Comparison of the Biological Degradation of Polyethylene terephthalate (PET), Polyvinylchloride (PVC), and Polystyrene (PS) Plastic Strips using Isolated Soil Actinomycetes

Abstract

INTRODUCTION

In people's daily life, plastic is commonly and widely used. It has been reported that there are around 100 million plastics produced every day, which, in the long run, will result in forms of pollution to the earth. For example, it is estimated that 1.15 to2.41 million tons of plastic wastes are entering the ocean each year, leading to water pollution. Hence, this study was conducted as a response to mitigate the forms of pollution caused by plastic use and production. Three types of plastic were compared for their biological degradation. Terephthalate (PET) is the world's packaging choice for many foods and beverages because it is hygienic, strong, lightweight, shatterproof, and retains freshness. PS, used in construction application, is a good insulator for it quickly accrues electrical charge. Polyvinylchloride (PVC) piping systems help prevent leakage and their exceptionally smooth surfaces reduce the cost of pumping fluids.

METHODS

All experiments were conducted in the laboratory of the Biology Department of Adamson University. Samples from soil garbage were collected following their recommended procedure. The soil samples were suspended in sterile distilled water and processed with starch casein agar. Emerging actinomycetes were determined through a biochemical test and gram staining. Plastic strip samples (PET, PVC, PS) were pre-treated before actual weight loss measurements. After significant growth of actinomycetes was detected, plastic strips were allowed to be decomposed in the culture media for 14 days. Weight loss of plastic strips was computed after.

RESULTS

All samples of plastic strips evaluated in the study decreased in weight. Results suggest microbial degradation. The PET plastic strip has the highest percentage of weight loss, which was at 36.40%. On the other hand, the PVC plastic strip led to only 8.60 % weight loss while the PS resulted in a 3.77% weight loss.

DISCUSSIONS

Comparison of the biological degradation of PET, PVC, PS plastic strips using isolated soil actinomycetes is the focal point of this study. As shown in the table, the PET plastic was affected by the actinomycetes while other plastics like PS was not as affected. In comparison to other research studies, this research study only had a short time for experimentation. Other studies took a long time but the results were amazingly good because the plastic was completely degraded. It took 3 months till it was completely degraded.