Recovery of landfill leachate as culture medium for two microalgae: Chlorella sp. and Scenedesmus sp.

Abstract

The microalgae culture medium should contain essential nutrients for their optimal growth. However, landfill leachate contains these nutrients; merely, the use of leachate in the cultivation of microalgae is not conceivable because of its high toxicity. This survey proposes to demonstrate the growth performance in terms of biomass production, chlorophyll contents and cell morphology of two microalgae, namely Chlorella sp. and Scenedesmus sp., in different concentrations of leachate (10%, 30%, 50%, 80% and 100% (v/v) crude leachate). Changes in chemical oxygen demand (COD), ammoniacal nitrogen (NH4+–N) and salinity content were also monitored. Results showed that when the two algae were mixed, the culture medium containing 10% (v/v) of leachate caused an optimal and selective growth of Chlorella and a total mortality for Scenedesmus cells. Also, this culture medium containing 10% (v/v) of leachate promoted the cell growth of Chlorella sp., of around 2 times in terms of cell density and 10 times in terms of chlorophyll content as compared to the result obtained for the standard culture medium “Bold’s Basal Medium (BBM).” Abatement rates of COD, NH4+–N and salinity of 60%, 100% and 10% were, respectively, achieved by pure cultures of Chlorella sp. Therefore, the strain of Chlorella sp. appeared resistant in this unfriendly environment as compared to the strain of Scenedesmus sp. As a perspective, the tested landfill leachate could be convenient for culturing Chlorella sp. for leachate purification and biofuel production.