The biological treatment of textile wastewater by means of activated sludge was analysed from the view-point of bioprocess engineering. The inhibitory action of single constituents of the synthetic textile wastewater such as anthraquinone dyestuff and two different kinds of surfactants, was determined in terms of effective concentration EC50. Kinetics of microbiological destruction of pollutants was described by Monod＇s equation. The kinetic paramenter of the equation: maximum specific rate of microbial growth, affininty constant and yield coefficient were identified from the experimental data obtained in the laboratory scale. The anthraquinone dyestuff did not undergo biodegradation within the experiments, therefore its sorption properties on the flocs of activated sludge were determined in terms of Freundlich isotherm.