Microporous adsorbent from winemaking waste for the recovery of Mn(VII) in liquid solutions

Abstract

Microporous activated carbon (MAC) was synthesized from winemaking waste and was used to adsorb Mn(VII) from aqueous solutions under various experimental conditions. Moreover, Mn(VII) adsorption on MAC was compared to other adsorbents and an ion-exchange resin, as well as those of other anionic complexes. Langmuir type-1 isotherm best fitted the adsorption process, whereas for all the studied temperatures (30 C-60 C), the experimental data fitted well with the pseudo-second-order kinetic model. The calculated activation energy was 8.1 kJ Á mol −1 , suggesting that Mn(VII) adsorption onto the MAC was a physical adsorption driven process. A reduction of Mn(VII) to Mn(II) occurs at a pH of 1 with the precipitation of MnO 2. Mn(VII) recovery from loaded-activated carbon using acidic conditions and different variables was investigated.

Ways of Application of the Circular Bioeconomy in the Wine Industry

“…There is also the possibility of producing activated carbon or biochar. Microporous activated carbon obtained from winery waste had a higher capacity to adsorb Mn(VII) than other commercial adsorbents [51] and could be used to successfully remove Pb 2+ from polluted water [52]. Biochar is less expensive to obtain than activated carbon and has a comparable adsorption capacity [43].…”

New Bioadsorbent Derived from Winemaking Waste Cluster Stalks: Application to the Removal of Toxic Cr(VI) from Liquid Effluents

“…Thus, these results indicate that the thickness of the aqueous boundary layer at 1000 min −1 was lowest and leads to a higher adsorption percentage. The decrease in the adsorption of Cr(VI) at higher stirring speeds could be due to the formation of local equilibria, which hinders the adsorption process [31,32]. According to these results, a stirring speed of 1000 min −1 was used in the subsequent experiments.…”

Fabrication of magnetic Fe3O4/MnO2/TiO2/polypyrrole heterostructure for efficient adsorption of Mn7+ from aqueous solution

“…22 Although there are many treatments for metal ions, few literatures for Mn(VII) are available. [23][24][25] Investigations and studies have shown that the separation of adsorbents accounts for 75% of the overall operating costs. Due to the strong magnetic properties of Fe 3 O 4 , it can be quickly separated from the solution.…”

“…This method has high efficiency, low cost as well as large adsorption capacity 22 . Although there are many treatments for metal ions, few literatures for Mn(VII) are available 23–25 …”