Study of Sorption Properties of Buckwheat Husk Biochar

Buckwheat grain processing produces a significant amount of buckwheat hulls, which are usually stored or incinerated, posing a threat to the environment, particularly to soil and air. The solution to this problem may lie in the production of biochar from buckwheat husks. Buckwheat husks have a favourable composition for biochar production. The resulting biochar can be used as an additive to compost to improve its characteristics, ensure a high-quality composting process and adsorb pollutants. Since the mechanisms of sorption of biochar produced from buckwheat husk are not yet well understood, the aim of this study is to investigate the sorption properties of biochar on the example of lead ion sorption. Comparison of the efficiency of lead ion sorption by different modified forms of raw materials shows that the method of biochar production significantly affects its sorption activity. An increase in the pyrolysis temperature has a positive effect on the sorption properties; the highest sorption is achieved at an initial concentration of lead ions of 1.00 mg/ml. The analysis of adsorption isotherms indicates a type L, which indicates minimal interaction between the adsorbed molecules. The kinetic parameters of the sorption process show that the system reaches equilibrium within a few hours, and the maximum sorption values are observed after 2.5-3 hours of incubation.