Main content area

Reverse osmosis concentrate conditioning for microalgae cultivation and a generalized workflow

Zhang, Di, Fung, Ka Y., Ng, Ka M.
Biomass and bioenergy 2017 v.96 pp. 59-68
Chlorella, dyeing, guidelines, microalgae, nutrient content, nutrient utilization, pH, reverse osmosis, salinity, toxicity, wastewater, wastewater treatment
Previous studies have demonstrated the feasibility of using wastewater as the nutrient source for microalgae cultivation. However, there is still a lack of guidance in wastewater conditioning to achieve optimum microalgae growth rate and complete N and P consumption in wastewater. In this study, a reverse osmosis concentrate (ROC) from the wastewater treatment unit of a dyeing company had been evaluated and conditioned for the phototrophic cultivation of Chlorella sp., with its toxicity, nutrient profile, salinity, pH and N/P ratio adjusted where necessary. After the wastewater was conditioned, Chlorella sp., which could not grow in the original ROC, achieved a growth rate comparable to that in an artificial medium. The percentages of N and P consumption were also balanced so that the nutrient utilization efficiency could be maximized. A generalized workflow and guidelines to develop wastewater conditioning plans for microalgae cultivation have also been proposed to guide the conditioning of wastewater streams for microalgae cultivation.