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Photoelectrochemical (PEC) detection technology is key for fighting pollution, leveraging the photoelectric conversion of the photoelectrode material. A specialized photoelectrode was developed to detect Hg2+ ions with exceptional sensitivity, utilizing an anodic PEC sensor composed of Er 3 NbO 7 /P@g-C 3 N 4 /SnS 2 ternary nanocomposite. Rare earth metal niobates (RENs) were chosen due to their underexplored potential, whose performance was enhanced through bandgap engineering and surface modification, facilitated by P@g-C 3 N 4 as an immobilization matrix and SnS 2 , belonging to the I-IV semiconductors category fostering hybrid heterojunction formation for boasting optical properties and suitable redox potentials. Introducing Hg2+ into the system, a specific amalgamation reaction occurs between reduced Hg and Sn. This reaction obstructs electron transfer to the FTO electrode surface, leading to the recombination of charges. The proposed PEC sensor exhibited remarkable analytical performance for Hg2+ detection, high sensitivity, a detection limit of 0.019 pM, excellent selectivity, and a detectable concentration range of 0.002–0.15 nM. Additionally, it demonstrated good recovery and low relative standard deviation when analyzing Hg2+ in water samples, highlighting the potential application of the heterostructure in detecting heavy metal ions via PEC technology. [Display omitted] • Er 3 NbO 7 /P@g-C 3 N 4 /SnS 2 was prepared by the sonochemical assisted hydrothermal method. • Er 3 NbO 7 /P@g-C 3 N 4 /SnS 2 /FTO was used for the photocatalytic detection of mercury (Hg2+). • A remarkably lower detection limit of 0.019 pM is achieved. • The practical feasibility of the photo driven sensor was evaluated in water samples like tap, pond and river water. [ABSTRACT FROM AUTHOR]

Despite the remoteness of the Antarctic continent and Southern Ocean, microplastic (MPs) contamination has been evidenced in recent years. However, the deep-sea compartments of the Southern Ocean are yet to be investigated. In the present study, we conducted a baseline MP assessment of the deep-sea waters and bottom sediments of the Bransfield Strait, Antarctica. A low abundance of suspected MPs was found. The average MP abundances in bottom sediments and water samples were 0.09 MP/g (range of 0–0.2 MP/g) and 7.00 MP/L (range of 0–16 MP/L), respectively. The majority of the particles were fibers identified as cellulose, although polyethylene terephthalate (PET) and polyacrylonitrile (PAN) was also detected. These results suggest low MP contamination levels in the Southern Ocean's deepest environmental compartments. However, future studies must aim to investigate the smallest MP fractions and, if possible, nanoplastic (<1 μm) contamination in these remote compartments. [Display omitted] • Microplastics were investigated in the Bransfield Strait. • There was a low prevalence of microplastic contamination in sediments (0–0.2 MP/g). • as well as water samples (0–16 MP/L). • Particles were mostly in the shape of fibers (100% and 90.5% in sediments and water). • Particles were mainly composed of cellulose (73.3% and 90.9% in sediments and water). [ABSTRACT FROM AUTHOR]

Water contamination is a serious environmental issue posing a significant global challenge. Roxarsone (ROX), a widely used anticoccidial drug is excreted in urine and feces, potentially disrupting natural habitats. Therefore, rapid and cost-effective ROX detection is essential. In this study, we developed a 2D sheet structure of zinc molybdate decorated on MXene (ZnMoO 4 /MXene) for detecting ROX using electrochemical methods. The materials were characterized using appropriate spectrophotometric and voltammetric techniques. The ZnMoO 4 /MXene hybrid exhibited excellent electrocatalytic performance due to its rapid electron transfer rate and higher electrical conductivity. The ZnMoO 4 /MXene-modified GCE (ZnMoO 4 /MXene/GCE) showed a broad linear range with high sensitivity (10.413 μA μМ−1 cm−2) and appreciable limit of detection (LOD) as low as 0.0081 μM. It also demonstrated significant anti-interference capabilities, excellent storage stability, and remarkable reproducibility. Furthermore, the feasibility of utilizing ZnMoO 4 /MXene/GCE for monitoring ROX in water samples was confirmed, achieving satisfactory recoveries. [Display omitted] • An electrochemical sensor is fabricated using a ZnMoO 4 /MXene nanocomposite. • This sensor determines Roxarsone with a low limit of detection of 0.0081 μM. • A wide linear range with excellent selectivity and stability is demonstrated. • The practicability of the developed sensor is estimated in water samples. [ABSTRACT FROM AUTHOR]

In this study, we present research on PFOS occurrence in surface and groundwater in Croatia. PFOS was detected and quantified at ultra-low concentrations (even ng/L) by means of LC-QTOF-MS analysis. PFOS was treated with solar photocatalysis using different reactor types, different irradiation intensities and photocatalytic formulations. Most experiments ended with only a slight change in PFOS concentrations, proving its super-resistance toward UV irradiation and oxidative species, e.g. OH radicals. In certain experiments, PFOS degradation extents were approximately 20% after 120 min of the photocatalytic process. Additionally, photocatalysis was coupled with ultrasound to increase PFOS degradation products, we discussed the tentative degradation mechanism and proposed a solution how to possibly beat its super-resistance. [Display omitted] • Quantification of PFOS in collected samples of surface water in NW Croatia. • Photo- and sonocatalysis at environmentally relevant PFOS concentration. • PFOS degraded to C5 compound in all experiments. [ABSTRACT FROM AUTHOR]

Owing to growing concerns about the adverse effects of phthalate plasticizers, non-phthalate plasticizers are being increasingly used as their replacement. However, information on the residual environmental concentrations and ecological risks posed by these plasticizers is limited. In this study, we analyzed the environmental contamination of 11 phthalates and 5 non-phthalate plasticizers in Class A and B rivers in Japan. In the considered river water samples, phthalates and non-phthalates were detected in the following order of detection frequency: phthalates (DEHP > DMP > DMEP > BBP > DNPP > DNP > DEEP > DBEP = DNOP) and non-phthalates (ATBC > DEHS > DEHA > TOTM = DIBA). Phthalate plasticizers were the most abundant and included DEHP (157–859 ng/L), DMP (

Agglomeration and passivation restrict the using zero-valent iron nanoparticles (nZVI). Enhancing the reactivity of nZVI is often accomplished by sulfurization. In this work, nZVI was sulfurized using SRB to produce biosulfurized nano zero-valent iron (BP–S-nZVI), which was then utilized as a catalyst to investigating its performance in an advanced oxidation process based on activated peroxomonosulfate (PMS). When the S/Fe was 0.05, 0.4 g/L of catalyst and 0.5 mM PMS were added to a 20 mg/L ciprofloxacin solution. In 120 min, a 90.4% clearance rate was reached. When the initial pH of the solution was within the range of 3–11, all exhibited acceptable degradation performance and were minimally affected by co-existing anions. In this activation system, hydroxyl, superoxide and sulfate radicals (•OH, O 2 •− and SO 4 •−, respectively) have been proven to be the main active species. Seven intermediates in the degradation process of CIP were identified by LC-MS analysis and two possible degradation pathways were proposed. In addition, the degradation rate of CIP was still able to reach 87.0% after five cycles, and the removal rate remained unchanged in the CIP solution with actual water samples as background. This study demonstrated that BP-S-nZVI as a catalyst for the activation of PMS for CIP degradation can still show good reactivity, which provides more possibilities for the practical application of BP-S-nZVI in the degradation of pollutants. [Display omitted] • Performance of BP-S-nZVI in an AOPs based on activated PMS. • The BP-S-nZVI/PMS system maintains high removal rates in the pH range of 3–11 and in the presence of coexisting anions. • Possible degradation mechanisms and pathways of CIP have been postulated. • BP-S-nZVI was still able to degrade CIP by 87% after five cycles. • BP-S-nZVI still shows good reactivity in real water bodies. [ABSTRACT FROM AUTHOR]

This study focused on investigating the concentrations, compositional profiles, partitioning behaviors and spatial variations of organophosphate esters (OPEs) in the Pearl River (PR), South China Sea (SCS) region, to evaluate their environmental risks. ∑OPEs concentrations in the surface water of the PR ranged from 117.5 to 854.8 ng/L in the dissolved phase and from 0.5 to 13.3 ng/L in the suspended particulate matter. In the surface seawaters of the northern and western parts of the SCS, ∑OPEs concentrations were 1.3–17.6 ng/L (mean: 6.7 ± 5.2) and 2.3–24.4 ng/L (mean: 7.6 ± 5.5), respectively. The percentage of chlorinated OPEs in surface water samples from the PR to the SCS was 79 ± 15%. Tripentyl phosphate (TPeP) (average: 28.3%) and triphenylphosphate (TPhP) (average: 9.6%) exhibited significant particulate fraction. A significant negative correlation (p < 0.05) between salt concentration and OPE congeners in seawater suggested that river runoff predominantly introduced OPEs into the coastal waters of the SCS. The findings also showed higher levels of OPEs in the PR and estuary than in offshore waters. The OPE loading from the PR into the SCS was estimated to be ∼119 t y−1. The presence of TCEP (RQ max = 2.1), TnBP (RQ max = 0.48) and TPhP (RQ max = 0.3) in PR water samples pose a high risk to aquatic organisms, whereas OPEs (RQ < 0.1) in SCS water samples do not pose a threat to aquatic organisms. This research emphasizes the environmental fate and impact of OPEs on surface waters of the PR and SCS. [ABSTRACT FROM AUTHOR]

The increasing presence of contaminants of emerging concern in wastewater and their potential environmental risks require improved monitoring and analysis methods. Direct toxicity assessment (DTA) using bioassays can complement chemical analysis of wastewater discharge, but traditional in vivo tests have ethical considerations and are expensive, low-throughput, and limited to apical endpoints (mortality, reproduction, development, and growth). In vitro bioassays offer an alternative approach that is cheaper, faster, and more ethical, and can provide higher sensitivity for some environmentally relevant endpoints. This study explores the potential benefits of using whole water samples of wastewater and environmental surface water instead of traditional solid phase extraction (SPE) methods for in vitro bioassays testing. Whole water samples produced a stronger response in most bioassays, likely due to the loss or alteration of contaminants during SPE sample extraction. In addition, there was no notable difference in results for most bioassays after freezing whole water samples, which allows for increased flexibility in testing timelines and cost savings. These findings highlight the potential advantages of using whole water samples in DTA and provide a framework for future research in this area. [Display omitted] • Adaption of in vitro bioassays of ecologically relevant endpoints for WET. • Freezing as a way of sample preservation is generally acceptable. • Samples were compared in whole water form to traditional SPE. • Samples in whole water were up to 50× more toxic than the corresponding extract. [ABSTRACT FROM AUTHOR]

This study aims the characterization of several tianeptine transformation products in ultrapure water by simulated sunlight irradiation. Tianeptine was completely degraded after 106 h of exposition following pseudo-first-order kinetics (half-life time = 12.0 ± 2.4 h). Furthermore, an ultra-high-performance liquid chromatography coupled with a high-resolution quadrupole time-of-flight-mass spectrometry method was developed and fully validated taking into account different method performance parameters for the quantification of tianeptine in river water up to a concentration of 400 pg L−1. Following a non-targeted approach based on mass data-independent acquisition, eight different transformation products not previously reported in the literature were identified and accordingly elucidated, proposing a photodegradation mechanism based on the accurate tandem mass spectrometry information acquired. Irradiation experiments were replicated for a tianeptine solution prepared in a blank river water sample, resulting in the formation of the same transformation products and similar degradation kinetics. In addition, a toxicity assessment of the photoproducts was performed by in silico method, being generally all TPs of comparable toxicity to the precursor except for TP1, and showing a similar persistence in the environment except for TP2 and TP6, while TP4 was the only TP predicted as mutagenic. The developed method was applied for the analysis of four river water samples. [Display omitted] • Tianeptine fully photodegrades in water after 106 h of simulated solar irradiation. • Tianeptine degradation kinetics in ultrapure water and river water are very similar. • Eight new transformation products of tianeptine were identified by HR MS/MS. • Same TPs were formed in both ultrapure water and river waters solutions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Operational conditions and water quality control Fe(II)/KPS acceleration. • H3NOH + converts Fe(III) to Fe(II), preserving hydroxyl and sulfate radicals. • Fe(II)/KPS/H3NOH + superior degradation in NMW, SEWTP, and river water samples. • Study showcases DNN's potential to optimize and understand intricate processes. • Optimal DNN for pararosaniline removal using 2 layers with tanh activation. [ABSTRACT FROM AUTHOR]

Atmospheres from indoor areas contain a range of volatile and semi-volatile compounds to which inhabitants are exposed through breathing. Despite different qualitative approaches have been proposed for the identification of compounds associated to the vapor phase of confined areas, active sampling remains as the preferred technique when quantitative data is required. Herein, we investigate the correlations existing between concentrations in air and water condensates obtained from indoor areas. To this end, samples of both matrices were simultaneously collected and analyzed by gas chromatography mass spectrometry. After validation of sample concentration approaches for a selection of compounds, the effect of different operational conditions, and environmental variables, in their concentrations in condensed water was assessed. Levels in this matrix were hardly affected by sampling time, air flow through the dehumidifier device, and the environmental temperature and humidity. Thus, air water distribution coefficients (K aw) could be estimated for fourteen out of sixteen pre-selected compounds. These values permitted a semiquantitative evaluation of their concentrations existing in air from different areas. In case of semi-volatile compounds (i.e. phenol, benzothiazole, phthalates), with log K aw below −4.8, analysis of 50 mL water samples permitted to achieve lower limits of quantification than active air sampling for 3 h at a flowrate of 1 m3 h−1. [Display omitted] • GC-MS quantification of volatile and semi-volatile species in water condensates. • Assessment of parameters controlling concentrations in condensed water. • Evaluation of air water partition coefficients for fourteen organic compounds. • Prediction of concentrations in air from water condensates analysis. [ABSTRACT FROM AUTHOR]

This work comprehensively demonstrates the ability of heterotrophic bacteria, isolated from a chloraminated system, to decay chloramine. This study non-selectively isolated 62 cultures of heterotrophic bacteria from a water sample (0.002 mg-N/L nitrite and 1.42 mg/L total chlorine) collected from a laboratory-scale reactor system; most of the isolates (93.3%) were Mycobacterium sp. Three species of Mycobacterium and one species of Micrococcus were inoculated to a basal inorganic medium with initial concentrations of acetate (from 0 to 24 mg-C/L) and 1.5 mg/L chloramine. Bacterial growth coincided with declines in the concentrations of chloramine, acetate, and ammonium. Detailed experiments with one of the Mycobacterium sp. isolates suggest that the common mechanism of chloramine loss is auto-decomposition likely mediated by chloramine-decaying proteins. The ability of the isolates to grow and decay chloramine underscores the important role of heterotrophic bacteria in the stability of chloramine in water-distribution systems. Existing strategies based on controlling nitrification should be augmented to include minimizing heterotrophic bacteria. [Display omitted] • From chloraminated system, heterotrophic bacteria (HB) were isolated. • 93.2% of the 59 isolates were belonging to Mycobacterium sp. • All tested isolates (3x Mycobacterium sp & 1x Micrococcus sp) decay chloramine. • Auto-decomposition by chloramine decaying protein is the primary mechanisms. • Chloramine management strategies should be enhanced to include HB. [ABSTRACT FROM AUTHOR]

Pesticides pollute natural water reservoirs through persistent accumulation. Therefore, their toxicity and degradability are serious issues. Carbendazim (CBZ) is a pesticide used against fungal infections in agricultural crops, and its overexploitation detrimentally affects aquatic ecosystems and organisms. It is necessary to design a logical, efficient, and field-deployable method for monitoring the amount of CBZ in environmental samples. Herein, a nano-engineered bismuth selenide (Bi 2 Se 3)/functionalized carbon nanofiber (f-CNF) nanocomposite was utilized as an electrocatalyst to fabricate an electrochemical sensing platform for CBZ. Bi 2 Se 3 /f-CNF exhibited a substantial electroactive surface area, high electrocatalytic activity, and high conductivity owing to the synergistic interaction of Bi 2 Se 3 with f-CNF. The structural chemical compositions and morphology of the Bi 2 Se 3 /f-CNF nanocomposite were confirmed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscopy (FESEM). Electrochemical analysis was carried out using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The voltammetry and impedance experiments exposed that the Bi 2 Se 3 /f–CNF–modified GCE has attained adequate electrocatalytic function with amended features of electron transportation (R ct = 35.93 Ω) and improved reaction sites (0.082 cm2) accessible by CBZ moiety along with exemplary electrochemical stability (98.92%). The Bi 2 Se 3 /f-CNF nanocomposite exhibited higher sensitivity of 0.2974 μA μM−1cm−2 and a remarkably low limit of detection (LOD) of 1.04 nM at a broad linera range 0.001–100 μM. The practicability of the nanocomposite was tested in environmental (tap and pond water) samples, which supports excellent signal amplification with satisfactory recoveries. Hence, the Bi 2 Se 3 /f-CNF nanocomposite is a promising electrode modifier for detecting CBZ. Fig 1: Preparation and fabrication of Bi 2 Se 3 /f-CNF nanocomposite for the electro-oxidation of CBZ in environmental water samples (Tap and pond water). [Display omitted] • Bi 2 Se 3 /f-CNF was prepared by sonochemical method. • Bi 2 Se 3 /f-CNF modified GCE was used for the electrocatalytic reduction of CBZ. • A wide linear range (1 nM-100 μM) and lower LOD (1.04 nM) for CBZ have been achieved. • Practical feasibility of the resultant sensor was evaluated in environmental samples. [ABSTRACT FROM AUTHOR]

Water bodies are frequently polluted, with sulfur oxides being the most common form of water pollution. Therefore, developing a detection mechanism for sulfur oxides in water bodies is particularly urgent. A new fluorescent probe YX-KZBD was designed and developed. This probe releases fluorescent signals with its own sulfurous acid recognition site, detects sulfurous acid based on the Michael addition reaction, and evaluates the pollution degree of sulfur oxides in the water environment through the transformation mode of the sulfur cycle. This probe has high energy transfer efficiency in aqueous solutions. In addition, the fluorescence data obtained by analyzing the water samples were linearly fitted with the gene abundance values of the functional genes of sulfur-producing bacteria, and a significant correlation was obtained. The Kriging interpolation model was used to evaluate the sulfate content distribution at each sampling point to understand the distribution of sulfur oxides in natural water intuitively. The fluorescence signal excited by the probe was also combined with a real-time quantitative polymerase chain reaction (qPCR), and sulfate-reducing and sulfur-oxidizing bacteria were introduced in the sulfur cycle, providing a new method to assess the extent of water pollution effectively. [Display omitted] • This probe associates the WQI-P value with sulfur producing bacteria. • Sulfur producing bacteria combine the sulfur cycle with fluorescence. • The fluorescence detection of the probe has specific selectivity for SO 3 2−. • The probe applies Kriging interpolation technology to water quality assessment. • Small molecule fluorescence probes combine optics with biological Earth models. [ABSTRACT FROM AUTHOR]

Herein, a coordination polymer gel is proposed for the determination of As(III) in real samples through multispectroscopic techniques viz. spectrophotometry, spectrofluorimetry, and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Taguchi L 32 (46 21) design and adaptive neuro fuzzy inference system (ANFIS) optimized the controllable factors affecting the extraction yielding an experimental S / N ratio of 39.94 dB. The fluorescence quenching (K SV = 2.63 × 106 L mol−1) was static with photoelectron transfer being the main mechanism confirmed by the density functional theory calculations. The limits of detection (LODs), limits of quantification (LOQs) and linear ranges were 0.038 μg L−1, 0.13 μg L−1 and 1.67–116.67 μg L−1, 0.40 μg L−1, 1.21 μg L−1 and 1.67–33.33 μg L−1, 1.07 μg L−1, 3.24 μg L−1 and 3.32–35.37 μg L−1 for the developed enrichment coupled ICP-AES, spectrophotometry and fluorescence sensing methods. Among these methods, the enrichment - ICP-AES method has the lowest LOD, LOQ and the widest linear range followed by the enrichment - spectrophotometry and fluorescene sensing methods. Spectrofluorimetry offers high sensitivity, selectivity, and possible real time monitoring, spectrophotometry provides a cost-effective and versatile option, while ICP-AES manifests multi-element analysis with high sensitivity and low interference. The developed methods were validated and employed for the successful determination of trace As(III) in real samples. The employment of these methods enhances the overall analytical capability for a wide range of sample types and concentrations. [Display omitted] • Coordination polymer gel enables multispectroscopic trace As(III) determination. • Taguchi with neural network and adaptive neuro fuzzy inference system for optimization. • DFT calculations confirmed PET as the main mechanism for fluorescence quenching. • LODs and LOQs being <10 μg L−1 for all the developed methods. • Successful As(III) determination in real samples establishes practical employability. [ABSTRACT FROM AUTHOR]

Most research on pharmaceutical presence in the environment to date has focused on smaller scale assessments of freshwater and riverine systems, relying mainly on assays of water samples, while studies in marine ecosystems and of exposed biota are sparse. This study investigated the pharmaceutical burden in bonefish (Albula vulpes), an important recreational and artisanal fishery, to quantify pharmaceutical exposure throughout the Caribbean Basin. We sampled 74 bonefish from five regions, and analyzed them for 102 pharmaceuticals. We assessed the influence of sampling region on the number of pharmaceuticals, pharmaceutical assemblage, and risk of pharmacological effects. To evaluate the risk of pharmacological effects at the scale of the individual, we proposed a metric based on the human therapeutic plasma concentration (H T PC), comparing measured concentrations to a threshold of 1/3 the H T PC for each pharmaceutical. Every bonefish had at least one pharmaceutical, with an average of 4.9 and a maximum of 16 pharmaceuticals in one individual. At least one pharmaceutical was detected in exceedance of the 1/3 H T PC threshold in 39% of bonefish, with an average of 0.6 and a maximum of 11 pharmaceuticals exceeding in a Key West individual. The number of pharmaceuticals (49 detected in total) differed across regions, but the risk of pharmacological effects did not (23 pharmaceuticals exceeded the 1/3 H T PC threshold). The most common pharmaceuticals were venlafaxine (43 bonefish), atenolol (36), naloxone (27), codeine (27), and trimethoprim (24). Findings suggest that pharmaceutical detections and concentration may be independent, emphasizing the need to monitor risk to biota regardless of exposure diversity, and to focus on risk quantified at the individual level. This study supports the widespread presence of pharmaceuticals in marine systems and shows the utility of applying the H T PC to assess the potential for pharmacological effects, and thus quantify impact of exposure at large spatial scales. [Display omitted] • Pharmaceuticals were detected in all fish from Caribbean coastal ecosystems. • 49 of 102 pharmaceuticals detected and 23 exceeded the 1/3 H T PC. • 39% of fish had pharmaceuticals at concentrations capable of pharmacological effects. • Number of detections and pharmaceutical concentrations varied across regions. • Exposure to pharmacologically active concentrations was unrelated to detections. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) draw considerable attention for their potential toxic effects in humans and environment. Drinking water is accepted as one of the major exposure pathways for PFASs. In this study, we measured concentrations of 10 perfluoroalkyl substances in 94 tap water samples collected in two different sampling periods (August 2017 and February 2018) from 33 provinces of Turkey, as well as in 26 different brands of plastic and glass-bottled water samples sold in supermarkets in Turkey. Perfluorohexanoic acid (PFHxA) , perfluorobutane sulfonate (PFBS) and perfluoropentanoic acid (PFPeA) were the most frequently detected PFASs in the samples of tap waters. The maximum concentrations in tap waters were measured as 2.90, 2.37, 2.18, 2.04, and 1.93 ng/L, for PFHxA, perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), and perfluorobutanoic acid (PFBA), respectively. The most abundant perfluorinated chemical in tap water samples was PFBA with 17%, followed by PFOS (13%), PFBS (12%), perfluoroheptanoic acid (PFHpA) (11%), PFHxA (11%), and PFOA (11%). The total PFASs concentration in tap water ranged from 0.08 to 11.27 ng/L. As regards bottled waters, the concentrations of PFASs were generally lower than those in tap water samples. These results revealed that tap water samples in Turkey might be considered generally safe based on the established guidelines around the world. However, due to their persistence and potential to accumulate and reach higher concentrations in the environment, careful monitoring of PFASs in all types of water is critical. Image 1 • PFASs were assessed in 94 tap water and 26 bottled water samples from Turkey. • PFHxA, PFBS, and PFPeA were detected most frequently in tap waters. • The maximum measured ∑PFASs level was 11.27 ng/L. • The maximum PFOA and PFOS levels were found 2.37 and 2.04 ng/L, respectively. • PFASs contents of bottled water samples were generally lower than tap waters. [ABSTRACT FROM AUTHOR]

The results of the validation study of the LC-ESI-MS/MS method for the determination of chlorate (ClO 3 −), perchlorate (ClO 4 −) and bromate (BrO 3 −) in water and food samples are summarized. Towards this, 284 samples of drinking water were analysed, out of which the 69% contained chlorate above the limit of quantitation (LOQ) of 0.01 mg/L, with maximum amount of 1.1 mg/L. Only 6 samples were found to be positive with perchlorate at levels <0.01 mg/L. Bromate was detected in 5 drinking water samples at levels above the LOQ, at concentrations up to 0.026 mg/L. For the validation of the method in food, 108 blank samples were spiked with chlorate and perchlorate for the LC-MS/MS analysis at two levels. In total 247 food samples from the market of 19 different commodities including fruits, vegetables, cereals and wine, were analysed. The maximum concentration of chlorate was found at 0.83 mg/kg in a sample of cultivated mushrooms. The number of samples contaminated with perchlorate was also small, with all the determined concentrations below the LOQ of 0.05 mg/kg. Experiments for the chlorate reduction in drinking water, showed that reverse osmosis treatment is effective in particular with newly installed cartridges. Finally, according to the results of the pilot study when chlorinated water is used for the plant irrigation, accumulation of chlorate is observed, especially in the green parts of the plant. Perchlorate was also detected in leafy samples, although it was not present in the irrigation water. Image 1023921 • Oxyhalides determination in food and drinking water was performed by LC-ESI-MS/MS. • 90% of drinking water samples contained chlorate; many above the regulatory limits. • Household water treatment devices except reverse osmosis failed to remove chlorate. • Market food samples do not contain chlorate if irrigation water is not chlorinated. • Chlorinated water irrigation leads to chlorate and perchlorate accumulation in plants. [ABSTRACT FROM AUTHOR]

In the previous decade, neonicotinoids (NEOs) and fipronil (FIP) have received increasing attention as environmental pollutants because the high toxicity of these insecticides to nontarget arthropods has been recognized. In this study, a new method was developed for the simultaneous determination of seven NEOs and FIP and its metabolites (FIPs) in seawater and river water samples using disk-based solid-phase extraction (SPE) and high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). The optimization of disk-based SPE extraction and HPLC separation parameters of target analytes was investigated. Under optimal conditions, the low limit of quantitation (LOQ) of 11 target analytes in actual water samples ranged from 0.05 ng/L to 0.50 ng/L. Satisfactory absolute recoveries (58.9%–109.9%), precision (relative standard deviations, ≤13.3%), and linearity (R 2 ≥ 0.995) were also achieved, thereby indicating that the developed method would be suitable to determine the target NEOs and FIPs in seawater and river water. Finally, the proposed method was applied to determine the amounts of these insecticides in authentic environmental water samples collected from Jiaozhou Bay, China, and its adjacent rivers. Nitenpyram, thiamethoxam, imidacloprid, clothianidin, and acetamiprid were detected, as well as FIPs in seawater and river water samples. This study is the first to report that NEOs and FIPs are detected in the coastal seawater. The total concentration of these insecticides ranged from ≤LOD to 11.19 ng/L, which indicates that these pesticides are eventually discharged into the marine environment. Therefore, it is necessary to investigate the temporal spatial distribution, migration and transformation, environmental fate, and bioavailability of these pesticides in further studies. Image 1 • SPE disk had favorablerecoveries for simultaneous enrichment of trace NEOs and FIPs. • A reliable analytical method was developed for NEOs and FIPs in water samples. • Several NEOs, FIP, and its metabolites were detected in Jiaozhou Bay coastal water. • The analysis of NEOs and FIPs in seawater was reported for the first time. • More attention has to be focused on environmental risks of the coastal area posed by NEOs and FIPs. [ABSTRACT FROM AUTHOR]

Globally freshwater ecosystems and associated biota including phytoplankton communities are at extreme risk from trace metal pollution originating from geogenic as well as from anthropogenic sources such as release of untreated industrial effluents. In the present study influence of iron- and arsenic-enrichments on structure and metabolism of phytoplankton communities of River Ganga, one of the largest rivers of South Asia, was assessed under laboratory-based microcosm experiments. Surface water samples were collected and subsequently enriched with higher than recommended concentrations of iron (10 mg/L) and arsenic (10 μg/L). The set-up comprised of nine containers of 25 L volume with three containers each for iron- and arsenic-enrichment and was maintained for 30 days. Trace metal enrichment rapidly changed the phytoplankton community structure and chemistry of nutrients uptake. Iron-enrichment prompted diatom blooms comprising of Thalassiosira , succeeded by green algae Coelastrum. Arsenic-enrichment maintained cyanobacteria for longer time-spans compared to the control and iron-enriched containers but significantly lesser abundance of diatoms. Variations in community composition was also reflected in nutrient uptake rates with silicate release in the arsenic-enriched containers at the end of the experiment. Changes in macronutrient dynamics also altered genus growth rates wherein both iron- and arsenic appeared to lower the death rate of Thalassosira but stimulated growth of other genera including Skeletonema and Pandorina. Iron appeared to influence lesser number of genera compared to arsenic which altered growth rates of both diatoms and green algae. This consequently influenced the gross primary productivity values which lowered both in the iron- and arsenic-enriched containers compared to the control owing to decrease in phytoplankton diversity. Iron appeared to drive phytoplankton communities toward a less general and more specialized composition with high abundance of selective species comprising of small diatoms such as Thalassio s ira , whereas arsenic appears to select for green algal enrichment in freshwater ecosystems. [Display omitted] • Enrichment of iron and arsenic using microcosm showed rapid change in uptake of nutrients by phytoplankton. • Iron-enrichment prompted diatom blooms followed by green algae.. • Arsenic-enrichment maintained cyanobacteria for longer time-span.. • Iron favored more specialized composition led by small-sized diatoms. • Gross primary productivity values found to be lower in iron- and arsenic-enriched conditions. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants (POPs) represent a possible hazard for the ecosystems, with adverse outcomes on wildlife and humans. POPs have always received interest from the scientific community, and they have also been subject to legal restrictions worldwide on their application and commercialization. Among the broad spectrum of POPs, per- and polyfluoroalkyl substances (PFASs) are considered emerging contaminants due to their potential effect on the ecosystem and human health. These contaminants are widely employed in countless applications, from surfactants and building materials to food packaging. On the other hand, their chemical structure gives them the ability to interact with the environment, causing possible toxic effects for humans and environment. Human biomonitoring is a necessary instrument to indagate the impact of PFASs on human health: in recent years several studies have found detectable levels of PFASs in several biological matrices in humans (blood, hair, nails, and urine). Here, we review the most recent scientific literature concerning analytical methods employed in the identification and quantification of PFASs focusing on biological matrices. It has been noted that liquid chromatography coupled with mass spectrometry is the main analytical instrumentation employed, while blood and/or serum samples are the main employed human matrices whereas the use of non-invasive matrices is still at the beginning. Various issues directly related to human metabolism of PFASs and the effective amount of PFAS absorbed from the environment still need to be investigated. [Display omitted] • Per- and Polyfluoroalkyl Substances (PFASs) occurrence and human biomonitoring. • PFASs identification and quantification in biological matrices. • Extraction, clean-up procedures, and instrumental conditions for PFASs analysis. [ABSTRACT FROM AUTHOR]

Humic acid (HA), the primary composition of natural organic matter (NOM) widely distributed in water and soil, can complex with heavy metal ions (HMIs), i.e., Cd(II) and Pb(II) in this study, which deters the accurate detection of HMIs using square wave anodic stripping voltammetry (SWASV). Hence, in this study, an efficient pretreatment method was proposed to restore the electrochemical signal of Cd(II) and Pb(II) by breaking the complexation based on AgNPs-doped SnO 2 photocatalyst combined with LP/UV irradiation. Optimization of the key parameters for electrochemical signal restoration including pH for photolysis, AgNPs doping rate, photocatalyst dosage and photolysis time were performed to further elevating the accuracy in the proposed pretreatment method over 96.9% for Cd(II) and Pb(II) in 15 min. The effect of different HA concentrations on SWASV signal of Cd(II) and Pb(II) was also investigated adopting the optimal parameters. Then, the UV–vis absorption spectra, crystal structure, and the morphology of AgNPs-doped SnO 2 photocatalyst were investigated to excavate the reasons behind the most excellent AgNPs doping rate to SnO 2 in signal restoration. Moreover, the behavior of HA degradation and transformation under LP/UV irradiation was studied to investigate the mechanism of electrochemical signal restoration. Finally, the feasibility of the proposed method was testified by comparing detection results with ICP-MS results using real water samples extracted from aquaculture water. [Display omitted] • The influences of humic acid on the SWASV signals of heavy metals were studied. • We proposed a water pretreatment method utilizing AgNPs-doped SnO 2. • The pretreatment parameters for SWASV detection of heavy metals were optimized. • We investigated the reasons for adopting AgNPs-doped SnO 2 in pretreatment. • The signal restoration mechanism was investigated. [ABSTRACT FROM AUTHOR]

The success of research in addressing a problem is heavily reliant on established methodologies and techniques from previous research findings. Therefore, precision and specificity are crucial to avoid drawing inaccurate conclusions. In this paper, we provide a critical commentary on a recently published research paper titled "Cost-effective remedial to microfiber pollution from wash effluent in Kolkata and Ranaghat" published in Chemosphere (DOI: https://doi.org/10.1016/j.chemosphere.2022.137548), which reports a study on microfiber pollution and its mitigation from drinking water and washing effluents in Kolkata and Ranaghat, India. Our comment focuses on the microfiber results reported by Mondal et al. (2023). Surprisingly, Mondal et al. (2023) reported microfibers in drinking water samples in higher concentration of microfibers (3000–5800 MFs/mL) compared to the washing effluents. This unusual variation in microfiber concentrations raises questions, especially considering the efficiency of conventional drinking water treatment plants in removing microfibers and exaggerated risk to public health. Based on our critical analysis of the methodology and data analysis reported by Mondal et al. (2023), we highlighted the significant errors and deficiencies present in the published article. These inaccuracies were due to inclusion of weight of suspended solids in the microfiber calculations. Our study highlighted the need of robust analytical methods for the quantification of microfibers in water sources. [ABSTRACT FROM AUTHOR]

In this work, a nanocomposite structured magnetic metal–organic framework named as Fe 3 O 4 @UiO-66-NH 2 was prepared via a simple hydrothermal approach. The as-mentioned nanocomposite was characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and the Brunauer–Emmett–Teller (BET) techniques. Using the Fe 3 O 4 @UiO-66-NH 2 as a nanosorbent, an easy and highly effective approach was developed to preconcentrate nine organic UV filters before gas chromatography–mass spectrometry (GC–MS) analysis. Different conditions influencing the extraction efficiency encompassing the sorbent amount, nature and volume of desorption solvent, desorption time, pH of the sample, and extraction time, were examined. Under the optimal experimental parameters, the Fe 3 O 4 @UiO-66-NH 2 -based magnetic solid phase extraction and GC–MS (MSPE–GC–MS) demonstrated linearity in the range of 0.03–1500 ng/L (R2 ≥ 0.9974) and the reproducibility, expressed as RSD, was ≤7.5%. The limits of detection ranged between 0.01 and 0.07 ng/L and limits of quantification were in the range of 0.03–0.4 ng/L. Finally, the suggested approach was satisfactorily utilized to determine nine organic UV filters in different water samples (analytical recoveries between 86.5% and 104.2%). [Display omitted] • Fe 3 O 4 @UiO-66-NH 2 was successfully synthesized via simple hydrothermal approach. • Fe 3 O 4 @UiO-66-NH 2 was used as a MSPE nanosorbent for the enrichment of organic UV filters in environmental water samples. • A new analytical method for the GC–MS detection of 9 organic UV filters in water is provided. • The approach has been proposed and validated demonstrating good analytical features. • The developed method has been effectively applied to analyze various environmental water. [ABSTRACT FROM AUTHOR]

Trihalomethanes (THMs) are classified as volatile organic compounds, considered to be a disinfection by-product during water disinfection process. THMs have been shown to be cytotoxic, genotoxic and mutagenic, with a risk of cancer when they contact with people directly. To protect public health and monitor water quality, it is important to monitor and measure THMs in drinking water. Therefore, it is crucial to develop fast, accurate, highly sensitivity and green analysis methods of THMs in various complicated matrices. Here, this review presents an overall summary of the current state of the pretreatment and detection methods for THMs in various sample matrices since 2005. In addition to the traditionally used pretreatment methods for THMs (such as headspace extraction, microwave-assisted extraction, liquid-liquid extraction), the new-developed methods, including solid-phase extraction, QuEChERS and different microextraction methods, have been summarized. The detection methods include gas chromatography-based methods, sensors and several other approaches. Additionally, benefits and limitations of different techniques were also discussed and compared. This study is anticipated to offer fruitful insights into the further advancement and widespread applications of pretreatment and detection technologies for THMs as well as for related substances. [Display omitted] • Advances in pretreatment and detection methods of THMs in water samples are reviewed. • The future trends of state-of-the-art techniques are thoroughly discussed. • Simple, fast, green microextraction techniques are raising substantial interest. • A comparison of various GC-based detection methods is presented. [ABSTRACT FROM AUTHOR]

Although phthalates (PAEs) are ubiquitous in drinking water, and phthalate monoesters (MPAEs) have been recognized as the bioactive metabolites of PAEs, little information is available regarding the occurrence of MPAEs in drinking water and the contributions of PAEs and MPAEs to human exposure. In this study, the concentrations of PAEs and MPAEs in 146 samples of drinking water collected from 24 cities throughout China were determined. The mean concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and di-2-ethylhexyl phthalate (DEHP) were 14.31 ± 26.28, 5.905 ± 11.57, 103.8 ± 310.5, 595.9 ± 1794, and 178.2 ± 422.0 ng/L, respectively. Monomethyl phthalate (MMP), monoethyl phthalate (MEP), monoisobutyl phthalate (MiBP), mono-n-butyl phthalate (MnBP), and mono-2-ethylhexyl phthalate (MEHP) were detected in drinking water for the first time, at mean concentrations of 12.1 ± 18.0, 2.4 ± 5.8, 11.3 ± 37.2, 36.3 ± 103, and 9.9 ± 18.0 ng/L, respectively. The geometric mean concentrations of MMP, MEP, MiBP, MnBP, and MEHP in urine samples collected from 1040 participants from 16 cities were 10.1, 19.3, 29.6, 47.3, and 3.63 μg/g creatinine, respectively. The concentrations of PAEs and MPAEs in drinking water and daily intakes (DIs) of PAEs from nine cities where drinking water and urine samples were simultaneously collected were used to estimate the contributions from drinking water. The percentages of DMP, DEP, DiBP, DnBP, and DEHP from drinking water accounted for DIs of 0.60%, 0.049%, 1.26%, 2.76%, and 0.56%, respectively. The percentages of MMP, MEP, MiBP, MnBP and MEHP via intake of drinking water accounted for urinary concentrations of 0.86%, 0.032%, 0.14%, 0.089%, and 0.045%, respectively. • MPAEs was for the first time determined in drinking water. • The percentages of PAEs from drinking water that accounted for daily intakes were 0.05%–2.76%. • The percentages of MPAEs from drinking water that accounted for the urinary concentrations were 0.02%–0.86%. [ABSTRACT FROM AUTHOR]

Abstract Herein, a method for the simultaneous determination of the currently prescribed sartan drugs (eprosartan, EPR; olmesartan, OLM; losartan, LOS; candesartan, CAN; telmisartan, TEL; irbesartan, IRB; and valsartan, VAL), and the biodegradation product valsartan acid (VALA), in water samples (raw and treated wastewater, river and tap water) was developed. Solid-phase extraction (SPE) and ultra-performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) were employed as concentration and determination techniques, respectively. Different sorbents and elution solvents were tested for sample preparation. Under optimized conditions, samples at neutral pH (6–8 units) were concentrated using mixed-mode (reversed-phase and anionic exchange) cartridges. Thereafter, the sorbent was washed with 5 mL of a methanol: water (1:1) solution, dried under a nitrogen stream and compounds were eluted with 2 mL of methanol: NH 3 (98:2). The accuracy of the method (accounting for SPE efficiency and matrix effects during electrospray ionization) was investigated using solvent-based calibration standards. Global recoveries, obtained for different water matrices (tap, river, treated and raw wastewater), ranged from 82% to 134%, with standard deviations between 2 and 18%. LOQs varied from 2 to 50 ng L−1. Analysis of un-spiked samples confirmed: (1) the incomplete removal of sartans at sewage treatment plants (STPs), (2) the formation of VALA during municipal water treatment, and (3) the presence of VALA in the processed tap water samples. Additional findings of the current study are the detection of hydroxylated derivatives of the sartan drugs IRB and LOS in wastewater, and the E-Z isomerization of EPR in environmental water samples. Graphical abstract Image 1 Highlights • Mixed-mode solid-phase extraction of sartan drugs and valsartan acid. • High extraction yields with reduced matrix effects for different water samples. • Presence of valsartan acid in drinking water catchments and tap water. • Isomerization of E -eprosartan to the Z -form in the aquatic environment. • Detection of hydroxylated metabolites of irbesartan and losartan in wastewater. [ABSTRACT FROM AUTHOR]

Abstract The widespread implementation of antiretroviral therapy medication has made antiretroviral drugs (ARVDs) a significant pharmaceutical class in regions of high HIV infection rates. However, relatively little is known regarding the environmental occurrence of these emerging contaminants, and this is especially true for their metabolites. In this work, we report analytical methods to study the simultaneous occurrence of a range of common ARVDs and some of their known metabolites in surface water and wastewater. A novel direct injection liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is reported for the analysis of ARVDs of different therapeutic classes and their selected metabolites in wastewater samples. In addition, a solid phase extraction (SPE) procedure was developed for pre-concentration of ARVs and metabolites from surface water samples. The respective methods proved suitable for the quantitative analysis of six parent ARVDs from three ARV classes, as well as three metabolites. Method validation showed average recoveries of 86% for the direct injection method, and 64% for the SPE method. With the exception of Zidovudine and the metabolites of Zidovudine and Ritonavir, all target ARVDs were detected in wastewater samples from two wastewater treatment plants in the Western Cape, South Africa. Higher concentrations were generally measured in influent compared to effluent samples, in the dry compared to the wet season as well as in chlorinated compared to uv -irradiated effluents. This study contributes for the first time quantitative data on the environmental occurrence of the known metabolites of Nevirapine (12-hydroxy-Nevirapine) and Efavirenz (8,14-dihydroxy-Efavirenz). Highlights • A new direct injection LC-MS/MS method was developed for antiretroviral drug (ARVD) analysis. • Five ARVDs and two hydroxylated metabolites were quantified in wastewater samples. • First report of metabolites 12-hydroxy-Nevirapine and 8,14-dihydroxy-Efavirenz in wastewater. • Seasonal variations observed in ARVD levels, especially during a severe drought period. • Wastewater treatment removal efficiencies varied for ARVDs and their metabolites. [ABSTRACT FROM AUTHOR]

Abstract Urban estuaries receive large volumes of effluents from municipal wastewater treatment facilities containing numerous contaminants, such as pharmaceuticals residues. Water was sampled for 16 highly prescribed pharmaceuticals at 17 sites along the Long Island Sound (LIS) estuary located in the Northeastern U.S. Pharmaceutical concentrations were highest in western LIS, ranging from non-detect to 71 ng L−1 and declining steadily eastward, while river samples from four major tributaries ranged from non-detect to 83 ng L−1. Two tracers, sucralose and caffeine, accurately predicted pharmaceutical behavior in LIS while only sucralose was effective at the river sites. Sucralose also tracked well with the salinity gradient in LIS, exhibiting conservative behavior along the transect. Attenuation factors were determined for measurable pharmaceuticals and compared against sucralose to estimate the magnitude of decline in concentrations that may be attributable to in situ degradation and partitioning. The results demonstrate sucralose's effectiveness as a tracer of wastewater-borne contaminants under estuarine conditions. Highlights • Sucralose demonstrated conservative behavior when compared to salinity. • New York Harbor is the major source of pharmaceuticals to the estuary. • Sucralose proved effective as a tracer of pharmaceuticals. • Attenuation factors identified varied behavior of pharmaceuticals. [ABSTRACT FROM AUTHOR]

Abstract The ban on perfluorooctanoic acid (PFOA) has led to the production and use of alternative fluorinated compounds such as GenX. Limited information is available on the occurrence of this PFOA substitute. In this pilot study, we investigated the presence of GenX in/on grass and leaf samples collected near a fluoropolymer manufacturing plant in the Netherlands and in drinking water produced from surface and surface-water influenced groundwater intake points within 25 km from the plant. GenX was detected in/on all grass and leaf samples collected within 3 km north-east from the plant, with levels ranging from 1 to 27 ng/g wet weight (ww) and 4.3–86 ng/g ww, respectively. The PFOA levels in/on grass and leaves were lower, ranging from 0.7 to 11 ng/g ww and 0.9–28 ng/g ww, respectively. A declining concentration gradient of GenX and PFOA with increasing distance from the plant was observed, which suggests that the plant is a point source of GenX and was a point source for PFOA in the past. In all drinking water samples, GenX and PFOA were detected with levels ranging from 1.4 to 8.0 ng/L and 1.9–7.1 ng/L, respectively. The detection of GenX, which is only used since 2012, in/on grass and leaves and in drinking water indicates that GenX is now distributed through the environment. The presence of GenX and PFOA in/on grass and leaves within 3 km north-east of the plant also suggests that these chemicals could also be present on the locally grown food in gardens around the factory. Graphical abstract Image 1 Highlights • GenX detected in grass and leaves collected within 3 km from Teflon plant. • Declining gradient of GenX with increasing distance from plant. • Strong indications of plant being a point source of GenX. • GenX and PFOA also detected in drinking water samples. [ABSTRACT FROM AUTHOR]

Abstract Microcystins (MCs) are hepatotoxins that have been considered to be a worldwide problem due the effects that they can cause to environmental and human health systems. The Iraí Reservoir, located in the South of Brazil, is used as a water supply and MCs concentrations have been reported in this ecosystem. This study aimed to determine the MCs concentrations in the Iraí Reservoir and to evaluate the MCs depuration time and the health of Geophagus brasiliensis using biomarkers. Water and fish samples were collected in the Iraí Reservoir from August 2015 to May 2016. Phytoplankton and chemical analyses were conducted using water samples and the fish were divided into two groups; the Immediate Group (IMM) and the Depuration Group (DEP). In the IMM group, the blood, liver, muscle, brain and gills were collected, in order to evaluate the genotoxic, biochemical and chemical biomarkers. The DEP group was used in the depuration experiment for 90 days, and after this period the fish were submitted to the same procedure as the IMM group. Our results suggested that fish accumulated MCs and it may have caused oxidative stress, neurotoxicity and molecular damage. Furthermore, MCs concentrations increased during the depuration time and it resulted in molecular damage over the first 30 days. After 90 days, the recovery of the antioxidant system occurred. The depuration started on the 15th day, however, the toxins were still present in the samples. Therefore, the effects and the persistence of MCs are a risk to environmental systems and human health. Highlights • The Iraí Reservoir is contaminated by Microcystins (MCs). • Fish have accumulated MCs above the established limit for human consumption. • Neurotoxicity, oxidative stress, molecular and liver damage were observed in fish. • A recovery of the antioxidant system and molecular damage was present 90 days after. • After the depuration time, MCs were still detected in the muscles of the fish. [ABSTRACT FROM AUTHOR]

Abstract Increasing metal consumption is driving the introduction of new techniques such as biomining to exploit low grade ores. The biomining impacts notably aquatic ecosystems, yet, the applicability of ecotoxicological tests to study the complex mixture effects of mining waters is insufficiently understood. The aim of the present work was to test if transcriptomic biomarkers are suitable and sensitive for the ecotoxicity assessment of biomining affected waters. The study site had been affected by a multimetal biomine, and the studied water samples formed a concentration gradient of contamination downstream from the biomining site. Cadmium and nickel were used as positive controls in the toxicity tests. Selected transcriptomic biomarkers, previously shown to be differentially regulated by metals, were used to evaluate the ecotoxicity of the water samples. Parallel samples were used to compare the transcriptomic biomarkers with the conventional acute D. magna toxicity test. In the acute test, one sample was acutely toxic to D. magna, when pH was adjusted according to the standard, whereas, in the native pH, three samples caused total immobility. Monooxygenase was up-regulated by the highest concentration of Cd in control samples and three of the water samples. Vtg-SOD was up-regulated by one of the water samples, and catalase by the second highest concentration of Cd. The results show that transcriptomic biomarkers in D. magna can be used as sensitive bioindicators for metal mixture toxicity assessment in complex environmental water samples. Highlights • Biomining affected waters show sub-lethal toxicity to Daphnia magna. • Water samples up-regulated monooxygenase , vtg-sod and catalase. • Transcriptomic biomarkers are more sensitive than acute toxicity tests. [ABSTRACT FROM AUTHOR]

Treatment of waters contaminated by per- and polyfluoroalkyl substances (PFAS) in large volumes remains a challenge to date. Treatment trains comprising separation and destruction technologies are promising to manage PFAS contamination. Foam fractionation (FF) and electrochemical oxidation (EO) are two cost-effective technologies for PFAS separation and destruction, respectively. This work systematically explored the performance of a treatment train of FF followed by EO (FF-EO) for treating PFAS in environmental water samples. For each treatment step, the dependence of the treatment performance on operational factors and other variables were analyzed statistically. The statistical analysis revealed PFAS enrichment and removal depend significantly on PFAS carbon chain length, solution conductivity, and PFAS concentration. Whether FF-EO treatment costs less energy than direct EO without FF mainly relies upon PFAS carbon chain length and TOC content in the sample. Both correlations were found to be linear. For all environmental water samples in this study, FF-EO is more energy-efficient than EO alone. [Display omitted] • Foam fractionation (FF) and electrochemical oxidation (EO) effectively treat PFAS. • PFAS chain length, concentration, solution conductivity significantly affect FF. • PFAS chain length, total organic matter significantly affect FF-EO energy cost. • FF-EO is more energy efficient than EO alone in treating environmental samples. [ABSTRACT FROM AUTHOR]

The colloidal transport of trace (Fe, Al, Ba, Pb, Sr, U) and ultra-trace (226Ra) elements was studied in a mining environment. An original approach combining 0.45 μm filtered water sampling, the Diffusive Gradient in Thin films (DGT) technique, mineralogical characterization, and geochemical modelling was developed and tested at 17 sampling points. DGT was used for the truly dissolved fraction of the elements of interest, while the 0.45 μm filtration includes both colloidal and truly dissolved fractions (together referred to as total dissolved fraction). Results indicated a colloidal fraction for Al (up to 50%), Ba (up to 86%), and Fe (up to 99%) explained by the presence of submicrometric grains of kaolinite, barite, and ferrihydrite, respectively. Furthermore, the total dissolved 226Ra concentration in the water samples reached up to 10–25 Bq/L (1.2–3.0 10−12 mol/L) at 3 sampling points, while the truly dissolved aqueous 226Ra concentrations were in the mBq/L range. Such high total dissolved concentrations are explained by retention on colloidal barite, accounting for 95% of the total dissolved 226Ra concentration. The distribution of 226Ra between the truly dissolved and colloidal fractions was accurately reproduced using a (Ra x ,Ba 1-x)SO 4 solid solution, with values of the Guggenheim parameter a 0 close to ideality. 226Ra sorption on ferrihydrite and kaolinite, other minerals well known for their retention properties, could not explain the measured colloidal fractions despite their predominance. This illustrates the key role of barite in such environments. The measured concentrations of total dissolved U were very low at all the sampling points (<4.5 10−10 mol/L) and the colloidal fraction of U accounted for less than 65%. U sorption on ferrihydrite could account for the colloidal fraction. This original approach can be applied to other trace and ultra-trace elements to complement when necessary classical environmental surveys usually performed by filtration on 0.45 μm. [Display omitted] • An innovative approach was developed to assess the colloidal transport of 226Ra and U. • Water sampling, DGT, and solid characterization were combined with geochemical modelling. • 226Ra colloidal transport is explained by coprecipitation into barite. • This approach can be applied to other trace elements. [ABSTRACT FROM AUTHOR]

Rivers are known for carrying out a fundamental role in the transportation of human debris from continental areas to the marine environment and have been identified as hotspots for plastic pollution. We characterized microplastics (MPs) along confluence areas in the Paraíba do Sul River basin, the biggest river in southeastern Brazil. This water body crosses highly industrialized areas, with the highest population density, and the major water demand in South America. Considering the important ecological function of this extensive watershed and the implications of MP pollution, we evaluate the spatial variation of MP concentration in the confluence areas and upstream from the confluence. Samples were taken from the superficial layer of the water column in February and June 2022, using manta net with 300 μm mesh size. A total of 19 categories and 2870 plastic particles were determined. The confluences areas of rivers showed the highest concentration of MPs, highlighting the confluences of the Paraiba do Sul and Muriaé rivers (0.71 ± 0.25 MP/m3), followed by Paraíba do Sul and Dois Rios rivers (0.42 ± 0.23 MP/m3) and Paraíba do Sul and Pomba rivers (0.38 ± 0.14 MP/m3). Black fibers were the main category, followed by blue fibers and blue fragments. The MPs in the surface waters of Paraíba do Sul River is significantly influenced by the sampling points spatiality. This result corroborates other studies around the world and reinforces the argument that affluents are important sources for the introduction of MPs in larger rivers. Nevertheless, our results provide a better understanding of the different contributing factors and occurrence of MPs in river basins. [Display omitted] • Microplastics were found in all surface water samples from the Paraiba do Sul River. • River confluence present greater concentration of microplastics upstream areas. • Fibers were predominant category of microplastics in Paraiba do Sul River. [ABSTRACT FROM AUTHOR]

In this work, an evaluation of the occurrence of fifteen phthalates, four metabolites and one adipate in different groundwater, seawater and wastewater samples has been carried out due to their relevance on human health as they act as endocrine disruptors. For this purpose, a sustainable, fast and easy-handling vortex-assisted liquid-liquid microextraction method using a natural hydrophobic deep eutectic solvent based on menthol and carvacrol as extraction agent, combined with ultra-high performance liquid chromatography-mass spectrometry technique, has been developed and applied for the first time. An optimization was performed to evaluate four important factors affecting the extraction performance, and an analytical validation was carried out in terms of matrix effect, linearity, extraction efficiency, and sensitivity. Recovery values were obtained in the range 72–119% for all analytes (except for monoethyl phthalate: 61.1–72.3%) with relative standard deviation values lower than 17%. Limits of quantification were found between 0.91 and 8.09 μg L−1. As a result of the assessment of 31 different environmental water samples, monoethyl phthalate, diethyl phthalate, dibutyl phthalate and bis (2-ethylhexyl) phthalate were detected and quantified at different concentrations in the range 2.59–21.17 μg L−1 in 6 samples, and diallyl phthalate, butyl benzyl phthalate, dipentyl phthalate, dicyclohexyl phthalate, dihexyl phthalate and bis (2-ethylhexyl) adipate were detected in 20 more, showing the exposition of the population to these hazardous substances. [Display omitted] • Occurrence of endocrine disruptors was evaluated in 31 environmental water samples. • A NAHDES-based VA-LLME was used to extract PAEs, MPEs and DEHA for the first time. • The method was validated in groundwater, seawater, and wastewater matrices. • Recovery in the range 61–119% and LOQ in the range 0.91–8.09 μg L−1 were obtained. • MEP, DEP, DBP and DEHP were found at concentrations between 2.59 and 21.17 μg/L. [ABSTRACT FROM AUTHOR]

The degradation of the diphenyl-ether herbicides aclonifen (ACL) and bifenox (BF) in water samples has been studied under different laboratory conditions, using in-tube solid-phase microextraction (IT-SPME) coupled to capillary liquid chromatography (capLC). The working conditions were selected in order to detect also bifenox acid (BFA), a compound formed as a result of the hydroxylation of BF. Samples (4 mL) were processed without any previous treatment, which allowed the detection of the herbicides at low ppt levels. The effects of temperature, light and pH on the degradation of ACL and BF have been tested using standard solutions prepared in nanopure water. The effect of the sample matrix has been evaluated by analysing different environmental waters spiked with the herbicides, namely ditch water, river water and seawater. The kinetics of the degradation have been studied and the half-life times (t 1/2) have been calculated. The results obtained have demonstrated that the sample matrix is the most important parameter affecting the degradation of the tested herbicides. The degradation of both ACL and BF was much faster in ditch and river water samples, where t 1/2 values of only a few days were observed. However, both compounds showed a better stability in seawater samples, where they can persist for several months. In all matrices ACL was found to be more stable than BF. In samples where BF had been substantially degraded, BFA was also detected, although the stability of this compound was also limited. Other degradation products have been detected along the study. [Display omitted] • The degradation of the herbicides bifenox and aclonifen in water has been studied. • Bifenox acid, the main degradation product of bifenox, has been also tested. • The effects of temperature, light, pH and sample matrix is reported. • Nanopure, ditch, river and sea water samples have been tested. • Degradation rates and half-life times in the different waters are reported. [ABSTRACT FROM AUTHOR]

The current study evaluated the effectiveness of Tamarindus indica L. seed polysaccharides in removing fluoride from potable water collected from Sivakasi,Viruthunagar district, Tamil Nadu, India. The physiochemical properties of the water samples were examined, and each parameter was compared to the standard prescribed by Bureau of Indian standards. Most of the parameters were within the permissible limit except for fluoride levels in the Sivakasi water sample. Polysaccharides were isolated from Tamarindus indica L. seeds and the fluoride removal efficacy of the polysaccharides was evaluated. The optimum treatment dosage of the isolated seed polysaccharides was determined using aqueous fluoride solutions of various ppm concentrations (1, 2, 3, 4, and 5 ppm). Tamarindus polysaccharides were added to the aqueous solutions in varying doses (0.02, 0.04, 0.06, 0.08, 1.0, and 1.2 g), and 0.04 g was observed to be the most effective at removing fluoride (by 60%). It was selected as the optimum dose for treating the fluoride-contaminated water sample. Following the treatment, fluoride concentration in the water sample dropped from 1.8 mg/L to 0.91 mg/L, falling below the BIS standard limit. The findings from the study demonstrated the use of T. indica L. seed polysaccharides as an effective natural coagulant for removing fluoride from potable water. GC-MS and FTIR analysis of the isolated polysaccharide samples were performed. The FTIR results revealed the functional groups that might attribute to the fluoride removal activity of the isolated polysaccharides. The observations from the study suggested that Tamarindus polysaccharides might be used as an alternative to chemical agent used for fluoride removal in order to preserve the environment and human welfare. [Display omitted] • Tamarindus indica L. is an effective natural coagulant. • Tamarindus indica L. seed powder was used to isolate polysaccharides. • The isolated polysaccharides removed 49% of fluorides from potable water sample. • Higher agglomeration saturation level is attained at 0.04 g polysaccharide treatment. [ABSTRACT FROM AUTHOR]

A sensitive electrochemical device was suggested via the modification of a simple graphite rod electrode (GRE) with cobalt hydroxide (Co(OH) 2) nanosheets. After closed circuit process on the modified electrode, the anodic stripping voltammetry (ASV) technique was used for measuring of Hg(II). In optimal experimental conditions, the suggested assay depicted a linear response over a broad range in the range 0.25–30 μg L−1, with the lowest detection limit of 0.07 μg L−1. Besides good selectivity, the sensor also indicated excellent reproducibility with a relative standard deviation (RSD) value of 2.9%. Moreover, the Co(OH) 2 -GRE showed satisfactory sensing performance in real water samples with appropriate recovery values (96.0–102.5%). Additionally, possible interfering cations were examined, but no significant interference was found. By taking some merits such high sensitivity, remarkable selectivity and good precision, this strategy is expected to provide an efficient protocol for the electrochemical measuring of toxic Hg(II) in environmental matrices. [Display omitted] • Co(OH) 2 nanosheets can be employed for the efficient electrochemical monitoring of toxic Hg(II). • Using ASV method, low detection limit can be obtained with the Co(OH) 2 -GRE. • The methodology was successfully applied for Hg(II) monitoring in real water samples. [ABSTRACT FROM AUTHOR]

In this study, an investigation on the pollution status, distribution, and ecological risk to the aquatic organisms of six organophosphate tri-esters (tri-OPEs) and two organophosphate tri-esters (di-OPEs) in surface water in urban Hanoi, Vietnam were conducted. In 37 surveyed water samples (6 rivers and 17 lakes), all eight targeted OPEs were discovered with a detection frequency (DF) of 41–100% and the concentration varied largely from below the method detection limit (

Passive sampling with in situ devices offers several advantages over traditional sampling methods (i.e., discrete spot sampling), however, data interpretation from conventional passive samplers is hampered by difficulties in estimating the thickness of the diffusion layer at the sampler/medium interface ( δ ), often leading to inaccurate determinations of target analyte concentrations. In this study, the performance of a novel device combining active and passive sampling was investigated in the laboratory. The active-passive sampling (APS) device is comprised of a diffusion cell fitted with a pump and a flowmeter. Three receiving phases traditionally used in passive sampling devices (i.e., chelex resin, Oasis HLB, and silicone rubber), were incorporated in the diffusion cell and allowed the simultaneous accumulation of cationic metals, polar, and non-polar organic compounds, respectively. The flow within the diffusion cell was accurately controlled and monitored, and, combined with diffusion coefficients measurements, enabled the average δ to be estimated. Strong agreement between APS and time-averaged total concentrations measured in discrete water samples was found for most of the substances investigated. Accuracies for metals ranged between 87 and 116%, except Cu and Pb (∼50%), whilst accuracies between 64 and 101%, and 92 and 151% were achieved for polar and non-polar organic compounds, respectively. These results indicate that, via a well-defined in situ preconcentration step, the proposed APS approach shows promise for monitoring the concentration of a range of pollutants in water. [ABSTRACT FROM AUTHOR]

The clastogenic effects of water samples in seven locations of Lake Sevan (Armenia) with the application of Trad-MCN (micronuclei) bioassay using Tradescantia (clone 02) were investigated. A significant increase in the frequency of micronuclei in tetrads of pollen microspores and tetrads with micronuclei exposed to the test samples compared to the control has been revealed. A multivariate analysis indicated linkage between the frequencies of occurrence of micronuclei in the cells and Ni and Co ions. The results were compared with the endpoints of another Tradescantia -based test system (stamen hair mutation test) performed on the same water samples and generation of the plant: occurrences of micronuclei in sporogenic cells coincided with that of non-surviving stamen hair. [ABSTRACT FROM AUTHOR]

Iodinated disinfection byproducts (DBPs) are an emerging category of halogenated DBPs in concern due to their high toxicity. Among them, polar iodinated DBPs, mainly including iodinated haloacetic acids (HAAs) and aromatic iodinated DBPs, were reported to be especially toxic. Thus, simultaneous determination of these polar iodinated DBPs in disinfected waters is of great significance for DBP studies. In this study, it was found that traditional liquid-liquid extraction, which was adopted for the determination of polar iodinated DBPs, was actually not suitable for the determination of monoiodoacetic acid (MIAA) and diiodoacetic acid (DIAA) due to the low recoveries, and thus a new SPE-HPLC-MS/MS method was developed for the simultaneous determination of iodinated HAAs and aromatic iodinated DBPs. The parameters for SPE pretreatment were optimized, including SPE cartridge, eluent volume, formic acid content in eluent, and sample pH before SPE. The new method was demonstrated to be sensitive and accurate with detection limits of 0.15, 0.04, 0.03, 0.02, 0.06, and 0.06 ng/L, quantitation limits of 0.48, 0.13, 0.10, 0.06, 0.19, and 0.19 ng/L, and precision of 8.3%, 6.0%, 12.3%, 8.8%, 11.4%, and 15.6% for MIAA, DIAA, 3,5-diiodo-4-hydroxybenzaldehyde, 3,5-diiodosalicylic acid, 2,6-diiodo-4-nitrophenol and 2,4,6-triiodophenol, respectively. The recoveries of these six polar iodinated DBPs were all in the range of 70–110%. The new method was applied to the determination of iodinated HAAs and aromatic iodinated DBPs in nine tap water samples, and they were detected with concentrations ranging from 0.03 to 3.97 ng/L, among which MIAA was detected in all the samples with the highest concentrations. [ABSTRACT FROM AUTHOR]

In this study, SPE method using a carbon aerogel(CA)-based sorbent was developed and evaluated for the simultaneous extraction of sulfur mustard (HD) degradation products from environmental water samples. Applied CAs proved to be very promising materials for use as SPE sorbents, due to their high porosity, very low density and a large specific surface area. 10 degradation products of HD, both aliphatic and cyclic (thiodiglycol (TDG), TDG sulfoxide, TDG sulfone, 3,5-dithia-1,7-heptanediol, 3,6-dithia-1,8-octanediol, 1,4-thioxane, 1,3-dithiolane, 1,4-dithiane, 1,2,5-trithiepane, and 1,4,5-oxadithiepane) were extracted on a CA-based SPE cartridge. The concentrations of target analytes in the eluate were determined by HPLC-DAD and CE-DAD. Several parameters affecting the extraction efficiency, including the kind and volume of the eluting solvent, sample loading flow rate, volume and ionic strength as well as the reusability of the cartridge, were investigated and optimized to achieve the best performance for the analytes. A series of quantitative parameters such as linear range, coefficient of determination, LOD, LOQ and precision were examined under the optimized conditions. High sensitivity (LODs 0.17–0.50 μM) and high precision (intraday RSD = 2.0–7.7% and interday RSD = 2.7–9.9%) for all the analytes were achieved. The performance of the CA-based sorbent was compared with that of commonly used SPE sorbents. Applied for the analysis of spiked pore water samples collected from the Bornholm Basin, one of the largest chemical warfare dumping sites in the Baltic Sea, the proposed method allowed high SPE recoveries of all the analytes ranging from 83.5 to 99.7% to be obtained. [ABSTRACT FROM AUTHOR]

Glyphosate (PMG) is one of the most widely used herbicides with a reported 8.6 million tons applied globally in 2016. Due to widespread use and limited understanding of long-term environmental impacts, it is expected that future monitoring requirements for PMG and its primary metabolite aminomethyl phosphonic acid (AMPA) in aquatic environments will increase, along with the need for low cost monitoring and risk assessment strategies. The aim of this study was to investigate a microporous polyethylene tube (MPT; 2-mm thickness, 17.6 cm 2 surface area, 35% porosity, 2.5 μm pore size) as a diffusive layer for the passive sampling of PMG and AMPA. Levels of PMG and AMPA sorbed to MPT were low ( K mw close to 1 mL g −1 ), validating MPT as a diffusive layer. Uptake experiments were conducted first under controlled laboratory conditions (pH = 6.8, 6 days), followed by an in situ freshwater lake system deployment (pH = 7.3, 11 days). PMG and AMPA accumulated linearly (slope relative standard deviation < 6%) under laboratory conditions with sampling rates ( R s ) of 18 and 25 mL d −1 , respectively. PMG in situ R s was 28 mL d −1 , and was not different from the one found in the laboratory. AMPA was below the limit of quantification (LOQ, 1 ng mL −1 ) in grab water samples, but was detected (>LOQ) in all passive samplers. Results illustrate the gain in sensitivity provided by the passive sampling technique, and the applicability of the device developed for the passive sampling of PMG and AMPA. [ABSTRACT FROM AUTHOR]

Lake Bosten is the largest oligosaline lake in arid northwestern China, and water from its tributaries and evaporation control the water balance of the lake. In this study, water quality and chromophoric dissolved organic matter (CDOM) absorption and fluorescence were investigated in different seasons to elucidate how hydraulic connectivity and evaporation may affect the water quality and variability of CDOM in the lake. Mean suspended solids and turbidity were significantly higher in the upstream tributaries than in the lake, the difference being notably more pronounced in the wet than in the dry season. A markedly higher mean first principal component (PC1) score, which was significantly positively related to protein-like components, and a considerably lower fluorescence peak integration ratio – I C : I T , indicative of the terrestrial humic-like CDOM contribution percentage, were observed in the lake than in the upstream tributaries. Correspondingly, notably higher contribution percentages of terrestrial humic-like components were observed in the river mouth areas than in the remaining lake regions. Furthermore, significantly higher mean turbidity, and notably lower mean conductivity and salinity, were recorded in the southwestern Kaidu river mouth than in the remaining lake regions in the wet season. Notably higher mean salinity is recorded in Lake Bosten than in upstream tributaries. Autochthonous protein-like associated amino-acids and also PC1 scores increased significantly with increasing salinity. We conclude that the dynamics of water quality and CDOM composition in remote arid Lake Bosten are strongly driven by evaporation and also the hydraulic connectivity between the upstream tributaries and the downstream lake. [ABSTRACT FROM AUTHOR]

Wastewater treatment plants (WWTPs) serve as point-source inputs for a variety of nutrients often dominated by nitrogenous compounds as a result of anthropogenic influence. These effluents can impact biogeochemical cycles in freshwater estuaries, influencing microbial communities in both the water and sediment compartments. To assess the impact of point source nutrients, a transect of sediment and pore water samples were collected from 4 locations in the Little River Sub-watershed including locations above and below the Little River Pollution Control Plant (LRPCP). Variation in chemistry and microbial community/gene expression revealed significant influences of the effluent discharge on the adjacent sediments. Phosphorus and sulfur showed high concentrations within plume sediments compared to the reference sediments while nitrate concentrations were low. Increased abundance of denitrifiers Dechloromonas , Dok59 and Thermomonas correlating with increased expression of nitrous-oxide reductase suggests a conversion of N 2 O to N 2 within the LRPCP effluent sediments. This study provides valuable insight into the gene regulation of microbes involved in N metabolism (denitrification, nitrification, and nitrite reduction to ammonia) within the sediment compartment influenced by wastewater effluent. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the bioavailability of trace metals (Chromium, Copper, Nickel, Lead, Zinc, Cadmium, Arsenic, and Mercury) in the commercially consumed Crassostrea gigas oysters collected over a 12-month growth period (2011–12) from an experimental cultivation farm in La Pitahaya, Sinaloa State, Mexico. Sediment and water samples were also collected from four different zones adjacent to the cultivation area to identify the concentration patterns of metals. The results revealed that sewage disposals, fertilizers used for agricultural practices and shrimp culture are the major sources for the enrichment of certain toxic metals. The metal concentrations in oysters presented a decreasing order of abundance (all values in mg Kg −1 ): Zn (278.91 ± 93.03) > Cu (63.13 ± 31.72) > Cr (22.29 ± 30.23) > Cd (14.54 ± 4.28) > Ni (9.41 ± 11.33) > Pb (2.22 ± 1.33) > As (0.58 ± 0.91) > Hg (0.04 ± 0.06). Bioconcentration Factor (BCF) and Biota Sediment Accumulation Factor (BSAF) exhibited that C. gigas in the region are strong accumulators for Zn and Cd respectively. Thus, the present study proves to fulfill the gap in understanding the rate of bioaccumulation of metals in C. gigas which is regarded as the most sought after oyster species globally. [ABSTRACT FROM AUTHOR]

There are several established methods for the determination of naphthenic acids (NAs) in waters associated with oil sands mining operations. Due to their highly complex nature, measured concentration and composition of NAs vary depending on the method used. This study compared different common sample preparation techniques, analytical instrument methods, and analytical standards to measure NAs in groundwater and process water samples collected from an active oil sands operation. In general, the high- and ultrahigh-resolution methods, namely high performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) and Orbitrap mass spectrometry (Orbitrap-MS), were within an order of magnitude of the Fourier transform infrared spectroscopy (FTIR) methods. The gas chromatography mass spectrometry (GC-MS) methods consistently had the highest NA concentrations and greatest standard error. Total NAs concentration was not statistically different between sample preparation of solid phase extraction and liquid-liquid extraction. Calibration standards influenced quantitation results. This work provided a comprehensive understanding of the inherent differences in the various techniques available to measure NAs and hence the potential differences in measured amounts of NAs in samples. Results from this study will contribute to the analytical method standardization for NA analysis in oil sands related water samples. [ABSTRACT FROM AUTHOR]