We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Long-term assessment of nanoplastic particle and microplastic fiber flux through a pilot wastewater treatment plant using metal-doped plastics
Summary
Using metal-tagged nanoplastics and microplastic fibers in a pilot wastewater treatment plant, researchers found that at least 98% of plastic particles were retained in the biosolids during steady-state operation, with the rest correlated with suspended solids in the effluent. The study demonstrates that managing total suspended solids is likely a good proxy for managing plastic removal in full-scale systems.
In recent years, several studies have investigated the flux of particulate plastic through municipal waste water treatment plants (WWTP). Challenges related to time consuming analytical methods have limited the number of sampling points and detection limits have hampered quantification of nanoplastic and microplastic fiber fluxes through WWTPs. By synthesizing nanoplastic particles and microplastic fibers labeled with a rare metal (Pd and In, respectively) which can be measured as a proxy for the plastic itself, we have circumvented major analytical pitfalls associated with (micro)plastic measurements. In this study, we spiked the labeled materials to a pilot WWTP mimicking the activated sludge process (nitrification, de-nitrification and secondary clarification). Using a mass flow model for WWTP sludge, we assessed the behavior of particulate plastic in relation to the removal of organic matter. Triplicate samples were collected from the mixed liquor and from the effluent at least twice weekly over the entire experimental run time of 40 d. Our findings show that in discrete grab samples during steady state conditions, at least 98% of particulate plastics were associated with the biosolids. A positive correlation between total suspended solids (TSS) and plastic concentrations was observed in the sludge as well as in the effluent. Because of the strong association between particulate plastic and TSS, TSS removal is likely a good indicator of plastic removal in a full scale WWTP. Therefore, additional process steps in a full-scale WWTP which further reduce the TSS load will likely retain nanoplastic particles and microplastic fibers effectively and consequently increase the removal rates.
Sign in to start a discussion.
More Papers Like This
Targeting nanoplastic and microplastic in wastewater
Researchers established a novel correlation between nanoplastic removal and total suspended solids (TSS) reduction during aggregation-based wastewater treatment, successfully predicting nanoplastic removal across a wide range of polymer types, sizes, surface functionalisations, and ageing histories under 41 different treatment conditions. The work addresses a key methodological gap in monitoring nanosized plastic pollutants in wastewater effluent streams.
Mechanistic understanding of microplastic fiber fate and sampling strategies: Synthesis and utility of metal doped polyester fibers
Researchers synthesized polyester microplastic fibers embedded with an indium metal tracer to simplify tracking fiber fate and transport, demonstrating that the label does not alter fiber behavior, leaches minimally, and that over 99.9% of fibers associate with activated sludge in wastewater treatment batch experiments.
An audit of microplastic abundance throughout three Australian wastewater treatment plants
Microplastic abundance was audited throughout three Australian wastewater treatment plants, tracking particles from influent through all treatment stages and into both effluent and biosolids. While treatment removed most microplastics from effluent, the majority were captured in biosolids — which are often land-applied — highlighting biosolids as the primary pathway for microplastics leaving wastewater treatment systems.
Long-Term Occurrence and Fate of Microplastics in WWTPs: A Case Study in Southwest Europe
A long-term monitoring study of a wastewater treatment plant in southwest Europe tracked microplastic concentrations across all treatment stages over multiple sampling campaigns, finding consistent plastic removal in the range of 90% but with treated effluent and sludge still containing substantial amounts. The study demonstrates the value of repeated sampling for understanding seasonal and operational variability in microplastic fate at WWTPs.
Transport and fate of microplastic particles in wastewater treatment plants
Researchers tracked microplastic particles through multiple stages of a wastewater treatment plant, finding that particles were concentrated in sludge but that a fraction passed through each treatment stage and remained in the final effluent.