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Open accessJournal ArticleDOI: 10.1088/1757-899X/206/1/012065

Optimization and Performance parameters for adsorption of Cr6+ by microwave assisted carbon from Sterculia foetida shells

01 Jun 2017-Vol. 206, Iss: 1, pp 012065
Abstract: Modeling of adsorption of Cr6+ on to activated carbon prepared from Sterculia foetida dried seed shells under different drying techniques namely sun, oven, and microwave drying (450W, 600W, 900W power). Optimization of process parameters such as pH, adsorbent dosage (g/ml), temperature (°C), contact time (min) were evaluated using Central Composite Rotatable Design (CCRD) of Response Surface Methodology (RSM). For batch adsorption studies at pH 3, adsorbent dosage of 1.5 g/ml, temperature 35°C and contact time 90 min were found to be optimum for the system under consideration and Microwave Activated Carbonized Sterculia foetida (MACSF) at 450W was found to be best suited for the adsorption of Cr+6 ions. The system was found to follow Langmuir type monolayer adsorption for the given operational parameters. SEM analysis was used to study the surface morphology of the carbon samples and the effect of pretreatment on carbonization.

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Topics: Sterculia foetida (60%), Adsorption (57%), Activated carbon (53%) ...read more
Citations
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Open accessJournal ArticleDOI: 10.1007/S13201-019-1120-8
Tsegaye Adane1, Daniel Haile1, Awrajaw Dessie1, Yohannes Abebe1  +1 moreInstitutions (1)
Abstract: Recently, rapid industrialization leads to excessive release of heavy metals such as Cr(VI) in the environment. Exposure to chromium (VI) can cause kidney and liver damage, depressed immune systems, and a variety of cancers. Therefore, treatment of Cr(VI) containing wastewater is mandatory. This study aims to optimize the removal of Cr(VI) from aqueous solution using locally available Teff husk activated carbon adsorbent. The laboratory-based study was conducted on the optimization of Cr(VI) removal efficiency of Teff husk activated carbon from aqueous solution. A central composite design was used to examine the effect of the interaction of process parameters and to optimize the process using Design Expert version 7.0 software. The optimized removal efficiency of Teff husk activated carbon (95.597%) was achieved at 1.92 pH, 87.83 mg/L initial concentration, 20.22 g/L adsorbent dose, and 2.07 H contact time. The adsorption of Cr(VI) on Teff husk activated carbon was found to be best fitted with pseudo-second-order kinetics and Langmuir isotherm model of the adsorption. Teff husk activated carbon can be used as an efficient adsorbent for removal of chromium (VI) from contaminated water. Column adsorption needs to be studied in the future.

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Topics: Activated carbon (53%), Husk (52%), Adsorption (52%)

9 Citations


Open accessJournal ArticleDOI: 10.3390/EN13153839
27 Jul 2020-Energies
Abstract: A liquid-solid circulating fluidized bed (LSCFB) helps to overcome the shortcomings of conventional fluidized beds by using a particle separation and return system as an integral part of the overall reactor configuration. Batch adsorption experiments were carried out for the removal of phenol from a synthetically prepared solution using fresh activated-carbon-coated glass beads. The morphological features and surface chemistry of the adsorbent were analyzed via SEM and FTIR techniques. The adsorbent dosage, contact time and temperature were varied along with solution pH to assess their effects on the adsorbent performance for phenol removal. Isotherm modeling showed that the phenol removal using the activated-carbon glass beads followed the Langmuir model. Effectively, it was observed at an adsorbent loading of 2.5 g/150 mL of feed volume and a contact time of 3 h produced an 80% efficiency in the batch study. Furthermore, on scaling it up to the column, the desired 98% phenol-removal efficiency was obtained with an adsorbent dosage of 250 g and contact time of 25 min. Adsorbent regeneration using 5% (v/v) ethanol showed a 64% desorption of phenol from the sorbent within 20 min in the LSCFB.

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3 Citations


Open accessJournal ArticleDOI: 10.31248/JBBD2019.093
30 Jun 2019-
Abstract: Adsorption has been widely used for the removal of heavy metals from waste water due to its availability, efficiency, profitability and its low cost of operation. In this study, locust bean seed shell powder prepared from locust been seed shell (LBSS) was used as adsorbent. Batch adsorption experiments were carried out in order to study the effect of process variables such as; adsorbent dosage, time, concentration, and temperature. The adsorbents both unmodified and modified were characterized using SEM, XRF, and FTIR. The results showed structural modification of the modified locust bean seed shell powder (MLBSSP). The adsorption equilibrium data of MLBSSP perfectly conform to Freundlich adsorption model based on its high correlation coefficient which is close to unity (0.9738). However, the kinetic studies showed that the process fit in well into pseudo second order due to its higher R2 (0.9662) in MLBSSP. The positive values obtained for change in enthalpy indicate that the adsorption process is endothermic in nature while the negative values obtained for change in entropy of the process reveal decrease in the randomness of the process and the positive values of change in Gibb’s free energy suggest non spontaneity of the adsorption process. The adsorbent (MLBSSP) shows excellent performance in removing Pb (II) ions from aqueous solutions and can be used as a substitute to the available expensive adsorbents since it is cheap, non-toxic and abundantly available.

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Topics: Freundlich equation (63%), Adsorption (59%), Endothermic process (51%)

Open accessJournal ArticleDOI: 10.47836/PJST.29.3.28
Abstract: This study investigates the properties and potential application of Mg-PKS biochar composite for methylene blue solution (MB) adsorption. The Mg-PKS biochar composite was developed from palm kernel shell biochar via steam activation followed by MgSO4 treatment and carbonization. The effect of process parameters such as solution pH (4-10), contact time (30-90 min) and adsorbent dosage (0.1-0.5 g) were investigated via central composite design, response surface methodology. Results revealed that the Mg-PKS biochar composite has irregular shapes pore structure from SEM analysis, a surface area of 674 m2g-1 and average pore diameters of 7.2195 μm based on BET analysis. RSM results showed that the optimum adsorption of MB onto Mg-biochar composite was at pH 10, 30 min contact time and 0.5 g/100 mL dosage with a removal efficiency of 98.50%. In conclusion, Mg treatment is a potential alternative to other expensive chemical treatment methods for biochar upgrading to the adsorbent.

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Topics: Palm kernel (61%), Biochar (55%)

Open accessJournal ArticleDOI: 10.1016/J.WRI.2021.100165
Abstract: Following the expansion of distillery industries, a large quantity of waste is being released to the environment containing high color-forming chemicals. This study aimed at degrading melanoidin pigment from distillery spent wash by using impregnated Sugarcane bagasse activated carbon (SCBAC) and Modified Bagasse Fly Ash (MBFA) as a comparative study. FTIR has revealed functional groups responsible for adsorption. A broad peak revealing an amorphous structure was observed for SCBAC while crystalline structure was observed in MBFA using XRD. SEM micrograph revealed an irregular macro-porous structure and regular structure for SCBAC and MBFA respectively. In the adsorption, important process parameters were optimized in response to color removal efficiency. At equilibrium, adsorption isotherm models, kinetics, mechanisms, and thermodynamics of the adsorption were studied. Langmuir model and Pseudo-second order result in the best fit for both adsorbents. Thermodynamics study revealed an exothermic process, feasibility, and spontaneity of the adsorption process for both adsorbents.

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Topics: Adsorption (56%), Activated carbon (52%), Langmuir adsorption model (51%) ...read more

References
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Journal ArticleDOI: 10.1016/S0032-9592(99)00005-9
Abstract: The biosorption of copper(II), nickel(II) and chromium(VI) from aqueous solutions on dried (Chlorella vulgaris, Scenedesmus obliquus and Synechocystis sp) algae were tested under laboratory conditions as a function of pH, initial metal ion and biomass concentrations Optimum adsorption pH values of copper(II), nickel(II) and chromium(VI) were determined as 50, 45 and 20 respectively, for all three algae At the optimal conditions, metal ion uptake increased with initial metal ion concentration up to 250 mg l−1 Experimental results also showed the influence of the alga concentration on the metal uptake for all the species Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of copper(II), nickel(II) and chromium(VI) by all the algal species

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Topics: Biosorption (62%), Freundlich equation (55%), Chromium (53%) ...read more

532 Citations


Journal ArticleDOI: 10.1016/J.WASMAN.2006.06.009
R. Malik1, D. S. Ramteke1, Satish R. Wate1Institutions (1)
01 Jan 2007-Waste Management
Abstract: In the present technologically fast changing situation related to waste management practices, it is desirable that disposal of plant waste should be done in a scientific manner by keeping in view economic and pollution considerations. This is only possible when the plant waste has the potential to be used as raw material for some useful product. In the present study, groundnut shell, an agricultural waste, was used for the preparation of an adsorbent by chemical activation using ZnCl2 under optimized conditions and its comparative characterisation was conducted with commercially available powdered activated carbon (CPAC) for its physical, chemical and adsorption properties. The groundnut shell based powdered activated carbon (GSPAC) has a higher surface area, iodine and methylene blue number compared to CPAC. Both of the carbons were used for the removal of malachite green dye from aqueous solution and the effect of various operating variables, viz. adsorbent dose (0.1–1 g l−1), contact time (5–120 min) and adsorbate concentrations (100–200 mg l−1) on the removal of dye, has been studied. The experimental results indicate that at a dose of 0.5 g l−1 and initial concentration of 100 mg l−1, GSPAC showed 94.5% removal of the dye in 30 min equilibrium time, while CPAC removed 96% of the dye in 15 min. The experimental isotherm data were analyzed using the linearized forms of Freundlich, Langmuir and BET equations to determine maximum adsorptive capacities. The equilibrium data fit well to the Freundlich isotherm, although the BET isotherm also showed higher correlation for both of the carbons. The results of comparative adsorption capacity of both carbons indicate that groundnut shell can be used as a low-cost alternative to commercial powdered activated carbon in aqueous solution for dye removal.

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Topics: Freundlich equation (61%), Powdered activated carbon treatment (61%), Adsorption (56%) ...read more

354 Citations


Journal ArticleDOI: 10.1016/J.CEJ.2008.01.020
Abstract: In this study, activated carbon was prepared from olive bagasse by physical activation of steam. The pore properties including the BET surface area, pore volume, pore size distribution and average pore diameter were characterized. BET surface area of the activated carbon was determined as 718 m 2 /g. The removal of Cr(VI) from aqueous solutions by adsorption has been studied. The effects of pH, contact time and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 2. The adsorption kinetics shows that pseudo-second order rate expression fitted the adsorption kinetics. Equilibrium isotherms were measured experimentally. Results were analyzed by the Langmuir, Freundlich, Dubinin-Redushkevich, Temkin and Frumkin equations using linearized correlation coefficient at different temperatures. The characteristics parameters for each isotherm have been determined. Models and isotherm constants were evaluated depending on temperature. Langmuir equation was found to fit the equilibrium data for Cr(VI) adsorption.

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Topics: Freundlich equation (67%), Adsorption (65%), BET theory (61%) ...read more

287 Citations


Journal ArticleDOI: 10.1016/J.JHAZMAT.2015.02.026
Abstract: Microwave-induced chemical activation process was used to prepare an activated carbon from cocoa shell for efficient removal of two anti-inflammatories, sodium diclofenac (DFC) and nimesulide (NM), from aqueous solutions. A paste was obtained from a mixture of cocoa shell and inorganic components; with a ratio of inorganic: organic of 1 (CSC-1.0). The mixture was pyrolyzed in a microwave oven in less than 10 min. The CSC-1.0 was acidified with a 6 mol L(-1) HCl under reflux to produce MWCS-1.0. The CSC-1.0 and MWCS-1.0 were characterized using FTIR, SEM, N2 adsorption/desorption curves, X-ray diffraction, and point of zero charge (pHpzc). Experimental variables such as initial pH of the adsorbate solutions and contact time were optimized for adsorptive characteristics of MWCS-1.0. The optimum pH for removal of anti-inflammatories ranged between 7.0 and 8.0. The kinetic of adsorption was investigated using general order, pseudo first-order and pseu do-second order kinetic models. The maximum amounts of DCF and NM adsorbed onto MWCS-1.0 at 25 °C are 63.47 and 74.81 mg g(-1), respectively. The adsorbent was tested on two simulated hospital effluents. MWCS-1.0 is capable of efficient removal of DCF and NM from a medium that contains high sugar and salt concentrations.

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Topics: Adsorption (54%), Activated carbon (54%), Aqueous solution (52%) ...read more

209 Citations


Journal ArticleDOI: 10.1016/J.CEJ.2011.11.002
K.Y. Foo1, B.H. Hameed1Institutions (1)
Abstract: This study presents the preparation of activated carbon from mangosteen peel via microwave assisted K 2 CO 3 activation. The operational parameters including chemical impregnation ratio, microwave power and irradiation time on the carbon yield and adsorption capability of the mangosteen peel derived activated carbon (MPAC) were investigated. The virgin characteristics of the prepared MPAC were examined by pore structural analysis, Scanning Electron Microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption isotherm, elemental analysis, surface acidity/basicity and zeta potential measurement. The adsorptive property of MPAC was tested using methylene blue as dye model compound. The best conditions resulted in MPAC with a maximum monolayer adsorption capacity of 379.63 mg/g and carbon yield of 80.95%, respectively. Equilibrium data were favorably described by Langmuir isotherm, while adsorption kinetics was best fitted to the pseudo-second-order model. The findings support the feasibility of mangosteen peel derived activated carbon as a promising and economic adsorbent.

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Topics: Activated carbon (58%), Adsorption (57%), Langmuir adsorption model (53%) ...read more

152 Citations