scholarly journals Influence of Acid Activation of a Mixture of Illite, Koalinite, and Chlorite Clays on the Adsorption of Methyl Violet 6B Dye

2021 ◽  
pp. 1761-1778
Author(s):  
Saba Adel Saed ◽  
Donia Aidan

The influence of acid activation of a mixture of illite, kaolinite, and chlorite clays collected from the area of Zorbatiya (east of Iraq) on the adsorption of methyl violet 6B (MV6B) as a cationic dye was studied. The activation was carried out by using 0.25M HCl and 0.25M . Raw and acid-activated clays were analyzed by atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). Batch adsorption method was used to study the adsorption of MV6B onto the raw and acid activated clays. The impacts of different factors on the adsorption process were studied, such as clay weight, agitation time, starting MV6B concentration, temperature, ionic strength, and solution pH. The adsorption process was described by using Langmuir, Freundlich, Temkin, and Dubinin- Radushkevich isotherm models. Thermodynamic parameters like  were estimated based on Vanʼt Hoff equation.

2021 ◽  
Vol 13 (2) ◽  
pp. 10-31
Author(s):  
Saba A. Saeed1 ◽  
◽  
Dunya E. AL-Mammar2 ◽  

This study examined the adsorption behavior of anionic dye (orange G) from aqueous solution onto the raw and activated a mixture of illite, kaolinite and chlorite clays from area of Zorbatiya (east of Iraq).The chemical treatment involved alkali and acid activation. The alkali activation obtained by treated the raw clay (RC) with 5M NaOH (ACSO) and the acid activation founded by treated it with 0.25M HCl (ACH) and 0.25M H_2 〖SO〗_4 (ACS). The thermal treatment carried out by calcination the produce activated clay at 750oC for acid activation and 105oC for alkali activation. Batch adsorption method was used to study the adsorption of orange G dye onto raw and activated clays. The impact of different factors related to the adsorption process was studied such as: agitation time, clay dosage, solution pH, starting OG dye concentration, temperature and ionic strength. The adsorption process was described by using Langmuir, Freundlich, Temkin and Dubinin-Raduchkevish isotherm models. Thermodynamic functions like change in enthalpy〖∆H〗^°, change in entropy 〖∆S〗^° and change in Gibbs free energy 〖∆G〗^°were estimated based on Vanʼt Hoff equation.


2019 ◽  
Vol 32 (1) ◽  
pp. 73-78
Author(s):  
P. Janaki ◽  
R. Sudha ◽  
T.S. Sribharathi ◽  
P. Anitha ◽  
K. Poornima ◽  
...  

The adsorption performance of sulphuric acid treated low cost adsorbent synthesized by using Citrus limettioides peel as an effective raw material for the removal of cadmium(II) from water. The batch adsorption method was carried out to optimize some parameters like contact time, pH and adsorbent dose. The nonlinear isotherm equations were used to calculate the different isotherm constant of five isotherm models namely Freundlich, Langmuir, Dubinin-Radushkevich, Redlich-Peterson and Sips. The Langmuir monolayer adsorption capacity of chemically modified Citrus limettioides peel was found to be 287.60 mg g-1. The negative values of ΔGº and ΔHº showed that the adsorption process is spontaneous and exothermic.


2019 ◽  
Vol 9 (4) ◽  
pp. 3996-4005 ◽  

Maize tassels (MT), an agro-based biomass waste was carbonised followed by thermo-chemical modification using tartaric acid. The functionalized activated carbon was further modified to yield a magnetic hybrid composite adsorbent. The adsorbent was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The adsorbent was evaluated for its efficiency to remove Cd(II) ions from aqueous solutions through batch adsorption studies following a Central Composite Design. Effects of solution pH, contact time, adsorbent dosage, initial metal concentration and temperature on Cd(II) adsorption were investigated. Optimization of the adsorption process was done using desirability function on the Design Expert V11 software. The desirability function showed that the optimum parameters were pH 5.29, contact time (67.50 min), dosage (0.575 g) and initial concentration (152.50 mg/L). The adsorption process was analysed using kinetic and isotherm models. The kinetics of the adsorption process followed the pseudo-second-order model (lowest sum of square error (SSE) values and correlation coefficients (R2) > 0.999) in addition to the intraparticle diffusion model. The isotherm data were consistent with the Langmuir isotherm as evidenced by the highest correlation coefficient (R2= 0.998). The thermodynamic parameters showed that the process was endothermic and spontaneous in nature. The adsorption capacity of the adsorbent was found to be 188.68 mg/g at 20 ⁰C which is higher than that of the previously reported magnetic maize tassel hybrid (52.05 mg/g). The adsorbent showed good removal efficiency on real effluent samples.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yie Chen Lu ◽  
Muhammad Raziq Rahimi Kooh ◽  
Linda Biaw Leng Lim ◽  
Namal Priyantha

In this study, a simple chemical modification was applied to a sustainable and abundantly available resource, kangkong root (KR), to remove methyl violet 2B (MV) dye. The chemically modified adsorbent (NaOH-KR) was obtained using NaOH solution treatment. Batch adsorption experiments were carried out to investigate the effects of pH, ionic strength, contact time, adsorbent dosage, and initial dye concentration. A regeneration experiment was also carried out to assess the potential of reusability. The adsorption process was modelled using various kinetics and isotherm models, whereby the best-fitting models were evaluated by using the coefficient of determination ( R 2 ) and error functions. The Sips ( R 2 = 0.9714 , χ2 =0.16) and pseudo-second-order ( R 2 = 0.9996 , χ 2 = 0.007 ) models were identified to best represent the adsorption process. The Sips model predicted a maximum adsorption capacity at 551.5 mg g-1 for NaOH-KR, which is 55% improvement in performance when compared to nonmodified KR. Lastly, the regeneration experiment showed that NaOH-KR was able to maintain reasonable dye removal even after five consecutive cycles of regenerating and reusing.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Moustafa A. Hamoud ◽  
Karam F. Allan ◽  
Refaat R. Ayoub ◽  
Mohamed Holeil ◽  
Mamdoh R. Mahmoud

AbstractSimultaneous removal of radiocobalt and manganese by adsorption onto polyacrylonitrile/hexadecyltrimethylammonium bromide/potassium copper hexacyanoferrate (PAN/HDTMA/KCuHCF) composite was studied. The synthesized composite was characterized by Fourier-transformed infrared (FT-IR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The influence of the solution pH was studied in the range 1.5–7.8 and the results showed the effectiveness of the synthesized composite for simultaneous adsorption of radiocobalt and manganese in the pH range 2.5–6 at an adsorbent mass of 4 g/L. Adsorption kinetic data of manganese at the studied concentrations were best fitted by pseudo-second-order kinetic model and the diffusion study showed that the adsorption process was controlled by film diffusion. Thermodynamic parameters (ΔGo, ΔHo and ΔSo) were estimated and the results indicated that adsorption processes of the concerned (radio)toxicants were spontaneous and endothermic in nature. Of the studied isotherm models, Freundlich and Langmuir were the best ones for describing the adsorption isotherm data of radiocobalt and manganese, respectively. The adsorption capacity of PAN/HDTMA/KCuHCF was found to be 23.629 (for radiocobalt) and 62.854 (for manganese). Desorption of Radiocobalt and manganese loaded onto PAN/HDTMA/KCuHCF composite was studied using various desorbing agents at different concentrations.


2019 ◽  
Vol 9 (21) ◽  
pp. 4486 ◽  
Author(s):  
Candelaria Tejada-Tovar ◽  
Angel Darío Gonzalez-Delgado ◽  
Angel Villabona-Ortiz

The removal of water pollutants has been widely addressed for the conservation of the environment, and novel materials are being developed as adsorbent to address this issue. In this work, different residual biomasses were employed to prepare biosorbents applied to lead (Pb(II)) ion uptake. The choice of cassava peels (CP), banana peels (BP), yam peels (YP), and oil palm bagasse (OPB) was made due to the availability of such biomasses in the Department of Bolivar (Colombia), derived from agro-industrial activities. The materials were characterized by ultimate and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) in order to determine the physicochemical properties of bioadsorbents. The adsorption tests were carried out in batch mode, keeping the initial metal concentration at 100 ppm, temperature at 30 °C, particle size at 1 mm, and solution pH at 6. The experimental results were adjusted to kinetic and isotherm models to determine the adsorption mechanism. The remaining concentration of Pb(II) in solution was measured by atomic absorption at 217 nm. The functional groups identified in FTIR spectra are characteristic of lignocellulosic materials. A high surface area was found for all biomaterials with the exception of yam peels. A low pore volume and size, related to the mesoporous structure of these materials, make these bioadsorbents a suitable alternative for liquid phase adsorption, since they facilitate the diffusion of Pb(II) ions onto the adsorbent structure. Both FTIR and EDS techniques confirmed ion precipitation onto adsorbent materials after the adsorption process. The adsorption tests reported efficiency values above 80% for YP, BP, and CP, indicating a good uptake of Pb(II) ions from aqueous solution. The results reported that Freundlich isotherm and pseudo-second order best fit experimental data, suggesting that the adsorption process is governed by chemical reactions and multilayer uptake. The future prospective of this work lies in the identification of alternatives to reuse Pb(II)-contaminated biomasses after heavy metal adsorption, such as material immobilization.


Soil Research ◽  
2014 ◽  
Vol 52 (2) ◽  
pp. 155 ◽  
Author(s):  
Chamali Laksala Nagodavithane ◽  
Balwant Singh ◽  
Yunying Fang

Biochar has been recognised as an effective amendment for the remediation of contaminated soils; however, there is limited knowledge on the effects of biochar ageing in soil on its adsorption behaviour for cationic and anionic species. Biochars are considered to develop negative charge from oxidation with ageing, which may create additional interaction mechanisms for adsorption processes. In the present study, surface charge characteristics and cadmium (Cd) and arsenate (AsO43–) adsorption behaviour of aged biochar were investigated in two soils with variable charge, an Oxisol and an Inceptisol, by comparing (i) unamended soils, and soils amended with (ii) fresh biochar (450°C) and (iii) biochar (450°C) aged for 12 months, applied at a rate of 2% w/w. Surface charge characteristics were assessed using the ‘index’ ion adsorption method, with a LiCl electrolyte. Batch adsorption studies were conducted using fresh and aged soil–biochar mixtures. In contrast to previous studies, the results provided no evidence of an increase in cation exchange capacity as a consequence of biochar ageing. There was an increase in Cd adsorption in the presence of aged biochar in both soil types compared with unamended soils and soils amended with fresh biochar. Results also indicated an increase in AsO43– adsorption in the Inceptisol amended with aged biochar, whereas a decrease in AsO43– adsorption was observed in the Oxisol amended with aged biochar. Overall, the study has highlighted that adsorption behaviour of aged biochar varies depending on the ion it interacts with, soil properties and solution pH.


2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Swarup Biswas ◽  
Umesh Mishra

Calcium pretreatedHevea brasiliensissawdust has been used as an effective and efficient adsorbent for the removal of copper ion from the contaminated water. Batch experiment was conducted to check the effect of pH, initial concentration, contact time, and adsorbent dose. The results conclude that adsorption capacity of adsorbent was influenced by operating parameters. Maximum adsorption capacity found from the batch adsorption process was 37.74 mg/g at pH of 5.6. Various isotherm models like Langmuir, Freundlich, and Temkin were used to compare the theoretical and experimental data, whereas the pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were applied to study the kinetics of the batch adsorption process. Dynamic studies were also conducted in packed-bed column using different bed depths and the maximum adsorption capacity of 34.29 was achieved. Characterizations of the adsorbent were done by Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy.


2015 ◽  
Vol 773-774 ◽  
pp. 677-681 ◽  
Author(s):  
Asyikin Sasha Mohd Hanif ◽  
Siti Aisyah Azmal ◽  
Mohd Khairul Ahmad ◽  
Fariza Mohamad

This work demonstrates the fabrication of Cu2O thin film onto a fluorine-doped tin oxide (FTO) glass substrate via electrodeposition method which was conducted in a solution containing copper (II) acetate monohydrate and lactic acid. While varying the deposition time ranging up to 80 minutes, the solution was kept constant at solution temperature of 40°C, solution pH 6.5 and current density-0.3 mA/cm2. The characteristics of electrodeposited Cu2O were investigated via x-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), current-voltage (I-V) test and surface profiler. The XRD results showed the intensity peak of Cu2O corresponded to reflection (111) increased when the deposition time increased. The topological characteristics from AFM characterization showed the increment of surface roughness decreased as the time increased from 5 to 60 minutes. However, the surface roughness decreased when the time reached 70 and 80 minutes. I-V characteristics of all electrodeposited Cu2O showed Ohmic behaviours indicating the successful fabrication of n-Cu2O thin film. From this study, the significant effect of deposition time of Cu2O was clearly observed and plays an important role in providing mechanism growth of the film.


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