18 research outputs found
Biosorption of Cd (II) and As (III) ions from aqueous solution by tea waste biomass
Biosorption of Cadmium (Cd (II)) and Arsenic (As (III)) ions from wastewater by tea waste biomass was examined in a batch experimental setup. The effects of pH and temperature on the biosorption were studied in this work. The optimum pH for the maximum efficiency of biosorption of Cd (II) and As (III) were found to be 5.5 and 7.5, respectively. The adsorption process was endothermic in nature and spontaneous. About 95 and 84.5% removal of Cd (II) and As (III) ions was obtained at 200 mg/l of adsorbate and 6 g/l and 7 g/l of adsorbent dosage, respectively. The present study showed that tea waste biomass can serve as a good and cheap substitute for conventional carbon- based adsorbents.Key words: Tea waste biomass, Cd (II), As (III), biosorption
Biosorptive behaviour of mango leaf powder and rice husk for arsenic(III) from aqueous solutions
The present study deals with the biosorption of As(III) from aqueous
solution using mango leaves powder (MLP) and rice husk (RH) in a batch
operation. Scanning electron microscopy and Fourier transformation
infrared spectrometry analysis shows the surface texture of biosorbents
and metal binding of functional groups of before and after biosorption
of As(III). The optimum pH was obtained at 7 and 6 with 7 and 6 g/l of
dosage of MLP and RH, respectively. The adsorption of As(III) onto MLP
and RH was favourably influenced by an increase in temperature.
Equilibrium data were well represented by the Freundlich isotherm
model. Nitric acid and ethylenediaminetetra acetic acid was found to be
a better eluant for the desorption followed by hydrochloric acid and
sodium hydroxide of As(III) with a maximum desorption efficiency of
69.5, 48.5 and 79.4, 86.3 %, respectively. The pseudo-second-order
kinetic model was found to best fitted of the experimental data over
the equilibrium time at 32 h. The positive values of heat of adsorption
(23.89 kJ/mol for MLP and 52.26 kJ/mol for RH) indicate the endothermic
nature of the adsorption process. The thermodynamic study showed the
spontaneous nature of the sorption of As(III) onto MLP and RH