Sustainable porous carbon derived from shrimp shell waste for multifunctional removal of organic dyes and heavy metals.

To address the growing need for sustainable wastewater treatment, porous carbon (PC) was successfully derived from shrimp shell waste (Penaeus monodon) via a sequence of acid pretreatment, hydrothermal activation, and controlled carbonization. The impact of carbonization temperature on the structural evolution and adsorptive efficacy was systematically evaluated. Thermal treatment at 1000 °C optimized the material architecture, yielding a high BET surface area of 662 m2 g-1 and a significantly stable zeta potential of -51.84 mV. This optimized PC exhibited superior adsorption toward methylene blue (MB), achieving a maximum capacity of 54.54 mg g-1 with over 90% removal efficiency under optimized pH and dynamic conditions. Furthermore, the PC demonstrated versatile performance in removing hexavalent chromium [Cr(vi)] and permanganate [Mn(vii)] at their respective optimal pH values, driven by a combination of electrostatic interaction, physical adsorption and pH-dependent redox reactions. These findings underscore the potential of shrimp-shell-derived carbon as a high-performance, eco-friendly and multifunctional platform for the remediation of both organic and inorganic pollutants in aqueous systems through complementary, pH-selective pathways.