Profile and Different Approaches for Size Characterization of Microplastics in Drinking Water from the Lisbon Water Supply System.

Microplastics (MPs) contribute to the overall pollution of water sources, affecting not only aquatic ecosystems but also water for human consumption (WHC). Currently, there needs to be a global consensus on safe levels of microplastics in WHC, which will allow regulatory efforts and risk assessments to be carried out. Therefore, this study aims to characterize MP particles in WHC of the Lisbon water supply system (LWSS) and compare two approaches to quantify these particles (length and width of the particles, and the area equivalent diameter (AED) of the particles).

Validation of an FT-IR microscopy method for the monitorization of microplastics in water for human consumption in Portugal: Lisbon case study.

The growing anthropogenic contamination of natural water by microplastics (MPs) confirms the urgent need to preserve this precious resource. MPs are part of the group of contaminants of emerging concern, and the occurrence studies in surface water and water for human consumption (WHC) are mandatory for environmental and human health risk assessment. This study aims to optimize and validate a Fourier transform infrared spectroscopy method coupled with optical microscopy (micro-FTIR) in transmission mode to monitor MPs in WHC.

Different approaches for estimation of the expanded uncertainty of an analytical method developed for determining pharmaceutical active compounds in wastewater using solid-phase extraction and a liquid chromatography coupled with tandem mass spectrometry method.

Although the evaluation of the uncertainty of an analytical method is a mandatory step in the method's validation, its applicability to the monitoring of trace compounds in complex samples is not simple, nor is it part of the routine of most laboratories, namely those dedicated to research. This manuscript focuses on the full validation of an analytical procedure for determining trace concentrations of twenty-four pharmaceutical active compounds (PhACs) in wastewaters using solid-phase extraction (SPE) and ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The method optimization was performed on different wastewater matrices, namely influents and final effluents from two distinct wastewater treatment plants (WWTPs).

Development of multi-residue gas chromatography coupled with mass spectrometry methodologies for the measurement of 15 chemically different disinfection by-products (DBPs) of emerging concern in drinking water from two different Portuguese water treatment plants.

In water treatment plants (WTPs), chemical agents, such as chlorine and ozone, might react with organic matter and anthropogenic contaminants, forming a high diversity of disinfection by-products (DBPs). Due to the potential toxicological effects, the identification of unregulated DBPs (UR-DBPs) is critical to help water managers in the selection of effective water treatment processes, contributing to improving water safety plans. Given the limited validated analytical methods to detect UR-DBPs, here we developed new multi-residue gas chromatography coupled with mass spectrometry methodologies for the detection and quantification of 15 UR-DBPs, including aldehydes, haloketones (HKs), nitrosamines and alcohols, in drinking water matrices.

Understanding the bioaccumulation of pharmaceutical active compounds by clams Ruditapes decussatus exposed to a UWWTP discharge.

Twenty-four pharmaceutical active compounds (PhACs) were evaluated in the soft tissues of clams Ruditappes decussatus exposed along a 1.5-km dispersal gradient of the treated effluent from an urban wastewater treatment plant discharging in Ria Formosa, and compared with those in the marine waters and discharged effluents. The clams were exposed for 1 month, in June-July 2016, 2017 and 2018.

Responses of benthic diatoms to waters affected by post-fire contamination.

Wildfire effects go beyond direct impact in terrestrial ecosystems. Specifically, the periphytic communities of aquatic ecosystems standing within and downstream the burnt areas are relevant ecological receptors of post-fire runoff contamination. Nevertheless, the off-site impacts of wildfires in these communities are limitedly studied so far.

Screening and Seasonal Behavior of Analgesics, Non-steroidal Anti-inflammatory Drugs, and Antibiotics in Two Urban Wastewater Treatment Plants.

Pharmaceutical active compounds (PhACs) belonging to analgesics, antibiotics, and non-steroidal anti-inflammatory drugs (NSAIDs) therapeutic classes were monitored in wastewater influents and effluents from two Portuguese urban wastewater treatment plants (UWWTPs) for 24 months. Both facilities were chosen due to their effluents are discharged in highly touristic and sensitive areas, Tagus river and Ria Formosa coastal lagoon, respectively. Target PhACs, acetaminophen, diclofenac, ibuprofen, naproxen, sulfadiazine, and sulfamethoxazole were measured using solid-phase extraction (SPE) coupled to liquid chromatography tandem mass spectrometry (LC-MS/MS).

Toxicological assessment of seven unregulated drinking water Disinfection By-products (DBPs) using the zebrafish embryo bioassay.

Disinfection By-products (DBPs) are formed during the chemical treatment of water for human consumption, by the reaction of raw water with chemical agents used in the different steps of the process. Disinfection is one of the most important steps, inactivating pathogens and preventing their regrowth during water distribution. However, it is also involved in DBPs formation due to the use of disinfectant agents, such as chlorine, which reacts with dissolved precursors, such as pharmaceuticals, toxins, pesticides, among others.

Hazard and mode of action of disinfection by-products (DBPs) in water for human consumption: Evidences and research priorities.

Disinfection of water system is an essential strategy to protect human health from pathogens and prevent their regrowth during water distribution, but the reaction of disinfectant agents with organic matter can lead to the formation of disinfection by-products (DBPs). Given their widespread occurrence, potential human health impacts and (eco)toxicity associated with exposure to DBPs are of particular interest due to their potential carcinogenicity and vary non-carcinogenic effects, such as endocrine disruption. Understanding the public health implications of this emerging issue is crucial for societies and decision-makers, supporting more effective water safety plans.

Bioaugmentation of membrane bioreactor with Achromobacter denitrificans strain PR1 for enhanced sulfamethoxazole removal in wastewater.

Achromobacter denitrificans strain PR1, previously found to harbour specific degradation pathways with high sulfamethoxazole (SMX) degradation rates, was bioaugmented into laboratory-scale membrane bioreactors (MBRs) operated under aerobic conditions to treat SMX-containing real domestic wastewater. Different hydraulic retention times (HRTs), which is related to reaction time and loading rates, were considered and found to affect the SMX removal efficiency. The availability of primary substrates was important in both bioaugmented and non-bioaugmented activated sludge (AS) for cometabolism of SMX.

Occurrence and behaviour of pharmaceutical compounds in a Portuguese wastewater treatment plant: Removal efficiency through conventional treatment processes.

Wastewater treatments can eliminate or remove a substantial amount of pharmaceutical active compounds (PhACs), but there may still be significant concentrations of them in effluents discharged into surface water bodies. Beirolas wastewater treatment plant (WWTP) is located in the Lisbon area and makes its effluent discharges into Tagus estuary (Portugal). The main objective of this study is to quantify a group of 32 PhACs in the different treatments used in this WWTP.

Chemical and biochemical characterization and in vivo safety evaluation of pharmaceuticals in drinking water.

The water constituents that are currently subject to legal control are only a small fraction of the vast number of chemical substances and microorganisms that may occur in both the environment and water resources. The main objective of the present study was to study the health impact resulting from exposure to a mixture of pharmaceuticals that have been detected in tap water at low doses. Analyses of atenolol, caffeine, erythromycin, carbamazepine, and their metabolites in blood, urine, feces, fat tissue, liver, and kidney after exposure to a mixture of these pharmaceuticals in treated drinking water were performed.

Comparison of UV photolysis, nanofiltration, and their combination to remove hormones from a drinking water source and reduce endocrine disrupting activity.

A sequential water treatment combining low pressure ultraviolet direct photolysis with nanofiltration was evaluated to remove hormones from water, reduce endocrine disrupting activity, and overcome the drawbacks associated with the individual processes (production of a nanofiltration-concentrated retentate and formation of toxic by-products). 17β-Estradiol, 17α-ethinylestradiol, estrone, estriol, and progesterone were spiked into a real water sample collected after the sedimentation process of a drinking water treatment plant. Even though the nanofiltration process alone showed similar results to the combined treatment in terms of the water quality produced, the combined treatment offered advantage in terms of the load of the retentate and decrease in the endocrine-disrupting activity of the samples.

Chlorination and oxidation of sulfonamides by free chlorine: Identification and behaviour of reaction products by UPLC-MS/MS.

Sulfonamides (SAs) are one class of the most widely used antibiotics around the world and have been frequently detected in municipal wastewater and surface water in recent years. Their transformation in waste water treatment plants (WWTP) and in water treatment plants (WTP), as well as, their fate and transport in the aquatic environment are of concern. The reaction of six sulfonamides (sulfamethoxazole, sulfapyridine, sulfamethazine, sulfamerazine, sulfathiazole and sulfadiazine) with free chlorine was investigated at a laboratory scale in order to identify the main chlorination by-products.

Occurrence of pharmaceuticals in a water supply system and related human health risk assessment.

A monitoring study of 31 pharmaceuticals along Lisbon's drinking water supply system was implemented, which comprised the analysis of 250 samples including raw water (surface water and groundwater), and drinking water. Of the 31 pharmaceutical compounds, only sixteen were quantified in the analyzed samples, with levels ranging from 0.005 to 46 ng/L in raw water samples and 0.

Ethylenediamine-N,N'-diglutaric acid (EDDG) as a promising biodegradable chelator: quantification, complexation and biodegradation.

[S,S]-ethylenediamine-N,N'-diglutaric acid (EDDG) has been gaining interest in the industrial sector as a promising chelator. In this study, the effective metal complexing capacity of EDDG over a wide pH range was modelled and its biodegradability assessed. Results showed that EDDG could effectively bind to several metallic ions in a wide pH range and was completely biodegraded after approximately 15 days by un-acclimatized sludge.

Experimental and statistical validation of SPME-GC-MS analysis of phenol and chlorophenols in raw and treated water.

A procedure based on solid-phase microextraction (SPME) and gas chromatography coupled with mass spectrometry (GC-MS) was developed and validated in order to analyse 10 phenols in water samples. The optimised conditions were obtained using polyacrylate fibre (PA), 20ml of sample volume, 10% NaCl, pH 4.0 and direct extraction at 35 degrees C and 1000rpm, for 40min.

Determination of several pesticides in water by solid-phase extraction, liquid chromatography and electrospray tandem mass spectrometry.

The analysis of pesticides in water samples is a problem of primary concern for quality control laboratories due to the toxicity level of these compounds and their public health risk. In order to evaluate the impact of pesticides in the Lisbon drinking water supply system, following the requirements of the European Union Directive 98/83/EC, we developed and validated an analytical method based on the combination of solid-phase extraction with liquid chromatography and tandem mass spectrometry. In this work, several pesticides were studied: imidacloprid, dimethoate, cymoxanil, carbendazime, phosmet, carbofuran, isoproturon, diuron, methidathion, linuron, pyrimethanil, methiocarbe, tebuconazole and chlorpyrifos.