The intrinsic characteristics of microalgae biofilm and their potential applications in pollutants removal — A review

Considering the water shortage, one of the reliable sources of water available is wastewater. Traditional methods of pollutants from wastewater treatment do not always meet the goals of resource sustainability. Using microalgae to treat pollutants from different wastewater is feasible, and microalgae biofilm technology is expected to alleviate the above shortcomings. This review mainly focuses on the algal biofilm structure and discusses the effects of light, substrate, temperature, and other possible factors on biofilms formation. Biomass dispersed in liquid media can be easily harvested by scraping microalgal biofilm systems that recover microalgae. Algae-bacteria biofilms can actually provide self-sustaining oxygen supply while removing organic matter, heavy metals, and antibiotics, thereby greatly reducing the cost of microalgae cultivation. The symbiosis of microalgae and bacteria is conducive to the formation of algal biofilms, which has greater environmental and economic benefits than monocultures. Therefore, microalgae biofilm can offer a significant theoretical reference for resource utilization from wastewater biofilm treatment.