Novi adsorpcioni medijumi za separaciju neorganskih polutanata otpadnih voda bazirani na termohemijskoj konverziji biomase / New adsorption mediums for the separation of inorganic pollutants of wastewaters based on thermochemical conversion of biomass

Lignocellulosic materials, as a part of municipal organic waste, were used as precursors for the preparation of low-cost activated carbons. Locally available lignocellulosic waste biomass, after thermochemical conversion to alternative adsorbents, was used to reduce concentration levels of Pb2+, Cd2+ and Ni2+ in model solutions and real wastewater samples. Phosphoric and sulfuric acid were used for thermochemical activation. Characterization of the activated carbon was performed by elemental analysis, FTIR, SEM/EDS and BET instrumental methods. The influence of various parameters on the adsorption were examined in order to determine the best conditions for achieving maximum efficiency. For better insight into the process of ions adsorption on the surface of the adsorbents, four models of adsorption isotherms were applied to experimental data. Adsorption mechanism was determined by applying six kinetic models. The nature of the process was investigated by determining thermodynamic parameters. Using Langmuir's model, the best adsorption capacity was accomplished on CScPA for Pb2+ , Cd2+ and Ni2+ ions, 171,39 mg/g, 198,74 mg/g and 76,27 mg/g, respectively. Regeneration of the saturated adsorbent was conducted with diluted H3PO4. Additionally, preliminary results indicated a strong affinity of the activated carbons for selected organic micropollutants and radionuclides. The analysis of production costs for the obtained activated carbons in real samples treatment, confirmed a possibility for a successful implementation of the prepared adsorption mediums in the field of wastewater treatment.