Green approach for Ni (II) ion sequestration from aqueous solution using <i>Phyllanthus emblica seed</i> coat

Nickel (Ni), a transition element, is widely distributed in the environmental segments through natural sources and anthropogenic activities. Nickel’s chronic exposure to human beings may cause allergies, cardiovascular issues, gastrointestinal distress, kidney issues, scarring of the lungs/cancer, inflammation, etc. Nickel compounds can be readily dissolved in water to form hydrated nickel (II) ions in an aqueous medium. The present study investigated the performance of an environmentally friendly adsorbent for sequestering Ni(II) ions from aqueous solution under various conditions. The Phyllanthus emblica(Amla) (PE) seed coat was used to remove Ni(II) ions from aqueous solution for the first time. The adsorption capacity of PE has been studied under various conditions, including concentration, pH, dose effect, and equilibrium time, to explore the optimal options for removal. Langmuir, Freundlich and Temkin isotherms were fitted to data. Freundlich fitted better (R² = 0.9911), indicating that the adsorption process is more likely heterogeneous and involves multilayer adsorption. Maximum nickel removal was observed at pH 7 and an adsorbent dose of up 0.1g/L.The Langmuir isotherm plot indicated a maximum adsorption capacity (qmax) of 15.32 mg/g. Theregeneration studies confirmed that the material can be reused with a small change in its adsorption efficiency after regeneration, making the processes more economical and reducing the amount of waste material.The outcomes of this research maycontribute to sustainable, cost-effective solutions for Ni(II)- contaminated water treatment.