An Investigation into the Feasibility of using MHETase and PETase for Water Treatment Due to the Increase of Microplastic Ingestion through Tap Water

Polyethylene terephthalate (PET) is the most abundantly produced plastic due to packaging and textiles, contributing to the widespread presence in the environment and the generation microplastics. Given microplastics high absorption rates and hydrophobicity they can accumulate toxic chemicals making them hazardous. When large quantities of microplastics infiltrate drinking water treatment facilities the public is exposed to these toxic chemicals, potentially resulting in various cancers and reproductive disorders. In response to the accumulating microplastics in the environment biochemical engineers have begun to analyze microbial solutions, such as enzymes MHETase and PETase, which can enzymically degrade PET polymers and metabolically assimilate them as a carbon nutrient source. However, it is unknown whether these enzymes can be adapted to drinking water treatment processes. To address this, an experimentation of inquiry was conducted to analyze the digestion rate of PET plastic when exposed to environments resembling those of drinking water treatment facilities. By introducing water samples collected from the Ann Arbor Drinking Water Treatment Facility and analyzing the change in phenol indicator color and mass of PET plastic samples. The research design concluded that despite the introduction of water samples there was no significant change in the digestion rate as compared to control samples, suggesting the feasibility of utilizing MHETase and PETase as a water treatment solution for PET microplastics within drinking water treatment facilities.