The increasing need for water resources and other factors in reducing these resources, along with the health and environmental problems of wastewater, make it clear that our linear water economy must evolve into a resilient circular water economy, where water is continuously reused and “contaminants” become the feedstocks for other economically valuable processes. Biofilters as an important emerging technique, which utilizes biological living things as catalysts to harvest valuable components. Cyanobacteria and microalgae's ability to be mixotrophs provides a competitive advantage against bacteria and fungi to be used in biofilters. Due to the reduction of environmental nutrients, heavy metals, and pathogens, the oxygen production for aerobic organisms, and the consumption of carbon dioxide, microalgae play a prominent role in purification processes. In this research, by examining different types of algal species and immobilization methods, the appropriate species were chosen for biofilters production. The performance of the optimally produced biofilter to reduce the pollution indicators of the industrial effluent was investigated. The results show the appropriate performance of the biofilter produced with AFC008 and AFC110 species to perfect removal of nitrate and phosphate and 76% COD reduction and 79% reduction of BOD in less than a week (along with aeration pretreatment).
