Prospective Life Cycle Assessment Prospective (LCA) of Activated Carbon Production, Derived from Banana Peel Waste for Methylene Blue Removal

Activated carbon (AC) has recently gained increasing attention for removing various contaminants from water. AC obtained by agroindustrial waste is considered one of the essential adsorbent materials, which plays a vital role in processes of adsorption in water purification and wastewater treatment. Given the extensive use of this material, it is essential to understand its entire production chain and environmental impact. In this work, banana peel waste (BPF) was submitted at NaOH activation followed by pyrolysis at 600 °C to produce activated biochar (BFAC), aiming to remove methylene blue (MB) from wastewater. BFAC was characterized by TGA, XRD, SEM, BET, and FTIR techniques. The influence of dye concentration (10, 25, 50, 100, 250, and 500 mg L^− 1) and zero point charge (ZPC) were investigated. Besides, a Life Cycle Assessment (LCA) was carried out to assess the environmental impacts of the developed process. BFAC presented a well-developed pore structure with a predominance of mesopores and macropores, which directly influenced the MB removal capacity. The highest efficiency for dye removal was 62% after 10 min to an initial concentration of 50 mg.L^-1. The adsorption isotherms were well defined by Langmuir, Freundlich, and Temkin isotherm models. The Langmuir model represented the best fit of experimental data for BFAC with a maximum adsorption capacity of 49.5 mg g^− 1. Regarding LCA, a prospective approach at the early stage of development was conducted to orient the transition from laboratory to industrial scale, aiming at providing a competitive CO₂-based technological route. The scenarios proposed suggest that this route is promising either from the life cycle assessment or the circular economy perspective. Thus, BFAC can be considered an adsorbent with great practical application for post-treatment wastewater effluents to remove contaminants.

Graphical Abstract