Particle balance and return loops for microplastics in a tertiary-level wastewater treatment plant

Pauliina Salmi*, Kalle Ryymin, Anna K. Karjalainen, Anna Mikola, Emilia Uurasjarvi, Julia Talvitie

*Tämän työn vastaava kirjoittaja

Tutkimustuotos: LehtiartikkeliArticleScientificvertaisarvioitu

6 Sitaatiot (Scopus)
16 Lataukset (Pure)


Microplastics (MPs) from households, stormwater, and various industries are transported to wastewater treatment plants (WWTPs), where a high proportion of them are captured before discharging their residuals to watersheds. Although recent studies have indicated that the removed MPs are mainly retained in wastewater sludge, sludge treatment processes have gained less attention in MP research than water streams at primary, secondary, and tertiary treatments. In this study, we sampled 12 different process steps in a tertiary-level municipal WWTP in central Finland. Our results showed that, compared to the plant influent load, three times more MPs circulated via reject water from the sludge centrifugation back to the beginning of the treatment process. Fibrous MPs were especially abundant in the dewatered sludge, whereas fragment-like MPs were observed in an aqueous stream. We concluded that, compared to the tertiary effluent, sludge treatment is the major exit route for MPs into the environment, but sludge treatment is also a return loop to the beginning of the process. Our sampling campaign also demonstrated that WWTPs with varying hydraulic conditions (such as the one studied here) benefit from disc filter-based tertiary treatments in MP removal.

JulkaisuWater Science and Technology
Varhainen verkossa julkaisun päivämäärä31 toukok. 2021
DOI - pysyväislinkit
TilaJulkaistu - 1 heinäk. 2021
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu


Sukella tutkimusaiheisiin 'Particle balance and return loops for microplastics in a tertiary-level wastewater treatment plant'. Ne muodostavat yhdessä ainutlaatuisen sormenjäljen.

Siteeraa tätä