Bio-degradation of 40 micron plastic bags by Aspergillus niger and optimization of pre-treatment methods

Abstract

Lack of degradability and the closing of landfill sites as well as growing water and land pollution problems have led to concern about plastics. Among the various types of plastics, the most extensively used type is polyethylene bags. A survey on 40 micron polyethylene bags was done by obtaining the information from the City corporation office, Belgaum, Karnataka, India on the amount of plastic waste generated in the city. Polyethylene bags having a thickness less than 40 micron are not recycled, thus have to be degraded. In this work, Aspergillus niger is been employed to degrade the 40 micron plastic. Various pre-treatment methods are used which include UV, nitric acid, thermal and UV + nitric acid treatments to effectively degrade the plastic. Different media having pre treated plastic as the carbon source are tested for the degradation of plastic along with the growth of the fungi. Incubation period was taken as 15 and 30 days. Optimization of pre-treatment methods was done to improve the degradation efficiency. Various analysis methods such as FTIR spectroscopy and dry-weight analysis were done to confirm the degradation of plastic.