Removal of Lead (II) Ions from Aqueous Solutions onto Activated Carbon Derived from Waste Biomass (original) (raw)
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Removal of Lead (II) Ions from Aqueous Solutions onto
2013
The removal of lead (II) ions from aqueous solutions was carried out using an activated carbon prepared from a waste biomass. The effects of various parameters such as pH, contact time, initial concentration of lead (II) ions, and temperature on the adsorption process were investigated. Energy Dispersive X-Ray Spectroscopy (EDS) analysis after adsorption reveals the accumulation of lead (II) ions onto activated carbon. The Langmuir and Freundlich isotherm models were applied to analyze equilibrium data. The maximum monolayer adsorption capacity of activated carbon was found to be 476.2 mg g −1. The kinetic data were evaluated and the pseudo-second-order equation provided the best correlation. Thermodynamic parameters suggest that the adsorption process is endothermic and spontaneous.
Kinetics and adsorption studies of lead (II) onto activated carbon using low cost adsorbents
Issue 2, 2018
The removal of Lead (II) from aqueous solutions using Fagopyrum esculentum Moench (Buckwheat) and Bambusa vulgaris (common bamboo) as adsorbents was investigated. The effects of various experimental parameters such as initial concentration, contact time and pH have been studied using batch adsorption technique. All the Adsorption isotherm models fitted well with the adsorption data. However, Freundlich isotherm displayed a better fitting model than the other two isotherm models due to high correlation coefficient (R2). This indicates the applicability of multilayer coverage of the Pb (II) on the surface of adsorbent. The adsorption kinetics was studied using four simplified models and it was found to follow the pseudo-second-order kinetic model which confirmed the applicability of the model. The adsorption mechanism was found to be chemisorption and the rate-limiting step was mainly surface adsorption.
An efficient activated carbon was prepared using palm oil mill effluent as a precursor. The adsorption capacity of activated carbon for lead ion and zinc ion from aqueous media was investigated under equilibrium conditions between 303.15 and 353.15 K. The activated carbon was analyzed using fourier transform infrared spectroscopy, field emission scanning electron microscope, energy dispersive X-Ray, and Nitrogen adsorption-desorption analysis. The adsorption capacity of activated carbon was studied by varying adsorbent dosage, contact time, and temperature. The equilibrium time was attained after 50 min for both ions. The data analysis was performed with different isotherm and kinetic models. Pseudo-second-order kinetic rather than pseudo first-order model is best fitted for both lead ion and zinc ion removal from wastewater. Further, the rate-determining step for both metal ions is chemisorption based on the suitability of the Elovich equation. Langmuir model provides the best fit for both removal of lead ion and zinc ion. The thermodynamic parameters shows the feasibility of adsorption of both ions is endothermic.
Journal of Colloid and Interface Science, 2004
Removal of lead from aqueous solutions by adsorption onto coconut-shell carbon was investigated. Batch adsorption experiments were performed to find out the effective lead removal at different metal ion concentrations. Adsorption of Pb 2+ ion was strongly affected by pH. The coconut-shell carbon (CSC) exhibited the highest lead adsorption capacity at pH 4.5. Isotherms for the adsorption of lead on CSC were developed and the equilibrium data fitted well to the Langmuir, Freundlich, and Tempkin isotherm models. At pH 4.5, the maximum lead adsorption capacity of CSC estimated with the Langmuir model was 26.50 mg g −1 adsorbent. Energy of activation (E a) and thermodynamic parameters such as G, H , and S were evaluated by applying the Arrhenius and van't Hoff equations. The thermodynamics of Pb(II) on CSC indicates the spontaneous and endothermic nature of adsorption. Quantitative desorption of Pb(II) from CSC was found to be 75% which facilitates the sorption of metal by ion exchange.
2020
Adsorption of lead (II) ions from aqueous solutions on low cost adsorbent prepared from coconut shell modified with polysiloxane was studied experimentally. The adsorption kinetics and thermodynamics were also investigated in batch experiments considering the time and temperature range of 5-20 minutes and 20-80 o C respectively. The removal efficiency (99.9%) of lead (II) ions was obtained at pH 8.0 and 20 minutes contact time. Pseudo-first order, pseudo-second order, Elovich and Intraparticle diffusion were employed to describe the rate of adsorption process, and the potential rate-controlling step on the adsorbent surface. This indicated that the pseudo-second order fits the data better. Thermodynamic parameters such as Gibb's free energy (∆G o), Enthalpy (∆H o), Entropy (∆S o) and Activation energy (Ea) for the adsorption process were evaluated as-22.462 kJmol-1 ,-25.142 kJmol-1 ,-8.131 kJmol-1 K-1 and-57.341 kJmol-1 respectively. These values show that the adsorption of lead (II) ions on MCSAC was exothermic and spontaneous in nature.
Continuous adsorption of lead ions in a column packed with palm shell activated carbon
Journal of Hazardous Materials, 2008
The continuous adsorption of lead ions from aqueous solution on commercial, granular, unpretreated palm shell activated carbon (PSAC) was studied. Effect of pH, flow rates and presence of complexing agents (malonic and boric acids) were examined. The breakthrough period was longer at pH 5 indicating higher adsorption capacity of lead ions at higher pH. Increase of the flow rate, expectedly, resulted in the faster saturation of the carbon bed. Presence of complexing agents did not improve adsorption uptake of lead ions. However, presence of malonic acid resulted in smoother pH stabilization of solution compared to single lead and lead with boric acid systems. The results on continuous adsorption of lead were applied to the model proposed by Wang et al. [Y.-H. Wang, S.-H. Lin, R.-S. Juang, Removal of heavy metals ions from aqueous solutions using various low-cost adsorbents, J. Hazard. Mater. B 102 (2003) 291-302]. The agreement between experimental and modelled breakthrough curves was satisfactory at both pHs.
Adsorption Science & Technology
Adsorption studies (kinetic, batch and dynamic assays) were carried out for lead removal from aqueous solutions using wastes from the wine industry. The adsorbents used were obtained from grape stalk and pomace #. These materials were carbonized, briquetted and activated with steam. Addition of a leaching step before activation lowered the high ash content of the materials. The products were characterized by elemental and proximate analysis, point of zero charge pH, specific surface area, pore-size distribution, Fourier transform infrared spectroscopy and surface acidic and basic groups. Considering the physicochemical and textural properties of the adsorbents, a comparative analysis of the results was made. These solids showed a marked basic character; therefore, the pH was a very important variable in adsorption tests, and thus it was necessary to maintain the pH in a favourable range. Batch equilibrium assays showed that the tested adsorbents had good adsorption capacities, better than the ones reported previously for similar materials. In dynamic tests, the removal of lead by both activated carbon briquettes was good and attributed to the coupling of adsorption and precipitation as a result of the increase in the pH values, which could not be controlled.
The effect of modification of activated carbon WG-12 on lead adsorption from water
DESALINATION AND WATER TREATMENT, 2018
The presented work aimed at comparing two types of gaseous modification: the conventional method using an external source of energy (heat) and an originally developed method utilizing Joule heat generated during the flow of electric current through a carbon bed. The conventional modification of the WG-12 activated carbon was conducted in a rotary furnace at a temperature of 400°C and 800°C, respectively. Modification of activated carbon in an experimental electric heating system (referred to as the SEOW) occurred in a process whereby activated carbon was heated up to 400°C during the flow of electric current through the carbon bed, followed by cooling down with air or carbon dioxide. Both activated carbon modification methods enhanced the adsorption capacity toward Pb(II) ions. The monolayer capacity, as calculated from the Langmuir isotherm for the initial carbon, was q m = 44.05 mmol/kg, while for carbon modified in the rotary furnace, q m = 112.36 mmol/kg, and for carbon modified on the SEOW stand, q m = 76.92 mmol/kg. The modification resulted in an increase in the specific surface area of activated carbon and the number of acid (mainly hydroxyl) functional groups. The advantage of activated carbon heating using the SEOW required much (up to several times) less energy, compared with the conventional method.
2021
Abstaract: The lead (II) is one of the hazardous metal ions produced from various industrial wastes and its existence needs to be addressed. Adsorption using activated carbon from lengkeng shell is proven to be able to absorb lead (II). The absorption stage was carried out by varying the pH (2, 3, 4, 5, and 6) and the concentration (50. 100, 150, 200, 250) mg /L by the column method. The results showed that the optimum conditions occurred at pH 5 and a concentration of 150 mg /L with an absorption capacity of 3.7058 mg/g.
Nigerian Journal of Tropical Engineering
Heavy metals contamination of water and wastewater is a common phenomenon. Industrial wastewaters are usually the cause of heavy metals pollution of the environment. In this work, the adsorptive removal of lead metal ions in aqueous solution is investigated using an activated carbon derived from coconut husk. The activated carbon was modified with NaOH and characterized for functional group, micro-structure and textural properties. The activated carbons have a surface area of 304.38 m 2 /g from 600 °C activation with NaOH modification and 281.19 m 2 /g (300 °C) without modification. FTIR demonstrated the different functional groups present and the SEM images showed the pores on the surface of the activated carbon due to the NaOH modification. The maximum adsorption capacity of 91.70 and 73.90 mg/g were obtained for the coconut husk modified and unmodified adsorbents respectively. The adsorption kinetics for lead metal ions onto both adsorbents can be described by a pseudo-second-ord...