Utilizing of sunflower seed husk through production of biochar and its application in systems for purification of water contaminated with cadmium

Abstract

The pollution of water streams is one of the most spread environmental problem whole the world due to its permanently increasing from one part, and the importance of water for the human health from the other. An approach for decontamination of polluted waters based on the ideology of the circular economy is investigated in this study. The wasted sunflower seed husks obtained during the cooking oil production were subjected to gasification process in pilot plant installation. Three biochar samples were obtained and characterized regarding main properties like carbon content, moisture, ash, volatile compounds, and specific surface area at different experimental conditions. For all samples was possessed high carbon content of 69-75 wt. % and well developed surface area of 262-321 m2/g. The biochar materials were subjected to experimental procedure for evaluation of their potential for adsorption of cadmium (Cd) ions from water solution with different concentration of the pollutant. The obtained reduction coefficient for all biochar samples reached up to 99.97 % for the initial concentration of Cd-ions from 1.1 mg/l to 562 mg/l. For the higher Cd concentrations in the range of 1124-11240 mg/l, the reduction decreased to 11-24 %. The highest adsorption capacity of 289.99 mg/g is obtained for the biochar sample subjected to gasification for 2 minutes.