ABSTRACT
The heterogeneous Fenton process can generate a large number of compounds that can be toxic to the environment, and more toxic by-products than the parent compounds can appear after the treatment process. The heterogeneous Fenton process is used to decompose contaminants by rapid oxidation in the presence of a catalyst. Iron oxides, commonly used as catalysts, are considered to be non-toxic, but there are reports of toxicity towards certain organisms. Therefore, studies on the stability of the catalysts used in the process and their potential threats to living organisms are necessary. It is essential to constantly work on the stability of the catalyst. The toxicity of the by-products is also crucial. According to the reports, the decrease in viability of organisms is organism-specific and dose-dependent, and the lethal effect is strictly related to the size of particles. Incomplete mineralization can also result in hazardous, potentially toxic compounds in the effluent. Thus, the toxicity of effluent also needs to be studied, and biodegradability needs to be increased to reduce the toxicity of the process.
