Efficacy of treated sodium alginate and activated carbon fibre for Pb (II) adsorption

Efficacy of treated sodium alginate (TSA) and activated carbon fibre (ACF) for aqueous Pb(II) uptake was comparatively investigated. By employing FTIR, SEM, EDX, XRD, point of zero charges and surface area measurements, the available functional groups, morphology, crystallinity, surface charge and surface areas of both adsorbents were respectively elucidated. The Pb(II) uptake performance of both adsorbents was also studied via batch mode at varied process conditions. The experimental isotherm and kinetic data for both adsorbents were best fitted to nonlinear forms of Langmuir and pseudo-first-order models, respectively. Similarly, intraparticle diffusion was the sole controlling mechanism. Despite the huge variation in the surface area, TSA (7.8 m(2)/g) with high carboxyl content (395.6 meq-COOH/100 g of sample) performed better by all standards than the ACF (975 m(2)/g). This finding showed that although the surface area of a given adsorbent is a key indicator of its adsorptive performance, the inherent surface functional groups play a superior role. The experimentally derived maximum adsorption capacities of 221.25 mg/g (for TSA) and 183.34 mg/g (for ACF) were recorded at an equilibrium time of 30 min and 45 min, respectively. Therefore, TSA and ACF demonstrated effectiveness for aqueous Pb (II) sequestration. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study compared the efficacy of treated sodium alginate (TSA) and activated carbon fibre (ACF) for aqueous Pb(II) uptake. Despite the significant difference in surface area, TSA with high carboxyl content outperformed ACF in adsorption performance. The findings emphasize the importance of surface functional groups in determining adsorptive performance.