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Using microalgae to treat wastewater has received growing attention in the world because it is regarded as a novel means for wastewater treatment. It is commonly recognized that large-scale cultivation and commercial application of microalgae are limited by the development of photobioreactor (PBR). Although there are a lot of PBRs for microalgae pure cultivation which used culture medium, specialized PBRs designed for wastewater treatment are rare. The composition of wastewater is quite complicated; this might cause a very different photosynthetic effect of microalgae compared to those grown in a pure cultivation medium. Therefore, PBRs for wastewater treatment need to be redesigned and improved based on the existing PBRs that are used for microalgae pure cultivation. In this review, different PBRs for microalgae cultivation and wastewater treatment are summarized. PBR configurations, PBR design parameters and types of wastewater are presented. In addition, the wastewater treatment efficiency and biomass productivity were also compared among each type of PBRs. Moreover, some other promising PBRs are introduced in this review, and a two-stage cultivation mode which combines both closed and open system is discussed as well. Ultimately, this article focuses on current problems and gives an outlook for this field, aiming at providing a primary reference for microalgae cultivation by using wastewater. [ABSTRACT FROM AUTHOR]

Wastewater contains high concentration of nutrients, like nitrogen and phosphorus, which have been identified as the main reasons for water eutrophication and serious ecological issues. Therefore, cultivating a tolerant and adaptive microalgae strain in wastewater is considered as a promising approach for sustainable biomass/lipid production. The potential usages of Desmodesmus sp. for biomass and lipid production within different artificial wastewater (AW) were investigated and the removal efficiencies of nutrient were compared. The maximum removal rate of chemical oxygen demand, ammonia nitrogen, nitrate nitrogen and phosphate were 272 mg/(L·d), 14.021 mg/(L·d), 7.774 mg/(L·d) and 3.347 mg/(L·d), respectively in AW2, AW3, AW5 and AW2. Maximum biomass (1.159 g/L) and lipid (280 mg/L) productions were observed in AW5, while the highest lipid content achieved was 37.42% in AW1. Fatty acid analysis showed that lipids extracted from AW-cultivated Desmodesmus sp. contained 59.57%-77.79% polyunsaturated fatty acids (30.6%-44.47% was linoleic acid). [ABSTRACT FROM AUTHOR]