Reutilization of waste biomass from sugarcane bagasse and orange peel to obtain carbon foams: Applications in the metal ions removal

• Published in: The Science of the total environment 2022-07, Vol.831, p.154883-154883, Article 154883
• Main Authors: Licona-Aguilar, Á.I., Torres-Huerta, A.M., Domínguez-Crespo, M.A., Palma-Ramírez, D., Conde-Barajas, E., Negrete-Rodríguez, M.X.L., Rodríguez-Salazar, A.E., García-Zaleta, D.S.
• Format: Article
• Language: English
• Subjects: Activated carbon; Adsorption; Biomass; Carbon foam; Cellulose; Citrus sinensis; Copper; Hydrogen-Ion Concentration; Industrial Waste; Ions; Kinetics; Lead; Metals adsorption; Metals, Heavy - analysis; Saccharum; Wastewater treatment; Water - chemistry; Water Pollutants, Chemical - analysis
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.154883

The high levels of heavy metals contained in residual water and the pollution generated by a large amount of unexploited agro-industrial waste are a serious problem for the environment and mankind. Therefore, in the present work, with the aim of treating and reducing the pollution caused by heavy metal ions (Pb, Cd, Zn and Cu), activated carbons (ACs) were synthesized from sugarcane bagasse (SCB) and orange peel (OP) by means of physical - chemical activation method in an acid medium (H3PO4, 85 wt%) followed by an activation at high temperature (500 and 700 °C). Thereafter, these materials were used to produce carbon foams (CF) by the replica method and to evaluate their adsorbent capacity for the removal of heavy metals from synthetic water. XRD, FTIR, DLS, BET, Zeta Potential (ζ), SEM-EDS and AAS were used to investigate their structures, surface area, pore size, morphology, and adsorption capacity. The results show that as-prepared CF have a second level mesoporous structure and AC present a micro-mesoporous structure with a pore diameter between 3 and 4 nm. The experimental adsorption capacities of heavy metals showed that the CF from OP present a better elimination of heavy metals compared to the AC; exhibiting a removal capacity of 95.2 ± 3.96% (Pb) and 94.7 ± 4.88% (Cu) at pH = 5. The adsorption values showed that the optimal parameters to reach a high metal removal are pH values above 5. In the best of cases, the minimum remaining concentration of lead and copper were 2.4 and 2.6 mg L−1, respectively. The experimental data for carbon adsorbents are in accordance with the Langmuir and BET isotherms, with R2 = 0.99 and the maximum homogenous biosorption capacity for lead and copper was Qmax = 968.72 and 754.14 mg g−1, respectively. This study showed that agro-industrial wastes can be effectively retrieved to produce adsorbents materials for wastewater treatment applications. [Display omitted] •Reutilization of agroindustrial wastes: orange peel (OP) and sugarcane bagasse (SCB)•Activated Carbons and Carbon foams synthesized for waste water treatment•Determination of interaction pathway among adsorbent materials and contaminants•A higher efficiency to heavy metals removal was obtained in OP in comparison with SCB.•CF from OP can eliminate up to 99% (Pb) and 97% (Cu).