LAUSR

Abstract The phosphorus-containing activated carbons have been obtained by activation of the low quality hay and the chars obtained by its pyrolysis with 50% phosphoric acid at 600 °C in a stream of nitrogen. Furthermore, the study was performed on two series of carbonaceous materials prepared from hay using different heating methods – microwave and conventional heating. These two groups of materials were compared, moreover the impact of microwave radiation on their physicochemical properties was checked. The samples obtained were characterized by ICP-OES, elemental analysisas well as determination of pH and the number of surface oxygen groups by the Boehm method. The porous structures of activated carbons were characterised by nitrogen adsorption using BET methods. Thermal properties of the samples were investigated by thermogravimetric (TG) analysis and differential thermogravimetry (DTG). The final products were activated carbons of well-developed surface area varying from 212 to 1300 m 2 /g, total pore volumes of 0.17–0.78 cm 3 /g. More favourable textural parameters have shown activated carbons obtained with the use microwave radiation, especially via one step activation. H 3 PO 4 activation of the low quality hay gave carbon materials containing 2–6% of phosphorus and surfaces showing acidic character. Results of the study suggest the feasibility of phosphoric acid activation of biomass, which leads to high quality activated carbons with high fractions of micropores. High content of phosphorusin the activated carbons studied offers the opportunities for the application of these materials for specific adsorption and catalytic processes used in environmental engineering.