Adsorption kinetics and isotherm studies for removal of copper phthalocyanine dye from aqueous medium using biodegradable adsorbent

The rising environmental concerns demand efficacious efforts to be executed for transforming waste substances into potent adsorptive materials for treating dye contaminated water. This study demonstrates the efficient removal of copper phthalocyanine organic dye, Remazol Turquoise Blue G-133 (RTB) using a biodegradable adsorbent synthesized from fallen Syzygium cumini leaves and granite obtained as waste of marble industry. The structural and morphological features of prepared adsorbent material– granite and Syzygium cumini leaf powder immobilized with sodium alginate to form beads (GR-SC@SAB), were investigated using SEM, FTIR, and XRD analyses. The adsorption parameters were optimized and probable adsorption route was studied using kinetic models. Batch experiments were modeled with 15 adsorption isotherms comprising of two, three and four parameter isotherms. It is evident from literature survey that the adsorption process for RTB onto biosorbent follows pseudo-second order and Langmuir monolayer adsorption. The thermodynamic studies indicate the exothermic nature and spontaneity of the adsorption process. The desorption studies demonstrated effective regeneration of GR-SC@SAB over multiple cycles, underscoring its reusability. The study validates GR-SC@SAB as a promising biosorbent due to its natural origin, cost effectiveness, biodegradability, and renewability.