The catalytic activity of different samples of catalysts known in the specialized literature, but also obtained by us, in the laboratory, in an autoclave at different temperatures and pressures, was studied. The kinetics of the decomposition process of hydrogen peroxide in the presence of the catalysts under study was studied at the installation set up in the laboratory. The hydrogen peroxide used was diluted 50 times and was 0.5412 N. 5 ml H2O2 (1:50) and 5 ml H2SO4 (1:4) were taken and titrated with 0.1 N KMnO4. Manganese ions, which are formed in the first titrant portions, catalyze the redox process and further discoloration of the solution occurs very quickly. The results of the study indicate that the Centaur catalyst, obtained in the USA at 300 revolutions per minute of the mixer, has the greatest activity in order to decompose hydrogen peroxide. AC-Co1 and AC-Cu1 catalyst samples were found to decompose hydrogen peroxide better than AC-Mn2 catalyst sample, all these kinetic curves being measured at 200 rpm of the mixer. If we compare the kinetics of the hydrogen peroxide decomposition process on the AC-Mn1+KMnO4 samples with AC-Mn1+KMnO4, held for 2 hours in the oven at 95 ◦C, with demineralized water added, we find a significant decrease in the catalytic activity of the sample kept for 2 hours in the oven, at 95 C, with demineralized water added. Probably, when heating the manganese, in the form in which it is, simply a part of it is washed away. The other 2 samples have a rather low catalytic activity, especially on AC-Mn2+KMnO4. With the increase in the speed of the mixer, the granulometric composition of the Sorbent AC catalyst undergoes transformations (it breaks down) and the catalytic activity decreases significantly. The best catalyst obtained by us AC-Mn1+KMnO4 does not remove ammonium ions (ammonia) from deep waters. We are going to test another pollutant from these water categories.