7.0. Kinetic studies revealed that the adsorption occurred in two stages: external mass transport in the first stage and intra-particular diffusion in the second stage. Adsorption was found to be rapid and equilibrium was attained in 60 min. The adsorption equilibrium data fitted the Freundlich isotherm equation reasonably well. The maximum adsorption capacity of FPBS for mercury(II) was found to be 132.25 mg/g. Desorption experiments showed that the process of adsorption was reversible and the adsorbent was easily regenerated with 0.1 M HCl up to 96.0% recovery.

A simple method to separate phosphorus sorption stages onto solid mediums

The sorption of phosphorus (P) onto solid mediums (soil, sediment and P removing materials) is characterized by a rapid sorption phase followed by a slow phase. No studies have yet attempted to quantitatively distinguish between the two stages. In this study, efforts are made to develop a method that can separate the sorption process into fast and slow stages. According to the geometrical shape of P sorption curves, a maximum curvature value points (MCVP) algorithm is presented as the change point based on the most widely used P sorption models (Langmuir and Freundlich isotherm equation, first-order, second-order and Elovich kinetic equation). Results showed that the MCVP successfully separates the sorption process into a fast stage and then a relatively slow one. General analysis formulas of the MCVP for the most commonly used models are described in this paper. Two steps are recommended before the MCVP calculation: first, independent and dependent variables should be plotted in the same order of magnitude (1:1 is the best), free from the axis scale effect; second, the model that best describes the data points should be used to quantify the MCVP. With the MCVP, it is easy for researchers to obtain the change point by substituting the parameters of sorption models, particularly for materials that have been tested before. The significance of this study is that it allows for optimization of the reaction time in P removal technology and furthers our understanding of P distribution characteristics in soil or sediment.

Adsorption Behavior of Basic Dye from Aqueous Solution onto Alkali Extracted Lignin

Alkali extracted lignin (AEL), isolated from corn stalks with dilute alkali solution under mild condition, was used as a low-cost adsorbent for the removal of methylene blue (MB) from aqueous solutions. Batch adsorption studies were conducted to evaluate various experimental parameters such as pH, contact time, and initial dye concentration for the removal of MB. The kinetic data were analyzed using pseudo-first-order and pseudo-second-order kinetic models, and the adsorption kinetics were found to be well represented by the pseudo-second-order kinetic model. The equilibrium data were perfectly fitted to the Langmuir isotherm equation when compared with Freundlich isotherm equation. Based on the Langmuir adsorption isotherm model, the predicted maximum monolayer adsorption capacity was found to be 121.20 mg g-1 (at 30 oC). The results showed that this adsorbent had a high adsorption capacity, making it a promising alternative for dye removal.

입상활성탄에 의한 합성폐수의 용존유기물질의 새로운 흡착등온 모델 및 운동학적 흡착 연구

본 논문은 입상활성탄에 의해서 합성폐수에서의 용존유기탄소의 흡착평형과 회분식 실험을 통해 흡착성질을 파악하고자 하였다. 흡착평형의 새로운 모델식을 제안하였고 이 식을 바탕으로 회분식 실험데이터를 모사하였다. 합성폐수의 유기성분은 Beef extract, Peptone, Humic acid, Tannic acid, Sodium lignin sulfonate, Sodium lauryle sulfate, Arabic gum powder, Arabic acid (polysaccharide), <TEX>$(NH_4)_2SO_4$</TEX>, <TEX>$K_2HPO_4$</TEX>, <TEX>$NH_4HCO_3$</TEX>, <TEX>$MgSO_4{\cdot}7H_2O$</TEX> 등으로 구성되었다. 농도가 낮은 영역 (0~2.5 mg/L)에서는 선형적인 흡착평형을 보여주었고, 농도가 높은 영역 (2.5~6mgl/L)에서는 우호적인 흡착평형을 보여주었다. 사용되어진 생물학적 처리방법에서 나오는 유출수의 합성폐수는 알려진 양으로 준비되어졌다. 흡착평형 모델링은 Freundlich, Langmuir, Sips 및 하이브리드 식을 이용하여 모사하였다. 특히, 선형과 Sips를 이용한 하이브리드 흡착평형식은 낮은 농도와 높은 농도 역에서 매우 좋은 흡착평형식이었다. 용수 및 폐수처리에 활성탄 흡착에 있어서, 선형식과 Sips식을 합친 새로운 하이브리드 식은 새로운 흡착평형식이 될 수 있었다. 하이브리드 흡착평형식 (선형+Sips)을 이용하여 LDFA 운동학적식을 통하여 다양한 흡착제 양에 따른 회분식 반응조에서의 실험데이터를 잘 모사할 수 있었다. In this study, we conducted the adsorption equilibrium and batch experiments of dissolved organic carbon (DOC) in the wastewater by granular activated carbon (GAC). The components of organic compound were Beef extract (1.8 mg/L), Peptone (2.7 mg/L), Humic acid (4.2 mg/L), Tannic acid (4.2 mg/L), Sodium lignin sulfonate (2.4 mg/L), Sodium lauryle sulfate (0.94 mg/L), Arabic gum powder (4.7 mg/L), Arabic acid (polysaccharide) (5.0 mg/L), <TEX>$(NH_4)_2SO_4$</TEX> (7.1 mg/L), <TEX>$K_2HPO_4$</TEX> (7.0 mg/L), <TEX>$NH_4HCO_3$</TEX> (19.8 mg/L), <TEX>$MgSO_4{\cdot}7H_2O$</TEX> (0.71 mg/L), The adsorption characteristics of DOC in synthetic wastewater was described using the mathematical model through a series of isotherm and batch experiments. It showed that there was linear adsorption region in the low DOC concentration (0~2.5 mg/L) and favorable adsorption region in high concentration (2.5~6 mg/L). The synthetic wastewater used was prepared using known quantities of organic and/or inorganic compounds. Adsorption modelling isotherms were predicted by the Freundlich, Langmuir, Sips and hybrid isotherm equations. Especially, hybrid isotherm of Linear and Sips equation was a good adsorption equilibrium in the region of the both the low concentration and high concentration. In applying carbon adsorption for treating water and wastewater, hybrid adsorption equation plus linear equation with Sips equation will be a good new adsorption equilibrium model. Linear driving force approximation (LDFA) kinetic equation with Hybrid (linear+Sips) adsorption isotherm model was successfully applied to predict the adsorption kinetics data in various GAC adsorbent amounts.

Synthesis of magnetic silica with quaternary ammonium salt and its application for chromium(VI) removal

The contamination of water bodies with heavy metals (e.g. chromium and arsenic) is a major problem. Thus, the demand for effective ways of removing these toxic ions is increasing. In this study, a novel quaternary ammonium salt (QAS) was designed and synthesised in situ on the surface of silica-encapsulated iron oxide nanoparticles (SEION) to be easily separated by an external magnet. The SEION grafted with QAS (QAS-SEION) were characterised by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and zeta potential. Adsorption experiments were conducted to evaluate the capacity of QAS-SEION for removing Cr(VI) from water. The results indicated that the adsorption of Cr(VI) on the QAS-SEION reached equilibrium within 120 min. A pseudo-second-order model was befitting to describe the kinetics of Cr(VI) adsorption. The adsorption isotherm of Cr(VI) on the QAS-SEION was observed to fit both the Langmuir isotherm equation and Freundlich isotherm equation notably well. The maximum adsorption amount calculated by the Langmuir isotherm equation was close to that obtained by experiment. Overall, QAS-SEION is a promising material for the removal of Cr(VI) from contaminated water.

Adsorption of Hg(II) in aqueous solutions using mercapto‐functionalized alkali lignin

ABSTRACTA novel adsorbent for Hg(II), mercapto‐functionalized alkali lignin (AL‐SH) was synthesized by Friedel–Crafts alkylation reaction and nucleophilic substitution reactions. The adsorbent was characterized by the techniques of Fourier transform‐infrared spectroscopy (FT‐IR), elementary analysis and thermogravimetric analysis, and N2 adsorption techniques. The effect of various parameters on Hg(II) adsorption process such as initial pH, contact time, ionic strength, initial Hg(II) concentration, temperature, and adsorbent dosage were investigated in detail through batch static experiments. The results indicated that the adsorption process of Hg(II) on AL‐SH was mainly dependent on the pH and the optimal pH value was at pH ranging from 4.0 to 6.0. The adsorption process was found to follow pseudosecond‐order kinetics and the main process was chemical adsorption, which equilibrated at 8 h. The adsorption isotherm was better described by Langmuir and Temkin isotherm equations compared to Freundlich isotherm equation and the maximum adsorption capacity obtained was 101.2 mg g−1 (pH = 4.0, 20°C, initial Hg(II) concentration was 200 mg L−1). The thermodynamic parameters of and were positive while was negative, revealed that the adsorption of Hg(II) onto AL‐SH was a spontaneous and endothermic process with increased entropy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40749.

Adsorption of arsenic from aqueous media using lateritic minerals: Equilibrium, kinetic and thermodynamic studies

Abstract The sorption behavior of arsenic on minerals from a lateritic weathering has been investigated to evaluate its potential for the decontamination of arsenic ions from aqueous media. Various physicochemical parameters such as pH, equilibration time, adsorbent dose, concentration of adsorbate, effect of diverse ions and temperature were studied in order to simulate the best conditions under which this material can be used as an adsorbent, employing batch method and radiotracer technique. Maximum adsorption was observed in buffer solutions having pH of 2.0 and 8–9, using 0.5 g of adsorbent for 6.674 · 10 –5 mol L –1 arsenic concentration in 10 min equilibration time. The sorption data followed the pseudo-second order reaction kinetics. The adsorption data fit both the Freundlich and Dubinin-Radushkevich isotherm equations over the range of 3.195 · 10 –5 to 3.195 · 10 –3 mol L –1 arsenic concentration. The characteristic Freundlich constants i.e. 1/n = 0.427 ± 0.009 and K = 3.04 × 10−4 ± 1.46 · 10 –5 mol g –1 have been computed for the sorption system. The sorption mean free energy from the Dubinin-Radushkevich isotherm is 12.00 ± 0.38 kJ mol –1 indicating ion-exchange mechanism of chemisorption. The uptake of arsenic increases with the rise in temperature (278.16–323.16 K). Thermodynamic quantities i.e. ΔG, ΔS and ΔH have also been calculated for the system. The sorption process was found to be endothermic.

Adsorption behavior of metal–organic frameworks for methylene blue from aqueous solution

A metal–organic frameworks (MOFs) based on copper-benzenetricarboxylates was applied to the adsorption of methylene blue (MB) from aqueous solution. Cu-BTC [BTC=1,3,5-benzenetricarboxylate] also known as HKUST-1 is a widely studied MOF. Cu-BTC mainly possessed mesopores, high surface area and big pore volume which is benefit for the adsorption capacity. Characterization of Cu-BTC were achieved by XRD, SEM micrographs, nitrogen adsorption–desorption analysis and FT-IR spectra. The kinetics characteristic and thermodynamic parameters were also analyzed. The experimental isotherms data were analyzed using Langmuir and Freundlich isotherm equations and the results indicated that the Langmuir isotherm showed a better fit for MB adsorption. Thermodynamic parameters were calculated by the Gibbs free energy function, confirming that the adsorption process was spontaneous and accompanied by exothermic. The maximum removal has been achieved at the pH=7.0. The possible mechanism and the adsorption behavior of the adsorption of MB onto Cu-BTC were investigated. The adsorbent Cu-BTC could be easily regenerated after washing with ethanol. The experimental results suggested that Cu-BTC materials have potential application for the wastewater treatment containing MB dye.

Removal of heavy metal using poly (N-vinylimidazole)-grafted-carboxymethylated starch

Carboxymethyl starch (CMS) grafted with N-vinyl imidazole was investigated for heavy metal removal from aqueous solutions. Poly (N-vinyl imidazole)-grafted carboxymethyl starch (PVI-g-CMS) was prepared in aqueous solution using potassium persulfate (KPS) as initiator. The produced grafted copolymer was characterized by FTIR, TGA, surface area and elemental analysis. The grafted material was used for the sorption of Mn(II), Zn(II) and Cd(II). Uptake parameters such as affinity of metal ions, effect of metal ion concentration, adsorbent amount and agitation time were investigated. The polymers were more sensitive to CdII and ZnII and the order of metal ion binding was Cd(II)>Zn(II)>Mn(II). The adsorption data was fitted very well in a Freundlich isotherm equation and the kinetics of adsorption was found to follow the pseudo-first order kinetic model.

FEASIBILITY STUDY OF MTBE PHYSICAL ADSORPTION FROM POLLUTED WATER ON GAC, PAC AND HUSK RICE CARBON IN BATCH PROCESS

MTBE or Methyl Tertiary Butyl Ether is an organic compound, which is used to increase the gasoline Octane Number. At the beginning of 80’s, by discovering the undesirable effects of tetra ethyl lead usage in fuel, MTBE started to be used worldwide. But gradually the undesirable effects of MTBE on environment had been revealed. There are many technologies for MTBE removal from polluted water. Adsorption is the most conventional and economical technology. In this research, some experiments have been done for studying the adsorption of MTBE on different solid adsorbent in batch process. In these experiments a fixed amount of adsorbents including Granular Activated Carbon (GAC), Powdered Activated Carbon (PAC) and the Husk Rice Carbon (HRC) have been put in different one litter covered vessels containing water polluted with known initial MTBE concentration and stirring them. By measuring MTBE concentration in the vessel at different times the effect of different operating parameters such as temperature and pH have been studied on adsorption and optimum condition have been determined. The batch experimental results have been used to calculate the constant parameters of Freundlich and Langmuir adsorption isotherm equations for these systems.