UC Irvine

Microplastics is an important class of contaminants of emerging concerns (CECs) and a rising environmental concern, as they have been ubiquitously detected in natural and engineered water systems. Water resource recovery facilities (WRRFs) have been found to be a sink as well as pathway of microplastics release to the environment. The target removal of microplastics from wastewater and reclaimed water needs to be built upon a comprehensive understanding of their occurrence and fate within WRRFs. To understand the seasonal occurrence and characteristics of microplastics in WRRFs, microplastics from wastewater influent, primary effluent, secondary effluent and tertiary effluent in a local WRRF were quantified and characterized over nine months with a set of validated methods for microplastics extraction. Higher abundance of microplastics were observed during winter season and laundry discharge was identified as a major contributor of microplastics in wastewater. Fine microplastics were abundantly found in the WRRF, especially in secondary and tertiary effluent, necessitating further investigation removing fine and nanoplastics. In addition, mini-hydrocyclone, a highly customizable and widely used hydraulic device, was tested as alternative for separating fine microplastics from water and wastewater, and achieved satisfactory separation efficiency. This confirmed their feasibility for pilot or full-scale applications.