The toxic effects of ammonium derivatives in the river water depend dramatically on their natural or synthetic origins and on their chemical structures. It has been proved that 1-naphtylamine (1-NA) and diphenylamine (DPA) breaking impact on the ammonium oxidation and especially on nitrite ions oxidation processes in natural waters is associated with its toxicity. The NH4+ oxidation process slows down for about five days and ten days in river water samples with 0.5 mg/L DPA and corresponding 0.5 mg/L 1-NA. The NO2− oxidation delay in model samples of river water with 0.025 and 0.05 mg/L 1-NA, is four days and 35 days in the one with 0.5 mg/L 1-NA. For the sample with 0.05 mg/L DPA the delay of the NO2− oxidation is approximately of six days and 25 days for sample with 0.5 mg/L, DPA. The laboratory simulations have revealed: (1) absorption–desorption, the micro biotic reaction to the instantaneous increase of the concentration of ammonium ion in the river water (so-called shock/stress effect) and (2) the NH4+ increase stimulated by a certain (0.05 mg/L) concentration of 1-NA.The diethylamine (DEA) decomposition leads to increasing with approximately 3.8 mg/L NH4+ in river water samples of 20.0 mg/L DEA.