Controlled electrochemical design of activated carbon surface chemistry: Enhanced copper recovery using functionalized walnut shell-derived sorbents - Dinara Abduakhytova; Saken Abdimomyn; Azhar Atchabarova; Mojtaba Mirzaeian; Rustam Tokpayev; Askar Mukanov; Graziella Liana Turdean; Fyodor Malchik; Mikhail Nauryzbayev (Journal of Water Process Engineering, 2025)