Singhal, NareshWang, Glenn2021-11-012021-11-012021https://hdl.handle.net/2292/57163Full Text is available to authenticated members of The University of Auckland only.The increasing number of non-degradable waste plastics is currently a common problem. Therefore, degrading recyclable plastics is essential to environmental engineering research. This experiment attempted to degrade three types of plastics: PET, PE, and PP. For decades, researchers have applied several methods like photo, chemical degradation, and biodegradation. Some studies have recently applied mechanical methods to degrade PET, while biochemists have utilised cultivated specific enzymes to degrade PE and PP. After reading relevant research, we planned to use a ball mill to hydrolyse PET and apply commercial enzyme preparations to degrade PE and PP. Likewise, we intended to select a suitable one amongst several methods like ultraviolet irradiation and microwave treatment as the pretreatment method of the reaction and determine the pretreatment effect on plastic degradation. In this thesis, some creative methods have been used, including ball milling with enzyme, microwave treatment with oxidation. Additionally, a new wet aging method has been established in the experiment. The results indicate that PET can undergo hydrolysis by ball milling with Novozym® 51032 and aging. Shifting the aging method to wet aging can significantly improve degradation yield; meanwhile, when using PET pretreated by microwave for hydrolysis reaction, the yield can reach 65%. In addition, the experiment verified that an enzyme laccase from aspergillus sp. can realise PE degradation through direct soaking.Restricted Item. Full Text is available to authenticated members of The University of Auckland only.Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htmhttp://creativecommons.org/licenses/by-nc-sa/3.0/nz/Thesis2021-09-23Copyright: the authorQ112957155