Exploring efficient photocatalytic degradation of humic acid from aqueous solution with plant-based ZnFe₂O₄@TiO₂ magnetic nanocomposite using Elaeagnus angustifolia tree bark methanolic extract

In the process of sanitizing drinking water, humic acid present in drinking water sources reacts with chlorine disinfectant and forms mutagenic defective, and carcinogenic disinfection byproducts such as trihalomethanes and haloacetic acids. In the present study, the methanolic extract of Elaeagnus angustifolia tree bark was used for the synthesis of ZnFe₂O₄@TiO₂ nanocomposite and then properties and structural elements and diagnostic features of nanoparticles were analyzed. According to the results, the ZnFe₂O₄@TiO₂ nanocomposites have an average crystalline size of ∼65-250 nm. Also, the effects of pH (3-11), nanoparticle dose (0.005-0.1 g/L), and humic acid concentration (2-15 mg/L) were examined up to 120 min of time. From the results, the highest removal percentages achieved about 100% at optimal conditions (pH = 3, nanocomposite dose= 0.05 g/L and humic acid initial concentration = 2 mg/L). The results of this research showed that the efficiency of nanocomposite at the highest concentration of humic acid that was investigated in this research (15 mg/L) was about 95.67%. Therefore, it can be concluded that this nanocomposite, while being cost-effective and environmentally friendly, is also very effective in removing humic acid from an aqueous solution.