Enhanced adsorptive composite foams for copper (II) removal utilising bio-renewable polyisoprene-functionalised carbon derived from coconut shell waste

Abstract

A bio -renewable polyisoprene obtained from Hevea Brasiliensis was used to produce functionalised carbon composite foam as an adsorbent for heavy metal ions. Functionalised carbon materials (C-SO3H, C-COOH, or C-NH2) derived from coconut shell waste were prepared via a hydrothermal treatment. Scanning electron microscopy images showed that the functionalised carbon particles had spherical shapes with rough surfaces. X-ray photoelectron spectroscopy confirmed that the functional groups were successfully functionalised over the carbon surface. The foaming process allowed for the addition of carbon (up to seven parts per hundred of rubber) to the high ammonia natural rubber latex. The composite foams had open pore structures with good dispersion of the functionalised carbon. The foam performance on copper ion adsorption has been investigated with regard to their functional group and adsorption conditions. The carbon foams achieved maximum Cu(II) adsorption at 56.5 $${\text{mg g}}_{\text{foam}}^{-1}$$ mg g foam - 1 for C-SO3H, 55.7 $${\text{mg g}}_{\text{foam}}^{-1}$$ mg g foam - 1 for C-COOH, and 41.9 $${\text{mg g}}_{\text{foam}}^{-1}$$ mg g foam - 1 for C-NH2, and the adsorption behaviour followed a pseudo-second order kinetics model.

Comprehensive study of lumped kinetic models and bio-oil characterization in microwave-assisted pyrolysis of Sargassum sp.

“…When compared to other studies, the CAC used in this research has a lower carbon content and higher levels of inorganic trace elements (Kettum et al , 2021; Zhang et al , 2018). 30,39 Coconut-based activated carbon fibers typically have a carbon content of 83.07 wt% and an oxygen content of 11.61 wt%, whereas raw coconut fibers contain 70.31 wt% carbon and 23.83 wt% oxygen. 39 CAC derived from coconut shell waste can have carbon contents as high as 90.89 at% and oxygen contents of 9.11 at%.…”

“…various inorganic elements: sodium (Na) at 2.30 wt% (1.40 at%), aluminum (Al) at 1.25 wt% (0.65 at%), silica (Si) at 2.41 wt% (1.20 at%), chlorine (Cl) at 5.73 wt% (2.26 at%), and potassium (K) at 5.88 wt% (2.11 at%). When compared to other studies, the CAC used in this research has a lower carbon content and higher levels of inorganic trace elements (Kettum et al, 2021;. 30,39 Coconut-based activated carbon fibers typically have a carbon content of 83.07 wt% and an oxygen content of 11.61 wt%, whereas raw coconut fibers contain 70.31 wt% carbon and 23.83 wt% oxygen.…”

“…Lumped models, comprising one-step reaction and competitive models, have been widely employed due to their simplicity compared to isoconversional models. 18,[30][31][32] While lumped kinetic models have been explored in previous research, focusing on the kinetics, 18,33,34 there exists a notable gap in scholarly endeavors pertaining to the characterization of reaction rate profiles emerging from these models. This study contributes novelty by elucidating the physical significance of various models, an aspect not previously addressed by prior authors.…”

Recent Progress on the Adsorption of Heavy Metal Ions Pb(II) and Cu(II) from Wastewater

“…The adsorption mechanism includes surface electrostatic attraction, surface complexation and co-precipitation. Kettum [ 148 ] prepared functional carbon materials (C-SO 3 H, C-COOH or C-NH 2 ) from coconut shell waste. The composite foam has a porous structure and good carbon dispersion.…”

“…[ 56 ] from Elsevier), ( b ) activated carbon (reproduced with permission from Ref. [ 148 ] from Nature), ( c ) carbon foam (reproduced with permission from Ref. [ 58 ] from Elsevier) and ( d ) magnetic activated carbon (reproduced with permission from Ref.…”