The impact of ozonation on PET and PVC microplastics in model urban wastewater

In the field of environmental pollutants, microplastics (MPs) present one of the biggest challenges. Several studies investigated different removal options of MPs and investigated its toxic impacts on the environment. One of the main sources of MPs pollution is wastewater. Different advanced oxidation processes (AOPs) are being investigated regarding MP treatment in wastewater, especially ozonation. Several studies found that it caused degradation of certain MPs. Therefore, a study was run using polyethylene terephthalate (PET) and polyvinyl chloride (PVC) MPs in model wastewater. 6 h ozonation was accomplished at two different ozone doses. Total organic carbon (TOC) and chemical oxygen demand (COD) were determined for samples during ozonation. It was found out that in both MPs-containing model wastewater, TOC and COD increased. This indicates that ozonation has led to the degradation of MPs. Wastewater containing PET had up to 85% higher TOC values compared to PVC containing wastewaters. After ozonation PET-containing wastewater had up to 29% higher COD values than the PVC-containing one. It can be concluded that the higher ozone dose, the more effective MPs degradation is.