COD Removal of Pine Cone‐Contaminated Water by Fenton and Fenton‐Type Processes Using Different Oxidants

Abstract The accumulation of pine tree components, which contain organic compounds like tannins, cellulose, and lignin, in water bodies can lead to an increase in chemical oxygen demand (COD). This study investigates the COD removal from pine cone‐contaminated water (PCW) using Fenton oxidation with various oxidants, including sodium persulfate (SPS), sodium perborate (SPB), and hydrogen peroxide (HP). The results show that the Fe 2+ /SPB and Fe 2+ /HP systems achieved COD removal efficiency (COD eff ) of 60.0 and 51.6%, respectively, after 300 min at pH 3. In contrast, the Fe 2+ /SPS system exhibited COD eff of 41.5 and 57.8% at pH 3 and 5.4 (pH of PCW), respectively. The oxidant efficiency followed the order: SPB >HP >SPS at pH 3, suggesting that SPB can be considered as a substitute for HP in Fenton oxidation. Remarkably, complete COD removal was achieved in 120 min with UV 254 light. Anion inhibition studies revealed that Br − completely inhibited COD eff , while , Cl − showed lesser inhibition. The inhibition of , and F − was pH‐dependent and influenced by the oxidant used. Kinetic analysis indicated that the Fe 2+ /HP system followed first‐order kinetics, whereas the Fe 2+ /SPS and Fe 2+ /SPB systems followed second‐order kinetics. Notably, the Fe 2+ /SPS system at pH 5.4 followed the Behnajady–Modirshahla–Ghanbery kinetic model.