Plasma-assisted MnO surface engineered activated carbon felt for enhanced heavy metal adsorption

This study explores the enhanced adsorption performance of activated carbon felt (ACF) for Cu(II) and Cd(II) ions, achieved using a dual-synergistic approach combining MnO coating and plasma treatment. ACF's intrinsic properties, including a high surface area (~ 1000–2000 m²/g), large porosity, and excellent mechanical stability, make it a promising material for environmental applications. However, its limited surface functional groups hinder its adsorption efficiency for heavy metals. Conventional acid treatments, though effective in introducing functional groups, compromise ACF's structural integrity and pose environmental hazards. The non-thermal plasma method addresses these challenges by introducing oxygen-rich functional groups and MnO species without using harmful chemicals, preserving the material's mechanical and morphological properties. This study addresses key challenges in adsorption technologies, such as inefficiencies in multi-contaminant systems and adsorbent degradation through plasma-aided modifications. The synergistic modification enhances adsorption performance by leveraging mechanisms such as ion exchange, complexation, and co-precipitation. Adsorption experiments revealed maximum adsorption capacities of 163.39 mg/g for Cu(II) and 214.59 mg/g for Cd(II), with an extended equilibrium time of 720 min at pH 5. This research highlights the significance of plasma-aided modification strategies for developing sustainable and efficient heavy metal adsorbents, contributing to advancements in wastewater treatment technologies.