Cell Reports Sustainability (Jan 2024)
Cascade engineering of bagasse into activated porous carbon for wide-pH-range aqueous mercury removal
Abstract
Summary: Low hierarchy and disruptive functionality of carbonaceous materials from biomass pyrolysis restrict their energy and environmental applications. Here, we report a cascade strategy to engineer bagasse into activated porous carbon with regulated morphology and functional groups. The initial pyrolysis of bagasse at 350°C –850°C facilitates curve sheet morphology and random meso-/micro-porosity. The subsequent alkali calcination leads to a micropore and comb-like structure with specific surface area and pore volume of 1,276.7 m2/g and 579.5 × 10−3 cm3/g, respectively. The last acid rinse removes the remaining –OH and –COO groups on the biochar surface. As a result, activated porous carbon processed at 450°C and activated with KOH/HCl exhibits the highest adsorption capacity of 103.4 mg/g at a rapid equilibrium rate fitted with Freundlich adsorption isotherm and facilitates steady mercury removal under pH 3–11. This study provides an effective approach to engineering agricultural waste into superior adsorbents for wastewater remediation. Science for society: Mercury contamination is a significant public health and environmental problem. Cost-effective and high-performance remediation methods have gained attention in both academic and industrial fields. Agricultural waste is an attractive resource as it provides rich carbon components with a modifiable structure to manufacture commercial adsorbents, namely, activated carbon. We present an approach that overcomes the existing issues in the complex structure and composition of activated carbon from waste heating. Highly orderly and regulated biochar fabricated from bagasse—sugarcane pulp—can be used for effective mercury adsorption under different conditions. This approach may facilitate the remediation of mercury-containing wastewater in a sustainable manner.
