Kinetic, isotherm and thermodynamic studies on biosorption of chromium(VI) by using activated carbon from leaves of Ficus nitida

Abstract

BackgroundKinetics, thermodynamics and equilibrium of the removal of chromium(VI) ions from aqueous solutions by using chemically activated leaves of Ficus nitida were investigated. Adsorption runs were performed as a function of pH, mass of biosorbent, contact time, initial concentration of chromium(VI) ions and temperature.ResultsThe optimum conditions for maximum removal of chromium(VI) ion from aqueous solutions (about 99 %) were found to be 0.80 g of chemically activated leaves of F. nitida, 25 min, 50.0 mg/L of initial concentration of chromium(VI). Values of thermodynamic activation parameters proved that the biosorption process is spontaneous and endothermic. Results were analyzed by using Langmuir, Freundlich and Temkin models.ConclusionsResults of the study showed that the chemically activated leaves of F. nitida can be used as low cost, ecofriendly and effective sorbent for the removal of chromium(VI) from aqueous solutions.Graphical abstractFicus nitida is an efficient bio-sorbent used for removal of Cr(VI) ion

Removal of Lead and Chromium from Aqueous Solution onto Flamboyant (<i>Delonix regia) Pod Activated Carbon

“…This technology has been widely preferred to other conventional methods such as ion -exchange, chemical precipitation, electro dialysis, membrane separations, reverse osmosis and solvent extraction in the removal of pollutants from wastewater due to its cost effectiveness, simple to design, ease of operation, availability and environmental friendliness (Adebisi et al, 2017). Various adsorbents such as clay mineral (Barbooti, 2015), activated carbons from agricultural waste materials (Amarasinghe and Williams, 2007;Choudhary et al, 2015;Garba et al, 2016;Olayinka et al, 2009;P. Sarma et al, 2015), magnesium oxide nanoparticles (Dargahi et al, 2016), vegetable waste biomass (Nadeem et al, 2014) as well as biological adsorbents (Ali and Alrafai, 2016;Deepa and Suresha, 2014;Lima et al, 2013) have been reported in the literature for lead and chromium removal from wastewater.…”

“…Various adsorbents such as clay mineral (Barbooti, 2015), activated carbons from agricultural waste materials (Amarasinghe and Williams, 2007;Choudhary et al, 2015;Garba et al, 2016;Olayinka et al, 2009;P. Sarma et al, 2015), magnesium oxide nanoparticles (Dargahi et al, 2016), vegetable waste biomass (Nadeem et al, 2014) as well as biological adsorbents (Ali and Alrafai, 2016;Deepa and Suresha, 2014;Lima et al, 2013) have been reported in the literature for lead and chromium removal from wastewater.…”

Removal from wastewater and recycling of azo textile dyes by alginate-chitosan beads

“…The negative values of ΔG° indicate the spontaneity and feasibility of the adsorption process. Since when the ΔG° values range between −20 and 0 kJ mol -1 , the adsorption is classified as physical adsorption, [32] in this study it is possible to affirm that the anionic dyes adsorption on AL-CH beads was mainly physical, involving electrostatic interactions. 3.6 Adsorption Kinetics.…”

“…7) ), allow to understand the nature of adsorption. They can be calculated using the following relations [32]:…”

Removal of an Azo Textile Dye from Wastewater by Cyclodextrin-Epichlorohydrin Polymers

“…Since the , for the γ-CD/EPI polymer, it is possible to affirm that the adsorption was principally physical. Indeed, some studies reported that the adsorption is classified as physical adsorption when the ΔG° values range between −20 and 0 kJ mol −1 , and as chemical adsorption when ΔG° values range from −80 to −400 kJ mol −1 [34]. The positive values of ΔS°, for both polymers, showed that the disorder of the systems increased at the solid solution interface during the adsorption of DB78 on polymers.…”