This study investigates the development and characterization of activated biocarbons produced from elderberry, hawthorn, and rowan processing residues via direct activation with CO₂. The effect of activation temperature (700 and 800 °C) and heating mode (conventional and microwave-assisted) on the physicochemical and adsorption properties of the obtained materials was systematically evaluated. The activated biocarbons were characterized in terms of textural parameters, morphology, elemental composition, as well as surface acid–base and electrokinetic properties. Their adsorption capacity towards three nonionic organic pollutants - poly(vinylpyrrolidone), Triton X-100, and Disperse Yellow 211 - was assessed. The obtained materials were characterized by a predominantly basic surface character and a moderately developed specific surface area ranging from 82 to 485 m² g⁻¹ , with micropores constituting the dominant fraction of the porous structure. This type of pore structure did not favor the adsorption of macromolecular compounds, resulting in a relatively low adsorption capacity. The adsorption capacity under the applied experimental conditions reached 5.80 mg g⁻¹ for poly(vinylpyrrolidone), 16.08 mg g⁻¹ for Triton X-100, and 12.04 mg g⁻¹ for Disperse Yellow 211, with the highest values obtained for the biocarbons activated at 800 °C using microwave-assisted heating. The stability of aqueous suspensions of the obtained materials and the influence of the nonionic polymer on these systems were also investigated. Depending on the type of activated biocarbon, either stabilization or destabilization of the suspension was observed.
Drying and curing are critical postharvest processes that determine the safety, stability, and chemical quality of Cannabis sativa L. inflorescences. In commercial cannabis production, these processes are often based on empirical practices rather than quantitatively optimized engineering principles. Improper control of drying conditions can result in excessive terpene loss, undesirable cannabinoid transformations, and increased microbial contamination, particularly from yeasts and molds. This review examines current knowledge on cannabis drying, curing, and storage with emphasis on the relationships among moisture content, water activity, microbial safety, and chemical quality. Literature describing postharvest cannabis processing is synthesized alongside broader drying and food engineering research to evaluate how temperature, relative humidity, airflow, and drying duration influence moisture removal, terpene retention, cannabinoid stability, and microbial proliferation. Water activity emerges as a critical parameter governing both product stability and microbial growth, highlighting the importance of controlled drying and curing environments. The review also discusses how curing and storage conditions influence chemical and microbiological stability after drying. Current research gaps are identified, particularly the limited availability of quantitative models describing moisture transport and drying kinetics in cannabis inflorescences. The integration of engineering-based process control, environmental monitoring, and predictive modeling may improve the consistency and safety of cannabis postharvest processing. Improved understanding of these relationships will support the development of optimized drying and curing protocols that balance microbial safety with preservation of chemical quality in cannabis products.
