The work demonstrates suppression of the inhibiting effect of the process of carbon dioxide absorption by chlorophyll-synthesizing microalgae Chlorella due to Sulphur oxide SO2, activators of phosphorus oxide P2O5 and nitrogen oxides NxOy The research presents experimental dependences of the dynamics of СО2 absorption by microalgae under the critical concentration of inhibitor SO2 in the presence of activators P2O5 and NxOy. The authors have composed mathematic models of growth of the population of microalgae Chlorella depending on concentration of the activators of phosphorus oxide and nitrogen oxides under permanent concentration of the Sulphur oxide inhibitor. The research determines an optimal value of total concentration of P2O5 activator in the presence of SO2 inhibitor, as well as an optimal value of total concentration of NO2 activator in the presence of SO2 inhibitor.