Treatment of dairy wastewater by microalgae Chlorella vulgaris for biofuels production

Abstract

In this study, two different initial concentrations of Chlorella vulgaris were injected into two types of dairy wastewater (referred to as wastewater and effluent, respectively) at a percentage of 25, 50, and 75% (v/v), and nutrient removal, microalgae growth and lipid accumulation were examined throughout cultivation (wastewater = before purification and effluent = after Purification). Different concentrations of injected algae, the type of applied wastewater, and different dilution ratios had an important effect on nutrient removal and microalgae growth. The highest amount of nutrients and algal cell number in the initial dose of algae (13 million cells/ml) and mediums of effluent and in wastewater related to dilutions (25, 50, and 75%) respectively. Concerning lipid accumulation in Chlorella vulgaris, the highest concentration was observed in effluent and wastewater at a dilution of 50% and 75%, respectively. In general, it can be concluded that wastewater is more suitable than effluent for lipid production. The aim of this study is production biofuels by biomass and low cost.