eva‎luation of factors affecting cellulose acetate biodegradation rate

3/12/2024 12:00:00 AM

The use of cellulose acetate polymers in cigarette filters, necessitates their degradation as an environmental pollutant in conditions similar to waste accumulation environments, such as the surface and depth of soil and stagnant and flowing waters. In order to facilitate the degradation process of these polymers, the ultraviolet irradiation method is used before bioremediation. In this research, the microbial remediation of the cellulose acetate polymer in two macro size (used cigarette filter with plug wrap, used cigarette filter without plug wrap and hand-made cellulose acetate sheet) and micro (smaller than 3mm) of handmade cellulose acetate sheet pre-treated with ultraviolet light was investigated. This study was carried out in two general stages: the first stage is the isolation of a suitable microbial mixture, adaptation and biodegradation of macro size polymers in two phases of liquid and soil with an auxiliary carbon source of phenol for 100 and 120 days, and the second stage is the use of selected of adapted microbes for the biodegradation of micro-polymers for 42 and 49 days, respectively. During the process of the first stage, four native species types of wood-rotting fungi and four mixed cultures in two phases of liquid and soil were investigated. Then two wood-rotting and two adapted activated sludge were selected for biodegradation of micro-polymers. The microbial growth and media pH were investigated during the biodegradation process and at the end, the quantitative and qualitative biodegradation of polymer samples was determined by SEM, FTIR, contact angle measurement and weight loss and size reductions (micro-polymers). SEM results confirm the formation of surface decay and cracks on the surface of polymers. The formation or removal of new functional groups, including hydroxyls, carbonyls and acetyls, was detected in the wavenumbers of 3000 and 1700 and 1200 cm-1 due to microbial degradation by FTIR, in contrast to the control samples. Reduction of the contact angle, which indicates the hydrophilicity of the surface, by 27 degrees occurred by the microbial treatment. The maximum weight loss of macro size polymers in liquid phase with cigarette filter used with plug wrap was 33% by activated sludge 1 and 31% in soil phase by wood-rotting fungi. For micro-polymers, 38% was obtained in the liquid phase by activated sludge 1 and 44% by wood-rotting fungi in the soil phase. Based on the kinetic studies on weight loss micro-polymers, the first-order equation fits well with the obtained data and the half-life time of about 61 days was calculated for both liquid and soil systems.

تخريب‌زيستي , سلولزاستات , فيلترسيگار , قارچ پوساننده چوب , ميكروپليمر

Biodegradation , Cellulose acetate , Cigarrete filter , Wood-rotting fungi , Micro-polymer

Mahsa Jamshidi

Parisa Hejazi