Toxicity of water treated with Fenton-like ferrite catalyst

Recently, there has been a rapid growth in the use of nanoparticles in water treatment processes. However, an important task is to study the toxicity of the materials used and the reaction products formed. The purpose of this study was to evaluate the impact of the proposed water treatment method on the ecosystem. Algae are excellent model organisms for studying the toxic effects of catalyst nanoparticles. This work investigates the toxicity of cobalt ferrite (CoFe2O4) and hydrogen peroxide (H2O2) on the microalgae Chlorella vulgaris Beij. (C. vulgaris). The growth rate of C. vulgaris depends on the residual concentration of H2O2, indicating a stressful physiological state of the microalgae. Exposure to sintered cobalt ferrite granules does not affect the growth of freshwater algae. At a residual H2O2 concentration of 11.9 mM, algal cells' morphology, membrane integrity, and viability were severely impaired. Hydrogen peroxide is known to cause oxidative stress, as evidenced by a decrease in the growth rate of C. vulgaris and an increase in the number of dead cells. The study showed that the high residual concentration of H2O2 is the main obstacle to the discharge of treated water into the natural ecosystem.