Removal of Nitrogen and Phosphorus from Saravan Landfill Leachate by Chlorella Vulgaris Microalgae

The aim of this study was to evaluate the removal of phosphate, nitrate and ammonium from Saravan landfill leachate by chlorella vulgaris. The effect of leachate on growth characteristics of chlorella vulgaris, including dry cell weight, chlorophyll and carotenoids content was also investigated. The experiment was performed as repeated measures in a completely randomized design with three replications. Leachate levels were considered as main plot (zero leachate (L0), diluted leachates of 1:1 (L11) and 2:1 (L21)) and sampling time (0, 2, 4, 6, and 8 days) as sub-plot. Total chlorophyll in L0 treatment was the maximum and in L11 treatment was significantly more than the one in L21 treatment (p < 0.05). Microalgae dry cell weight and nutrient removal increased over time, so that the highest amount of dry cell weight and the lowest amount of nutrients in leachate (L11) was observed at 8th day after incubation. The percentage removal of phosphate, nitrate and ammonium at the end of 8th day of incubation was 92.76, 56.94 and 98.70, respectively. The kinetic equation of biomass production was also determined in relation to phosphate, nitrate and ammonium removal. The results showed that the nutrient removal followed the first-order model, and Monod's equation was able to well describe the growth of microalgae under restricted substrate conditions. The R2 values of Lineweaver–Burk for phosphate and ammonia were 0.97 and 0.99, respectively. Therefore, this equation can be used to remove phosphate and ammonium. Finally, it seems that chlorella vulgaris can be used for bioremediation of Saravan leachate.