A new insight to the physical interpretation of activated carbon and iron doped carbon material: sorption affinity towards organic dye

To enhance the potential of activated carbon (AC), iron incorporation into the AC surface was examined in the present investigations. Iron doped activated carbon (FeAC) material was synthesized and characterized by using surface area analysis, energy dispersive X-ray (EDX), temperature programmed reduction (TPR) and temperature programmed desorption (TPD). The surface area of FeAC (543 m2/g) was found to be lower than AC (1043 m2/g) as a result of the pores widening due to diffusion of iron particles into the porous AC. Iron uploading on AC surface was confirmed through EDX analysis, showing up to 13.75 wt.% iron on FeAC surface. TPR and TPD profiles revealed the presence of more active sites on FeAC surface. FeAC have shown up to 98% methylene blue (MB) removal from the aqueous media. Thermodynamic parameters indicated the spontaneous and exothermic nature of the sorption processes

Adsorption behavior of PB(II) onto xanthated rubber (Hevea brasiliensis) leaf powder

A plant waste, rubber (Hevea brasiliensis) leaf powder was modified with carbon disulfide (xanthation) for the purpose of introducing sulfur groups, and the adsorbent performance in removing Pb(II) ion was evaluated. Pb(II) adsorption was confirmed by spectroscopic analysis, which involved Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The amount of Pb(II) adsorbed increased with increasing pH, contact time and concentration but slightly decreased with increasing ionic strength. Adsorption equilibrium was achieved in less than 60 min and followed the pseudo-second order model. The isotherm data indicated that Pb(II) adsorption on xanthated rubber leaf (XRL) fitted well with Langmuir isotherm model. The maximum adsorption capacity computed from the Langmuir isotherm model was 166.7 mg/g. Pb(II) adsorption occurred via ion-exchange and complexation mechanisms

Kinetic investigations on AC and FeAC (a) pseudo–first order (b) pseudo–second order models.

<p>Kinetic investigations on AC and FeAC (a) pseudo–first order (b) pseudo–second order models.</p

Determination of the pH of zero point of charge (pH_<i>ZPC</i>) for AC and FeAC.

<p>Determination of the pH of zero point of charge (pH_<i>ZPC</i>) for AC and FeAC.</p

FTIR spectra of AC and FeAC before (a,b) and after MB adsorption (c,d) respectively.

<p>FTIR spectra of AC and FeAC before (a,b) and after MB adsorption (c,d) respectively.</p

Dimensionless characteristic curves of MB sorption by (a) AC and (b) FeAC at various temperatures.

<p>Dimensionless characteristic curves of MB sorption by (a) AC and (b) FeAC at various temperatures.</p

Elovich equation’s dimensionless parameter for the kinetics of MB by different types of adsorbents.

<p>Wherein, raw materials for a, b and c were corncob, fir wood and cane pith, respectively.</p><p>Elovich equation’s dimensionless parameter for the kinetics of MB by different types of adsorbents.</p

Effect of ionic strength on the MB uptake by (a) AC and (b) FeAC.

<p>Effect of ionic strength on the MB uptake by (a) AC and (b) FeAC.</p

Regeneration studies of spent adsorbents using (a) H₂SO₄ (b) NaOH (c) NaNO₃ (d) distilled water.

<p>Regeneration studies of spent adsorbents using (a) H₂SO₄ (b) NaOH (c) NaNO₃ (d) distilled water.</p