Complex experimental studies on the effect of electron irradiation on the deposition rate of activated sludge in water systems by optical method were carried out. To determine the parameters of activated sludge (biomaterial), an experimental setup was created. Silt in an amount of 1 g, placed in a flask of water with a volume of 25 ml, was carefully shaken and installed between the laser and the detector. The dependence of light intensity (green and red laser lines) on time was removed. The obtained dependences of the density (r) on time (t) have the same nature for different radiation sources. The experimental curves of the dependence of the activated sludge density on time are satisfactorily described by the exponential model.