Biotechnological degradation of the radioactive cellulose containing waste

Abstract

The constant increasing of radioactive waste quantity elaborates effective and safe methods for their influence upon the environment reduction. The aim of the study is to develop biotechnological methods for the radioactive cellulose-containing waste (cotton textile) compaction and to investigate the process of radionuclides adsorption with some microorganism biomass. Strains of Trichoderma and Aspergillus fungi, degrading the cotton textile, were investigated. The most effective one was selected. The optimum conditions for the textile pre-treatment resulting in a high cellulose destruction activity were also determined. The best results were obtained in case of thermochemical textile pre-treatment by autoclaving in a 3% aqueous solution of NaOH during 90 min. To achieve the effective textile degradation, the necessity of enzymatic inductors introduction into the nutrient medium was established. Cultivation under these conditions in 15 days revealed considerable textile destruction by the fungus Trichoderma reezei. The compaction proved to be increased more than two times this; besides, a removal ratio up to 54% for 60 Co was achieved by the fungus. Textile biodestruction with industrial enzymes was also studied. It was found necessary to inoculate the biodestruction system with yeast cells to reduce the glucose inhibition. The sorption of 60 Co , 90 Sr , 137 Cs in fungi and yeast biomass was also studied. The observed results formed the initial data for working up a technology for the textile biodegradation.