Illuminating Bacterial Contamination in Water Sources: The Power of Fluorescence-Based Methods.

Bacterial contamination of water sources is a significant public health concern, and therefore, it is important to have accurate and efficient methods for monitoring bacterial concentration in water samples. Fluorescence-based methods, such as SYTO 9 and PI staining, have emerged as a promising approach for real-time bacterial quantification. In this review, we discuss the advantages of fluorescence-based methods over other bacterial quantification methods, including the plate count method and the most probable number (MPN) method. We also examine the utility of fluorescence arrays and linear regression models in improving the accuracy and reliability of fluorescence-based methods. Overall, fluorescence-based methods offer a faster, more sensitive, and more specific option for real-time bacterial quantification in water samples.

Assessment of legacy and emerging PFAS in the Oder River: Occurrence, distribution, and sources.

The purpose of the study was to evaluate the occurrence and distribution of emerging contaminants, poly- and perfluoroalkyl substances (PFAS), in the Polish Oder River, aiming to uncover new insights into their environmental impact. The research aimed to identify potential sources of PFAS, assess water quality levels, and verify compliance with European Union environmental quality standards. The concentrations of 25 PFAS (20 legacy and 5 emerging) in 20 samples from intakes upstream and downstream of urban areas were analyzed using novel, developed in these studies, environmental analytical procedures involving solid phase extraction and liquid chromatography-tandem mass spectrometry. The presence of 14 PFAS was confirmed, and the concentration of Σ14PFAS ranged from 7.6 to 68.0 ng/L. The main components were short-chain analogs. PFBA was the most abundant, accounting for about one-third of all PFAS detected. An exception was observed in the waters of the Gliwice Canal, where ADONA represented half of the detected Σ14PFAS. Alternative PFOS replacements were found in all samples. In 11 of 20 water samples, environmental quality standards for PFOS exceeded the limit of 0.65 ng/L. In 5 of 9 cases, the ability of urban areas to increase PFAS levels in the river was determined. 9.5%-54.4% share of alternative PFAS in relation to the sum of the targeted PFAS showing their increasing use as substitutes for phased-out PFOS. Hierarchical cluster analysis was used to identify potential sources of PFAS. Analysis revealed that PFAS in the Oder River most likely originated from domestic and agricultural wastewater, as well as chemical industry discharges. However, the occurrence of PFAS in the Oder River is low and comparable to other recent European studies. These findings provide valuable insights for environmental management to mitigate the risks associated with PFAS pollution in Polish rivers. Moreover, the developed analytical procedure provides a valuable tool that can be successfully applied by other researchers to monitor PFAS in rivers around the world.

Heavy metal profile with health risk peculiarities in Enugu State and their long-term challenges in drinking water.

Health authorities are particularly concerned about water security in Enugu, southeast Nigeria and heavy metal (HM) pollution. The HM profiles of 51 samples collected from 17 different commercial bottled water brands in Enugu were examined using an flame atomic absorption spectroscopy. Cd, Cr, Cu, Pb, Ni, and Zn had mean values of 0.15 ± 0.03, 0.03 ± 0.02, 0.16 ± 0.03, 0.13 ± 0.02, and 0.02 ± 0.01 mg/L, respectively. The highest levels of Pb2+ were 0.27 mg/L in Exalté, Ni2+ 0.26 mg/L in Jasmine, Cd2+ 0.36 mg/L in Ezbon, Cr3+ 0.07 mg/L in Trinity, Cu2+ 0.04 mg/L in Bigi, and Zn2+ 0.02 mg/L in Aquarapha. The amounts of Cr, Cu, and Zn were below the allowable limits; nevertheless, the Pb content in eight bottled water samples exceeded both the Nigerian and World Health Organization (WHO)/U.S. Environmental Protection Agency (USEPA) permissible limits. The Cd2+ and Ni2+ levels in the 11th and 4th bottled water samples were above the WHO/USEPA-approved limits. Statistical evaluation revealed significant differences in the amounts of HM ions in the samples (p < 0.05). The findings indicated that concentration levels of Cd2+ Ni2+, and Pb2+ pose a public health concern that needs to be addressed due to potential risk to consumer health.

Analyses of drinking water quality during a protracted cholera epidemic in Malawi - a cross-sectional study of key physicochemical and microbiological parameters.

Anecdotal evidence and available literature indicated that contaminated water played a major role in spreading the prolonged cholera epidemic in Malawi from 2022 to 2023. This study assessed drinking water quality in 17 cholera-affected Malawi districts from February to April 2023. Six hundred and thirty-three records were analysed. The median counts/100 ml for thermotolerant coliform was 98 (interquartile range (IQR): 4-100) and that for Escherichia coli was 0 (IQR: 0-9). The drinking water in all (except one) districts was contaminated by thermotolerant coliform, while six districts had their drinking water sources contaminated by E. coli. The percentage of contaminated drinking water sources was significantly higher in shallow unprotected wells (80.0% for E. coli and 95.0% for thermotolerant coliform) and in households (55.8% for E. coli and 86.0% for thermotolerant coliform). Logistic regression showed that household water has three times more risk of being contaminated by E. coli and two and a half times more risk of being contaminated by thermotolerant coliform compared to other water sources. This study demonstrated widespread contamination of drinking water sources during a cholera epidemic in Malawi, which may be the plausible reason for the protracted nature of the epidemic.

Negative effects of cigarette butt leachate on freshwater phytoplankton communities.

We experimentally tested the effects of different concentrations of cigarette butt leachate on freshwater phytoplankton chlorophyll-a, species richness, cell density, and community composition. For this, we sampled the phytoplankton from a eutrophic lake and acclimated it for 24 h in microcosms. We then conducted the experiment in microcosms maintained for 96 h. The experiment consisted of four treatments: control and leachate from 1 butt L-1 (T1), 5 butts L-1 (T5), and 10 butts L-1 (T10), which were prepared by diluting a stock solution of leachate from 50 butts L-1. We found that algal chlorophyll-a content was not affected by different leachate concentrations. In contrast, phytoplankton cell density decreased in a dose-dependent manner as concentrations of the leachate increased. Similarly, the number of species was highest in the control group relative to all other treatments, with T1 and T5 showing higher species richness than T10. Additionally, the exposition to different concentrations of the leachate impacted community composition across all treatments in comparison to the control group. Our results suggest that cigarette butt leachate alters the number of cells and species, as well as the distribution of abundance, without necessarily reducing chlorophyll-a concentrations. Our findings indicate that to gain a comprehensive understanding of the effects of cigarette butt leachate on freshwater ecosystems, it is essential to evaluate more realistic scenarios that incorporate aquatic communities, rather than isolated species.

A critical review on the separation of heavy metal(loid)s from the contaminated water using various agricultural wastes.

Wastewater contamination with heavy metal(loids)s has become a worldwide environmental and public health problem due to their toxic and non-degradable nature. Different methods and technologies have been applied for water/wastewater treatment to mitigate heavy metal(loid)-induced toxicity threat to humans. Among various treatment methods, adsorption is considered the most attractive method because of its high ability and efficiency to remove contaminants from wastewater. Agricultural waste-based adsorbents have gained great attention because of high efficiency to heavy metal(loids)s removal from contaminated water. Chemically modified biosorbents can significantly enhance the stability and adsorption ability of the sorbents. The two mathematical models of sorption, Freundlich and Langmuir isotherm models, have mostly been studied. In kinetic modeling, pseudo-second-order model proved better in most of the studies compared to pseudo-first-order model. The ion exchange and electrostatic attraction are the main mechanisms for adsorption of heavy metal(loid)s on biosorbents. The regeneration has allowed various biosorbents to be recycled and reused up to 4-5 time. Most effective eluents used for regeneration are dilute acids. For practical perspective, biosorbent removal efficiency has been elucidated using various types of wastewater and economic analysis studies. Economic analysis of adsorption process using agricultural waste-based biosorbents proved this approach cheaper compared to traditional commercial adsorbents, such as chemically activated carbon. The review also highlights key research gaps to advance the scope and application of waste peels for the remediation of heavy metal(loid)s-contaminated wastewater.

This review provides new information and insights on the potential utilization of agriculture-based biosorbents for the removal of contaminants, especially heavy metal(loid)s from toxic water/wastewater, as well as their mechanisms, adsorption efficiency, and regeneration ability. For practical perspective, biosorbent adsorption efficiency was elucidated by using various types of wastewater and economic analysis studies.

Exploring the potential of bacterial-augmented floating treatment wetlands for the remediation of detergent-contaminated water.

Due to industrialization and urbanization, the use of detergents inadvertently led to contamination of aquatic environments, thus posing potential threat to aquatic organisms and human health. One of the main components of detergents is linear alkylbenzene sulfonate (LAS), which can cause toxic effects on living organisms, particularly aquatic life in the environment. In this study, floating treatment wetlands (FTWs) mesocosms were developed and augmented with LAS-degrading bacteria. The plant species, Brachiaria mutica (Para grass), was vegetated to establish FTWs and bacterial consortium (1:1:1:1) of Pseudomonas aeruginosa strain PJRS20, Bacillus sp. BRRH60, Acinetobacter sp. strain CYRH21, and Burkholderia phytofirmans Ps.JN was augmented (free or immobilized) in these mesocosms. Results revealed that the FTWs removed LAS from the contaminated water and their augmentation with bacteria slightly increased LAS removal during course of the experiment. Maximum reduction in LAS concentration (94%), chemical oxygen demand (91%), biochemical oxygen demand (93%), and total organic carbon (91%) was observed in the contaminated water having FTWs augmented with bacterial consortium immobilized on polystyrene sheet. This study highlights that the FTWs supported with immobilized bacteria on polystyrene sheets can provide an eco-friendly and sustainable solution for the remediation of LAS-bearing water, especially for developing countries like Pakistan.

This pilot-scale study provided insights to resolve the detergent-contaminated wastewater issue, using floating treatment wetlands (FTWs) augmented with bacteria. The FTWs augmented with bacteria immobilized on a polystyrene sheet and vegetated with Brachiaria mutica led to high degradation of LAS, a toxic compound of detergent, from the contaminated water.

YOLOv8-C2f-Faster-EMA: An Improved Underwater Trash Detection Model Based on YOLOv8.

Anthropogenic waste deposition in aquatic environments precipitates a decline in water quality, engendering pollution that adversely impacts human health, ecological integrity, and economic endeavors. The evolution of underwater robotic technologies heralds a new era in the timely identification and extraction of submerged litter, offering a proactive measure against the scourge of water pollution. This study introduces a refined YOLOv8-based algorithm tailored for the enhanced detection of small-scale underwater debris, aiming to mitigate the prevalent challenges of high miss and false detection rates in aquatic settings. The research presents the YOLOv8-C2f-Faster-EMA algorithm, which optimizes the backbone, neck layer, and C2f module for underwater characteristics and incorporates an effective attention mechanism. This algorithm improves the accuracy of underwater litter detection while simplifying the computational model. Empirical evidence underscores the superiority of this method over the conventional YOLOv8n framework, manifesting in a significant uplift in detection performance. Notably, the proposed method realized a 6.7% increase in precision (P), a 4.1% surge in recall (R), and a 5% enhancement in mean average precision (mAP). Transcending its foundational utility in marine conservation, this methodology harbors potential for subsequent integration into remote sensing ventures. Such an adaptation could substantially enhance the precision of detection models, particularly in the realm of localized surveillance, thereby broadening the scope of its applicability and impact.

Drinking Water Contaminant Concentrations and Birth Outcomes.

Previous research in the US has found negative health effects of contamination when it triggers regulatory violations. An important question is whether levels of contamination that do not trigger a health-based violation impact health. We study the impact of drinking water contamination in community water systems on birth outcomes using drinking water sampling results data in Pennsylvania. We focus on the effects of water contamination for births not exposed to regulatory violations. Our most rigorous specification employs mother fixed effects and finds changing from the 10th to the 90th percentile of water contamination (among births not exposed to regulatory violations) increases low birth weight by 12% and preterm birth by 17%.

Phenolic compounds in water: Review of occurrence, risk, and retention by membrane technology.

Phenolic compounds are one of the main contributors to water source contamination worldwide. In this review, the data collected on Elsevier, Scopus, and Pubmed, considering papers published between 2000 and 2023, showed more than 60 different phenols have been identified in water matrix (<0.065-179,000,000 ng L-1). The highest concentration reported was in surface water canals in India. The most recurrent and studied compound was bisphenol A (n = 93) in concentrations ranging from 0.45 to 2,970,000 ng L-1. The solid phase extraction (HBL Oasis cartridge) and methanol as solvent was the method of pre-concentration most used followed by gas chromatography for the determination of phenols in water samples. The importance of drinking water guidelines incorporating more phenolic compounds was emphasized given the variety of these compounds quantified in water matrix. The human health risk assessment (HRA) was performed for the min-max concentrations of the pollutants reported in the literature. High HRA even at the lowest concentrations for 2-nitrophenol, 2,6-dichlorophenol, 3,4,5-trichlorophenol, 2,3,4,6-tetrachlorophenol, and 2,4-dinitrophenol was recognized. The cancer risk estimated was considered possible for 3-methylphenol, 2,4-dimethylphenol, 2,4,6-trichlorophenol, pentachlorophenol, and 2,4-dinitrophenol in the highest concentrations. The in-depth discussion of mechanisms, advantages, challenges, and carbon footprint of membrane technologies in water treatment and phenols retention demonstrated the great potential and trends for the production of safe drinking water, highlighting reverse osmosis, as a mature technology, and membrane distillation, as an emergent technology.

Genetic diversity of KPC-2-producing Klebsiella pneumoniae complex from aquatic ecosystems.

During the COVID-19 pandemic, the occurrence of carbapenem-resistant Klebsiella pneumoniae increased in human clinical settings worldwide. Impacted by this increase, international high-risk clones harboring carbapenemase-encoding genes have been circulating in different sources, including the environment. The blaKPC gene is the most commonly disseminated carbapenemase-encoding gene worldwide, whose transmission is carried out by different mobile genetic elements. In this study, blaKPC-2-positive Klebsiella pneumoniae complex strains were isolated from different anthropogenically affected aquatic ecosystems and characterized using phenotypic, molecular, and genomic methods. K. pneumoniae complex strains exhibited multidrug-resistant and extensively drug-resistant profiles, spotlighting the resistance to carbapenems, ceftazidime-avibactam, colistin, and tigecycline, which are recognized as last-line antimicrobial treatment options. Molecular analysis showed the presence of several antimicrobial resistance, virulence, and metal tolerance genes. In-depth analysis showed that the blaKPC-2 gene was associated with three different Tn4401 isoforms (i.e., Tn4401a, Tn4401b, and Tn4401i) and NTEKPC elements. Different plasmid replicons were detected and a conjugative IncN-pST15 plasmid harboring the blaKPC-2 gene associated with Tn4401i was highlighted. K. pneumoniae complex strains belonging to international high-risk (e.g., ST11 and ST340) and unusual clones (e.g., ST323, ST526, and ST4216) previously linked to clinical settings. In this context, some clones were reported for the first time in the environmental sector. Therefore, these findings evidence the occurrence of carbapenemase-producing K. pneumoniae complex strains in aquatic ecosystems and contribute to the monitoring of carbapenem resistance worldwide.

Behavioral outcomes and exposure to perfluoroalkyl substances among children aged 6-13 years: The TEDDY child study.

BACKGROUND: Although some studies report that exposure to per- and polyfluoroalkyl substances (PFAS) during pregnancy and early life stages of a child could adversely impact neurodevelopment, literature shows mixed evidence. OBJECTIVES: Using an ecological framework for human development, we assessed the association of risk factors for environmental PFAS exposure and childhood PFAS concentrations with behavioral difficulties among school-age children exposed to PFAS from birth, while also controlling for the important influence of the parenting and familial environment. METHODS: The study participants included 331 school-age children (6-13 years) born in a PFAS-contaminated area in the Veneto Region (Italy). We study the associations between environmental risk factors of maternal PFAS exposure (residential time, consumption of tap water, residence in Red zone A or B), and breastfeeding duration with parent assessments of children's behavioral problems (using the Strengths and Difficulties Questionnaire [SDQ]), adjusting for socio-demographic, parenting and familial variables. The direct relationships between serum blood PFAS concentrations and SDQ scores was evaluated in a subset of children (n = 79), both with single PFAS and weighted quantile sum (WQS) regressions. RESULTS: Poisson regression models reported positive associations between high consumption of tap water and externalizing SDQ scores (Incidence Rate Ratio [IRR]: 1.18; 95% confidence interval [CI]: 1.04-1.32) and total difficulty scores (IRR: 1.14; 95% CI: 1.02-1.26). Childhood perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were associated with higher internalizing SDQ scores (4th vs. 1st quartile, PFOS IRR: 1.54, 95% CI: 1.06-2.25), externalizing scores (4th vs. 1st quartile, PFHxS IRR: 1.59, 95% CI: 1.09-2.32), and total difficulty scores (4th vs. 1st quartile, PFOS IRR: 1.37, 95% CI: 1.05-1.71; PFHxS IRR: 1.54, 95% CI: 1.09-1.90). The WQS regressions confirmed the associations reported by single-PFAS analyses. CONCLUSIONS: We observed cross-sectional associations of tap water consumption and childhood PFOS, and PFHxS concentrations with greater behavioral difficulties.

A single exposure to sub-lethal concentrations of a glyphosate-based herbicide or fluoxetine-based agent on growth performance in Nile tilapia.

The aim of the present study was to determine e whether a single acute 96 hr exposure of a glyphosate-based herbicide (GBH) to Nile tilapia fingerlings affected growth performance during the first 90 days of culture. This association was considered as GBH increases serotoninergic activity that affect fish anorexically. Although these findings were based upon chronic investigations, this study was designed to examine whether a single, acute, but excessive concentration GBH might impair growth performance in fish. In parallel, fish were also exposed to fluoxetine (FLU), a drug that selectively inhibits the reuptake of serotonin in brain synapses, leading to increased serotoninergic activity. Data demonstrated a decreased growth performance in fingerlings exposed to GBH or FLU compared to unexposed fingerlings. In fact, FLU-exposed fingerlings exhibited lower average weight and length, diminished weight gain, which resulted in lower final biomass. GBH-exposed fish, despite displaying a lower mean body weight, exhibited a biomass similar to biomass on controls. These body weight differences were noted after 30-60- and 90-day growth period in clean water. In an aquaculture context, these observed changes may be considered harmful to the production or economic performance of large-scale farming as currently practiced in tilapia farming.

Potential of magnetic quinoa biosorbent composite and HNO3 treated biosorbent for effective sequestration of chromium (VI) from contaminated water.

The present study aims to prepare novel quinoa biosorbent (QB), acid activated QB (QB/Acid) and its nanocomposite with magnetic nanoparticles (QB/MNPs) for batch scale Cr removal from contaminated water. The Cr adsorption was systematically studied at different pH (2-9), adsorbent dosage (1-3 g/L), initial concentration (25-200 mg/L), contact time (180 min) and competing ions in water. Maximum Cr adsorption was observed onto QB/MNPs (57.4 mg/L), followed by QB/Acid (46.35 mg/g) and QB (39.9 mg/g). The Cr removal by QB/MNPs was higher than QB/Acid and QB. Results revealed that the highest Cr removal was obtained at optimum pH 4, 25 mg/L, and 2 g/L dosage. The FTIR spectra displayed various functional groups on adsorbents surface serving as a potential scaffold to remove Cr from contaminated water. The equilibrium and kinetic Cr adsorption data best fitted with Freundlich and pseudo-second order models, respectively (R2 ≥ 0.96). The QB/MNPs showed excellent reusability in five adsorption/desorption cycles (4.7% decline) with minor leaching of Fe (below threshold level). The coexisting ions in groundwater showed an inhibitory effect on Cr sequestration (5%) from water. The comparison of Cr adsorption by QB/MNPs and QB/Acid showed better potential for Cr sequestration than various previously explored adsorbents in the literature.

Quinoa is a cereal crop and after harvesting quinoa straws are either burnt or thrown away which can cause several environmental problems. It would be beneficial to utilize quinoa straws and its modified forms as adsorbents for the water remediation. Therefore, current study aims to estimate the adsorption capacity of quinoa biomass as biosorbent (QB) and its modifications (QB/Acid and QB/MNPs) to treat Cr (VI) contaminated water. The influence of various parameters governing the Cr removal from water has been evaluated. The reusability of QB/MNPs has also been evaluated for its economical use without losing effectiveness for Cr removal from water. The comparison of Cr adsorption by QB/MNPs and QB/Acid showed better adsorption potential for Cr sequestration than various previously explored adsorbents in the literature.

Experimental study of the sorption properties of natural zeolite-containing tripolite and their ability to purify aqueous solutions contaminated with Ni and Zn.

Sorption properties of natural zeolite-containing tripolite from the Khotynetsky deposit (Russia, Oryol region) were studied to evaluate their possibility to purify ground waters contaminated by technogenic Ni2+ and Zn2+. According to experimental data the total ion-exchange capacity of the natural tripolite sample equaled to 1.79 mg-eq/g. The kinetic experiments showed that equilibrium in the studied rock-solution system took place after 500 h of interaction. In the range of the used Ni2+ and Zn2+ concentrations (2-10 mg/L) after 21 days of interaction with natural tropolite suspension, the sorption of the studied ions can be approximated by a linear isotherm, zinc being sorbed much better than nickel: the average values of distribution coefficients (Kd) obtained for 0.003 N CaCl2 aquatic solution equaled to 2.7 × 103 ml/g for Ni2+ and 6.7 × 103 ml/g for Zn2+. Therefore, natural zeolite-containing tripolite of the Khotinetsky deposit can be used for extraction of technogenic Ni2+ and Zn2+ from natural surface and ground waters contaminated by these ions and can be considered as an effective natural sorbent for solving environmental problems.

Improving the practicality of recombinant Escherichia coli biosensor in detecting trace Cr(VI) by modifying the cryogenic storage conditions of biosensors and applying simple pretreatment.

Hexavalent chromium (Cr(VI)) is a global environmental pollutant. To reduce the risk caused by Cr(VI), a simple, accurate, reproducible, and inexpensive method for quantifying Cr(VI) in water and soil should be developed. In this study, three types of recombinant Escherichia coli biosensors (namely T7-lux-E. coli, T3-lux-E. coli, and SP6-lux-E. coli biosensor) containing promoters (T7, T3, and SP6), chromate-sensing regulator chrB, and the reporter gene luxAB were constructed. This study investigated the effects of cryogenic freezing temperature and time on trace Cr(VI) measurement by using recombinant E. coli biosensors. The results indicated that the activity of thawed frozen SP6-lux-E. coli cells stored at -20 °C for 270 days did not differ from that of freshly prepared cells. Turbidity and conductivity in water samples and organic matter in soil interfered with Cr(VI) measurement using the biosensor. The SP6-lux-E. coli biosensor exhibited a wide measurement range and a low deviation of <5% for measuring Cr(VI) in various Cr(VI)-contaminated water and soil samples and required only a simple pretreatment or extraction process even after 270-day storage at -20 °C. To the best of our knowledge, this is the first study to report the use of recombinant biosensors for accurately measuring Cr(VI) in both water and soil.

Synthesis and application of novel microporous framework of nanocomposite from trona for photocatalysed degradation of methyl orange dye.

Photocatalysed degradation of environmental contaminants is one of the most fashionable technologies in the purification of water because the method converts toxic products to nontoxic ones. In this study, a method has been developed to synthesize novel nanocomposites of Na-Ca-Al-Si oxides for the first time. The average surface area, pore volume and pore size for the novel product were 1742.55 m2/g, 0.3499 cc/g and 3.197 nm respectively. The crystal parameters were a = 7.1580 Å, b = 7.4520 Å, c = 7.7160 Å, α = 115.0600, ß = 107.3220, γ = 100.4380, density (calculated) = 2.0 × 103g/cm3 and cell volume = 332.7 Å3 respectively. The average crystalline size deduced from the Scherrer equation (i.e. 6.9393 nm) was higher than the value of 1.024 nm obtained from the graphical method. The FTIR and UV spectra of the nanocomposites were unique and provided baseline information that characterises the new product. XRD profiling of the new product reveals the existent of a silica framework consisting of NaAlSi3O3 and CaAl2Si2O8 The synthesized nanocomposites is an effective photocatalyst for the degradation of methyl orange dye in water, with aoptimum efficiency of 96% at an initial dye concentration of 10 ppm, the adsorbent dosage of 0.5 g,contact time of 90 min and pH of 2.5. The Langmuir-Hinshelwood, modified Freundlich and pseudo-second kinetic models were significant in the description of the photocatalytic kinetics of the degraded dye molecules.

An IoT-based water contamination analysis for aquaculture using lightweight multi-headed GRU model.

Maintaining the quality of water is essential for the health and productivity of aquatic organisms, including fish in aquaculture ponds. However, water contamination can severely impact fish health and survival, making it necessary to develop monitoring systems that can detect early signs of water contamination. Initial deep learning models had limitations in capturing the temporal and spatial dependencies of time-series data, which can lead to inaccurate predictions. In this paper, we propose a smart monitoring system that uses IoT devices to collect water quality data and segment it into contaminated and non-contaminated categories based on a water toxic index (WTI), a measure of water contamination levels. To address the limitations of early deep learning models for classification of toxic and non-toxic water quality, an enhanced light-weight multi-headed gated recurrent unit (MHGRU) model that captures the spatial and temporal dependencies of water quality parameters. Our study demonstrates that the proposed model outperforms existing models, achieving an impressive accuracy of 99.7% when evaluated on real-time data. Notably, our model also excels when tested on a public dataset, achieving an accuracy of 99.12%. In comparison, best performed existing ANN models achieve accuracies of 99.52% and 98.71% on the respective datasets.

Lethality and Acetylcholinesterase Inhibition in a Native Invertebrate Species Exposed to Water Samples of an Impacted Stream (Reconquista River Basin, Argentina).

The study of multiple biomarkers in bioindicator species is a useful tool to evaluate water quality in addition to physicochemical analysis. The aim of this work was to study the toxicity of water samples from two sites with different anthropogenic impacts (R: near a residential area and FP: close to horticultural farms and industrial waste treatment plants) from Las Catonas sub-basin (Reconquista River basin) in the native gastropod Biomphalaria straminea. Some physicochemical parameters and chlorpyrifos concentration were measured in water samples. Snails were exposed in laboratory conditions 48 h to the water samples and neurotoxicity, behavior, lethality and acetylcholinesterase, carboxylesterase, glutathione S-transferase, glutathione reductase and catalase activities were measured. In water from FP, chlorpyrifos was detected and conductivity and pH were higher than in R. Lethality (60%) and a decrease (30%) in acetylcholinesterase were observed in snails exposed to FP indicating that water contamination causes high toxicity in B. straminea.

Protocol with non-toxic chemicals to control biofilm in dental unit waterlines: physical, chemical, mechanical and biological perspective.

Biosafety in dentistry aims to combat cross-contamination and biofilm in dental unit waterlines. The aim was to investigate from a physical, chemical, mechanical and biological perspective, a protocol for using chemical products (citric acid, sodium bicarbonate and sodium chloride) to improve and maintain water quality in dental unit waterlines. Change in microhardness and corrosion tendency were observed in stainless steel samples. On the polyurethane surfaces, there were changes in color, microhardness and roughness. Anti-biofilm evaluations revealed a significant reduction in the biofilm biomass, metabolic activity and residual biofilm. These findings suggest that the protocol analyzed in this study showed an innovative potential against biofilm in dental unit waterlines, preserving the physical, chemical and mechanical properties of the materials.