One of the main characteristics of a petroleum disperse system (PDS) is the average particle diameter of the dispersed phase. The simplest and most affordable analytical method to determine this characteristic is photoelectrocolorimetry. It has been shown that the use of low-energy wave (constant magnetic field of 0.1-0.4 T, ultrasound of 50 kHz) treatment and hydrogen sulfide scavengers leads to a change in the degree of dispersion of the system along with the degree of removal of hydrogen sulfide, which is determined from the residual hydrogen sulfide content in fuel oil. The method makes it possible to study the interaction of PDS structural elements and provides information on the disperse composition of fuel oil, which can be used to determine the most favorable conditions for the removal of hydrogen sulfide from fuel oil.