Wastewater treatment plant effluent as a source of microplastics: review of the fate, chemical interactions and potential risks to aquatic organisms

Abstract

Wastewater treatment plant (WWTP) effluent has been identified as a potential source of microplastics in the aquatic environment. Microplastics have recently been detected in wastewater effluent in Western Europe, Russia and the USA. As there are only a handful of studies on microplastics in wastewater, it is difficult to accurately determine the contribution of wastewater effluent as a source of microplastics. However, even the small amounts of microplastics detected in wastewater effluent may be a remarkable source given the large volumes of wastewater treatment effluent discharged to the aquatic environment annually. Further, there is strong evidence that microplastics can interact with wastewater-associated contaminants, which has the potential to transport chemicals to aquatic organisms after exposure to contaminated microplastics. In this review we apply lessons learned from the literature on microplastics in the aquatic environment and knowledge on current wastewater treatment technologies, with the aim of identifying the research gaps in terms of (i) the fate of microplastics in WWTPs, (ii) the potential interaction of wastewater-based microplastics with trace organic contaminants and metals, and (iii) the risk for aquatic organisms.

Microplastics in the gastrointestinal tracts of fish and the water from an urban prairie creek

“…Small numbers per litre released in effluent can translate to large numbers of plastics in aquatic systems, considering the large volumes of treated effluent released from WWTPs worldwide. As a result, studies have shown that wastewater effluent is a source of microplastics to aquatic systems (see reviews in Estahbanati and Fahrenfeld 2016;Ziajahromi et al 2016). …”

Occurrence, sources, human health impacts and mitigation of microplastic pollution

“…MPs are dispersed into the ocean all over the world. Often detected in beaches (Herrera et al 2017;Imhof et al 2018;Naji et al 2017), seabed sediments (Karlsson et al 2017;Van Cauwenberghe et al 2013), wastewater effluents (Magnusson and Norén 2014;Murphy et al 2016;Ziajahromi et al 2016), surface waters (Eriksen et al 2013;La Daana et al 2017), freshwater systems (Horton et al 2017b) and even sea ice in the Arctic (Lusher et al 2015;Obbard et al 2014;Waller et al 2017), and the Antarctic (Waller et al 2017) transported by ocean and wind. MPs also have been observed in the atmosphere, as well as in indoor and outdoor environments (Dris et al 2017;Gasperi et al 2018).…”

Micro-and macro-plastics in marine species from Nordic waters

“…Conversely, consumers may adequately dispose of waste products with the intention of items reaching recycling or landfill facilities, but adverse weather conditions can displace items into the environment. In the case of microplastics generated from consumers, through the use of cosmetics and personal care products containing microbeads or washing synthetic clothing, small plastics can pass through wastewater treatment plants depending on the sophistication of the equipment, number of treatment stages and procedures used (Napper et al, 2015;Ziajahromi et al, 2016;Mahon et al, 2017).…”