Utilizing surface modified poultry feathers for senary multi-metal water purification: kinetic and thermodynamic behavior of heavy metal-laden biosorbent

This study optimized poultry feathers (PFs) in two steps to remove six trace metals (Cr⁶⁺, As³⁺, V⁵⁺, Co²⁺, Ni²⁺, Cd²⁺) from contaminated water and evaluated the spent biosorbent's thermal and energy potential. PFs were surface-modified with tetrahydrofuran (THF) and optimized <i>via</i> response surface methodology. Optimal pre-treatment (30 °C, 47 min, 0.015 g ml^-1) and biosorption (0.17 g, 0.5 h) conditions improved removal of Co²⁺ (+31.5%), Ni²⁺ (+19.5%), Cd²⁺ (+0.6%), and V⁵⁺ (+6.1%), but reduced Cr⁶⁺ (-24.1%) and As³⁺ (-1.8%). Thermogravimetric analysis showed higher activation energies for spent biosorbent, with diffusion-controlled degradation confirmed by Coats-Redfern analysis. This dual optimization enhances metal removal and supports scalable bioenergy recovery.