River Water Samples Research Articles

Fast analysis of short-chain and ultra-short-chain fluorinated organics in water by on-line extraction coupled to HPLC-HRMS

A rapid on-line solid-phase extraction liquid chromatography high-resolution mass spectrometry (on-line SPE-LC-HRMS) method was developed to analyze 11 ultra-short and short-chain PFAS in surface water. Analytical optimization involved screening 7 chromatographic columns and 5 on-line SPE columns, as well as evaluating SPE loading conditions, filters, sample acidification, chromatographic mobile phases, and SPE loading mobile phases. The optimized method was then applied to 44 river water samples collected in Eastern Canada, including sites near airports with fire-training areas. Among the 11 targeted PFAS, the most frequently detected were trifluoroacetic acid (TFA, 4.6–220 ng/L), perfluorobutanoic acid (PFBA, 0.85–33 ng/L), perfluoropentanoic acid (PFPeA, 1.2–2100 ng/L), trifluoromethane sulfonic acid (TMS, 0.01–4.3 ng/L), and perfluorobutane sulfonic acid (PFBS, 0.07–450 ng/L). Levels of C3-C5 perfluoroalkyl carboxylic acids (PFCAs), C2-C4 perfluoroalkyl sulfonates (PFSAs) and n:3 polyfluoroalkyl acids (n = 2,3; n:3 acids) were significantly higher in water bodies near fire-training area sites compared with rivers in urban areas. In contrast, TFA, TMS, and 1:3 acid were not significantly elevated, likely reflecting atmospheric deposition or other diffuse sources for these compounds. Nontarget and suspect screening analysis revealed an abundance of other ultra-short and short-chain PFAS in AFFF-impacted water bodies. Perfluoroalkyl sulfonamides (FASA, C2, C3, and C5), perfluoroalkyl sulfonamide propanoic acids (FASA-PrA, C1-C2) and n:3 acids (n = 1, 4, and 5) were detected for the first time in environmental surface waters.

Changes in the Physico-Chemical Properties as Pollution Indicators in the Chari River Water Samples Along the Banda Township at Sarh-Chad

Changes in the Physico-Chemical Properties as Pollution Indicators in the Chari River Water Samples Along the Banda Township at Sarh-Chad

The Impact of Combined Sewer Overflows on Pharmaceutical and Illicit Drug Levels in New York/New Jersey Waterways.

Pharmaceuticals and drugs of abuse are organic micropollutants of emerging concern in both surface and groundwater worldwide. These compounds are considered to be pseudo-persistent because of their continuous release into water systems. The presence of these compounds in the environment at any concentration poses a potential risk to nontarget organisms. The main sources of these contaminants are wastewater treatment plants (WWTPs) and combined sewer overflows (CSOs). The primary goal of our study was to identify and quantify a panel of 28 commonly prescribed pharmaceuticals (mood-altering drugs, cardiovascular drugs, antacids, antibiotics) and high-prevalence drugs of abuse (cocaine, amphetamines, opioids, cannabis) in river water samples collected from 19 locations in the Hudson and East rivers in New York City. The second goal was to investigate the possible source (WWTP or CSOs) of these micropollutants. Samples were collected weekly from May to August 2021 (n = 224) and May to August 2022 (n = 232), and placed at -20 °C until analysis by liquid chromatography-tandem mass spectrometry. The most frequently detected analytes in 2021 were metoprolol (n = 206, 92%), benzoylecgonine (n = 151, 67%), atenolol (n = 142, 63%), and methamphetamine (n = 118, 53%), and in 2022 the most frequently detected were methamphetamine (n = 194, 84%), atenolol (n = 177, 76%), metoprolol (n = 177, 76%), and 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine (n = 159, 69%). Measured concentrations ranged from the limit of detection (0.50-5.00 ng/L) to 103 ng/L. More drugs and higher concentrations were detected in water contaminated by Enterococci (>60 most probably number) and after rainfall, indicating the influence of CSOs. The presence of drugs in samples with little to no Enterococci and after dry weather events indicates that WWTPs contribute to the presence of these substances in the river, probably due to a low removal rate. Environ Toxicol Chem 2024;43:1592-1603. © 2024 SETAC.

Effective electrochemical detection of furazolidone based on iron tungstate decorated carbon black composite modified glassy carbon electrode

Furazolidone (FUZ), an antibiotic drug widely used to treat bacterial and protozoal infections, poses significant risks to human health and domestic animals. Therefore, detecting FUZ is crucial to prevent environmental contamination. In this study, Iron Tungstate (FeWO4) nanosheets were synthesized using the hydrothermal technique and anchored with Carbon black (CB) to form a FeWO4/CB nanocomposite. This composite was applied onto a glassy carbon electrode (GCE) for electrochemical FUZ detection. Material characterization involved various techniques such as field emission scanning electron microscope (FESEM), high resolution-transmission electron microscope (HR-TEM), energy dispersive X-ray analysis (EDS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy. Additionally, electrochemical impedance spectroscopy (EIS), cyclic voltammetry studies (CV), and differential pulse voltammetry (DPV) were conducted to assess the electrochemical behavior of the FeWO4/CB/GCE electrodes. The FeWO4/CB electrode demonstrated a low detection limit of 0.01 μM, a wide linear response range of 0.01–135 µM, and a higher sensitivity of 1.3 μA μM−1 cm−2. Moreover, the electrodes exhibited excellent repeatability, reproducibility, and stability. Practical application of the FeWO4/CB/GCE electrodes included the successful detection of FUZ in tap water and river water samples with a high recovery percentage. Additionally, these electrodes were utilized in the field of biotechnological applications for practical FUZ detection.

Quality by design−aided acid-free synthesis of self P, N, S-doped black seed-derived carbon quantum dots for application as a nanosensor for eltrombopag environmental and bioanalysis and pharmacokinetic assay

Herein, we developed a rapid, one-step, and cost-effective methodology based on the fabrication of water-soluble self-nitrogen, sulfur, and phosphorus co-doped black seed carbon quantum dots (BSQDs) via microwaveirradiation in six minutes. Our synthesis approach is superior to those in the literature as they involved long-time heating (12 h) with sulfuric acid and sodium hydroxide and/or high temperatures (200 °C). A full factorial design was applied to obtain the most efficient synthesis conditions.BSQDs displayed excitation-independent emissions, demonstrating the purity of the synthesized BSQDs, with a maximum fluorescence at 425 nm after excitation at 310 nm. Eltrombopag olamine is an anti-thrombocytopenia drug that is also reported to cause toxicity in river water based on its Persistence, Bioaccumulation, and Toxicity (PBT). The synthesized BSQDs were employed as the first fluorometric sensor for environmental and bioanalysis of eltrombopag. The fluorescence of BSQDs decreased with increasing concentrations of eltrombopag, with excellent selectivity and sensitivity down to 30 ppb. BSQDs were successfully applied as sensing probes for the detection of eltrombopag in medical tablets, spiked and real human plasma samples, and river water samples, with an overall recovery of at least 97 %. The good tolerance to high levels of foreign components and co-administered drugs indicates good selectivity and versatility of the proposed methodology. Plasma pharmacokinetic parameters such as t1/2, Cmax, and t max of eltrombopag were evaluated to be 9.91 h, 16.0 μg mL−1, and 5 h, respectively. Moreover, the green character of the BSQDs as a sensor was proved by various analytical greenness scales.

Senna auriculata extract-assisted biogenic synthesis of yellow emissive gold nanoclusters for quantitative detection of glyphosate in food and environmental samples

The green chemistry approach was unitized for the development of fluorescent nanomaterial. The objective of this study is to develop plant-based fluorescence nanomaterials via environment-friendly and biocompatible approach. Here, water-soluble yellow emissive gold nanoclusters were synthesized by using extract of Senna auriculata leaves and 1.25 mM of HAuCl4·xH2O via microwave-assisted method. Senna auriculata-AuNCs (S. auriculata-AuNCs) exhibit excellent solubility, good quantum yield (QY), stability, and biocompatibility. The ultra-small (<5 nm) size of S. auriculata-AuNCs displayed yellow emission and were characterized by using fluorescence, UV–visible, FT-IR, HR-TEM, zeta potential, DLS, XPS, and XRD techniques. S. auriculata-AuNCs display an intense emission of 620 nm when excited at 500 nm. The as-synthesized S. auriculata-AuNCs act as an effective sensor for sensing glyphosate pesticide via the “turn-off” mechanism. Moreover, S. auriculata-AuNCs showed a good performance in detecting glyphosate with a wider linear range from 0.05 to 100 µM, offering the detection limit of 32.0 nM for glyphosate. Additionally, S. auriculata-AuNCs are also able to visualize Saccharomyces cerevisiae cells, and successfully applied in assaying glyphosate pesticide in apple, rice, river, and canal water samples.

Development of folding-based and signal-amplified fluorescence aptasensors using G-quadruplex quinclorac aptamer variants engineered via exonuclease digestion and circular dichroism spectroscopy

The lack of inherent structure-switching functionality and inadequate affinity in aptamers hinders the construction and application of aptasensors. While exonuclease digestion-based strategies have been employed to engineer small-molecule aptamers with the structure-switching functionality and construct dual-exonuclease (exonuclease I and exonuclease III) digestion-based aptasensors, such studies targeting G-quadruplex (G4) aptamers remain scarce. This study focused on the exonuclease digestion and circular dichroism spectroscopy analysis of a G4 quinclorac (QNC) aptamer, Qapt-51, intending to design a functionalized QNC aptamer and a universal signal amplification strategy for constructing folding-based and sensitive dual-exonuclease digestion-based aptasensors, respectively. The exonuclease digestion results demonstrated that QNC-binding Qapt-51 inhibited the dual-exonuclease digestion. Combining the results from the circular dichroism spectroscopy, we further proposed a digestion mechanism for Qapt-51 involving a G4 conformational switch. Inspired by this mechanism, a functionalized Qapt-51 variant (Qapt-45A) was rationally designed to construct a simple and rapid folding-based fluorescence aptasensor. Additionally, we developed an exonuclease III- and phosphorodiamidate morpholino oligomer-assisted fluorescence signal amplification strategy, which can work in the dual-exonuclease digestion system. Leveraging this strategy integrated with the dual-exonuclease digestion of another Qapt-51 variant (AQ), a homogeneous signal-amplified fluorescence aptasensor was constructed to sensitively detect QNC without requiring the functionalized aptamers. These two aptasensors achieved detection limits of 560 ng/mL and 8.5 ng/mL for QNC. They successfully detected QNC in rice and river water samples with recoveries of 108.6%-87.5%. We hope that the successful development of these two aptasensors can provide valuable insights and references for the broader construction of G4 aptamer-based sensing systems.

Hydrogeochemical characteristics of shallow groundwater and salinization evaluation in the coastal aquifers of Cangzhou, China

To investigate the hydrogeochemical characteristics of shallow groundwater and evaluate groundwater salinization state in Cangzhou, China, two sampling campaigns have been conducted. In summer, 33 groundwater samples, 3 seawater samples and 5 river water samples were collected. In winter, 22 groundwater samples were collected. The hydrochemical type was determined by the Piper diagram. Evolution mechanisms of groundwater were analyzed by the Gibbs diagram. The trend of de-salinization or salinization of groundwater was determined by the hydrochemical facies evolution diagram. The groundwater salinization grade was evaluated by both the seawater intrusion groundwater quality index (GQISWI) and the attribute recognition model based on entropy weight (ARMEW). The Piper diagram shows that Na+ is the dominant cation and Cl- is the dominant anion in shallow groundwater, and the groundwater in this area is mainly of Cl-Na type followed by Cl-Ca·Mg type. The evaporation-crystallization process has significant influence on the evolution of saline groundwater. In summer, most brackish groundwater exhibit compositions of the freshening stage with direct cation exchange, and most saline groundwater is mainly at the seawater intrusion stage with reverse cation exchange. In winter, compared to the summer season, more groundwater samples in the middle of study area exhibit intrusion trend, and without obvious Na-HCO3 facies. In summer, values of GQISWI range from 20.47 to 75.38 with an average of 59.31. The GQISWI gradually increases from east to west, denoting the degree of groundwater salinization is alleviated from coast to inland. In winter, values of GQISWI range from 54.47 to 79.09 with an average of 66.00, slightly higher than that in summer. The proportion of no salinization (Grade I), minor salinization (Grade II) and serious salinization (Grade III) of groundwater samples in Cangzhou identified by ARMEW is 3.0%, 21.2% and 75.8% in summer, respectively. In winter, the proportion is 9.1% for Grade II and 90.9% for Grade III. The GQISWI index shows the largest area of Grade II, and ARMEW presents the largest area of Grade III in both seasons. Compared with GQISWI index, ARMEW model gives more conservative evaluation results of groundwater salinization. The results provide useful information on the groundwater salinization status for the local area, and help for the management of groundwater resources in Cangzhou.

Detection of &lt;I&gt;Giardia&lt;/I&gt; cyst and &lt;I&gt;Taenia&lt;/I&gt; eggs in river water samples collected from Aleto River in Eleme Local Government Area, Rivers State, Nigeria

This study aimed at detecting Giardia cyst and Taenia eggs in river water samples collected from Aleto River in Eleme Local Government Area, River State, Nigeria, to check for potability and purity of water.Water samples of river water were collected from two points (downstream and midstream) of Aleto river. Labelled clean sample bottles with tightly-fitted lids were used to collect water samples from the river and stored in coolers with ice packs to maintain their temperature and transportation to the laboratory. Collected water samples were transferred into sterile vial tubes and centrifuged at 2000 rpm for five minutes, after which the supernatant fluids were discarded, while the sediments smeared using spatula on labelled slides stained with specific dyes, using the wet mounts, trichome stain technique, and modified Ziehl–Neelsen techniques, and viewed under the light microscope to identify the presence of parasites.This study showed the presence of ten trophozoites of Giardia lamblia and ten eggs of Taenia species isolated from the river water samples collected. These findings highlight the potential health risks associated with waterborne parasites and emphasizes the importance of effective water quality management to safeguard public health. Furthermore, the observation of parasites underscores the need for comprehensive water quality assessment and monitoring. This study highlights the contamination of the river with parasitic organisms and urgently needs effective water management strategies to mitigate the risks to public health. Vital interventions encompass enhancing sanitation practices, curbing fecal contamination, and augmenting water quality surveillance mechanisms.

UiO-66@Fe3O4 nanocomposite as an adsorbent in dispersive solid phase extraction of metformin in surface water and wastewater

Metformin, an anti-hypoglycemic medication, has been used for decades due to its efficiency and is the most consumed pharmaceutical drug worldwide. Consequently, monitoring its concentration in environmental water is important due to its suspected effect on human health and aquatic life. This study reported the extraction, preconcentration, separation and determination of metformin (MET) in waters. Dispersive solid phase extraction (dSPE) using UiO-66@Fe3O4 nanocomposite as a sorbent was used to extract and preconcentrate MET. The high-performance liquid chromatography-diode array detector (HPLC-DAD) achieved the separation and quantification of MET in the samples. Experiemental design was used to optimise influential variables in the extraction and preconcentration of MET. The linearity, limit of detection (LOD) and limit of quantification (LOQ) for MET were 0.5–100 μg L−1 (R2 = 0.9987), 0.16 μg L−1 and 0.53 μg L−1, respectively. The intraday (n = 10 same-day replicates) and interday (n = 5 consecutive days) precisions reported as relative standard deviations (RSD %) were less than 5%. The accuracy of the method expressed as percentage recovery (%R) ranged from 84 to 112%. The method was applied to extract and preconcentrate MET in wastewater and river water samples. The MET was detected in greater concentrations in wastewater than in river water samples. The validation based on specificity, trueness, linearity, precision, and application to the analysis of MET in real samples showed that the combination of dSPE and HPLC-DAD methods is applicable for MET monitoring in surface water and wastewater. Furthermore, the dSPE/HPLC-DAD method was rapid, simple and suitable for estimating the concentrations of MET in South African surface water and wastewater for the first time. Lastly, the environmental risk caused by the occurrence of MET in surface water was investigated in terms of hazard quotient (HQ). The HQ values were less than unity, suggesting a low possibility risk for the aquatic organisms.

Pompon mum-like ionic covalent organic framework nanocomposites for efficient solid-phase extraction of nonsteroidal anti-inflammatory drugs

Molecularly imprinted ionic covalent organic framework nanocomposites (MI-IC-COF@SnO2) were prepared as potential adsorbents for the enhanced adsorption of nonsteroidal anti-inflammatory drugs (NSAIDs) from aqueous solution. The resulting material exhibited a pompon mum-like structure, featuring a large surface area, and well-defined mesopores. The presence of uniform positive ions within the three-dimensional skeleton of MI-IC-COF@SnO2 facilitated a rapid adsorption rate and high adsorption capacity for target analytes. Thermodynamic fitting revealed the adsorption process of NSAIDs to be feasible, endothermic, and spontaneous. Additionally, the adsorbent material exhibited respectable selectivity, as evidenced by imprinting factor values ranging from 2.8 to 6.7. Utilizing MI-IC-COF@SnO2 as the sorbent, a solid-phase extraction method coupled with high-performance liquid chromatography-ultraviolet detection (SPE-HPLC-UV) was developed and optimized. The proposed method demonstrated good linear range with determination coefficients of 0.998–0.999, and low limit of detection (0.18–1.35 µg L−1). Recoveries of NSAIDs in urine and river water samples were 78.1 %–106.1 %, with relative standard deviations lower than 12.5 %. This rapid and sensitive method enables the determination of NSAIDs at trace levels in complex matrices, providing reliable and reproducible results.

Pollution characteristics and risk assessment of organophosphate esters (OPEs) in typical industrial parks in Southwest China.

As alternative substances of PBDEs, organophosphate esters (OPEs), an emerging organic pollutant, were increasingly produced and used in many kinds of industries and consumer products. However, OPEs also have various adverse toxic effects. Information on the pollution levels and exposure to OPEs in related industries is still limited. This study presented data on OPE contamination in the soil, leaf, and river water samples from seven typical industrial parks in Southwest China. Total concentration of seven OPEs (Σ7OPE) including tri-n-butyl phosphate (TnBP), tris-(2-ethylhexyl) phosphate (TEHP), tris-(2-butoxyethyl) phosphate (TBEP), tris-(2-carboxyethyl) phosphine (TCEP), triphenyl phosphate (TPhP), tris-(1,3-dichloro-2-propyl) ester (TDCPP), and tris-(chlorisopropyl) phosphate (TCPP) in the soil samples (36.2 ~ 219.7 ng/g) and the surrounding river water samples (118.9 ~ 287.7 ng/L) were mostly lower than those in other studies, while the Σ7OPE level in the leaves (2053.3 ~ 8152.7 ng/g) was relatively high. There were significant differences in the concentration and distribution of OPEs in the surrounding environment of different industrial parks. TDCPP, TnBP, and TCPP could be used as the characteristic compound in soil samples from auto industrial park, river samples from shoe making industrial park, and leaf samples from logistics park, respectively. The parameter m (the content ratio of chlorinated OPEs to alkyl OPEs) was suggested to distinguish the types of industrial park preliminary. When m ≥ 1, it mainly refers to heavy industries sources such as automobiles, electronics, and machinery, etc. When m<1, it mainly for the light industrial sources such as textile industry, transportation services, and resources processing, etc. For logistics park, furniture park and Wuhou comprehensive industrial park, the volatilization of materials was the main sources of OPEs in the surrounding environment, while more effort was required to strengthen the pollution control and management of the waste water and soil in the pharmacy industrial park, shoe making industrial park and auto industrial park. Risk assessment showed that there was a negligible non-cancer and carcinogenic risk in the soil, while high attention should be paid to the non-cancer risk for children.

Rapid and sensitive determination of legacy and emerging per- and poly-fluoroalkyl substances with solid-phase microextraction probe coupled with mass spectrometry

This study was designed to develop a rapid and sensitive method for quantifying legacy and emerging per- and polyfluoroalkyl substances (PFASs) in environmental samples with solid-phase microextraction (SPME) coupled with mass spectrometry (MS). An innovative SPME probe was fabricated via in situ polymerization, and the probe coating was optimized with response surface methodology to maximize the fluorine–fluorine interactions and electrostatic properties and ensure high selectivity for the target PFASs with enrichment factors of 48–491. The coupled SPME and MS provided a rapid and sensitive method for analyses of PFASs, with excellent linearity (r ≥ 0.9962) over the concentration range 0.001–1 μg/L and remarkably low detection limits of 0.1–13.0 ng/L. This method was used to analyze trace PFASs in tap water, river water, and wastewater samples and proved to be a simple and efficient analytical method for selective enrichment and detection of contaminants in the environment.

Synthesis of potash alum from waste aluminum cans for the purification of river water

Abstract This study explored the synthesis of potash alum from disposed aluminum cans for water purification. The effect of the labels on the cans on the yield of alum was also investigated as it is economically beneficial for industry. Single crystals of potash alum were obtained and characterized by powder X-ray diffraction (P-XRD) and Fourier transform infrared (FTIR) spectroscopy. Through a series of jar test experiments, the characterized alum samples were used to purify river water samples. Some of the parameters investigated include; pH, turbidity, total suspended solids (TSS), total dissolved solids (TDS), electrical conductivity (EC) and chemical oxygen demand (COD). The results show that the alum samples were able to reduce the turbidity by 100 % and substantially decrease the TSS, TDS and COD over the five-hour period of study. However, there were slight increases in acidity and EC which could be corrected by other methods

Hydrazone-linked covalent organic framework functionalized with cysteine as a fluorescence sensor and Exploration of paper chip for p-nitrophenol detection

The large use and emission of p-nitrophenol (p-NP) seriously pollute the environment and endanger human health. In this work, a hydrazone-linked fluorescent covalent organic framework (BATHz-COF) was simply synthesized at room temperature and covalently linked N-acetyl-L-cysteine (NALC) via the "thiol-ene" click reaction, where carboxyl groups were introduced to improve dispersion and fluorescence intensity. As a rapid, good selectivity and reusability fluorescence sensor, the obtained COF-NALC has been used for quantitative analysis of p-NP predicated on the internal filtering effect (IFE). Under optimal conditions, COF-NALC enabled quantitative detection of p-NP with a linear range of 5–50 μM and the detection limit was 1.46 μM. The application of COF-NALC to the detection of p-NP in river water samples was successful, and the satisfactory recoveries were 98.0%–109.3%. Furthermore, the fluorescent COF paper chips constructed by in situ growth were combined with a smartphone to build a visual platform for the quick and real-time detection of p-NP, providing an excellent illustration for the development of intelligent fluorescence sensing in environmental analysis.

River Water Quality Analysis Using Arduino-Based Sensor of the Cikapundung River, Indonesia

River Water Quality Analysis Using Arduino-Based Sensor of the Cikapundung River, Indonesia

Microplastics in remote region of the world: Insights from the glacier of Geladandong, China

Although microplastics have been detected in different remote areas, people are still short of knowledge for environmental background of microplastics in remote area. In this work, we collected air, snow, river and lake water samples from Geladandong region (the origin of the Yangtze River) of the Tibetan Plateau, along with microscopy and Micro-FTIR analyses. Microplastics abundance (0.13–19.8 items/L) was the low as compared with other remote areas worldwide, and the morphology of fiber and film, material of PP and PET, and size of <300 μm were the main microplastics features. Due to natural aging during the transport processes, microplastics were degrading to smaller particle in Geladandong. Air mass trajectory analysis shows microplastics in Geladandong is transferred by repeated atmospheric transport from no human activity place. All these results suggested that Geladandong is an ideal research area for environmental background value and characteristic of microplastics. In conjunction with data from other remote regions, we established the background values for microplastics in remote areas. This work provides quantitative evidence for establishing environmental quality standards, and monitoring environmental changes.

An overview on persistent organic pollutants levels in the White Drin River, Kosovo

The purpose of this study was to assess the concentrations of persistent organic pollutants in the White Drin River, Kosovo region. The study focused on organochlorine pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and benzene, toluene, ethylbenzene, and xylenes. The White Drin River originates from Peja, Kosovo, and extends to the Albanian border near Kukesi, making it a significant water body. It is potentially affected by anthropogenic pollution due to its passage through Kosovo’s urban areas, villages, farms, and industries. Sampling was conducted at 15 stations along the river, from the river waterfall to the Albanian border, during two distinct periods in 2023 (January – February and August – September). Organochlorine pollutants were concurrently extracted using liquid-liquid extraction followed by analysis using capillary gas chromatography equipped with an electron capture detector. Polycyclic aromatic hydrocarbons were isolated through a two-step liquid-liquid extraction, with dichloromethane and hexane. Benzene, toluene, ethylbenzene, and xylenes were isolated using headspace solid – phase microextraction assisted by polydimethylsiloxane fibre. Qualitative and quantitative analyses of polycyclic aromatic hydrocarbons, and benzene, toluene, ethylbenzene, and xylenes, were conducted via gas chromatography with a flame ionization detector. The analyses showed the presence of persistent organic pollutants in the river water samples during both sampling periods. Elevated concentrations of volatile polychlorinated biphenyls, benzene, toluene, ethylbenzene, and xylenes, and polycyclic aromatic hydrocarbons, were observed in the water samples during both periods. This study underscores the significance of investigating organic pollutants in Kosovo’s water systems, considering both local geographic concerns and the broader global issue of environmental pollution

Multi-biological risk in groundwater-surface water system under landfill stress: Driven by bacterial size and biological toxicity

The variation in bacterial size and biotoxicity leads to different ecological risks. However, the diversity of bacterial size and virulence in bacterial communities has been neglected, leading to limitations and inaccuracies in risk assessment. Surface-subsurface interactions lead to the complexity, variability, and insidiousness of pathogen transmission in the environment. Mountainous landfills are considered as a major source of pathogens in subsurface systems. Although numerous studies have reported the geographic distribution of microbes in landfills, there is a lack of knowledge regarding the impacts on the microbial spatial distribution of bacterial size, which is a key factor affecting microbial migration and risks. In this study, the groundwater, river water, soil and leachate samples were collected inside and around a typical mountainous urban landfill, which is close to a river with a high hydraulic gradient and a strong surface–subsurface interaction. Small-sized (<0.2 μm) and large-sized (>0.2 μm) bacteria were separated to verify the variability of migration potential and spatial distribution of different sizes of bacteria in groundwater-surface water and soil, investigating the driving factors and accessing the biological risk of different sizes of bacteria. The results revealed notable differences in spatial distribution and driving factors among various bacterial sizes. Small-sized bacterial communities in groundwater and soils exhibited clear trends towards leachate along the water flow direction. In contrast, large-sized bacterial communities remained stable and resembled native bacterial communities. Groundwater hydrodynamics was the main driving force affecting the spatial distribution of small-sized bacteria. The small-sized bacteria showed a higher content of virulence genes which were predominantly expressed for invasion. Thus, small-sized bacteria exhibited a stronger migration potential and a higher biological risk. Due to the surface–subsurface interactions, the bacterial communities in river water were more similar to that in groundwater after rain. Our results provide strong support to guide the management of subsurface system safety in mountainous landfills.

Hydrodynamic Cavitation – A Promising Technology for Water Treatment

In today's context, water treatment assumes paramount importance due to the scarcity of potable water and the escalating needs of the global population. Hydrodynamic Cavitation (HC) emerges as a promising application in wastewater treatment, particularly when integrated with Advanced Oxidation Processes (AOPs). The study begins with a critical examination of the literature on combined approaches involving hydrodynamic cavitation, followed by experimental findings. The primary objective was to mitigate the chemical oxygen demand (COD) of the sample through HC in conjunction with hydrogen peroxide and Fenton reagent. Subsequently, each run was executed, and the output value obtained from HC was determined. Throughout the research, samples of river water were procured from the Mula-Mutha River in Pune. HC treatment reduced the COD of river water by approximately 60.83 % at 3 pH. Notably, the highest degradation was observed at 9 pH with the use of Sodium persulphate, with the optimal concentration estimated to be 600 ppm. Moreover, a COD reduction exceeding 89 % with a dosage of 15 mM H2O2. Treatment with Fenton reagent for 60 min demonstrated a remarkable COD decrease of up to 93 %, with an optimal H2O2 to FeSO4 molar ratio of 10:1 and at 3 pH. The Fenton procedure alone or in combination with H2O2 and HC proved to be the most efficient for river water characterized by extremely high COD levels, yielding the greatest reduction during experimental trials. The kinetics of HC degradation conformed to a first-order rate law, with the value of a rate constant (K = 7.21 × 10-4 s−1).