scholarly journals Batch Adsorption Assessment of Neem Nut Carbon for Abating Chromium(VI) in Wastewater

Author(s):  
S. Sophie Beulah ◽  
K. Muthukumaran

Discharge of Cr(VI) laden effluents is highly toxic and decontaminating the wastewater from Cr(VI) is necessary for Environmental Protection. An investigation on the adsorption characteristics of activated carbon prepared from neem nut (NNC) for the removal of Cr(VI) from wastewater by varying the parameters such as carbon dose, pH, equilibration time by batch studies was found to be effective for the removal of Cr(VI) from wastewater. Carbon characteristics of activated neem nut carbon were ascertained. Evaluation were done by varying the pH from 1 to 6, carbon dose from 0.1 g to 0.5 g and equilibration time from 1 to 6 hours. Maximum Cr(VI) removal of 95% took place when batch studies were done at an optimal pH of 2, carbon dose of 0.2 g//100mL, and equilibration time of 4 hours. Freundlich and Langmuir adsorption isotherm models were considered for analysis.

2020 ◽  
Vol 81 (2) ◽  
pp. 321-332 ◽  
Author(s):  
Abir Melliti ◽  
Jamel Kheriji ◽  
Hanen Bessaies ◽  
Béchir Hamrouni

Abstract The occurrence of boron in water and its inefficient removal are the key issue in desalination and water treatment. Adsorption by fixed-bed column is usually used to remove mineral and organic contaminants from the aqueous phase. The adsorption of the boron onto activated carbon, prepared from palm bark, is studied. Batch adsorption experiments are developed to determine the equilibrium time and the best isotherm model. The kinetic adsorption data can be described by the second-order equation. Among the adsorption isotherm models, Langmuir and Sips models give better fit of the equilibrium data. The calculated thermodynamic parameters show that the boron adsorption is exothermic in nature. The effects of inlet boron concentration, feed flow rate and weight of activated carbon on the fixed-bed adsorption are determined by two-level factorial experimental design. Breakthrough and saturation times are higher at high adsorbent weight and low flow rates. The increase of boron initial concentration decreases breakthrough and saturation times. The volume treated per gram of activated carbon is higher at lower initial concentrations and at higher adsorbent weight. Compared to other models, the Yan model fits better the experimental data of the breakthrough curves with R2 of 0.993.


2015 ◽  
Vol 737 ◽  
pp. 533-536 ◽  
Author(s):  
Dong Xue Xiao ◽  
Chang Ling Fang ◽  
Jun Zhou ◽  
Xiao Yi Lou ◽  
Jiu Hua Xiao ◽  
...  

Ferric hydrosulfate minerals are commonly byproducts of biotic oxidation of Fe (II) in acid mine drainage and biohydrometallurgy like biogenic jarosite. In this study, adsorption of Cr (VI) on jarosite was a rapid process and the optimum pH for Cr (VI) adsorption was found at 7.0. The variation of Cr (VI) adsorbed on jarosite fitted the Langmuir adsorption isotherm models and the maximum adsorption capacity was 3.23 mg/g. It was evident that anion exchange mechanism was responsible for Cr (VI) adsorption on jarosite based on the sulfate leaching data and optimum pH experiments.


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Yemane Tadesse Gebreslassie

The release of dyes from dying industries such as leather, paper, and textiles is an important cause of environmental pollution. In the present study, the batch adsorption measurements were carried out using stimulated aqueous solutions and the effect of operating variables such as initial malachite green concentration, amount of adsorbent, solution pH, contact time, and solution temperature, were investigated. The experimental result showed that the percentage removal decreased with an increase in initial dye concentration but increased as pH of the solution, contact time, and adsorbent dose increased. The equilibrium data were analyzed using Langmuir adsorption isotherm, Freundlich adsorption isotherm, and Tempkin isotherm models, and it was observed that the Langmuir adsorption isotherm better described the adsorption process. The monolayer adsorption capacity of activated carbon prepared from fig leaves for malachite green adsorption was found to be 51.79 mg/g at 298 K. Furthermore, the adsorption kinetics of the dye was investigated, and the rate of adsorption was found to follow the pseudo-first-order kinetic model with intraparticle diffusion as one of the rate-determining steps. The negative value of ΔG0 and the positive values of ΔH0 indicate the spontaneous and endothermic nature of the adsorption process, respectively. The experimental result obtained in the present study and comparison with other reported adsorbents indicate that activated carbon prepared from fig leaves could be used as a low-cost alternative adsorbent for the removal of malachite green from aqueous solution.


Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract


2008 ◽  
Vol 5 (3) ◽  
pp. 499-510 ◽  
Author(s):  
M. Venkata Subbaiah ◽  
S. Kalyani ◽  
G. Sankara Reddy ◽  
Veera M. Boddu ◽  
A. Krishnaiah

Removal of chromium(VI) from aqueous solution was studied using abundantly availabletrametes versicolor polyporusfungi as biosorbing medium under equilibrium and column flow conditions. Various sorption parameters such as contact time, effect of pH, concentration of Cr(VI) and amount of biomass on the adsorption capacity of the biosorbent were studied. The equilibrium adsorption data were fitted to Freundlich and Langmuir adsorption isotherm models and the model parameters are evaluated. In addition, the data were used to predict the kinetics of adsorption. The results indicated that the adsorption of Cr(VI) on fungi followed second order kinetics. The column flow adsorption data were used to predict break through curves. The fungi loaded with Cr(VI) was regenerated with 0.1 M NaOH solution and the regenerated biomass was used in the subsequent adsorptiondesorption cycles. The experimental results demonstrated that thetrametes versicolor polyporusfungi could be used as sorbent for immobilizing Cr(VI).


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Magdalena Hofman ◽  
Robert Pietrzak

Carbonaceous material (brown coal) modified by pyrolysis, activation, and enrichment in nitrogen, with two different factor reagents, have been used as adsorbent of phenol from liquid phase. Changes in the phenol content in the test solutions were monitored after subsequent intervals of adsorption with selected adsorbents prepared from organic materials. Significant effect of nitrogen present in the adsorbent material on its adsorption capacity was noted. Sorption capacity of these selected materials was found to depend on the time of use, their surface area, and pore distribution. A conformation to the most well-known adsorption isotherm models, Langmuir, and Freundlich ones, confirms the formation of mono- and heterolayer solute (phenol) coverage on the surface of the adsorbent applied herein. The materials proposed as adsorbents of the aqueous solution contaminants were proved effective, which means that the waste materials considered are promising activated carbon precursors for liquid phase adsorbents for the environmental protection.


2014 ◽  
Vol 535 ◽  
pp. 637-640 ◽  
Author(s):  
Wen Si Wang ◽  
Yu Bin Zeng ◽  
Qing Quan Deng ◽  
Jia Wen Pan

Abstract. The effects of various parameters and the adsorption isotherms for the Cr(VI) removal by nano β-FeOOH and its innovative composite material with surfactant hexadecyltrimethylammonium bromide (HDTMA) modified zeolite (β-FeOOH/SMZ) were investigated and compared by batch adsorption experiments. The structure information and surface images of nano β-FeOOH and β-FeOOH/SMZ were characterized by X-ray diffraction (XRD) and Field-emission scanning electron microscopy (FE-SEM). From the experimental work, both β-FeOOH and β-FeOOH/SMZ were effective adsorbents in Cr (VI) removal, while β-FeOOH/SMZ was found to show higher adsorptivity than β-FeOOH. Additionally, the isotherm experimental data fits the Langmuir adsorption isotherm more closely, and the maximum adsorption capacity of Cr(VI) on β-FeOOH and β-FeOOH/SMZ can attain 20.79 mg/g and 22.08 mg/g, respectively.


Author(s):  
Muhmmad Ilyas ◽  
Waqas Ahmad ◽  
Hizbullah Khan

Abstract Serious environmental deterioration caused by synthetic waste plastics, and the pollution of freshwater resources are the most alarming and remarkable challenges of the 21st century. Therefore, immense scientific efforts are being paid towards the management of waste plastics and treatment of polluted water. The current study is report the utilization of waste polyethylene terephthalate (wPET) and waste polystyrene (wPS) for fabrication of activated carbon (AC) and its application for the removal of hazardous polycyclic aromatic hydrocarbons (PAHs) pollutants from water. AC was prepared from wPET and wPS by carbonization under N2 atmosphere followed by chemical activation with 1M KOH and 1M HCl. The AC was characterized by SEM, surface area analysis (SAA), and FT-IR spectroscopy. Adsorption of PAHs from aqueous solutions through AC was examined by batch adsorption tests. The optimum parameters for maximum adsorption of PAHs were found to be; initial PAHs concentration 40 ppm, 2 h contact time, pH 3, 5, and 7, 50 °C temperature and adsorbent dose of 0.8 g. Kinetic and isotherm models were applied to evaluate the adsorbent capacity for PAHs adsorption. The kinetic study shows that the adsorption of these PAHs onto AC follows the pseudo-second-order kinetics. The experimental results demonstrated that Langmuir isotherm model best fitted the data. The thermodynamic factors calculated such as entropy change (ΔS°), enthalpy change (ΔS°) and free energy change (ΔG°) show that the adsorption process is non-spontaneous and endothermic in nature. Results were also compared with the efficiencies of some commercial adsorbents used in practice. This examination revealed that the novel plastic derived AC possesses a large potential for elimination and recovery of PAHs elimination from industrial wastewater.


2018 ◽  
Vol 5 (2) ◽  
pp. 91-99
Author(s):  
Marzieh Bagheri ◽  
Mohammad Nasiri ◽  
Bahareh Bahrami

Nowadays, due to increasing usage of dye in various industries and its destructive effects on health and environment, it is necessary to remove dyes from industrial wastes. Although few studies can be found on using pine cone for removal of different dyes, it has not been used yet to remove Reactive Blue 203 (RB203) dye. The purpose of this study is to investigate RB203 dye adsorption using activated carbon produced from pine cone. Optimal values of influencing factors for RB203 dye removal were obtained. The results showed that the maximum removal was occurred at a pH of 2, temperature of 30˚C, dye concentration of 30 mg/L, adsorbent dosage of 100 mg/L, and contact time of 15 min. The maximum removal percentage was 98.48%. In order to study the synthesized activated carbon, some characterization methods including scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy and Brunauer-Emmett-Teller (BET) have been used. Investigation of adsorption isotherm models revealed that adsorption of RB203dye can be described through D-R and Temkin isotherm models. Additionally, RB203 dye removal follows the pseudo-firstorder kinetic equation.


2017 ◽  
Vol 23 (3) ◽  
pp. 399-409 ◽  
Author(s):  
Muhammad Din ◽  
Kiran Ijaz ◽  
Khalida Naseem

In the present work, Saccharum bengalense (SB) was treated with sulfuric acid to enhance its efficiency. Methyl violet (MV), a cationic dye, was removed from aqueous medium using acid modified S. bengalense (A-SB). Different parameters like adsorbent dosage, stirring speed, temperature, contact time and effect of initial concentration of dye on rate of adsorption of dye from aqueous medium was studied. Experimental data obtained from adsorption of MV was analyzed by applying pseudo first order, pseudo second order and intra-particle diffusion models and it was found that the data best follows the pseudosecond order kinetics. Thermodynamic parameters indicate that adsorption reaction was spontaneous, feasible and endothermic in nature. Different adsorption isotherm models, like Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin, were used to study the mechanism of adsorption process and experimental data was well fitted by the Langmuir adsorption isotherm.


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