The possibility of using phosphorus-containing wastewater as a raw material for the cultivation of the green algae strain Chlorella vulgaris ASLI-1 can represent an effective processing of phosphorus-containing by-products. A laboratory experiment was made to study the effect of the concentration of phosphorus-containing wastewater on the biomass density of the green alga strain Chlorella vulgaris ASLI-1. Three weeks after sowing, we measured the biomass density of algae in various components of the phosphorus-containing wastewater. Compared to the control (distilled water), the addition of phosphorus-containing wastes did not adversely affect the culture of green algae, with the exception of a 20% medium where algal cells were discolored and had a low biomass density, 104 CFU. However, more research is needed to better study the response of green algae to phosphorus-containing waste, to determine the amount of phosphorus in cells and solution. In addition, evaluate the agronomic efficiency of the Chlorella vulgaris ASLI-1 strain, cultivated on phosphorus-containing waste, when applying fertilizers for growing vegetables.