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The application of the agricultural waste of cashew nut shells (CNSs) from the Ivory Coast is proposed for the production of activated carbon (AC) used in water treatment by the physical activation. Washed and crushed CNSs are carbonized at 800°C. The crushed CNS carbonizate is activated by the physical method in a temperature range from 400 to 700°C. The specific surface (SBET) and porous structure of the AC samples are investigated by low-temperature nitrogen desorption and X-ray structural (X-ray phase) analysis. The results show that an increase in the activation temperature at a fixed time leads to an increase in the material specific surface, the development of a microporous structure, and an increase in the summary volume of mesopores and micropores of AC. The X-ray phase analysis data shows that the degree of graphitization, interplanar spacing, and crystallite sizes vary insignificantly. The possibility of using CNSs to fabricate AC no worse in sorption properties than its analogs currently in use to purify water is proven.

The specific surface and porous structure of viscose-based carbon fibers produced by the Krasnoyarsk Plant of Chemical Fibers are investigated by low-temperature nitrogen adsorption using an ASAP 2020 device. The dependence of their specific surface and character of the pore-size distribution on gas-phase activation modes in the carbon dioxide stream at a temperature of 900°C is shown. It is established that the adsorption surface of carbon fibers can rise from 0.3 to 1900 m2/g during the activation. It is revealed that the prolongation of the activation time leads to an increase in the specific fiber surface owing to the appearance of numerous new micropores and the development of the microporous structure.

A method for the preparation of carbon fiber for drainage under surgical treatment for glaucoma was developed. The carbon fiber was obtained from hydrated cellulose. In the process of the production of carbon fiber, viscose thread underwent thermal stabilization at 270°C, carbonization at 600°C, and graphitization at 1200, 1400, and 2400°C. After graphitization, the fiber underwent surface activation in a flow of atmospheric oxygen for 1 h at a temperature of 600°C or in a flow of carbon dioxide at 900°C, which caused an increase in the sorption capacity and specific surface area of the fiber by a factor of hundreds. The physicochemical properties of the carbon fiber were determined, and the electron-microscopic studies of the cross section of a fiber 7.9 μm in diameter were performed at magnifications of 10 000, 30 000, and 50 000.