Inactivation of harmful algal bloom by an environmentally friendly photocatalyst under photo-Fenton-like degradation process

In the present work, the photo-Fenton-like process based on the use of the Fe_2.5Co_0.3Zn_0.2O₄/CuCr-LDH composite was applied for the removal of green algal cells. First, the biological activity of the composite was proved with the antibacterial tests against the S. aureus; thereafter, it was used for the removal of Scenedesmus quadricauda algal cells under the photo-Fenton-like process. Interestingly, compared with the individual processes, the photo-Fenton-like process displayed a synergistic effect in the deactivation of green algal cells. The effect of various parameters such as the initial concentration of the algal cells, concentration of the hydrogen peroxide (HP), and the solution pH on the total algal. The maximuml was assessed. Maximum algal removal efficiency was obtained in the presence of the algal cell concentration of 3.5 × 10⁹ cells mL⁻¹, 0.1 g L⁻¹ composite, and HP concentration of 10 mM. Furthermore, the microscopic and SEM images of the algal cells before and after the photo-Fenton-like process proved their appropriate destruction. The reduction of the chlorophyll content after 60 and 120 min of the process was observed revealing the destruction of the algal cell walls. Finally, the disintegration of the macromolecules in the algal cell walls was proved by the GC-MS technique.