Characteristics of microplastic pollution in sewage treatment plants

Abstract

In this study, we investigated the actual state of pollution in sewage, which is considered to be a pollution source of marine microplastics. As a result, the MPs number density was 1,500 / m³ to 2,000 / m³ (median). At this sewage treatment plant, more than 99% of 100µ-5mm microplastics were recovered. This is equivalent to the amount recovered from previous studies, confirming that the sewage treatment plant functions as one of the MPs recovery. However, when simple discharge is carried out, the number density of MPs tends to increase. The size of microplastics in sewage tended to decrease as the number density increased.