Development of nano CaO2-loaded lignin nanoparticles for simultaneous phosphorus, nitrogen, and COD elimination from water

ABSTRACT The excessive existence of N, P, and COD in surface water may well promote eutrophication. Therefore, the development of methodologies capable of removing the excess amount of these nutrients from water sources is of significant importance. This study introduces a novel hybrid adsorbent that integrates nano CaO2 with lignin nanoparticles, combining the oxidative properties of CaO2 with the abundant and cost-effective lignin to achieve efficient simultaneous N, P, and chemical oxygen demand (COD) removal. Hence, this study presents the development of a hybrid adsorbent composed of nano CaO2 and lignin nanoparticles for simultaneous N, P, and COD removal from water environments. The developed nanocomposite was capable of removing phosphorus over a broad pH range and the optimal performance was obtained at neutral pH. The nanocomposite showed fast elimination kinetics of around 64 min. The findings obtained from the treatment of a real sewage water sample showed that the CaO2@lignin could remove 94.62% (=6.09 mg/g), 96.35% (=35.13 mg/g), and 73.09% (=352.54 mg/g) of -P, -N, and COD, respectively. Current research reveals the multifunctional nature of the CaO2@lignin nanocomposite, which exhibits broad pH tolerance, high removal efficiencies, and rapid elimination kinetics without the need for external energy inputs or complex equipment.