Characterization of microalgae-bacteria consortium cultured in landfill leachate for carbon fixation and lipid production

•Microalgae-bacteria consortium was cultivated in the landfill leachate.•The TN was removed by 90% in medium with 10% leachate spike ratio.•Maximum lipid productivity and carbon fixation was 24.1 and 65.8mgL−1d−1.•Humic substances in the landfill leachate were decomposed. The characteristics of cultivating high-density microalgae-bacteria consortium with landfill leachate was tested in this study. Landfill leachate was collected from Laogang landfill operated for over 10years in Shanghai, China. The maximum biomass concentration of 1.58gL−1 and chlorophyll a level of 22mgL−1 were obtained in 10% leachate spike ratio. Meanwhile, up to 90% of the total nitrogen in landfill leachate was removed in culture with 10% leachate spike ratio with a total nitrogen concentration of 221.6mgL−1. The fluorescence peak of humic-like organic matters red shifted to longer wavelengths by the end of culture, indicating that microalgae-bacteria consortium was effective for treating landfill leachate contaminants. Furthermore, with the leachate spike ratio of 10%, the maximum lipid productivity and carbon fixation were 24.1 and 65.8mgL–1d–1, respectively. Results of this research provide valuable information for optimizing microalgae culture in landfill leachate.