Sorption Of Methylene Blue Dye Research Articles

Improvement of the sorption capacity of methylene blue dye using slag, a steel by product

A steel by-product, the slag collected from the blast furnace, was exploited as an adsorbent to remove methylene blue dye in solution by batch adsorption under the impact of contact time, mass of solid, agitation speed, pH, temperature, particles size, and initial concentration. The slag is mainly composed of silica, alumina and lime with a considerable specific surface (320.46 m2/g), which increased its adsorbent power. The experimental data revealed that the methylene blue (MB) dye adsorption on the slag is favorable (R = 93.3%) and the maximum adsorbed capacity after 50 min of contact amounts to 140.44 mg/g. The adsorption isotherms revealed that the adsorption of methylene blue dye was performed on a homogeneous monolayer surface, and their parameters confirmed that the process is favorable and physically achievable. The kinetic study specified that the methylene blue dye sorption is more adapted to the pseudo-second-order kinetic model (R2 = 0.99). In accordance to the diffusion investigation, exterior diffusion under the diffusional and kinetic regimes and internal diffusion under the diffusional regime alone successively controlled the passage of the pollutant from solution to adsorbent. According to the values of free energy, enthalpy, and entropy, the MB dye adsorption is spontaneous, exothermic, and less entropic. Additionally, the free energy and enthalpy values suggest that this process was performed physically (physical adsorption) under the influence of electrostatic interactions. Based on the results of the desorption investigation, the slag could potentially be recycled four times in a row using hydrochloric acid (0.5 M) as a desorbent.

Isotherm and kinetic investigations of sawdust-based biochar modified by ammonia to remove methylene blue from water

Chemical industry effluent may pose significant environmental risks to both human health and the economy if it is not properly managed. As a result, scientists and decision-makers are paying increasing attention to developing a sustainable, low-cost wastewater treatment technique. This work aims to investigate the adsorption of Methylene Blue (MB) dye present in water using biochar derived from sawdust modified by boiling in an ammonia solution (SDBA). The properties of SDBA were characterized by BET, SEM, XRD, BJH, FT-IR, DTA, EDX and TGA analyses. The presence of –OH and –NH groups in SDBA was confirmed by FTIR, which proved that the NH4OH treatment of biochar successfully added nitrogen groups on its surface. The influence of pH (2 to 12), MB dye initial concentration (20 to 120 mg/L), adsorbent dosage (0.5 to 4.0 g/L) and contact time (0 to 180 min) on the adsorption process has been investigated. The adsorption of MB dye is more favorable at basic pH, with optimum adsorption at pH 8. Using a starting concentration of 20 mg/L of MB dye and a 4.0 g/L SDBA dose, the maximum percent clearance of MB dye was 99.94%. Experimental results were fitted to the Freundlich (FIM), Tempkin (TIM) and Langmuir (LIM) isotherm models (IMs). The FIM fitted the equilibrium data well, with a 643.74 mg/g Qm. Various error function models were used to test the data obtained from IMs. According to Error Function results, experimental data showed that it fits better for LIM and FIM. Kinetic studies indicated that the MB dye adsorption procedure followed pseudo-second-order (PSOM) kinetics based on film diffusion (FDM), pseudo-first-order (PFOM) and intra-particle diffusion models (IPDM). MB dye sorption on the SDBA involved electrostatic interaction, surface participation, hydrogen bond and π–π interactions. The adsorption mechanism of MB dye by SDBA was proposed as physical adsorption via the electrostatic attraction process. SDBA is an effective adsorbent in removing MB dye from water. Six adsorption–desorption cycles of the MB dye were run through the regeneration of SDBA with only a minimal amount of adsorption capacity loss, demonstrating the reusability of manufactured SDBA.

Kinetics and Thermodynamics of Sorption of Methylene Blue Dye Onto Raw Groundnut Shell Biosorbent

Dyes are one of the hazardous chemicals found in wastewater produced by textile and allied industries that need to be removed from the wastewater before it is released into water bodies. The sorption efficiency of raw groundnut shell (RGS), an agricultural waste, was tested on methylene blue (MB) dye through a batch adsorption experiment. Physicochemical analysis of the RGS indicated good biosorbent properties. Fourier transform infrared (FTIR) spectroscopy analysis of the RGS revealed the presence of heterofunctional groups. The effect of various biosorption parameters such as initial dye concentration, contact time, and biosorbent dosage was systematically investigated. The quantity of MB adsorbed increased as the initial concentration and contact time increased and decreased with an increase in biosorbent dose. A maximum uptake capacity of 29.3 mg/g was recorded for 50 mg/L MB initial concentration. The equilibrium data from the batch adsorption experiments were fitted well into Freundlich isotherm and pseudo-second-order kinetic models. The results from this study indicate that RGS can serve as an alternative, low-cost, eco-friendly and efficient adsorbent for the removal of MB dye from wastewater.

Breakthrough studies for the sorption of methylene blue dye from wastewater samples using activated carbon derived from waste banana peels

AbstractIn the current study, an activated carbon derived from waste banana peel using H2SO4 was applied for the first time in a packed-bed column for methylene blue (MB) dye removal from wastewater. The pore structure and surface of banana peel activated carbon (BPAC) were investigated using X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and Brunauer-Emmett-Teller analysis to discover the mechanism of MB sorption. The produced BPAC by H2SO4 activation agent has surface area of 361.86 m2/g and exhibits good thermal stability. The extent of MB breakthrough performance was examined by optimizing flow rate, bed mass, and initial concentration at pH 9. The column’s dynamics revealed a strong dependence of breakthrough curves as a function of process conditions. The breakthrough time (tb), volume of liters processed (L), and adsorption exhaustion rate all increased as bed mass increased but decreased as flow rate and initial concentration increased. Applying linear regression to the experimental data, Yoon-Nelson and Thomas’ kinetic model was used to extract column characteristic parameters that could be used in process design. Using environmental water, the waste banana peel activated carbon material demonstrated effectiveness in removing MB to below acceptable levels by processing 1.16 L of water with an initial MB concentration of 40 mg/L using 8 g of sorbent. Nitric acid (3M) was able to regenerate the exhausted bed. Moreover, the sorbent was reused four times with no significant capacity loss. It can be concluded that waste banana peel activated carbon medium is an alternative solution to remediate MB-contaminated wastewater.

Chestnut Shell-Activated Carbon Mixed with Pyrolytic Snail Shells for Methylene Blue Adsorption.

Activated carbon has been used to treat organic dyes in water systems; however, the adsorption capacity of the samples studied was limited by the specific surface area and influenced by the pH of the aqueous solution. In this study, a hybrid adsorbent consisting of a mixture (MCS) of activated chestnut shell biochar (CN) and pyrolyzed snail shell material (SS) was developed to solve this problem, with the waste snail shell samples being processed by pyrolysis and the chestnut shell samples chemically pretreated and then pyrolyzed. The BET and SEM results revealed that the SS had a mesoporous fluffy structure with a higher specific surface (1705 m2/g) and an average pore diameter of about 4.07 nm, providing a large number of sites for adsorption. In addition, XPS and FTIR results showed that the main component of SS was calcium oxide, and it also contained a certain amount of calcium carbonate, which not only provided an alkaline environment for the adsorption of biochar but also degradation and photocatalytic capabilities. The results showed that the MCS3-1 sample, obtained when CN and SS were mixed in the ratio of 3:1, had good capacity for adsorption for methylene blue (MB), with 1145 mg/g at an initial concentration of 1300 mg/L (92% removal rate). The adsorption behaviors were fitted with the pseudo-second-order kinetic model and Freundlich isotherm model, which indicated that the adsorption was multilayer chemisorption with a saturated adsorption capacity of 1635 mg/g. The photocatalytic capacity from the SS composition was about 89 mg/g, and the sorption of MB dye onto the sorbent reached equilibrium after 300 min. The results suggested that MCS3-1 has enormous potential for removing MB from wastewater.

UTILIZATION OF ACTIVATED CARBON FROM CANDLENUT SHELLS (Aleurites Moluccana) AS METHYLENE BLUE ADSORBENT

Candlenut shell is a potential material to be used as activated carbon. This study aims to explore the kinetics and isotherm of adsorption of activated carbon from the shell of candlenut against the methylene blue (MBe) dye in the solution. Activation of carbon from the shell of candlenut was carried out physically for 1 h at 700 °C and proceeded with chemical activation using 10% zinc chloride (ZnCl2) solution to produce each physical (ACp-CS) and chemically (ACc-CS) activated carbon. The presence of functional groups in ACp-CS and ACc-CS was identified by an infrared (IR) spectrometer, while the surface topography of the materials was analyzed by a Scanning Electron Microscope (SEM). Adsorption of MBe solution by ACp-CS and ACc-CS with a dosage amount of 0.1 g was optimum at an interaction time of 100 min and at pH of 10, resulting in the amount of adsorbed dye 44.269 and 45.932 mg g-1 , successively. The sorption of MBe dye by ACp-CS and ACc-CS tends to attend kinetics model of the pseudo-secondorder (PSO) underrate constant (k2) grades of 15.49 x 10-3 and 6.30 x 10-3 (g mg-1 min-1) and the isotherm model of the Freundlich (AIMF) by factor values of adsorption capacity (KF) were 4.60 and 5.99 x 10-5 (mg g-1) (L mg-1) 1/n , successively. Activated carbon from the shell of the candlenut has the potential to be applied as an adsorbent to absorb dyes in liquid waste before being released to the surrounding

Microwave enhanced sorption of methylene blue dye onto bio-synthesized iron oxide nanoparticles: kinetics, isotherms, and thermodynamics studies

To adequately address the grave human health risks and environmental damage caused by the uncontrolled utilization of organic dyes, we greenly synthesized iron oxide nanoparticles (IONPs) using Spirulina platensis micro-algae for sequestration of cationic methylene blue (MB) dye from an aqueous solution. The nano-engineered sorbent was thoroughly scrutinized by different spectral analyses of; FT-IR, SEM, EDX, BET surface area, TEM, VSM, UV/Vis spectroscopy, and PHPZC measurement. The adsorption of MB was methodically carried out in a batch process to investigate the effects of initial pH (2.2−10.4), adsorbent concentration (0.5−5.0 g L–1), initial dye concentration (10−1000 mg L–1), contact time (0−230 min), and adsorption temperature (298 K, 308 K, 318 K, and 328 K). The outlined results inferred that the maximum adsorption capacity of MB dye by IONPs (surface area of 134.003 m2/g, a total pore volume of 0.3715 cc/g, and average pore size of 5.54 nm) was 312.5 mg g–1 under the optimized pH value (i.e., pH = 10.4). Collectively, the adsorption kinetics profile showed that the experimental data were in good agreement with the PSORE model, and the equilibrium adsorption isotherm data were quantitatively dominated by the Langmuir model. The thermodynamic findings conformed to the endothermic nature of the adsorption process. Interestingly, the proposed microwave scenario enhanced the adsorption rate and the equilibrium was attained in a very short time (only 1 min), compared with the normal sorption conditions (∼70 min). Repeatability of the spent sorbent was successfully emphasized for 5 times of adsorption/desorption cycles using 0.5 M of HCl. The productive adsorbent admirably sequestered MB dye from spiked real specimens (>83%). These results demonstrated that IONPs can be considered as a cost-efficient adsorbent in practical applications such as wastewater purification.

Fractal kinetics for sorption of Methylene blue dye at the interface of Alginate Fullers earth composite beads

The present work highlights the kinetics of sorption of Methylene blue dye (MB) through Alginate-Fuller's earth (ALFE) composite bead interface using the fractal approach. The ALFE beads were characterized using FESEM, FTIR, and BET surface analysis studies. The specific surface area and pore volume of the ALFE beads as obtained by BET analysis are 11.6412 m2/g, and 3.2953 cm3/g respectively indicating mesoporosity. Montmorillonite was found to be the major component of Fullers earth from XRD analysis. The bead's adsorption efficiency was optimized for different experimental conditions like pH, adsorbent dosage, MB concentration, and contact time. The adsorption data was found to fit well using the Freundlich and modified Langmuir- Freundlich adsorption isotherm model, thereby reflecting the adsorbent's energetically heterogeneous surface. The heterogeneity exponent 'h' was more than zero, thereby proving the fractal approach to be more appropriate for explaining sorption's kinetics. The time-dependant pseudo first order instantaneous rate coefficient kinst,1 when plotted against the contact time showed a gradual decrease, thereby bringing out the presence of three different stages in the sorption process differing in their sites of sorption and also in the amount of MB sorbed. The ALFE beads were reusable, and the simulated kinetic data using the fractal approach could be instrumental in designing a continuous flow reactor in an MB dye treatment plant.

Continuous sorption of methylene blue dye from aqueous solution using effective microorganisms-based water hyacinth waste compost in a packed column

The current research article investigates the remediation of methylene blue (MB), in continuous operation mode, utilizing compost as an adsorbent. The adsorbent was prepared from the water hyacinth plant waste by using effective microorganism (EM) which acts as a decomposer for the materials used. EM contains the various microbes that are responsible for the decomposition and it is available in the dormant liquid form which requires activation. The researcher performed a continuous study in which the following parameters are varied—bed complexity and flow rate. The findings of the study revealed that a maximum uptake of 301.79 mg/g was achieved and the removal efficiency is found to be around 85.44%. The overall sorption time zone, exhaustion time, breakthrough time, and volume of dye treated are also calculated. Modeling of experimental data is performed using bed depth service time (BDST) model and Thomas model. 0.01 M HCL was used as an elutant for the regeneration studies and maximum desorption efficiency of 85.44% was obtained.

Evaluation of Methylene Blue Sorption onto Low-Cost Biosorbents: Equilibrium, Kinetics, and Thermodynamics

This paper presents a study on batch sorption of methylene blue dye from aqueous solution onto Ginkgo biloba sorbent, a waste material produced during the Fall season in many parts of the world. Batch kinetics, equilibrium, and thermodynamic studies were conducted to evaluate the effect of contact time (0–150 min), sorbent dose (0.5–3.0 g/L), pH (2–11), temperature (30–50°C), initial MB concentration (10–30 mg/L), and particle size (177 μm—590 μm) on the methylene blue dye sorption. More than 99% removal of methylene blue was observed within 120 minutes. A Lagergren pseudo-first-order model, a pseudo-second-order model, and intraparticle diffusion models fitted well to the kinetics experimental data. Langmuir and Freundlich isotherm models also fitted well with the observed equilibrium data. Additionally, removal of methylene blue increased with increase in solution pH. Higher sorption capacity (∼20 mg/g) was observed with smaller particle size (170 μm) as compared to larger particle sizes (590 μm). Thermodynamic parameters such as ∆G°, ∆H°, and ∆S° indicated that the sorption process was feasible, spontaneous, and endothermic in nature. The study shows that Ginkgo biloba leaves have the potential to be an efficient sorbent for the removal of methylene blue from surface water samples.

3D-структуры на основе восстановленного оксида графита и наночастиц золота и их сорбционные свойства

Описано получение гидро- и аэрогелей на основе восстановленного оксида графита и наночастиц золота, полученных методом Туркевича. Наночастицы золота, согласно данным просвечивающей электронной микроскопии, имеют сферическую форму и средний размер 16–18 нм. Для характеризации полученных 3D-структур использована сорбция растворов красителя метиленового голубого. Проведено сравнение сорбционных свойств гидро- и аэрогелей, показано, что аэрогель сорбирует более эффективно (>80%), чем композит на основе гидрогеля (~50%). Сформированная пористая 3D-структура аэрогеля эффективно сорбирует молекулы красителя, а наночастицы золота, входящие в состав аэрогеля, способствуют его разрушению под воздействием видимого света. Сорбция красителя аэрогелем чистого оксида графита проходит с наибольшей эффективностью при комнатной температуре, в нейтральной среде и без использования дополнительных восстановителей. Введение в аэрогели наночастиц золота позволяет увеличить эффективность сорбции на 15%.

Comparative study for adsorption of methylene blue dye on biochar derived from orange peel and banana biomass in aqueous solutions.

Biochar pyrolyzed at 800 °C from banana (Bb) and orange peels (OPb) was applied for sorption of methylene blue (MB) dye in a batch system. OPb showed better affinity for MB dye than Bb with rapid increase in sorption capacity and percent removal for both biochars attaining equilibrium at 30 min. Chemisorption was suggested as the rate limiting step based on the best fitting of the pseudo-second-order reaction kinetics to the batch adsorption data. Linear increase in sorption capacity was seen as the initial MB dye concentration increased from 50 to 300 mg g-1 with a 40 % decrease in removal efficiency. An increase of 90 mg g-1 in sorption capacity for both biochars with a 15 and 30 % increase in removal efficiency for OPb and Bb, respectively, was observed after increasing the solution pH from 2 to 6 or 8. An increase in sorption capacity of about 150 mg g-1 was seen by increasing the biochar dose from 0.1 to 0.5 g. Langmuir isotherm model represented the adsorption data well as reflected by the high values of R2 (0.99) when using both biochar, while least representation of adsorption data was seen in H-J isotherm as estimated from very low R2 (0.6-0.66) for both types of biochar. An endothermic nature of MB dye sorption was suggested based on the linear increase in sorption capacity with an increase in solution temperature from 30 to 60 °C. This was further confirmed by the observed positive changes in standard entropy and standard enthalpy while negative values of Gibbs-free energies proposed the non-spontaneous natures of MB dye sorption on to both biochars. The effective sorption of MB dye demonstrated the potential of plant-based biochar as economically viable adsorbents for MB dye.

3D Structures Based on Reduced Graphite Oxide and Gold Nanoparticles and Their Sorption Properties

The preparation of hydro- and aerogels based on reduced graphite oxide and gold nanoparticles obtained by the method of Turkevich is described. According to the transmission electron microscopy data, gold nanoparticles have a spherical shape and an average size of 16‒18 nm. Sorption of methylene blue dye from water solutions was used to characterize the obtained 3D structures. The sorption properties of hydro- and aerogels were compared; it was shown that aerogels sorb the dye more efficiently (>80%) than a composite based on hydrogel (~50%). The formed porous 3D structure of the aerogel efficiently sorbs the molecules of the dye, while the gold nanoparticles facilitate its destruction under the visible light. Sorption by aerogels of pure graphite oxide is most efficient at room temperature, in a neutral medium, and in the absence of additional reducing agents. Introduction of gold nanoparticles to aerogels led to an increase of the maximal sorption by 15%.

Eco-friendly synthesis of Cynomorium coccineum extract for controlled production of copper nanoparticles for sorption of methylene blue dye

A biological extract of Cynomorium coccineum was used for the synthesis of copper nanoparticles using copper sulphate as a starting matter. Fourier transform infrared spectroscopy (FT-IR) showed the presence of the functional groups characteristics of biological extract, i.e., triterpenes, phenolics, flavonoids, and other reducing agents. SEM analysis showed that the surface of the particles were clusters and rough. The Elemental analysis by energy-dispersive X-ray (EDX) proved the purity of the particles, showing the presence of elemental copper oxide which was surrounded with some elements of the plant. X-ray diffraction (XRD) pattern confirmed that the crystalline nature of the particles was affected by temperature. The average crystallite size was calculated to be about 14.2 nm. The total weight loss registered within the thermogravimetric (TG) analysis was 52.8%, suggesting that about 47.2% of the metallic copper is present in the prepared copper nanoparticles which supported the data reported within EDX analysis. The adsorption characteristics of the nanoadsorbents were examined using methylene blue as adsorbate and the bio-sorption capacity reached 64 mg/g at room temperature. The values of B and bt, calculated from Temkin equation, increased with the increase in temperature (295–328 K), indicating endothermic adsorption and strong dye-nanoadsorbent interaction. The mean free energy (E = 100–129.1 kJ/mol), calculated from Dubinin-Radushkevich indicated that the chemisorption is the process involved for the adsorption of methylene blue. In summary, the results obtained in this study deliver the design and the synthesis of new materials for removing pollutants.

Effect of oxidative treatment on composition and properties of sorbents prepared from sugarcane residues

Efficient sorbents for the removal of cationic dye were prepared from sugarcane bagasse (stalk) and straw (leaves) by oxidative pre-treatment with hydrogen peroxide (H2O2) in acetic acid. The effects of variables, such as concentration of H2O2, temperature and time on the properties of the fiber sorbents obtained were studied according to a 23 full-factorial design. For comparison, an oxidative treatment of sugarcane biomass with glacial acetic acid was also used. The yields of the materials obtained and their chemical composition were characterized and compared. Fourier transform infrared spectroscopy, field-emission scanning electron microscopy and benzene vapor adsorption were used to investigate the structural properties and morphology of the initial materials and sorbents. The sorption of methylene blue dye was used to assess the efficiency of dye removal by the sorbents. The pre-treatment conditions significantly affected the sorbent yield, their chemical composition (contents of cellulose, lignin and ash) as well as their sorption properties. The cellulosic sorbent (C-sorbent) from sugarcane bagasse obtained by pre-treatment with H2O2 in acetic acid and the lignocellulosic sorbent (LC-sorbent) from sugarcane straw obtained by pre-treatment with glacial acetic acid, had the highest sorption capacity for the methylene blue dye. For both types of sorbents, the sorption capacity increased with chemical pretreatment as a result of an increase in pore volume.

Removal of methylene blue from aqueous solutions using polyaniline/graphene oxide or polyaniline/reduced graphene oxide composites

ABSTRACT The polymeric nanocomposites polyaniline/graphene oxide (PANI/GO) and polyaniline/reduced graphene oxide (PANI/RGO) were synthesized for effective dye removal through the adsorption process. Synthesized composites were characterized by XRD, SEM, TEM and FTIR analyses. The sorption of methylene blue dye (MB) on the PANI/GO or (PANI/RGO) composites were studied as a function of contact time, concentration, temperature, adsorbent dosage and pH, and the results showed that MB sorption was dependent on pH value. The optimum concentration of the dye and the contact time for sorption of MB on PANI/GO or PANI/RGO was determined to be 270 min and 50 mg/L, respectively while the adsorbent dosage of PANI/GO and PANI/RGO were determined to be 0.4 and 0.3 g, respectively. At optimum conditions, the nature of the adsorption process have been investigated by kinetic and isotherm models. The results showed that the adsorption process followed the pseudo first-order kinetics this noticed from the higher value of correlation coefficient (R 2 = 0.991) and was best suited to the Langmuir model. The maximum dye adsorption capacity of PANI/GO and PANI/RGO were estimated to be 14.2 and 19.2 mg g−1 respectively. From the results, it can be assured that the PANI/RGO is more effectively than PANI/GO for the removal of dye pollutants in water.

Methylene Blue dye sorption by hybrid materials from technical lignins

New hybrid sorbents were synthesized from technical lignins and silica and were applied for the removal of Methylene Blue dye (MB) from aqueous solution. Kraft softwood lignins from LignoBoost (LBL) and CleanFlowBlack (CFBL) processes were used to understand the influence of molecular weight and functionality of initial lignins on the properties of the final hybrids. The synthesized materials were applied as adsorbents for the removal of MB from aqueous solutions. The effects of parameters such as contact time, initial concentration of dye and initial pH on the adsorption capacity were evaluated. The hybrids exhibited higher adsorption capacity than the initial macromolecules of lignin with respect to MB. The hybrid based on CFBL exhibited an adsorption capacity of 60 mg/g; this value was 30% higher than the capacity of the hybrid based on LBL, which was 41.6 mg/g. Lignin hybrid materials extract 80–99% of the dye in a pH range from 3 to 10. The equilibrium and kinetic characteristics of MB uptake by the hybrids followed the Langmuir isotherm model and pseudo-second-order model, rather than the Freundlich and Temkin models, the pseudo-first-order or the intraparticle diffusion model. The attachment of the dye to the hybrid surface was confirmed via FE-SEM and FTIR spectroscopy. The mechanism for MB adsorption was proposed. Due to the high values of regeneration efficiency of the surface of both lignin-silica hybrid materials in 0.1 M HCl (up to 75%) and ethanol (99%), they could be applied as effective sorbents in industrial wastewater treatment processes.

Sorption characteristics of methylene blue onto <i>Nypa fruiticans</i> lignin

The sorption characteristics of soda lignin extracted from Nypa fruiticans for the removal of methylene blue dye from aqueous solution was investigated in this study, as an ethically sound way of utilizing this unexploited abundant natural resource. Equilibrium data were fitted to the Langmuir and Freundlich isotherm equations while the sorption dynamics were examined with the pseudo-first and second-order kinetic models. The influence of operational variables, namely, time, temperature, liquor-to-solid ratio and temperature, on the removal efficiency was determined using a second-order factorial equation. The Langmuir adsorption isotherm satisfactorily described the sorption of methylene blue dye unto the lignin matrix with a monolayer adsorption capacity of 16.67 mg/g. The sorption kinetics followed the pseudo-second-order kinetic model. The factorial equation derived reproduces the experimented data with errors less than 5%. The influence of the operational variables showed that the maximum variation in the highest uptake of methylene blue was caused by changes in concentration of methylene blue (a change of 32.7 units) while the liquor-to-solid ratio has little or no effect onthe dye uptake.Keywords: adsorption, methylene blue, lignin, factorial design, isotherms, sorption kinetics

Sorption of Methylene Blue Dye from Aqueous Solution Using an Agricultural Waste

Millions of tons of prickly (peel) bark of cactus fruit (PBCF) are produced per year. This work is to use this agricultural waste as a low cost biomaterial for the treatment of water contaminated with organic pollutant. PBCF has been characterized by several analytical techniques i.e. SEM, EDS and FTIR spectroscopy. In addition, the determination of iodine value which gives information on area surface. PBCF were used to remove Methylene blue (MB) from the aqueous solution. Experiments were carried out as function of contact time, initial dose of PBCF, initial pH aqueous solution, initial concentration of MB (90-2000 mg L-1), and temperature (20-40°C). The pseudo-second-order was the best applicable model to describe the sorption of MB by Prickly bark of cactus fruit. The equilibrium sorption data of Methylene blue by Prickly barks of cactus fruit were analysed by Langmuir and Freundlich models. The preliminary results indicate that the Langmuir model provides the best correlation of the experimental data with an important capacity of sorption of Methylene blue onto Prickly bark of cactus fruit (222.22 mg g-1). Moreover the parameters of the Freundlich model showing that the sorption of MB onto PBCF is favourable. Finally, the sorption capacity of PBCF is compared to those of other sorbents materials reported in the literature.

Use of beach bivalve shells located at Port Said coast (Egypt) as a green approach for methylene blue removal

Bivalve shells of Anadara uropigimelana were firstly tested as a potential biosorbent for methylene blue (MB) recovery from an aqueous solution, Scanning electron microscopy (SEM), energy dispersive X-Ray analysis (EDX), Fourier-transform infrared (FTIR) and zeta potential measurements were used to characterize bivalve shells sorbent. The influence of variables including pH, amount of sorbent, contact time, concentration of the dye and temperature on MB sorption has been investigated. Percentage removal of 93.6% were obtained under optimum conditions of variables (initial pH of 10.4, sorbent dose of 1gL−1, initial MB concentration of 20mgL−1, and temperature of 25±1°C). The sorption of MB dye onto the sorbent could reach equilibrium after 10min. Equilibrium data were well fitted to the Langmuir model. Sorption isotherm results showed that the maximum sorption capacity of MB by bivalve shells was 1000μgg−1. Thermodynamic analysis showed that the sorption of MB onto bivalve shells increased with increasing temperature from 25 to 55°C, indicating the endothermic nature of the sorption process. Meanwhile, the positive values of ΔSo suggest the increased randomness at the solid/solution interface during the MB sorption. The sorbent was successfully tested for color removal from dyeing facility. This work shows that the bivalve shells hold promises acting as effective sorbent to remove dyes in the wastewater.