Coupling Wastewater Treatment with Microalgae Biomass Production: Focusing on Biomass Generation and Treatment Efficiency

Abstract

Combination of suitable algae species with wastewater condition is important to achieve high productivity of algae with remarkable removal of contaminants. However, the usage of algae in treating wastewater has not yet to show sufficient removal efficiency when the biomass productivity is extremely enhanced. This review aims to scrutinize and discuss: (1) several promising species for this coupling method; (2) main wastewater characteristics related to the microalgae biomass production and their removal efficiency; (3) metal occurrences and other biotic factors; and (4) constraint of microalgae biomass production and wastewater treatment process. Microalgae such as Chlorella, Spirulina and Scenedesmus are among the most utilized microalgae because of their utilities. Chemical oxygen demand (COD) total nitrogen (TN), and total phosphorous (TP) concentrations affect biomass yield of algae cultivation. Metals occurrences, light intensity and carbon dioxide availability play an important role in process of algae cultivation with diverse optimum levels of each factor. Sufficient but not excess concentration of N and P solely for building biomass and other metabolism activities, mixotrophic condition for algae to digest organic carbon, and heavy metals defense mechanisms are expected to address constraint of biomass generation demand and wastewater treatment efficiency.