Corn. bentonite was activated with HCI soln. to increase its sp. surface area by 228 percentage points (p.p.). Changes of diam., pore volume, as well as area and volume of micropores were also obsd. The impregnation of bentonite with nanometric ZrO2 resulted in deterioration of the adsorption capacity of bentonite. The bentonite adsorbents were used for removal of H2S from biogas under anaerobic conditions. The ZrO2 modified bentonite was less efficient than the HCl-activated one, where 99% removal H2S from N-2 stream was achieved.