Search Results (1,494)

Background: Access to safe and reliable water and sanitation remains a critical public health and development challenge, with rural and low-income communities being disproportionately affected by inadequate services and heightened exposure to waterborne diseases. Despite global efforts and infrastructure-based progress indicators, significant disparities persist, and these often overlook users’ perceptions of water quality, reliability, and safety. This study explores the determinants of household satisfaction with drinking water in rural areas, comparing subjective user feedback with official access data to reveal gaps in current monitoring approaches and support more equitable, user-centered water governance. Methods: This study was conducted in Kazakhstan’s Atyrau Region, where 1361 residents from 86 rural villages participated in a structured survey assessing household access to drinking water and perceptions of its quality. Data were analyzed using descriptive statistics and multinomial logistic regression to identify key predictors of user satisfaction, with results compared against official records to evaluate discrepancies between reported experiences and administrative data. Results: The field survey results revealed substantial discrepancies between official statistics and residents’ reports, with only 58.1% of respondents having in-house tap water access despite claims of universal coverage. Multinomial logistic regression analysis identified key predictors of user satisfaction, showing that uninterrupted supply and the absence of complaints about turbidity, odor, or taste significantly increased the likelihood of higher satisfaction levels with drinking water quality. Conclusions: This study underscores the critical need to align official water access statistics with household-level experiences, revealing that user satisfaction—strongly influenced by supply reliability and sensory water quality—is essential for achieving equitable and effective rural water governance. Full article

A novel near-infrared (NIR) squaraine-based chemosensor, SQ-68, has been designed and synthesized for the sensitive and selective detection of Cu²⁺ and Ag⁺ ions, offering a compact solution for multi-analyte sensing. SQ-68 demonstrates high selectivity, with its performance influenced by the solvent environment: It selectively detects Cu²⁺ in acetonitrile and Ag⁺ in an ethanol–water mixture. Upon binding with either ion, SQ-68 undergoes significant absorption changes in the NIR region, accompanied by visible color changes, enabling naked-eye detection. Spectroscopic studies confirm a 1:1 binding stoichiometry with both Cu²⁺ and Ag⁺, accompanied by hypochromism. The detection limits are 0.09 μM for Cu²⁺ and 0.38 μM for Ag⁺, supporting highly sensitive quantification. The sensor’s practical applicability was validated in real water samples (sea, lake, and tap water), with recovery rates ranging from 73–95% for Cu²⁺ to 59–99% for Ag⁺. These results establish SQ-68 as a reliable and efficient chemosensor for environmental monitoring and water quality assessment. Its dual-analyte capability, solvent-tunable selectivity, and visual detection features make it a promising tool for rapid and accurate detection of heavy metal ions in diverse aqueous environments. Full article

The quality of water in households can be affected by plumbing design and materials, water usage patterns, and source water quality characteristics. These factors influence stagnation duration, disinfection residuals, metal release, and microbial activity. In particular, stagnation can degrade water quality and increase lead release from lead service lines. This study employs numerical modeling to assess how combined corrosion control and flushing strategies affect lead levels in household taps with lead service lines under reduced water use. To estimate potential health risks, the U.S. EPA model is used to predict the percentage of children likely to exceed safe blood lead levels. Lead exceedances are assessed based on various regulatory requirements. Results show that exceedances at the kitchen tap range from 3 to 74% of usage time for the 5 µg/L standard, and from 0 to 49% for the 10 µg/L threshold, across different scenarios. Implementing corrosion control treatment in combination with periodic flushing proves effective in lowering lead levels under the studied low-consumption scenarios. Under these conditions, the combined strategy limits lead exceedances above 5 µg/L to only 3% of usage time, with none above 10 µg/L. This demonstrates its value as a practical short-term strategy for households awaiting full pipe replacement. Targeted flushing before peak water use reduces the median time that water remains stagnant in household pipes from 8 to 3 h at the kitchen tap under low-demand conditions. Finally, the risk model indicates that the combined approach can reduce the predicted percentage of children with blood lead levels exceeding 5 μg/dL from 61 to 6% under low water demand. Full article

Microplastics are pervasive environmental pollutants that pose risks to human health through ingestion and inhalation. This review synthesizes current practices to reduce exposure and toxicity by examining major exposure routes and dietary interventions. More than 130 papers were analyzed to achieve this aim. The findings show that microplastics contaminate a wide range of food products, with particular concern over seafood, drinking water, plastic-packaged foods, paper cups, and tea filter bags. Inhalation exposure is mainly linked to indoor air quality and smoking, while dermal contact poses minimal risk, though the release of additives from plastics onto the skin remains an area of concern. Recommended strategies to reduce dietary exposure include consuming only muscle parts of seafood, moderating intake of high-risk items like anchovies and mollusks, limiting canned seafood liquids, and purging mussels in clean water before consumption. Avoiding plastic containers, especially for hot food or microwaving, using wooden cutting boards, paper tea bags, and opting for tap or filtered water over bottled water are also advised. To mitigate inhalation exposure, the use of air filters with HyperHEPA systems, improved ventilation, regular vacuuming, and the reduction of smoking are recommended. While antioxidant supplementation shows potential in reducing microplastic toxicity, further research is needed to confirm its effectiveness. This review provides practical, evidence-based recommendations for minimizing daily microplastic exposure. Full article

Objective: This study aimed to determine the possibility of creating a new animal model in which diabetic retinopathy (DR) progresses due to hypertension caused by salt loading. Methods: Male Spontaneously Diabetic Torii (SDT) fatty rats were divided into two groups: one group received 0.3% saline water starting at 8 weeks of age for a duration of 16 weeks (salt SDT fatty group), while the control group was provided with tap water (SDT fatty group). In addition, Sprague-Dawley (SD) rats receiving tap water served as normal controls. Retinal function was assessed by electroretinography (ERG) at 8 and 24 weeks of age. At 24 weeks, following perfusion with fluorescein dextran, the eyes were enucleated, and retinal flat mounts were prepared for vascular evaluation. Retinal thickness and the number of retinal folds were assessed histologically, and ultrastructural changes in the retina were examined using transmission electron microscopy. Results: Saline administration did not lead to significant changes in food consumption or body weight among the groups. In the salt SDT fatty group, blood pressure was significantly elevated, while blood glucose levels showed a slight reduction. ERG analysis showed that the amplitude of oscillatory potential (OP)1 waves was suppressed, and the latencies of OP3, OP4, and OP5 waves were prolonged. Although no significant changes were noted in retinal thickness or the number of retinal folds, thickening of the retinal capillary basement membrane was evident in the salt SDT fatty group. Conclusions: Hypertension induced by 0.3% saline promotes DR progression in SDT fatty rats. This model may help clarify the role of hypertension in DR. Full article

The cigarette butt (CB) recycling process yields several byproducts, including cleaned filters, solid debris (mainly paper and tobacco), and wastewater. This study aimed to assess, for the first time, the long-term suitability of these recycled byproducts for turfgrass cultivation. Under controlled conditions, Paspalum vaginatum Swartz was grown in sand–peat substrate, either unmodified (control) or amended with small pieces of uncleaned CBs or solid byproducts from CB recycling at concentrations of 25% or 50% (v/v). In additional tests, turfgrass grown in unmodified substrate received wastewater instead of tap water once or twice weekly. Over 7 weeks, physiological and biometric parameters were assessed. Plants grown with solid debris showed traits comparable to the control. Those grown with intact CBs or cleaned filters had similar biomass and coverage as the control but accumulated more carotenoids and antioxidants. Wastewater significantly enhanced plant growth when applied once weekly, while becoming toxic when applied twice, reducing biomass and coverage. After scalping, turfgrass recovered well across all treatments, and in some cases biomass improved. Overall, recycled CB byproducts, particularly wastewater used at optimal concentrations, can be a sustainable resource for promoting turfgrass growth. Full article

Due to the growing issue of plastic pollution over recent decades, it is essential to establish well-defined and appropriate methodologies for their extraction from diverse environmental samples. These particles can be found in complex agricultural matrices such as compost, sediments, agricultural soils, sludge, and wastewater, as well as in less complex samples like tap and bottled water. The general steps of MPs extraction typically include drying the sample, sieving to remove larger particles, removal of organic matter, density separation to isolate polymers, filtration using meshes of various sizes, oven drying of the filters, and polymer identification. Complex matrices with high organic matter content require specific removal steps. Most studies employ an initial drying process with temperature control to prevent polymer damage. For removal of organic matter, 30% H₂O₂ is the most commonly used reagent, and for density separation, saturated NaCl and ZnCl₂ solutions are typically applied for low- and high-density polymers, respectively. Finally, filtration is carried out using meshes selected according to the identification technique. This review analyzes the advantages and limitations of the different methodologies to extract microplastics from different sources, aiming to provide in-depth insight for researchers dedicated to the study of environmental samples. Full article

Selenium (Se) is an essential trace element involved in antioxidant redox regulation, thyroid hormone metabolism, and cancer prevention. Among its different forms, elemental selenium (Se⁰), particularly at the nanoscale, has gained growing attention in food, feed, and biomedical applications due to its lower toxicity and higher bioavailability compared to inorganic selenium species. However, the detection of Se⁰ in real samples remains challenging as current analytical methods are time-consuming, labour-intensive, and often unsuitable for rapid analysis. In this study, we developed a method for rapidly measuring Se⁰ using carbon nanodots (CNDs) produced from the Maillard reaction between glucose and glycine. The fabricated CNDs were water-dispersible and strongly fluorescent, with an average particle size of 3.90 ± 1.36 nm. Comprehensive characterisation by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), fluorescence spectroscopy, and Raman spectroscopy confirmed their structural and optical properties. The CNDs were employed as fluorescent probes for the selective detection of Se⁰. The sensor showed a wide linear detection range (0–12.665 mmol L⁻¹), with a low detection limit (LOD) of 0.381 mmol L⁻¹ and a quantification limit (LOQ) of 0.465 mmol L⁻¹. Validation with spiked real samples—including ultra-pure water, tap water, and soft drinks—yielded high recoveries (98.6–108.1%) and low relative standard deviations (<3.4%). These results highlight the potential of CNDs as a simple, reliable, and environmentally friendly sensing platform for trace-level Se⁰ detection in complex food and beverage matrices. Full article

In this study, a magnet-integrated fabric phase sorptive extraction (MI-FPSE) protocol was developed in combination with high pressure liquid chromatography—diode array detection (HPLC-DAD) for the simultaneous determination of five phenylurea pesticides (i.e., chlorbromuron, diuron, linuron, metoxuron, monuron) in environmental water samples. To produce the MI-FPSE device, two individual sol-gel coated carbowax 20 M (CW 20 M) cellulose membranes were fabricated and stitched to each other, while a magnetic rod was inserted between them to give the resulting device the ability to spin and serve as a stand-alone microextraction platform. The adsorption and desorption step of the MI-FPSE protocol was optimized to achieve high extraction efficiency and the MI-FPSE-HPLC-DAD method was validated in terms of linearity, sensitivity, selectivity, accuracy, and precision. The limits of detection (LODs) were found to be 0.3 μg L⁻¹. The relative recoveries were 85.2–110.0% for the intra-day and 87.7–103.2% for the inter-day study. The relative standard deviations were better than 13% in all cases. The green character and the practicality of the developed procedure were assessed using ComplexGAPI and Blue Analytical Grade Index metric tools, showing good method performance. Finally, the developed method was successfully used for the analysis of tap, river, and lake water samples. Full article

Mabroom dates (Phoenix dactylifera L.) are recognized as one of the most important crops in Qatar. Fresh fruit dates are susceptible to mould and post-harvest spoilage, resulting in a significant financial loss. Octanoic fatty acid (OFA) has been shown to regulate the growth of mould-causing organisms such as fungi and bacteria. It is known to have antibacterial properties. The objective of the current study was to evaluate the in vitro effect of OFA on the post-harvest pathogens of Mabroom fruits. Fresh, apparently healthy, and fully ripe Mabroom dates were obtained from the National Agriculture and Food Corporation (NAFCO). The chosen fruits were packed in sterile, well-ventilated plastic boxes and transported to the lab under controlled conditions. The fruits were distributed into five groups (G1 to G5). The groups G1, G2, and G3 received 1%, 2%, and 3.5% OFA, respectively, while G4 was left untreated and G5 was washed only with tap water as a positive control treatment. Each group contained 200 g of fresh and healthy semi-soft dates. The samples were then dried and incubated in a humidity chamber at 25 °C ± 2 for seven days. The signs and symptoms of decay were monitored and recorded. The presence of pathogens was confirmed via phenotypic and microscopic-based methods. The results showed a significant difference (p ≤ 0.05) among the groups. OFA at 3.5% had the strongest inhibitory action against post-harvest pathogens, followed by OFA2%. However, there were no differences (p ≤ 0.05) between OFA1% and the control groups. Aspergillus spp., Penicillium spp., Rhizopus spp., and Botrytis spp. were most abundant in the control group, followed by OFA2% and OFA1%, respectively. In conclusion, octanoic fatty acid at 3.5% may improve the quality of date fruits through its high antimicrobial activity, reduce the effect of post-harvest decay, minimize the loss of date fruits during storage, and improve the sustainability of date fruits. Further experiments are necessary to confirm the effectiveness of OFA as a green solution for sustainable date fruit production. Full article

The present study aimed to optimize amaranth microgreen production by evaluating key factors such as the seeding density (SD), substrate type (ST), electrical conductivity (EC), and the application intervals of the nutrient solution. A split-plot experimental design was employed, with three EC levels (tap water at 0.3 dS m⁻¹) and nutrient solutions at 1.0 (50% half-strength) and 2.0 dS m⁻¹ (100% full-strength) assigned to the main plots. The subplots combined two ST (coconut fiber and phenolic foam) with four SD (25, 50, 75, and 100 g m⁻²). Two experiments were conducted using this setup, varying the application intervals of water or nutrient solutions for either two or four hours. Asteca amaranth microgreens were cultivated for eight days (a total of 10 days from sowing). The traits analyzed were seedling height (SH), seedling fresh matter (SFM), SFM yield (SFMY), seedling dry matter (SDM), SDM yield (SDMY), water content in seedling, and water productivity of SFM. The results showed that using a half-strength nutrient solution was sufficient for amaranth production compared to using water alone. Coconut fiber outperformed phenolic foam across all evaluated parameters. Based on these findings, we recommend cultivating amaranth microgreens at a SD of 80 g m⁻² on coconut fiber substrate using a nutrient solution of 1.0 dS m⁻¹ EC applied at 2 h intervals. Full article

Gas–water two-phase flow in horizontal and inclined wells is significantly influenced by gravitational forces and spatial asymmetry around the wellbore, resulting in complex and variable flow patterns. Accurate measurement of water holdup is essential for analyzing phase distribution and understanding multiphase flow behavior. Water holdup imaging provides a valuable means for visualizing the spatial distribution and proportion of gas and water phases within the wellbore. In this study, air and tap water were used to simulate downhole gas and formation water, respectively. An array capacitance arraay tool (CAT) was employed to measure water holdup under varying total flow rates and water cuts in a horizontal well experimental setup. A total of 228 datasets were collected, and the measurements were processed in MATLAB (2020 version) using three interpolation algorithms: simple linear interpolation, inverse distance interpolation, and Lagrangian nonlinear interpolation. Water holdup across the wellbore cross-section was also calculated using arithmetic averaging and integration methods. The results obtained from the three imaging algorithms were compared with these reference values to evaluate accuracy and visualize imaging performance. The CAT demonstrated reliable measurement capabilities under low- to medium-flow conditions, accurately capturing fluid distribution. For stratified flow regimes, the linear interpolation algorithm provided the clearest depiction of the gas–water interface. Under low- to medium-flow rates with high water content, both inverse distance and Lagrangian methods produced more refined images of phase distribution. In dispersed flow conditions, the Lagrangian nonlinear interpolation algorithm delivered the highest accuracy, effectively capturing subtle variations within the complex flow field. Full article

The use of Auxenochlorella pyrenoidosa (formerly Chlorella pyrenoidosa) and its intracellular substances (ISs) to promote biofloc development has been extensively studied. To identify the key components of the ISs of A. pyrenoidosa that drive biofloc formation, algal-extracted polysaccharides (AEPSs) and algal-extracted proteins (AEPTs) were isolated from the ISs. In this study, we established four groups: ISs, AEPSs, AEPTs, and tap water (TW, control), to investigate the effects of AEPSs and AEPTs on biofloc formation dynamics, water quality parameters, and microbial community composition. The results indicated no significant differences were observed between the ISs and AEPSs groups during the cultivation period. AEPSs significantly enhanced flocculation efficiency, achieving a final floc volume of 60 mL/L. This enhancement was attributed to the selective promotion of floc-forming microbial taxa, such as Comamonas, which can secrete procoagulants like EPS, and Pseudomonas and Enterobacter, which have denitrification capabilities. Water quality monitoring revealed that both AEPSs and AEPTs achieved nitrogen removal efficiencies exceeding 50% in the biofloc system, with AEPSs outperforming AEPTs. This is closely related to the fact that the microorganisms with increased flocculation contain numerous nitrifying and denitrifying bacteria. So, the intracellular polysaccharides were the key component of the ISs of A. pyrenoidosa that drive biofloc formation. These findings provide critical insights into the functional roles of algal-derived macromolecules in biofloc dynamics and their potential applications in wastewater treatment. Full article

The inherent hydrophobic nature of PVDF material renders it challenging to establish a stable aqueous hydration layer, thereby limiting its suitability as a substrate for the preparation of nanofiltration (NF) membranes. In this study, we developed a novel modification approach that effectively enhances the hydrophilicity of PVDF substrates through the incorporation of sulfonic acid-doped polyaniline (SPANI) and hyperbranched polyester (HPE) into the PVDF casting solution, followed by cross-linking with trimesoyl chloride (TMC). The introduction of SPANI and HPE, which contain reactive polar amino and hydroxyl groups, improved the hydrophilicity of the substrate, while the subsequent cross-linking with TMC effectively anchored these components within the substrate through the covalent linking between TMC and the reactive sites. Additionally, the hydrolysis of TMC yielded non-reactive carboxyl groups, which further enhanced the hydrophilicity of the substrate. As a result, the modified PVDF substrate exhibited improved hydrophilicity, facilitating the construction of an intact polyamide layer. In addition, the fabricated TFC NF membrane demonstrated excellent performance in the advanced treatment of tap water, achieving a total dissolved solid removal rate of 57.9% and a total organic carbon removal rate of 85.3%. This work provides a facile and effective route to modify PVDF substrates for NF membrane fabrication. Full article

Microplastics (MPs) have emerged as pervasive environmental contaminants due to their widespread presence across various ecosystems, including their use in single-use plastic food ware and table salt dispensers. This issue coincides with the presence of heavy metals in water sources in Doha, Qatar. Fourier Transform Infrared (FTIR) analysis revealed that the plastic plate and spoon were composed of polyolefin, with the spoon exhibiting additional peaks that indicated oxidation or the presence of additives. Thermogravimetric Analysis (TGA) revealed that the spoon exhibited higher thermal stability, retaining approximately 10% of its mass at 700 °C, than the plate, which retained 2%, indicating the presence of complex additives or contamination. MPs in food-grade salt samples were verified through filtration and Fourier Transform Infrared (FTIR) Spectroscopy, identifying polymers such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). These MPs likely stem from exposure to packaging or environmental contaminants. FTIR spectra confirmed the integrity of the polymers after treatment. Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES) analysis revealed varying levels of heavy metals in bottled and tap water, with notable findings including detectable arsenic and lead in both, higher calcium and magnesium in bottled water, and the presence of copper present in tap water only, highlighting potential health and infrastructure-related concerns. These results highlight the possible risks associated with exposure to MPs and heavy metals from everyday products and water sources, underscoring the need for enhanced regulatory oversight and safer material choices to ensure protection. Full article