Thermo-oxidative Reactivation of Active Coal Used in Streptomycin Production

The spent active coal of streptomycin production contains on its surface the remains of inorganic acids, organic-originated alcohols and waste products, spores, mycelium of Streptomyces griseus, which after entering the environment with wastewater cause a significant harm to it. The recycling of that coal and its reuse betters the economics of production and prevents harmful impurities from entering the environment together with that coal. Here it is demonstrated that thermal heating up to 300 °C allows to increase the adsorption activity according to methylene blue test and pH of aqueous extract of recycled sorbents close to the regulatory values, which raises the possibility of their re-use in the production of streptomycin. The raise of temperature more than 300 °C leads to decomposition of high-molecular organic substances on the surface of a coal with subsequent formation of a carbon film which covers the adsorbing pores and worsens the adsorption properties of active coal. After treatment with water vapor at a temperature of 800 °C the characteristics of the active coal meet the regulatory requirements of streptomycin production. Rational way to dispose an active coal which lost its recyclability is a burning at temperatures more than 800 °C. This completely neutralizes all the harmful impurities.