Acetaminophen Sorption Using Invasive Lantana camara Biochar toward Achieving Sustainable Development Goals

Lantana camara L., or simply Lantana, a widespread weed, was chosen to develop an eco-friendly biochar. Lantana contains toxic compounds such as triterpenoids and alkaloids, which can cause skin irritation and allergic reactions. Ingesting Lantana leaves can lead to severe symptoms, including nausea and liver damage. Lantana pollen can exacerbate respiratory conditions like asthma. Effective management strategies are essential to mitigate these health risks. Pharmaceutical pollution is an emerging crisis in wastewater and even groundwater. This is exacerbated by the huge global consumption of pharmaceuticals. Converting Lantana into biochar offers a solution that was tested for removing acetaminophen (ACM) as a model pharmaceutical compound, addressing both environmental and health concerns. Lantana is globally ranked among the top 10 worst invasive species. In India, ∼132,000 km² of pasture lands and ∼303,607 km² of forest lands are colonized by Lantana, making it a reliable biochar feedstock. Lantana biochar (LB700) was produced through slow pyrolysis of dried Lantana at 700 °C (ramp rate = 7 °C/min) and subsequently employed for aqueous ACM sorption. LB700 was characterized by its Brunauer–Emmett–Teller (BET) surface area, morphology, functional groups, crystallinity, and elemental composition. Batch ACM sorption was performed to find the influence of pH, initial ACM concentration, LB700 dose, and temperature. Equilibrium sorption data were interpreted using Freundlich, Langmuir, Temkin, Toth, Redlich–Peterson, and Sips isotherm models, while kinetic data were analyzed using pseudo-first- and second-order rate equations. Maximum ACM adsorption (4.5 mg/g) occurred at pH 2 with 1.0 g/L of LB700 dose. ACM sorption drastically reduced after pH 8 due to electrostatic repulsion between deprotonated ACM and negatively charged LB700. Pseudo-second-order equation best-fitted with kinetic data (R² = 0.91–0.97). A maximum Langmuir adsorption capacity of 13.2 mg/g was obtained at 40 °C. The spontaneity and endothermicity of the reaction were inferred from negative ΔG° (−19.73 to −24 kJ/mol) and positive ΔH° (20.82 kJ/mol) values, respectively. The π–π stacking, H-bonding, van der Waals interactions, and pore diffusions are the dominant interactions. This study ingeniously addresses two pressing issues, Lantana invasion and pharmaceutical wastewater management, by providing an alternative solution through large-scale conversion of Lantana into biochar for treating pharmaceutical wastewater. Moreover, by converting Lantana into biochar, it effectively mitigates the health effects associated with this invasive plant, ensuring the preservation of environmental health and safety. Furthermore, it emphasizes the paramount importance for pharmaceutical industries to proactively treat their effluents, thereby safeguarding both environmental health and safety. Thus, this work strongly aligns with the United Nations Sustainable Development Goals including Clean Water and Sanitation (Goal 6) and Good Health and Well-Being (Goal 3).