Аннотация:The effect of the salt background on the behavior of iron, chromium, manganese, and zinc in model solutions and mixtures of river and sea water under laboratory experimental conditions has been studied. The possibility of coagulation and peptization of colloids of iron(III) and chromium(III) with increase of the salt background of solutions has been assessed. The role of the zinc and manganese sorption-desorption processes in the distribution of these elements between the suspended matter and the solution during mixing of river and sea water has been studied.