Process development of guava leaves with alkali in removal of zinc ions from synthetic wastewater

•Guava leaves transformed into porous carbon via eco-friendly KOH activation.•Thorough material characterization (SEM, FTIR, XRD, BET) enhances understanding.•Material displays high Zn(II) ion adsorption (14.49 mg/g), promising real-world use.•Study dives into detailed kinetic and isotherm analyses, unraveling adsorption mechanisms. This research investigation delves into the efficient removal of zinc ions from synthetic wastewater through the utilization of KOH treated guava leaves as an adsorbent. The study employs advanced analytical techniques including SEM, FTIR, XRD, and BET analysis to characterize the physicochemical properties of the treated guava leaves. The research extensively explores the impact of various experimental factors on the adsorption process, encompassing agitation time, adsorbent dosage, pH levels, and desorption, to identify optimal conditions for maximum Zn (II) ion removal. The research methodology involves subjecting guava leaves treated with KOH to thorough analysis using SEM, FTIR, XRD, and BET techniques to gain insights into their physical and chemical attributes. The study systematically investigates the adsorption process by manipulating crucial parameters such as agitation time, adsorbent dosage, and pH levels. Different isotherm models including Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich are applied to comprehend the adsorption mechanism. Additionally, kinetic calculations are performed, leading to the determination that the pseudo-second-order model best fits the removal of zinc metal. The research uncovers essential findings regarding the efficacy of KOH treated guava leaves as an adsorbent for zinc ions. Optimum conditions are pH 3 are identified, an adsorbent dosage of 100 mg/L, and an equilibrium period of 20 min, resulting in peak efficiency of the adsorption process. The study reveals an adsorption capacity of 14.5 mg/g for the studied metal, emphasizing the potential of KOH treated guava leaves as an efficient adsorbent for zinc ions. The adsorption capacity is 5.1 mg/g for the untreated guava leaves. The findings underscore the feasibility of utilizing this eco-friendly approach for wastewater management, thereby contributing to environmental remediation and pollution control efforts. The research highlights the practical application of KOH treated guava leaves in wastewater treatment processes, advocating for further exploration and optimization of this sustainable solution to address heavy metal c