Kinetics of landfill leachate remediation and microalgae metabolism as well as energy potential evaluation

Understanding kinetics of microalgae growth in landfill leachate are essential to operate landfill leachate remediation with microalgae in the most efficient manner possible. In the study, kinetics of microalgae Chlorella vulgaris growth, nutrients uptake and metabolism in response to major influencing factors were investigated. Energy potential of microalgae in landfill leachate was assessed to provide guide for large-scale application. Results showed that the highest maximum specific growth rate of 2.31 d−1 was obtained under low light intensity of 60 μmol/m2/s (dilution rate = 10%, CO2 concentration = 5%), while the highest maximum biomass concentration of 1.64 g/L was obtained under light intensity of 160 μmol/m2/s (dilution rate = 10%, CO2 concentration = 7%). The specific uptake kinetics of nutrients by microalgae presented obvious difference between various species and obvious luxury uptake of NO3− was observed. Metabolism flow of intracellular compositions under various operating conditions were quantitatively depicted. Energy yield analysis indicated that the highest volumetric energy yield (37.13 kJ/L) was comparative to the volumetric heat value of natural gas (35.59 kJ/L). [Display omitted] •Time- and space-evolving profiles of landfill leachate properties was studied.•Kinetics of microalgae growth, metabolism and nutrients uptake were investigated.•The optimum conditions for directional adjustment of products were obtained.•Energy yield of microalgae in leachate was similar with heat value of natural gas.