scholarly journals Removal of Fluoride from Drinking Water Using Protonated Glycerol Diglycidyl Ether Cross-Linked Chitosan Beads

2021 ◽  
Vol 15 (2) ◽  
pp. 205-216
Author(s):  
P.N.S. Pathirannehe ◽  
◽  
T.D. Fernando ◽  
C.S.K. Rajapakse ◽  
◽  
...  
Keyword(s):  
Contact Time ◽  
Freundlich Isotherm ◽  
Diglycidyl Ether ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Chitosan Beads ◽  
Modified Chitosan ◽  
Chemically Modified ◽  
Adsorption Data

In this study, physically and chemically modified chitosan; protonated glycerol diglycidyl ether cross-linked chitosan beads (GDCLCB/H+) were prepared and characterized using FTIR and SEM. The optimum defluoridation capacity (DC) of GDCLCB/H+ was observed at the initial F- ion concentration of 15 mg/l, adsorbent dosage of 0.6 g, contact time of 30 min and pH of the solution was in the range of 5–7 at 303 ± 2 K. The equilibrium adsorption data fitted well with Langmuir and Freundlich isotherm models. The maximum adsorption capacity (q0), obtained from Langmuir isotherm for F-adsorption was found to be 2000 mg/kg, which was significantly higher than that of unmodified chitosan (192.3 mg/kg) and most of the chitosan-based sorbents reported in the literature. Water samples collected from Medawachchiya, Sri Lanka, were treated with the adsorbents and the results suggested that GDCLCB/H+ could be used as an effective defluoridation agent.

scholarly journals Adsorption of Mn2+ from Aqueous Solution Using Manganese Oxide-Coated Hollow Polymethylmethacrylate Microspheres (MHPM)

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Dhiraj Dutta ◽  
Jyoti Prasad Borah ◽  
Amrit Puzari
Keyword(s):  
Aqueous Solution ◽  
Manganese Oxide ◽  
Adsorption Capacity ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Coated Sand

Results of investigation on adsorption of Mn2+ from aqueous solution by manganese oxide-coated hollow polymethylmethacrylate microspheres (MHPM) are reported here. This is the first report on Mn-coated hollow polymer as a substitute for widely used materials like green sand or MN-coated sand. Hollow polymethylmethacrylate (HPM) was prepared by using a literature procedure. Manganese oxide (MnO) was coated on the surface of HPM (MHPM) by using the electroless plating technique. The HPM and MHPM were characterized by using optical microscopy (OM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Optical and scanning micrographs were used to monitor the surface properties of the coated layer which revealed the presence of MnO on the surface of HPM. TGA showed the presence of 4-5% of MnO in MHPM. Adsorption isotherm studies were carried out as a function of pH, initial ion concentration, and contact time, to determine the adsorption efficiency for removal of Mn2+ from contaminated water by the synthesized MHPM. The isotherm results showed that the maximum adsorption capacity of MnO-coated HPM to remove manganese contaminants from water is 8.373 mg/g. The obtained R 2 values of Langmuir isotherm and Freundlich isotherm models were 1 and 0.87, respectively. Therefore, R 2 magnitude confirmed that the Langmuir model is best suited for Mn2+ adsorption by a monolayer of MHPM adsorbent. The material developed shows higher adsorption capacity even at a higher concentration of solute ions, which is not usually observed with similar materials of this kind. Overall findings indicate that MHPM is a very potential lightweight adsorbent for removal of Mn2+ from the aqueous solution because of its low density and high surface area.

scholarly journals Adsorptive Removal of Methyl Red from Aqueous Solution using Charred and Xanthated Sal (Shorea robusta) Sawdust

2020 ◽  
Vol 1 (1) ◽  
pp. 37-44
Author(s):  
Krishna Bahadur Dawadi ◽  
Mahesh Bhattarai ◽  
Puspa Lal Homagai
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Low Cost ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Methyl Red ◽  
Adsorptive Removal ◽  
Shorea Robusta ◽  
Chemically Modified ◽  
Saw Dust

Adsorptive removal of methyl red (MR) from aqueous solution onto chemically modified Charred Sal (Shorea robusta) Saw-Dust (CSSD) and Xanthated Sal Saw-Dust (XSSD) has been investigated. The surface modification is characterized by Fourier transformed infra-red (FTIR) spectroscopy, scanning electron microscopy (SEM) and elemental Analysis. Different parameters are studied such as contact time, optimum pH, and initial ion concentration. Maximum dye removal is observed at pH 4 for charred and xanthated Sal saw dust. The dye can be quantitatively removed onto the surface of these adsorbent. At a contact time of 3-4 hours maximum adsorption capacity (qmax) for CSSD and XSSD are found to be 70 mg/g and 130 mg/g respectively. Adsorption kinetic data are best fitted onto pseudo second order. The obtained result indicated an excellent alternative for the treatment of dye contaminated waste water using such chemically modified Sal saw dust at low cost with better efficiency.

Thermodynamic Studies for Adsorption of Cd2+ and Pb2+ from Waster Water on Modified Walnut Shell

2015 ◽  
Vol 737 ◽  
pp. 622-626
Author(s):  
Shao Hua He ◽  
Dan Wang ◽  
Qing Qiu Kong ◽  
Xi Wu
Keyword(s):  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Walnut Shell ◽  
Isotherm Models ◽  
Model Parameters ◽  
Maximum Adsorption Capacity ◽  
Adsorption Data ◽  
Batch Technique ◽  
Adsorption Processes ◽  
Langmuir Isotherm Model

The adsorption isothermal curve and thermodynamic adsorption of Cd2+ and Pb2+ on modified walnut shell from waster water were investigated using batch technique. The equilibrium adsorption data are fitted to Langmuir and Freundlich isotherm models and the model parameters are evaluated. The Langmuir isotherm model shows a better fit to adsorption data than the Freundlich isotherm model for the sorption of Cd2+ and Pb2+ on modified walnut shell. The maximum adsorption capacity of Cd2+ and Pb2+ by modified walnut shell is found to be 32.68 mg·g-1 and 84.75 mg·g-1 at 298K temperature, respectively. The adsorption processes of Cd2+ and Pb2+ has feasibility and spontaneous nature. Thermodynamic parameters depict the endothermic nature of sorption and the process is spontaneous and favorable.

scholarly journals REACTIVE AZO DYE ADSORPTION USING ZEOLITIC MATERIAL: CONTACT TIME, pH, TEMPERATURE AND EFFECT OF SALTS

2012 ◽  
Vol 09 (17) ◽  
pp. 48-59
Author(s):  
Carina Pitwak MAGDALENA ◽  
Denise Alves FUNGARO ◽  
Patricia CUNICO
Keyword(s):  
Contact Time ◽  
Low Cost ◽  
Dye Adsorption ◽  
Correlation Coefficients ◽  
Coal Ash ◽  
Freundlich Isotherm ◽  
Reactive Dye ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Synthetic Dyes

Textile effluents, when not correctly treated, cause a high impact to the environment. The synthetic dyes are used in the fibber dying process, but part of them is discarded to receiving water body. The adsorption is a technique that has been used successfully for an effective removal of color. In this work, the adsorption of reactive dye Remazol Red RB from aqueous solution using zeolite of coal ash as low cost adsorbent was studied. The zeolite was synthesized by hydrothermal treatment with NaOH solution. The effect of experimental parameters such as contact time, pH, temperature and adding salt was investigated. The kinetics studies indicated that the adsorption followed the pseudo-second-order model with correlation coefficients > 0.99. The equilibrium was reached after 360 min of contact time. The experimental data were analyzed using Langmuir and Freundlich isotherm models and the data fitted well to the Langmuir isotherm. The maximum adsorption capacity of zeolite of coal ash for Remazol Vermelho RB was 1.20 mg g-1 with adsorption efficiency between 75 and 91%. The dye adsorption was more efficient in the presence of salts.

scholarly journals Adsorption of methyl blue with activated carbon derived from peanut shell

2019 ◽  
Author(s):  
Amit Nilabh
Keyword(s):  
Activated Carbon ◽  
Contact Time ◽  
Agricultural Waste ◽  
Chemical Activation ◽  
Methyl Blue ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Peanut Shell ◽  
Adsorption Data ◽  
Adsorbent Dose

In this study we synthesized activated carbon (AC) sourced from peanut shell, an agricultural waste, for the adsorption of methyl blue from its aqueous solution. AC was produced via chemical activation method and was characterized using various tools like XRD, FESEM and Raman spectroscopy. Adsorption experiments were carried in different batches with varying initial concentration, adsorbent dose, contact time, pH and temperature. The optimized parameters for adsorption were found to be that of initial dye concentration of 150 mg/L, adsorbent dose of 120 mg/L, temperature equals to 50C, contact time of 50 minutes and pH equals to 8. Adsorption data were used to figure out isotherm models, kinetics as well as thermodynamics of the process. It was concluded that maximum adsorption capacity is coming to be 714.28 mg/g, and the adsorption is favoring the Tempkin isotherm model. Also it was observed that the process is endothermic and spontaneous in nature.

scholarly journals ADSORPTION OF FLUORIDE USING SIO2 NANOPARTICLES AS ADSORBENT

2020 ◽  
Vol 2 (2) ◽  
pp. 1-9
Author(s):  
Davoud Balarak ◽  
Yousef Mahdavi ◽  
Ali Joghatayi
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Low Cost ◽  
Freundlich Isotherm ◽  
Sio2 Nanoparticles ◽  
Second Order ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Initial Concentration ◽  
High Doses

Presence of Fluoride in water is safe and effective when used as directed, but it can be harmful at high doses. In the present paper SiO2 nanoparticles as a adsorbent is used for removal of fluoride from aqueous solution. The effect of various operating parameters such as initial concentration of F-, Contact time, adsorbent dosage and pH were investigated. Equilibrium isotherms were used to identify the possible mechanism of the adsorption process. Maximum adsorption capacity of the SiO2 nanoparticles was 49.95 mg/g at PH=6, contact time 20 min, initial concentration of 25 mg/L, and 25±2 ◦C temperatures, when 99.4% of Fwere removed. The adsorption equilibriums were analyzed by Langmuir and Freundlich isotherm models. It was found that the data fitted to Langmuir (R2=0.992) better than Freundlich (R2=0.943) model. Kinetic analyses were conducted using pseudo first-and second-order models. The regression results showed that the adsorption kinetics was more accurately represented by a pseudo second-order model. These results indicate that SiO2 nanoparticles can be used as an effective, low-cost adsorbent to remove fluoride from aqueous solution.

scholarly journals Application of Chemically Modified Industrial Slag to As(III) Adsorption from Wastewater: Kinetics and Mass Transfer Analysis

2021 ◽  
Vol 68 (2) ◽  
pp. 341-354
Author(s):  
Arijit Dutta Gupta ◽  
Vivek Jaiswal ◽  
Vivek Bhadauria ◽  
Harinder Singh
Keyword(s):  
Mass Transfer ◽  
Freundlich Isotherm ◽  
Maximum Adsorption Capacity ◽  
Transfer Coefficients ◽  
Uptake Capacity ◽  
Brick Kiln ◽  
Batch Mode ◽  
Chemically Modified ◽  
Adsorption Data ◽  
Pseudo Second Order

In the present study, brick kiln slag (BKS) has been utilized for low concentration As(III) adsorption in batch mode. BKS was modified with H2SO4 (SA) and NaOH (SB) for enhancing As(III) uptake capacity. Maximum adsorption capacity (13.7 mg/g) was observed for SA at 298 K, pH = 7.0, adsorbent dose = 0.3 g and time = 70 min which was 1.4 times higher than that of SB. Adsorption data modelled into Freundlich isotherm and pseudo-second-order kinetics. Mass transfer coefficients decreased with increase in As(III) concentration. Film diffusion significantly dominated the adsorption of As(III) ions irrespective of the initial concentration. Dimensionless Sherwood number (Sh) interrelated As(III) concentration (Co) as: Sh = 2.97(Co)–0.376, Sh = 4.12(Co)–0.215, Sh = 4.83(Co)–0.588 for H2SO4 modified, NaOH modified and native slag respectively. Low temperature (298 K) favoured As(III) adsorption (based on ΔG° value). Therefore, the modified slag can be used as an effective adsorbent for As(III) remediation from groundwater.

scholarly journals Adsorption of cadmium and copper onto natural clay: isotherm, kinetic and thermodynamic studies

2018 ◽  
Vol 20 (2) ◽  
pp. 198-207 ◽  
Keyword(s):  
Mass Transfer ◽  
Metal Ions ◽  
Contact Time ◽  
Freundlich Isotherm ◽  
Adsorption Rate ◽  
Isotherm Models ◽  
Experimental Conditions ◽  
Adsorption Data ◽  
Removal Of Heavy Metals ◽  
Heavy Metals Ions

Clay of the Middle Atlas Mountains region, Morocco, was used to investigate the removal of heavy metals ions (Cadmium and Copper) from aqueous solutions with respect to several experimental conditions including pH, contact time, initial solute concentrations, temperature and ionic strength. Kinetic study revealed that metal ions uptake was fast with 90% or more of the adsorption occurring within first 30 min of contact time. Adsorption rate increased with the increasing initial metal ions concentrations and the sorption rate was well fitted by the pseudo-second-order rate model. The data according to mass transfer and intraparticle diffusion models confirmed diffusion of solutes inside the clay particles as the rate-controlling step and more important for the adsorption rate than the external mass transfer. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherm models. Equilibrium and kinetic adsorption data showed that clay displays a high selectivity with an affinity order of Cd > Cu. Thermodynamic parameters including the Gibbs free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) changes indicated that the present adsorption process was feasible and endothermic in the temperature range of 25–45 °C.

scholarly journals Removal of Methyl Violet 2B from Aqueous Solution Using Casuarina equisetifolia Needle

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad Khairud Dahri ◽  
Muhammad Raziq Rahimi Kooh ◽  
Linda B. L. Lim
Keyword(s):  
Experimental Data ◽  
Contact Time ◽  
Methyl Violet ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Maximum Adsorption Capacity ◽  
Casuarina Equisetifolia ◽  
Dye Pollutants ◽  
Methyl Violet 2B ◽  
Before And After

One of the major contaminants of water bodies is dye pollutants that come from textile, paper, and leather industries. In this study, Casuarina equisetifolia needle (CEN) is used to remove methyl violet 2B (MV) from aqueous solutions. Batch experiments were done to investigate the contact time, effect of pH, initial dye concentrations, and temperature. Langmuir and Freundlich isotherm models were used to describe the interaction between the adsorbate and adsorbent. The sorption mechanism was described using Lagergren 1st order, pseudo 2nd order, and Weber-Morris intraparticle diffusion models. FTIR spectroscopy was used to analyze the functional groups of CEN before and after sorption with MV. Optimal conditions were found to be at room temperature with 2 h contact time and no pH adjustment was needed. Experimental data was best fitted onto Langmuir model with maximum adsorption capacity of 164.99 mg/g, while pseudo 2nd order best described the experimental data for the kinetics study. Thermodynamic parameters such as change in Gibbs free energy (), enthalpy (), and entropy () were also investigated.

Preparation and Application of Zinc Chloride-Modified Cocoa (Theobroma cacao) Pod Husk-Based Carbon for the Removal of Acid Dyes

2017 ◽  
Vol 889 ◽  
pp. 221-225
Author(s):  
Nur Aqilah Zainal ◽  
Shariff Ibrahim ◽  
Borhannuddin Arifin
Keyword(s):  
Aqueous Solution ◽  
Zinc Chloride ◽  
Agricultural Waste ◽  
Freundlich Isotherm ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Acid Dyes ◽  
Chemically Modified ◽  
Cocoa Pod Husk

Cocoa pod husk, an agricultural waste was chemically modified using Zinc Chloride (ZnCl2) and used as an adsorbent for removal of acid dyes; (i) Acid Violet 17 (AV17) and (ii) Acid Yellow 36 (AY36) from aqueous solution. The raw (CPHC) and chemically modified cocoa pod husk carbon (ZCPHC) were characterized by Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray (EDX). The adsorption was performed on removing AV17 and AY36 from aqueous solution in batch adsorption system. The experimental data was simulated using Langmuir and Freundlich isotherm models. The isotherm study revealed that the AV17 adsorption on ZCPHC matched well with the Langmuir model, whereas AY36 adsorption on ZCPHC fitted well with Freundlich model. The maximum adsorption capacity determined from the Langmuir isotherm was 11.02 mg/g and 11.37 mg/g for AV17 and AY36 respectively at room temperature.

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