0
Article Tier 2 Detection Methods Environmental Sources Food & Water Marine & Wildlife Remediation Sign in to save

Microplastics in sewer sediments of the Parisian combined sewer network

AI summary Read the abstract

Researchers investigated microplastic accumulation in sewer sediments within the Paris combined sewer network, finding significant quantities of plastics deposited in sediment during low-flow periods that could be resuspended and flushed into wastewater treatment plants or directly into the Seine River during heavy rainfall. Sewer systems are an understudied but important pathway for microplastic transport in urban environments.

Polymers
Study Type Environmental

A sewer management system consists of sewer network and wastewater treatment plants (WWTPs). Since microplastics (MPs) were detected in wastewater, their occurrence and fate in WWTPs has been investigated in the last decades, while it was not the case of sewer networks. Sedimentation occurs inside sewer networks when contaminants detach from wastewater and settle down instead of being transported to WWTPs. This happens due to moderate flow rate of sewage during nights and dry periods, leading to the formation of wet deposits, named sewer sediments. Once the flow rate increases rapidly during wet weather, sewer sediments might be resuspended, releasing contaminants into wastewater. In case of heavy rain events, when combined sewer overflows happen, wastewater is discharged into the environment without treatment. MPs, found abundant in wastewater, may act similarly to other contaminants – trapped in sewer sediments and released later during intense events. To examine this hypothesis, samples were collected from sand chambers inside Parisian combined sewer networks to have a first idea about MP content inside sewer sediments. This study will increase the knowledge on the occurrence and fate of MPs in the whole sewer system. The collected sewer sediments were highly heterogeneous from organic-rich to grainy components. They were freeze-dried to remove water content and sieved through 5mm mesh to discard large items. A subsample of 0.5g then underwent chemical oxidation with H2O2 and density separation with NaI to isolate MPs from the environmental matrix. The full subsample was scanned with the automated µ-FTIR mapping (Nicolet iN10 MX, Thermo Scientific). Data processing was done with the siMPle software to identify the polymers composing the particles. MPs were detected in all samples, ranging from 5×103 to 178×103 particle/kg dry weight with polypropylene as the most abundant polymer. Besides, the correlation of MPs with TOC content will be explored. Also see: https://micro2022.sciencesconf.org/427316/document

More Papers Like This

Article Tier 2

Microplastic accumulation in sewer sediments and its potential entering the environment via combined sewer overflows: a study case in Paris

AI summary Read the abstract

Researchers measured microplastic levels in sewer sediments in Paris and found extremely high concentrations, similar in composition to raw wastewater. During heavy rain events, these contaminated sediments get flushed into rivers through sewer overflows, releasing large amounts of microplastics into the environment. The study reveals that urban sewer systems are a significant hidden reservoir of microplastic pollution that can rapidly contaminate waterways used for recreation and drinking water.

Article Tier 2

Microplastic accumulation in sewer sediments and its potential entering the environment via combined sewer overflows: a study case in Paris

AI summary Read the abstract

During heavy rainfall events in Paris, sewer sediments containing densely accumulated microplastics — up to 178,000 particles per kilogram of dry sediment — are resuspended and discharged directly into rivers via combined sewer overflows. This previously overlooked pathway means that stormwater overflow events can rapidly transfer large quantities of microplastics stored in urban sewer networks into freshwater ecosystems.

Article Tier 2

Occurrence and fate of microplastics in Parisian combined sewer network

AI summary Read the abstract

This study investigated the occurrence and fate of microplastics in the combined sewer network of Paris, tracking particles from urban inputs through the wastewater system. Significant amounts of microplastics were found throughout the system, with storm events increasing concentrations. Combined sewer overflow events can release untreated microplastic-laden water directly into rivers during heavy rain.

Article Tier 2

Microplastics in sewer sediments of the Parisian combined sewer network

AI summary Read the abstract

Scientists found tiny plastic bits (microplastics) buried in the muck at the bottom of Paris's sewer system, showing that these particles build up in urban infrastructure, not just oceans and rivers. This matters because sewer sediments can be a hidden reservoir of microplastics that may eventually wash into waterways or affect water treatment processes, adding to the pollution that ends up in our environment, and potentially our food and water supply.

Article Tier 2

Macro and microplastics in stormwater and combined sewer overflows in Paris megacity

AI summary Read the abstract

This French study quantified macro and microplastics in stormwater and combined sewer overflows in the Paris metropolitan area, identifying these urban discharge events as significant pathways for plastic pollution to reach aquatic environments. The results highlight the role of urban infrastructure and rainfall events in transporting plastic debris from cities to waterways.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper