Bachelor thesis is focused on monitoring the purity of the surface flow of the river Nitra. Selected basic quality parameters and heavy metals were monitored. The monitoring took place in three samples. Analysis of metals was realized with different methods. The results point to current above-limit values, especially Hg, Cu and Zn. The Bachelor thesis deals with natural adsorbents, bentonites and zeolites, their occurrence, features and their chance of use in Slovakia in the next part. In the experimental part, specific adsorbents were used with the aim of sorption of heavy metals. The results show acceptability or unacceptability of used adsorbent.