Removal of Pb(II) and Cd(II) From Aqueous solution Using Oxidized Activated Carbons Developed From Pecan Shells.

Youssef, A.M.; El-Khouly, Sahar M.; El-Nabarawy, Th.

doi:10.5714/cl.2008.9.1.008

Cited by 16 publications

(18 citation statements)

References 25 publications

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“…Application of such a model allowed us to estimate a mean sorption energy ( E = 0.338 kJ mol −1 ) about 21 % lower than that obtained for Hg adsorption onto C. vulgaris biomass , about one half those reported for Pb 2+ and Zn 2+ adsorption onto thiolated tea ( Camellia sinensis ) seed shell , and much lower than the energy threshold value ascribed to chemical sorption (8 kJ mol −1 ) . These results, which agree with the indications arisen from the earlier kinetic study, confirm the occurrence of a physical biosorption mechanism.…”

Section: Resultsmentioning

confidence: 96%

Kinetics and Isotherms of Mercury Biosorption by Dry Biomass of Arthrospira (Spirulina) platensis

et al. 2019

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Inorganic mercury was effectively removed from water solutions by means of dry biomass of Arthrospira (Spirulina) platensis as biosorbent. The results obtained at defined pH and biomass concentration as well as variable Hg concentrations were used to estimate biosorption kinetics and isotherm parameters. Biosorption kinetics was best described by the pseudo-first-order model of Lagergren that allowed estimating an average specific rate constant as high as 0.044 min -1 , while the Dubinin and Radushkevich model was the best fitting isotherm. Hg biosorption seemed to occur via physisorption. Considering the wide dissemination of A. platensis and its easy cultivation, these results point to its biomass as a low-cost biosorbent to treat Hg-contaminated waters.

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Section: Resultsmentioning

confidence: 96%

Kinetics and Isotherms of Mercury Biosorption by Dry Biomass of Arthrospira (Spirulina) platensis

et al. 2019

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“…The thermodynamics indicate the adsorption mechanism. If the value of E = 8-16 kJ/mol then the adsorption process flows by chemical ion-exchange, and if E < 8 kJ/mol the adsorption process is physical in nature; whereas if the value is more than 16 kJ/mol, the adsorption process is chemisorption in nature (Youssef et al 2008). The adsorption free energy of ammonium on RHB (12.91 kJ/mol) and S-RHB (8.91 kJ/mol), therefore, indicates an ion exchange, while C-RHB tends to be physical sorption.…”

Section: Adsorption Of Ammoniummentioning

confidence: 99%

Low cost and easy rice husk modification to efficiently enhance ammonium and nitrate adsorption

Mathurasa

Damrongsiri

2018

Int J Recycl Org Waste Agricult

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Purpose This research aimed to study the adsorption of ammonium and nitrate by simply modifying the surface of the rice husk using slow pyrolysis and surfactants modification. Methods Rice husk biochar was prepared by slowly pyrolyzing at 500 °C, 2 h. The rice husk and its biochar were modified by cetyltrimethylammonium bromide or sodium dodecylbenzenesulfonate. FTIR, BET and zeta potential measurements were used to characterize the obtained adsorbents. Results Slow pyrolysis increased the specific surface area and decreased the surface charge of rice husk while surfactant clogged the pore but could change the charge of a surface. Adsorption of both ammonium and nitrate on rice husk, its biochar, and their modification with surfactants fitted Freundlich and Langmuir isotherms, indicating heterogeneity in adsorption. Slow pyrolysis gave the highest ammonium removal with maximum adsorption capacity of 44 mgN/g and it was a physical process. The cetyltrimethylammonium bromide modification gave a significant nitrate removal on both rice husk and its biochar with maximum adsorption of 278 and 213 mgN/g, respectively, which is higher than a commercial adsorbent. Conclusions These two modification techniques gave great adsorption enhancement with cost-effectiveness as compared to other reviewed methods which could use as a nitrogen-rich fertilizer and fertilizer retainment in crop production.

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“…The activation energy provides insight into the undergoing process of adsorption although it is not necessarily supported in determining the rate controlling step. For adsorption process in the nature of physisorption, E < 8 kJ/mol, and ion exchange, E exist within the range of 8 -18 kJ/mol [14]. Alternatively, for film-diffusion-controlled process, E < 16 kJ/mol, particle diffusion -controlled, E is 21 -38 kJ/mol, and chemical-reaction-controlled, E > 50 kJ/mol [15].…”

Section: ) Dubinin -Radushkevich (Dr) Isothermmentioning

confidence: 99%

Equilibrium, Kinetic and Adsorption Mechanisms of Chromium (VI) on Characterized Activated Carbon Synthesized from Phosphoric Acid Activation of Coconut Shells

Seidu¹,

Li²,

Zhou³

2018

IJEMA

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Over the years, water pollution due primarily to the discharge of toxic heavy metals from industrial activities has served as a major challenge in our quest to provide clean drinking water to millions of people across the world. Numerous cheap and environmentally friendly methods and technologies have been developed for the treatment of wastewater contaminated with heavy metals. Key among these technologies is the use of adsorbent as it is the most economical and efficient. In this present study, coconut shells were used to develop microporous adsorbent (activated carbon) through chemical activation by phosphoric acid (H 3 PO 4 ). An analysis of the effect of various process parameters such as pH, temperature, initial metal ion concentration, adsorbent dose and contact time was conducted through batch adsorption of hexavalent chromium [Cr (VI)] on prepared AC sample. Initial Cr (VI) concentration was investigated through a range of 10 -50 mg/L with the study showing an optimum concentration for AC of 20 mg/L for percentage removal (93.3%) but adsorption capacity (Q e ) was highest for 50 mg/L (4.512 mg/g). The optimum conditions for adsorbent dose, contact time and temperature were determined as 6 g/L, 100 minutes and 30°C respectively for the prepared AC. Maximum adsorption was recorded for pH (2) at 88.2 5% (removal) and 4.41 mg/g (adsorption capacity) for AC. The experimental data obtained were modelled using various isotherms, including adsorption equilibrium isotherms, adsorption kinetic study and adsorption mechanisms with positive correlations (better fit) obtained for Freundlich isotherm, D-R isotherm (slightly), pseudo-second-order kinetic and Boyd models.

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Removal of Pb(II) and Cd(II) From Aqueous solution Using Oxidized Activated Carbons Developed From Pecan Shells.

Cited by 16 publications

References 25 publications

Kinetics and Isotherms of Mercury Biosorption by Dry Biomass of Arthrospira (Spirulina) platensis

Kinetics and Isotherms of Mercury Biosorption by Dry Biomass of Arthrospira (Spirulina) platensis

Low cost and easy rice husk modification to efficiently enhance ammonium and nitrate adsorption

Equilibrium, Kinetic and Adsorption Mechanisms of Chromium (VI) on Characterized Activated Carbon Synthesized from Phosphoric Acid Activation of Coconut Shells

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