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

During wet weather events, combined sewer overflows (CSOs) transfer large amount of particulate matter and associated pollutants into surrounding water bodies, thereby deteriorating the recipients' ecological health. Resuspension of sewer sediments during these events contributes significantly to pollution level of these discharges. However, how much this in-sewer process contributes to CSOs' quality regarding microplastic (MP) pollution is little known.

Tracking the formation potential of vivianite within the treatment train of full-scale wastewater treatment plants.

Phosphorus recovery is a vital element for the circular economy. Wastewater, especially sewage sludge, shows great potential for recovering phosphate in the form of vivianite. This work focuses on studying the iron, phosphorus, and sulfur interactions at full-scale wastewater treatment plants (Viikinmäki, Finland and Seine Aval, France) with the goal of identifying unit processes with a potential for vivianite formation.

Wild type and variants of SARS-COV-2 in Parisian sewage: presence in raw water and through processes in wastewater treatment plants.

The presence of SARS-CoV-2 RNA has been extensively reported at the influent of wastewater treatment plants (WWTPs) worldwide, and its monitoring has been proposed as a potential surveillance tool to early alert of epidemic outbreaks. However, the fate of the SARS-CoV-2 RNA in the treatment process of WWTP has not been widely studied yet; therefore, in this study, we aimed to evaluate the efficiency of treatment processes in reducing SARS-CoV-2 RNA levels in wastewater. The treatment process of three WWTPs of the Parisian area in France was monitored on six different weeks over a period of 2 months (from April 14 to June 9, 2021).

Fate of SARS-CoV-2 coronavirus in wastewater treatment sludge during storage and thermophilic anaerobic digestion.

Since the COVID-19 outbreak has started in late 2019, SARS-CoV-2 has been widely detected in human stools and in urban wastewater. No infectious SARS-CoV-2 particles have been detected in raw wastewater until now, but it has been reported occasionally in human stools. This has raised questions on the fate of SARS-CoV-2 during wastewater treatment and notably in its end-product, wastewater treatment sludge, which is classically valorized by land spreading for agricultural amendment.

Modelling the benefits of urine source separation scenarios on wastewater treatment plants within an urban water basin.

Stringent discharge regulations are encouraging researchers to create innovative and sustainable wastewater treatment solutions. Urine source separation (USS) is among the potent approaches that may reduce nutrient peak loads in the influent wastewater and improve nutrient recovery. A phenomenological model was used to simulate dynamic influent properties and predict the advantages gained from implementing USS in an urban water basin.

From Alpha to Omicron BA.2: New digital RT-PCR approach and challenges for SARS-CoV-2 VOC monitoring and normalization of variant dynamics in wastewater.

Throughout the COVID-19 pandemic, new variants have continuously emerged and spread in populations. Among these, variants of concern (VOC) have been the main culprits of successive epidemic waves, due to their transmissibility, pathogenicity or ability to escape the immune response. Quantification of the SARS-CoV-2 genomes in raw wastewater is a reliable approach well-described and widely deployed worldwide to monitor the spread of SARS-CoV-2 in human populations connected to sewage systems.

Modeling, simulation and control of biological and chemical P-removal processes for membrane bioreactors (MBRs) from lab to full-scale applications: State of the art.

Phosphorus (P) removal from the domestic wastewater is required to counter the eutrophication in receiving water bodies and is mandated by the regulatory frameworks in several countries with discharge limits within 1-2mgPL. Operating at higher sludge retention time (SRT) and higher biomass concentration than the conventional activated sludge process (CASP), membrane bioreactors (MBRs) are able to remove 70-98% phosphorus without addition of coagulant. In full-scale facilities, enhanced biological phosphorus removal (EBPR) is assisted by the addition of metal coagulant to ensure >95% P-removal.

Normalization of wastewater coagulation-flocculation trials and implications in terms of variability in treatment performance and comparison of commercial coagulants.

Normalizations by TSS or P-PO initial concentrations are consistent as they are correlated to the Jar-test performances. Jar-tests results are independent of the wastewater quality variations in terms of TSS and P-PO and independent of the WWTP origin of the water. A notable variability in the TSS results indicates that the pollutant's initial load has to be taken into account even with normalizations.

Impacts from urban water systems on receiving waters - How to account for severe wet-weather events in LCA?

Sewage systems are a vital part of the urban infrastructure in most cities. They provide drainage, which protects public health, prevents the flooding of property and protects the water environment around urban areas. On some occasions sewers will overflow into the water environment during heavy rain potentially causing unacceptable impacts from releases of untreated sewage into the environment.

Early assessment of a rapid alternative method for the estimation of the biomethane potential of sewage sludge.

This short communication briefly presents a rapid method using a fluorescent redox indicator, similar to resazurin, in order to estimate the biodegradability of sewage sludge during anaerobic digestion (AD). The biodegradability and by extension the Biochemical Methane Potential (BMP) of nineteen municipal sludge samples (primary, biological and tertiary) were investigated and estimated in only 48 h. Results showed the relevance to follow the metabolic activity of anaerobic sludge by the kinetic of probe reduction.

Influence of the water quality improvement on fish population in the Seine River (Paris, France) over the 1990-2013 period.

Over the past 20 years, rules concerning wastewater treatment and quality of water discharged into the environment have changed considerably. Huge investments have been made in Paris conurbation to improve waste water treatment processes in accordance with the European Water Framework Directive. The interdepartmental association for sewage disposal in Paris conurbation (SIAAP) carried out a monitoring of both fish assemblages and water quality in the Seine River around the Paris conurbation (France) since the early 90's.

Nitrite accumulation during denitrification depends on the carbon quality and quantity in wastewater treatment with biofilters.

This study aims to understand the mechanisms of nitrite appearance during wastewater denitrification by biofilters, focusing on the role of the carbon source. Experiments were carried out at lab-scale (batch tests) and full-scale plant (Parisian plant, capacities of 240,000 m(3) day(-1)). Results showed that the nature of the carbon source affects nitrite accumulation rates.

Municipal wastewater treatment by biofiltration: comparisons of various treatment layouts. Part 2: assessment of the operating costs in optimal conditions.

This work aims to compare the operation costs (energy, reagents, waste management) for the three layouts usually used in wastewater treatment plants incorporating biofilters, using technical and economical data acquired during 10 years of operation of a Parisian plant (Seine Centre, 240,000 m(3) d(-1) -800,000 equivalent inhabitants). The final objective is to establish general economical data and tendencies that can be translated from our study to any biofiltration plant. Our results evidenced the savings achieved through the treatment process combining upstream and downstream denitrification.

Municipal wastewater treatment by biofiltration: comparisons of various treatment layouts. Part 1: assessment of carbon and nitrogen removal.

One of the largest wastewater treatment plants in the Paris conurbation (240,000 m(3)/d) has been studied over several years in order to provide technical and economical information about biological treatment by biofiltration. Biofiltration systems are processes in which carbon and nitrogen pollution of wastewater are treated by ascendant flow through immersed fixed cultures. This paper, focused on technical information, aims: (1) to compare performances of the three biological treatment layouts currently used in biofiltration systems: upstream denitrification (UD), downstream denitrification (DD) and combined upstream-downstream denitrification (U-DD) layouts; and (2) to describe in detail each treatment step.

Occurrence and removal of priority pollutants by lamella clarification and biofiltration.

This study investigates the occurrence of all priority substances (n = 41) listed in the Water Framework Directive and additional substances (n = 47) in raw sewage, as well as the removal performance of lamella clarification and biofiltration techniques. Once the efficiency of both types of techniques has been assessed for typical wastewater parameters, the differences in each technique's ability to remove pollutants becomes obvious; nevertheless, pollutant removal in quantitative terms still depends on the physico-chemical properties of the compounds used and operating conditions within the selected facility. For lamella clarification, the removal of organic chemicals was found to be primarily correlated with their sorption potential and, hence, strongly dependent upon log K(ow) of the compound under study.

Decrease of atmospheric deposition of heavy metals in an urban area from 1994 to 2002 (Paris, France).

Total atmospheric deposition, i.e. both wet and dry ones, was sampled during three different sampling periods between 1994 and 2002.

Sources, distribution and variability of hydrocarbons and metals in atmospheric deposition in an urban area (Paris, France).

Total atmospheric deposition, i.e., both wet and dry deposition, was sampled during 11 months in the "Ile-de-France" region, France.

Hydrocarbons and heavy metals in the different sewer deposits in the 'Le Marais' catchment (Paris, France): stocks, distributions and origins.

The knowledge of the pollution stored in combined sewers is of prime importance in terms of management of wet weather flow pollution since sewer deposits play a significant role as source of pollution in combined sewer overflows. This work, which focused on the hydrocarbon (aliphatic and aromatic hydrocarbons) and metallic (Fe, Zn, Pb, Cu and Cd) pollution fixed to the different kinds of sewer deposits (gross bed sediment [GBS], organic layer [OL] and biofilm), was performed in order to provide a complete overview of the contaminant storage in the 'Le Marais' combined sewer (Central Paris, France). Firstly, our results have shown that, for all kinds of pollutants, a major part was stored in the GBS (87 to 98%), a lesser part in the OL (2 to 13%) and an insignificant part in the biofilm (<1%).

Trace metal determination in total atmospheric deposition in rural and urban areas.

The wet, dry and total atmospheric depositions of some metals (Al, Cd, Cr, Cu, Fe, Na, Pb and Zn) were sampled at two sites and atmospheric fallout fluxes were determined for these locations. This work, led by two different research groups, allowed to reach two main goals: to define a simple analytical procedure to secure accurate shipboard sampling and analysis of atmospheric deposition, and to assess anthropogenic impacts of heavy metals to the environment. The first step about the validation step showed that the prevalent deposition type was dry deposition which represents 40, 60 and 80% for Cd, Cu and Pb, respectively.