Potential cultivation of halophilic oleaginous microalgae on industrial wastewater

Abstract

M ICROALGAE cultivation offers an effective solution for wastewater treatment, as they provide a tertiary bio-treatment coupled with the production of valuable biomass, which can be further used for different purposes. Using wastewater for microalgal cultivation is beneficial for minimizing the use of water, reducing the cost of nutrient addition and removing nitrogen and phosphorus from wastewater.Lipids obtained from marine Nannochloropsis oculata and Tetraselmis chuii microalgae have received growing attention for the production of biofuels. In the present study, the effluent of El-Malyaa Company (EMC) and Salt and Soda Company (ESC) were used as growth media for the two tested oleaginous marine microalgae. Wastewater was used in different ratios with sterilized seawater, or mixed with synthetic medium (F/2). The growth was evaluated by optical density and dry weight, total lipids content and productivity were also determined.The results showed that the tested species were capable of growing on the effluent wastewater of the two companies. In addition, dilution of the industrial wastewater with seawater or its mixing with synthetic culture medium (F/2) increased growth of the two tested marine microalgae. The maximum growth was recorded using a ratio of 25:75 of F/2 medium: the effluent of both companies. However, the highest lipid content and lipid productivity were recorded using a ratio of 75:25 of F/2 medium: the effluent of both companies. Therefore, this study suggests that it is possible to utilize a mixture of industrial wastewater and synthetic medium for potential biomass and lipid production from microalgae for biofuel production.