Fast synthesis of high surface area bio-based porous carbons for organic pollutant removal

Abstract

A fast, facile and one-pot chemical activation method was used to develop porous carbons with high surface area and excellent phenolic micropollutant adsorption performance from renewable precursors. This method was applied to three precursors: naturally abundant, but often underestimated wildfire-damaged boreal peats, corn starch, and cellulose. Porous carbon formation was accomplished through precursor impregnation with ZnCl 2 powder and their simultaneous pyrolysis under inert N 2 flow at 400 or 600 °C for 1 h. The maximum adsorption capacities of these bio-sorbents towards a model contaminant, p -nitrophenol, in simulated wastewater were equal to or superior than using a commercial activated carbon (CAC), Norit GSX (> 530 mg/g) over wide initial concentration ranges (20–2000 mg/L). p -nitrophenol adsorption best fitted Freundlich and Redlich-Peterson isotherms, suggesting multilayer chemisorption. Low concentration p -nitrophenol (20 mg/L) adsorption into the bio-sorbents was rapid in the first 4 h, and could reach high removals (> 98%). The method presented here yielded bio-sorbents with similarly high adsorption performance regardless of the precursor type, while avoiding energy-intensive processing steps during sorbent production. This study gives a useful alternative for manufacturing new sorbents from other upcycled carbonaceous and/or bio-based materials to remove micropollutants and heavy metals. Fast, single-step chemical activation for manufacturing bio-based porous carbons. Efficient adsorption towards aqueous phenolic micropollutant from batch studies. A competitive substitute of charcoal activated carbons for water purification.

Carbon Adsorbents Obtained from Pistachio Nut Shells Used as Potential Ingredients of Drinking Water Filters

“…A highly developed specific surface area, appropriate porosity and a variety of surface groups of activated carbon make it a versatile and effective adsorbent of organic and inorganic compounds of various structure and molecule size. In addition to excellent adsorption properties, the production of activated carbon is relatively cheap, especially when bio-precursors, such as sawdust, nut shells, fruit stones or waste parts of plants, e.g., herbs, are used for its preparation [22][23][24][25].…”