BIOTECHNOLOGICAL DEGRADATION OF THE RADIOACTIVE CELLULOSE-CONTAINING WASTE

The constant increasing of radioactive waste quantity elaborates effec tive and safe methods for their influence upon the environment reducti on. The aim of the study is to develop biotechnological methods for th e radioactive cellulose-containing waste (cotton textile) compaction a nd to investigate the process of radionuclides adsorption with some mi croorganism biomass. Strains of Trichoderma and Aspergillus fungi, deg rading the cotton textile, were investigated. The most effective one w as selected. The optimum conditions for the textile pre-treatment resu lting in a high cellulose destruction activity were also determined, T he best results were obtained in case of thermochemical textile pre-tr eatment by autoclaving in a 3% aqueous solution of NaOH during 90 min. To achieve the effective textile degradation, the necessity of enzyma tic inductors introduction into the nutrient medium was established, C ultivation under these conditions in 15 days revealed considerable tex tile destruction by the fungus Trichoderma reezei. The compaction prov ed to be increased more than two times this; besides, a removal ratio up to 54% for Co-60 was achieved by the fungus. Textile biodestruction with industrial enzymes was also studied. It was found necessary to i noculate the biodestruction system with yeast cells to reduce the gluc ose inhibition. The sorption of Co-60, Sr-90, Cs-137 in fungi and yeas t biomass was also studied. The observed results formed the initial da ta for working up a technology for the textile biodegradation. (C) 199 8 Elsevier Science B.V. All rights reserved.