Thermodynamic and kinetic studies of biosorption of iron and manganese from aqueous medium using rice husk ash

Abstract

The adsorption behavior of rice husk ash with respect to manganese and iron has been studied by batch methods to consider its application for water and waste water treatment. The optimum conditions of adsorption were determined by investigating the effect of initial metal ion concentration, contact time, adsorbent dose, pH value of aqueous solution and temperature. Adsorption equilibrium time was observed at 120 min. The adsorption efficiencies were found to be pH dependent. The equilibrium adsorption experimental data were found to fit the Langmuir, Freundlich and Temkin isotherms for iron, but fitted only Langmuir isotherm for manganese. The pseudosecond order kinetic model was found to describe the manganese and iron kinetics more effectively. The thermodynamic experiment revealed that the adsorption processes involving both metals were exothermic. The adsorbent was finally applied to typical raw water with initial manganese and iron concentrations of 3.38 mg/l for Fe and 6.28 mg/l, respectively, and the removal efficiency was 100 % for Mn and 70 % for Fe. The metal ions were desorbed from the adsorbent using 0.01 M HCl, it was found to quantitatively remove 67 and 86 % of Mn and Fe, respectively, within 2 h. The results revealed that manganese and iron are considerably adsorbed on the adsorbent and could be an economic method for the removal of these metals from aqueous solutions.

Artificial intelligence modeling of cadmium(II) biosorption using rice straw

“…The enhancement of metal removal with increase in pH can be illustrated by a decrease in competition between proton and the metal cations for the same functional groups. Additionally, the decrease in positive charge of the adsorbent results in a lower electrostatic repulsion between the metal cations and the surface (Adekola et al 2014 the rice straw (adsorbent) might be loosened and converted to glucose, which would contribute to a decline in the adsorption efficiency. Similarly, BD has direct impact on Cd 2?…”

The Effects of Operational Parameters on the Iron(III) Uptake by Micro‐Algae Dunaliella salina

“…The interactions of microorganisms and metals in aqueous media have been intensively studied and well documented . Metals can be removed and concentrated from the solution through a two‐step process: biosorption of metal ions followed by bioaccumulation.…”

“…Iron is one of the most dangerous metals for the environment and human health. The main source of water pollution with iron is metallurgy, chemical, paint industry, and printing activities . There is a particular interest in the use of the metal‐binding capacities of microorganisms for technological purposes such as the removal of metal contaminants from the aqueous media or the biorecovery …”

Biosorption of Fe (II) from Aqueous Solution by Brewing Waste: Equilibrium and Kinetic Studies

“…Comparatively, different efficiency of Fe (II) removal have been reported for several adsorbent. For instance, rice husk ash -70% [28], maize cob -48% [29], coconut coir fibre -59% [30], dried biomass of activated sludge -95% [31], cucumis melo rind -98% [23]. Generally, the physical nature and pre-treatment method plays a major role in the variation of metal ion adsorbed.…”