Phycoremediation Processes for Secondary Effluent from Sewage Treatment Plants Using Photosynthetic Microorganisms: A Review

Abstract

Taking into account the worrying scenario of water scarcity, it is essential to enable more efficient technologies for wastewater treatment. Wastewater may be treated by conventional biological processes that remove pathogenic organisms, particulate and soluble organic compounds, and other components. However, secondary effluents from treatment plants may still contain toxic elements or high concentrations of inorganic nutrients (mainly nitrogen and phosphorus), which enable the growth of photosynthetic microorganisms in water bodies, resulting in eutrophication. In this context, cultivation of photosynthetic microorganisms in secondary wastewater from sewage treatment allows the removal of nutrients from such wastewater, reducing the possibility of eutrophication. Moreover, microalgal biomass, produced in this tertiary wastewater treatment, may be harvested by different methods with the potential for different applications, such as fertilizer and biofuel.

Ozone, hydrogen peroxide, and peroxymonosulfate disinfection of MS2 coliphage in water

“…The secondary effluent contains a small amount of dissolved organic matter and some suspended solids that may influence disinfection efficacy. 35 These organic compounds consume oxidants, though the suspended solids may adsorb viruses such that oxidation is more difficult. However, the three oxidants still achieve the 4-log inactivation that is conventionally required for practical applications, indicating that the three oxidants have the potential for practical water disinfection applications.…”