Concentrations In River Water Research Articles

Microplastic Concentrations in Sediments and Waters Do Not Decrease in Two Rivers Flowing Through the Kruger National Park, South Africa

Plastics are manufactured for various purposes but result in microplastic pollution in aquatic ecosystems. Riverine microplastic occurrence, spatial distribution, and impact have been globally documented but not well understood in Africa. We quantified 36 984 microplastics in riverbed sediment and river water along the Olifants and Sabie rivers, Kruger National Park (KNP), South Africa. These rivers have independent catchments. The microplastic profiles (size, polymer, morphotype, and colour) differed significantly between rivers. Riverbed sediment microplastic (mostly beads) concentrations ranged between 2022 to 9971 n/kg dm, and 2237 to 27 259 n/kg dm, for the Olifants and Sabie rivers respectively. Microplastic (mostly fragments) concentrations in river water ranged between 11 to 50 n/L in the Olifants River, and 4.0 n/L to 41 n/L in the Sabie River. Polyethylene terephthalate (PET) was prevalent in sediment (39%) and water (32%). Concentrations varied along both river stretches but the expected concentration decrease downstream was not observed. This raises transboundary concerns, as all the KNP rivers cross into Mozambique and from there into the Indian Ocean. Given the pervasive plastic pollution already present, there is a need for significant upstream and in-park interventions to reduce the concentration of microplastic in rivers flowing through conservation areas.

Comparative performance of electronegative membrane filtration and automated concentrating pipette for detection of antibiotic resistance genes and microbial markers in river water samples

The target viral and bacterial concentrations in river water are essential for environmental monitoring and public health studies. Filtration-based methods are commonly employed, yet challenges arise due to recoverability and filter pore size. This study aimed to compare the performance of electronegative membrane filtration (EMF) and automated Concentrating Pipette (CP) Select (InnovaPrep) methods for quantifying antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), and bacterial and viral markers in river water samples. Fifty-four river water samples were collected from upstream and downstream locations in a river in Japan. The CP Select method was modified by adding MgCl2 and using different tips. The recovery efficiencies for total coliforms and Escherichia coli were assessed, and class 1 integron-integrase gene (intI1), 16S rRNA, gene encoding sulfonamide resistance (sul1), cross-assembly phage (crAssphage), pepper mild mottle virus (PMMoV), and Escherichia coli gene (sfmD) were detected. CP Select showed recovery efficiencies of 45 %–63 % for total coliforms and 17 %–35 % for E. coli. The intI1, 16S rRNA, sul1, crAssphage, PMMoV, and sfmD concentrations using the modified CP Select method were 10.1 ± 0.5, 8.7 ± 0.2, 7.7 ± 0.2, 6.7 ± 0.2, 5.4 ± 0.2, and 3.5 ± 0.5 log10 copies/L, respectively. Higher intI1 and sul1 concentrations were observed downstream, with the highest contribution percentage (22 % and 21 %) using CP Select or EMF. The modified CP Select method with 0.05 μm tips yielded more quantifiable results for all target genes and greater PMMoV concentrations (p < 0.05). Positive correlations were found among bacterial, ARG/MGE, and viral markers (Spearman's ρ = 0.71 for 16S rRNA and sfmD, 0.88 for intI1 and sul1, and 0.64 for PMMoV and crAssphage). The modified CP Select method demonstrated effective recovery of bacteria and quantification of ARGs, MGEs, and microbial markers in river water. Further studies are required to validate these methods and confirm their applicability in diverse environmental contexts.

Supramolecular colorimetric sensor array combined with machine learning for benzimidazoles fungicides discrimination and prediction

Due to their slight structural differences, the rapid identification of benzimidazole fungicides is challenging. In this study, three benzimidazole fungicides (FBZ, CBZ and TBZ) with similar structures were added to the 2C30@3Q[8] host–guest complex. The solutions changed color, suggesting that a reaction occurred. Based on this host–guest interaction, a supramolecular colorimetric sensor array was constructed by extracting the red, green and blue (RGB) color change of the host–guest complex in response to fungicides. Linear discriminant analysis (LDA) identified and distinguished the benzimidazole fungicides with similar structures. The supramolecular colorimetric sensor array was in the 1–20 μM range. The Euclidean distance of the array showed excellent linear correlation with the fungicide concentration, with a 10−7 mol/L detection limit and a signal-to-noise ratio of 3. The colorimetric sensor array clearly distinguished between the binary and ternary fungicide mixes. The sensor array was integrated with machine learning to predict TBZ concentrations in river water. The applicability of the supramolecular colorimetry sensor array was verified by distinguishing and identifying three benzimidazole fungicides in river water and fruit skin.

Impact of legacy and unintentionally produced polychlorinated biphenyls (PCBs) in effluents from two wastewater treatment plants in rivers near Barcelona, Spain

Polychlorinated biphenyls (PCBs) are a family of 209 congeners listed as Persistent Organic Pollutants in the Stockholm Convention. Although there has been a lot of focus on those congeners present in the Aroclor or Clophen technical mixtures commercialized in the past (legacy PCBs), other industrial processes such as paint and pigment production can generate other congeners as byproducts (Unintentionally Produced PCBs or UP-PCBs). The present study focuses on the analysis of 72 PCB congeners (including 42 UP-PCBs) in the two major rivers surrounding the city of Barcelona -Llobregat and Besós rivers-, and their levels in two wastewater treatment plants during the production of effluents and reclaimed water. It was observed that WWTP can efficiently remove PCBs from untreated water during sludge production where concentrations are six orders of magnitude higher than in water (in the ng g−1 and pg L−1 ranges, respectively). Although PCB levels in the effluent and reclaimed water replenishing the rivers are not negligible, these do not significantly increase the concentrations already found in the studied rivers, and in most cases PCB concentrations in river water are reduced after merging with the reclaimed water due to dilution effect. The presence of UP-PCB-11 (not present in the Aroclor technical mixtures) in the analyzed water and sludge samples is significant (ranging from 22 to 25 % of the total PCB amount in the Besós river), being often one of the most abundant PCB congeners.

Occurrence, transport and sources of metals and metalloids in the Bangpakong River in the eastern economic corridor area of Thailand

The occurrence of elements in river water is affected by various factors, including mobility, weathering and transport processes and anthropogenic contributions. A total of six water sampling campaigns were conducted from 2021 to 2022 to study the factors affecting the occurrence of twelve elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn and Se) in the Bangpakong River. The total concentrations of all the elements were within the levels set by the national surface water quality standard. Comparisons of dissolved elemental concentrations in the study area with the global average for dissolved elemental concentrations in pristine rivers indicated contamination with Al, As, Co, Mn, Zn and Se in the river water. Based on the percentage of each element in particulates to the total concentration, Al (80.6 %), Cr (71.9 %), Cu (69.9 %), Fe (95.6 %), Mn (76.6 %), Pb (74.7 %), and Zn (70.6 %) were mainly transported in the particulate phase in both the dry and wet seasons. However, As (65.5 %), Co (60.3 %), and Se (77.6 %) were mainly transported in the dissolved phase in both seasons. The ratios of the dissolved Se concentration in river water to the Se concentration in the Earth's crust indicated significant and high mobility, especially in downstream sites, likely due to Se leaching from alluvial sediments. Seawater intrusion is likely the cause of As and Zn contamination in the dry season. Weathering of rocks and soils likely causes Al, Co, and Mn contamination in the wet season. The anthropogenic sources of contamination include the discharge of Mn and Zn from fertilizers in agriculture and the use of formulated feed in aquaculture. Approximately 52.98, 25.23, 5.68 and 0.63 tons of Fe, Al, Mn and Zn, respectively, are estimated to be transported from the river into the Gulf of Thailand each year.

Anthropogenic gadolinium in the Tone River (Japan): an update showing a 7.7-fold increase from 1996 to 2020

BackgroundAnthropogenic gadolinium (Gd), originating from Gd-based contrast agents (GBCAs) used in magnetic resonance imaging (MRI), is widely identified in the aquatic environment with concerns about toxicity and accumulation. We aimed to present new data on anthropogenic Gd in the Tone River, which has the largest drainage area in Japan, and then to compare the current data with those obtained in 1996.MethodsThe water samples were collected on August 9−10, 2020, at 15 different locations of the Tone River in Japan. The concentrations of the rare earth elements (REEs) were measured by inductively coupled plasma-mass spectrometry and normalized to Post-Archean Australian Shale to construct shale-normalized REE patterns. The degree of Gd-anomaly was defined as the percentage of anthropogenic Gd to the geogenic background and used to compare the water samples from different locations. Pearson’s correlation coefficients were calculated.ResultsAll the samples displayed positive Gd anomalies. The Gd-anomaly ranged from 121 to 6,545% and displayed a repeating decrease-and-increase trend. The Gd-anomaly showed strong positive correlations to the number of hospitals (r = 0.88; p < 0.001) and their MRI units (r = 0.89; p < 0.001).ConclusionsOur study revealed notable anomalies of Gd concentrations in river water in Japan, with strong positive correlations to the number of major hospitals and their MRI units. Compared with the previous report in 2000, the Gd-anomaly in Tone River increased from 851% (sampled in 1996) to 6,545%, i.e., 7.7 times, reflecting the increased use of GBCAs in hospitals.Relevance statementNotable Gd concentration anomalies in river water in Japan were observed. This result underlines the importance of more extensive research on anthropogenic gadolinium, and investigations of risks to human health as well as the development of effective removal technologies may be necessary.Key points• All water samples from Tone River displayed positive Gd anomalies.• The Gd anomalies increased to 7.7 times higher over the past 24 years.• Correlations between Gd values and the number of hospitals and MRI units were observed.Graphical

Trends of Major Ions in a Carpathian River in Poland: The Influence of Flow and Damming

Flow influences major ion concentrations in river water, therefore, it seems that it can differentiate ion concentrations in mountain rivers in different hydrological years. This study aimed to determine the impact of flow on the major ion concentrations in the Carpathian Raba River above and below the Dobczyce Reservoir (southern Poland) in hydrologically dry (HD), average (HA), and wet (HW) years (period April–October) in the period 2010–2017. In the river above the reservoir, the flow negatively affected the concentrations of most major ions under all hydrological conditions, which resulted in their significant differences between (1) the studied hydrological years (except for SO42−)–higher in the HD years than in the HA or HW years–and (2) seasons–higher Mg2+, Na+, K+, Cl−, and SO42− concentrations (mainly point sources of pollution) were identified in summer or autumn than in spring in the HD and HA years. The dam reservoir strongly modified the ion concentrations in the downstream river. It significantly decreased all major ion concentrations only in the HD years, when they were high in the upstream river, and Ca2+, Mg2+, or HCO3− concentrations in all the studied hydrological years. There, the ion concentrations were not related to the flow that resulted in their insignificant differences between the studied hydrological years (with the exception of HCO3−, Ca2+, and Cl−) and different seasonal changes to those in the river above the dam. The obtained results allow for predicting conditions favouring an increase in the salinity of mountain river waters; therefore, they are important for appropriate management and water use opportunities.

Zn-doped CeO2 nanorod based dispersive solid phase micro-extraction of lead in water, black pepper, lentils and tea samples

In this work, pristine CeO2 and Zn-doped CeO2 nanorods were prepared through facile hydrothermal process and characterized. The Zn- doped CeO2 was first used for dispersive solid phase micro extraction (d-SPµE) of lead in water and food. The conditions affecting d-SPµE of lead were optimized. They were pH, adsorption/elution contact time, eluent type/volume/concentration, interfering ion effects and sample volume. The sample pH, eluent concentration/volume and sample volume were 3, 2 mol L−1 HCl/1 mL and 60 mL, respectively. The adsorption/desorption kinetics of the developed d-SPµE were very fast, and the extraction time was only 30 s (30 s for adsorption and without vortexing for elution). The preconcentration factor (PF) and limit of detection (LOD) of the d-SPµE for lead were 60 and 2.0 µg L−1, respectively. The RSD% (n=5) of the extraction method was found to be ≤ 3.0%. The high tolerable interfering ion concentrations were obtained. The sorbent could be used for 46 times. The method was confirmed with analyses of NW-TMDA 54.6 Lake water, SPS-WW1 Batch 114 Wastewater and NIST 1573a Tomato Leaves certificate reference materials. The trace lead concentrations in wastewater, dam water, river water, sea water, tea, lentils, and black pepper were determined by d-SPµE-FAAS.

Mercury Pollution from Ilegal Gold Mining Activities and Its Impact on Human Health in the Anahoni River, Kaiely Bay, Maluku: A Review

Illegal gold mining in the Anahoni River area, Kaiely Bay, Maluku, intensifies mercury pollution, posing grave environmental and health risks. Statistical analyses reveal a significant correlation between illegal mining and escalating mercury levels, necessitating urgent intervention. Environmental impacts include biomagnification in fish, affecting indigenous communities dependent on these resources. Health risks encompass neurological, reproductive, and respiratory implications, warranting targeted public health interventions. Examining the broader context, the global dimension of mercury pollution underscores the interconnected nature of the issue, requiring collaborative efforts. The toxicological aspects of mercury and its biogeochemical cycling inform potential mitigation strategies. Methodologically, systematic literature reviews, field investigations, and socio-economic assessments provide a holistic understanding of mercury contamination. Results highlight alarming mercury concentrations, with significant correlations between mercury levels, deforestation, and fish abundance, emphasizing the need for evidence-based policy decisions. Human health implications are evident through a positive correlation between mercury concentrations in river water and human hair samples, emphasizing the direct link between environmental exposure and health risks. Environmental impacts extend beyond human health, affecting ecosystems and necessitating global collaboration. The study underscores the importance of comprehensive policy frameworks, international collaborations, and community engagement in addressing the socio-economic roots of illegal gold mining. Mitigation strategies encompass regulations, sustainable practices, alternative technologies, and community-based initiatives. This review contributes to a nuanced understanding of mercury pollution in the Anahoni River, providing insights into the interconnected challenges and opportunities for sustainable solutions within a concise framework.

Anthropogenic gadolinium sources and remediation in highly urbanized river in the Beijing-Tianjin-Hebei (BTH) region, China: Insights from buffer zone and three-dimensional tracer system

As a newly emerging microcontaminant, rare earth elements (REEs), especially gadolinium (Gd) in surface water, are attracting great environmental concern in large urban cities. The Beijing-Tianjin-Hebei (BTH) region stands as the preeminent urban agglomeration in northern China, whereas the riverine Gd characteristics and environmental impacts on this region remain inadequate. This study analyzed 27 river water samples in BTH, all of which displayed evidently positive Gd anomalies ranging 1.44–290.75. Spearman correlation indicated the positively correlated REEs concentrations in river water with urban land and cultivated land. A three-dimensional tracing system was established involving anthropogenic Gd (Gdanth) and conventional ion ratios (NO3−/Na+, Cl−/Na+). This system effectively discerned the influences originating from sewage treatment plants, wastewater treatment plants, hospitals, and factories within the BTH region. Gd-based contrast agents (GBCAs) manifest notable potential ecological toxicity and adverse health effects when getting exposed. However, traditional wastewater treatment methods demonstrate limited efficacy in removing these pollutants completely from urban water. To deal with this challenge, this study proposed a new method by combining the latest GBCAs remediation technology with mixing membrane wastewater treatment. This technology may shed light on the potential of an economical and operational procedure of handling medical wastewater specifically in urban water.

Enrichment of arsenic in the Yarlung Tsangpo basin, Southern Tibetan Plateau: Provenance, process, and link with tectonic setting

Geogenic As enrichment is prevalent in freshwater systems worldwide, yet the connection between such enrichment and regional tectonics remains poorly understood, especially within orogenic environments like the Tibetan Plateau. To provide new insights into the sources and processes of arsenic, as well as its relationship with tectonics in the plateau basin, we selected the Yarlung Tsangpo basin, situated at the collision zone between the Indian (Himalaya block) and Eurasian plates (Lhasa block) as the study area. We analyzed and compared the chemical compositions of waters and sediments across various litho-tectonic domains. This also involved assessing arsenic concentrations in river waters, suspended particulate matter (SPM), sediments, geothermal waters, and rocks. The main findings are as follows: (a) High-arsenic geothermal waters and igneous rocks are common in the Lhasa block, and the discharge of these geothermal waters is the main source of dissolved As in river water, whereas erosion of igneous rocks contributes most of the As in sediments. (b) Metal oxides adsorb dissolved As, which leads to further As enrichment in the sediments. (c) The occurrence of high As concentrations in the southern Tibetan Plateau can be explained by a crustal cycling model. Arsenic likely originated in Neo-Tethys oceanic crustal rocks and was concentrated in the upper crust of the active continental margin (Lhasa block) during geological cycling at convergent plate boundaries. These studies highlight the role of tectonic settings on influencing arsenic enrichment in the plateau basin.

Discrimination of metal contaminant sources in river sediments influenced by mining and smelting activities using stable Pb and Zn isotopes.

To determine the sources and pathways of lead (Pb) and zinc (Zn) in river sediments contaminated with metals from mining and smelting activities, metal concentrations and Pb and Zn isotope ratios were measured in river water and sediment, and potential metal contaminant samples (imported Zn concentrates, smelting wastes, soils around the smelter, mine ores, and riverside tailings). Zn and cadmium (Cd) concentrations in river water and sediment samples were 30- and 11-25-fold higher, respectively, near the smelter than upstream, while a 6-fold increase in sediment Pb concentrations was detected over the same region. Sediment samples near the smelter (207Pb/206Pb = 0.8638 and 208Pb/206Pb = 2.0960) were observed to have a different Pb isotopic composition from upstream of the smelter (207Pb/206Pb = 0.8322 and 208Pb/206Pb = 2.0502), with δ66Zn values increasing from -0.01 to 0.82‰. Analysis of Pb and Zn isotopes and concentrations revealed that dust-contaminated soils were a major Pb source, and baseline sediments were found to be contaminated by regional mining tailings. For Zn in sediments, the main Zn sources were groundwater-derived Zn (δ66Zn = 1.02 ± 0.43‰, n = 4), dust-contaminated soils (δ66Zn = -0.18 ± 0.08‰, n = 3), and tailings-contaminated sediments (δ66Zn = 0.01 ± 0.07‰, n = 10). Endmember mixing model results showed that dust-contaminated soils contributed 78% and 64% of sediment Pb and Zn, respectively, within 2km of the Zn smelter, decreasing to negligible levels after 47.1km downstream. Downstream of the smelter, groundwater-derived Zn contributed 54% of sediment Zn, whereas tailings contaminated sediments contributed 70% and 25% of Pb and Zn, respectively.

Effect of Physico-Chemical Parameters and Inorganic Nutrient Ions in Relation with Seasonal Algal Diversity of River Ichhamati, West Bengal, India.

The present study reflects seasonal algal diversity as a source of food for fishes in the river Ichhamati during October 2021 to August 2022. To understand the seasonal algal pattern in the river Ichhamati, physicochemical parameters of river water such as Hardness, Conductivity, pH, Total Dissolve Solids, Turbidity, Dissolve Oxygen, Salinity, Turbidity, Total Alkalinity, Salinity, Biological Oxygen Demand as well as biologically significant inorganic ion concentrations in river water namely sodium, potassium, calcium, carbonate, bicarbonate, nitrate, chloride were also evaluated during study period. It is found that physico-chemical parameters and inorganic ions in river water play an important and significant role in seasonal algal growth. Throughout the study period it was established that river Ichhamati is not very rich in floral diversity. During study time it was observed that dominant group of algae in this river are Chlophytes, Cyanophytes and Bacilariophyceae, including Species of Oscillatoria Nostoc, Klebsormidium, Spirogyra, Lyngbya, Chlorococcum, Chlorella, Diatoms in all seasons. During spring, summer and monsoon Conductivity, salinity, TDS and hardness of river water is high. Ichhamati contained adequate Na+, K+ and NO3- in summer and monsoon season. High rate of bio-mineralisation during winter was found due to presence of high calcium ion concentration and also high TDS along with high salinity as well as high hardness of river water.

Regional‐scale effects of deer‐induced forest degradation on river ecosystem dynamics

AbstractAlmost all ecosystems are open systems, meaning that significant changes in one ecosystem can lead to unexpected changes in others. Deer overabundance has become a problem worldwide, leading to forest degradation that has impacts on not only terrestrial, but also aquatic ecosystems. This study aims to investigate the regional‐scale importance of large herbivores in inter‐ecosystem interactions by examining the effects of deer‐induced forest degradation on fish populations. We selected similar‐scale catchments from river systems in Hyogo, Japan, that differed in the time since deer‐induced forest degradation. Conventional surveys for fish densities and microhabitat environments were conducted in 23 catchments, and surveys using quantitative eDNA metabarcoding were conducted in 95 catchments. We examined the relationships between fish population densities, microhabitats, and time since forest degradation, considering confounding effects. Data from 8 and 17 fish taxa detected by snorkeling and eDNA methods, respectively, were available for statistical analysis. Snorkeling‐counts (Individuals/1 m transect) and eDNA concentrations (Copies/L) in river water were strongly correlated. Fine sediments on riverbeds were increased in the 3–15 years following forest degradation and decreased after 16 years. Population densities of sand‐preferring fishes, as inferred from both eDNA and snorkeling, reasonably followed this pattern. These patterns may be caused by the depletion of fine sediments on mountain slopes. The results of this study suggest that deer‐induced worldwide alternation may also occur in aquatic ecosystems.

Assessment of nitrogen budget in detailed spatial pattern using high precision modeling approach with constructed accurate agricultural behavior

Changes in the nitrogen cycle due to fertilizer use can cause severe environmental pollution, particularly groundwater pollution, and threaten biosphere integrity. There are many difficulties and limitations in assessing groundwater pollution and a detailed nitrogen budget in an agricultural catchment. Previous methodologies have failed in an accurate assessment of the nitrogen budget in detailed spatial patterns. Herein, we designed a new modeling approach to assess the nitrogen budget using detailed spatial patterns in an agricultural catchment in the Nara Basin. We revised the Soil and Water Assessment Tool file output format, added the results for river nutrient concentrations and ammonia volatilization to the original output file. In this study, we calibrated and validated crop harvests, paddy evapotranspiration, streamflow, and river water concentrations of nitrate–nitrogen and total nitrogen to improve model accuracy as much as possible. Among them, data for evapotranspiration was obtained from a newly released Landsat dataset. The results showed that the amount of nitrogen leaching in rice paddies was 42 kg/ha, accounting for 65 % of total leaching in the study catchment. Cambisols and Fluvic Gleysols were prone to denitrification, and nitrogen leaching or denitrification occurred relatively more readily in low-slope areas. Furthermore, a detailed analysis of nitrogen cycle processes with high spatial precision indicates that areas with severe surface water pollution may also exhibit significant groundwater pollution. Our findings provide new solutions for assessing the nitrogen budget and groundwater pollution in catchments.

Adsorption and detection tramadol in aqueous solution by fluorescent- magnetic molecularly imprinting polymers

BackgroundThe usage of tramadol (TR) as one of the most common analgesics is expansively growing in the world. Therefore, there is an urgent requirement for a rapid and reliable method for the on-site detection of tramadol in different samples. The elimination half-life of tramadol is about 6 h, and its removal from body is relatively slow. So, it is very critical providing a method for rapid detection of tramadol. MethodsIn this study, three magnetic nanocomposites (Fe3O4, Fe3O4/SiO2, and Fe3O4/SiO2/CMC) and molecularly imprinted polymers (MIPs) based on those in the presence of graphene quantum dots (GQDs) were synthesized and investigated for selective adsorption and detection of TR in aqueous solution. For the characterization of synthesized materials, XRD, FT-IR, SEM, VSM, and the response surface method (RSM) were also employed to optimize and estimate the effective parameters of TR adsorption by these materials. Significant findingsThe results of investigating the absorption ability of nanocomposites showed that the Fe3O4/SiO2/CMC composite has higher absorption ability than the other two nanocomposites. Moreover, Fe3O4/SiO2/CMC has an excellent ability to adsorb of TR with a removal percentage of 97.46 % at pH = 7, initial TR concentration = 15 mg/L, composite dosage = 1.5 g/L, and contact time = 6 min. According to the experimental results, the imprinting factors (IF) of MIP-Fe3O4, MIP-Fe3O4/SiO2, and MIP-Fe3O4/SiO2/CMC are 1.02, 1.72, and 2.19, respectively. Therefore, the MIP-Fe3O4/SiO2/CMC was chosen as a selective sensor, and the sensitivity of its response was investigated. The detection of TR was performed by fluorescence spectroscopy at a concentration range of TR of 0 to 250 µM, and a sensitivity of 3.13 a.u./µM and limit of detection of 2.08 µM were determined. Also, the river water and artificial urine samples (with TR of 10 µM) was detected using MIP-Fe3O4/SiO2/CMC, and the results of the sensor showed a TR concentration of river water is 9.97 µM and artificial urine is 10.456 µM and which is very good and acceptable precision.

Hydrochemical background of 222Rn in surface waters of Lower Silesia (SW Poland)

The purpose of the conducted research was to create the first Polish database on 222Rn activity concentration in surface (river) waters in one of Poland’s 16 voivodeships (the highest-level administrative division unit in Poland), and thereby complement the worldwide database on 222Rn activity concentration in such waters. To this end, the research area was limited to Lower Silesian voivodeship (6.4% of the area of Poland; 7.8% of its population), which, in geological terms, can be divided into three parts differing in geological structure, characterised by a decreasing proportion of crystalline rocks on the surface. The ranges of 222Rn activity concentrations measured in these areas were: 0.21–24.44 Bq/dm3 for the Sudetes, 0.08–4.27 Bq/dm3 for the Fore-Sudetic Block, and 0.09–3.37 Bq/dm3 for the Fore-Sudetic Monocline. Based on the obtained 222Rn activity concentrations in river waters, the authors determined the hydrochemical background. It was: 0.26–1.33 Bq/dm3 for the Sudetes, 0.18–0.92 Bq/dm3 the Fore-Sudetic Block, and 0.12–0.48 Bq/dm3 for the Fore-Sudetic Monocline. The range of 222Rn activity concentrations measured in river waters in the whole Lower-Silesian voivodeship was 0.08–24.44 Bq/dm3. It means that river waters in this voivodeship satisfy the radiologic requirements for water intended for human consumption in terms of 222Rn activity concentration.

Water environment response of urban water networks in the Pearl River Delta (China) under the influence of typhoon rain events

Abstract Identifying water quality parameter concentrations and their drivers is important for the prevention and control of water environment pollution. In this study, we constructed an inverse model of water quality parameters based on measured water quality parameters and remote sensing spectral data for this study area using artificial neural networks. We investigated the water environment response of the urban water network in the Pearl River Delta under the influence of typhoon rain events and explored their spatial heterogeneity using a multiscale geographically weighted regression model. The results indicate that in regions with a high level of urbanization, the dissolved oxygen (DO) concentration in river water is lower, and the ammonia nitrogen (NH3-N) concentration is higher. Under the influence of typhoon rain events of varying intensities, the response of water quality parameters in the urban water network of Zhongshan City varies. The intensity of rainfall determines the impact of typhoon rain events on water quality parameter concentrations. Our results are expected to improve the understanding of water quality trends under the influence of typhoon rain events and help policymakers and planners better develop water environment control strategies during typhoon transit.

Method validation and environmental monitoring of triethanolamine ester quaternary ammonium compounds

In this study water and sediment samples, collected from the River Nene (Northamptonshire) at several sites in the vicinity of the Great Billing sewage treatment plant (STP), were analysed for triethanolamine quaternary compounds (TEAQ, ester quats). A method was developed using liquid chromatography tandem mass spectrometry (LC/MS/MS) with a electrospray ionisation source (ESI). Ten components were determined using a characterised commercial sample of Tallow TEAQ as a standard. To our knowledge this is the first time environmental concentrations of a wide spectrum of individual homologues of TEAQ have been reliably quantified covering a broad range of environmental matrices (STP influent, STP effluent, surface waters and sediments), due to the challenging nature of the analytical method. The method featured novel solutions for the determination of long and multiple chain length alkyl quats, controlling loss processes, background contamination and chromatographic performance. TEAQ compounds were found to be highly removed in the sewage treatment plant resulting in low effluent concentrations. Low concentrations in both river water and sediment samples were found also. In many cases levels were below the Method Detection Limit (MDL). In river water samples, mean values of TEAQ compounds found were 210–398 ng/L for C16:0/C18:0 TEAQ diester and 126–287 ng/L for C18:0/C18:0 TEAQ diester. River sediment was found to contain mean TEAQ levels of 7.07–12.5, 19.7 to 40.3 and 7.04–35.1 μg/kg dry weight for C16:0/C16:0, C16:0/C18:0, and C18:0/C18:0 TEAQ, respectively. At Great Billing STP monoesters and diesters of TEAQ were shown to be efficiently removed (>97 and 99 %, respectively), although limited samples were taken on this occasion.

Spatial and temporal distribution of geochemical elements and their processes in different size fractions–Miri River (NW Borneo)

The toxicity, persistence, and propensity for accumulation of metals in aquatic environments have raised significant concerns globally. Expansion of urbanization with the growth of industrial and agricultural sectors in Miri City results in a high concentration of pollutants that flow directly into the Miri River. Hence, this study provides a comprehensive analysis of the Miri River water quality, focusing on spatial and temporal variations. River water samples were collected in two different time periods and analysed for physico-chemical parameters includes major ions, nutrients, metals and isotopes. Particularly, the metals were analysed in different size fractions (particulate and colloid) of the suspended solids. Geochemical plots, pollution index, geochemical modelling and factor analysis were used for the data analysis. Interpretation of data reveals that the mean concentration of metals in river water were increased from downstream to the upstream of the river irrespective of the seasons. Major ions were mostly derived from the chemical weathering of source rocks, which was supported by the Gibbs plot. Piper plot indicates the seasonal shifting of water types from Ca–Mg to Na–Cl. Isotopic signatures reveal direct atmospheric precipitation and evaporation were the major origins of river water. Fe was the dominant metal concentration in river water irrespective of the seasons (mean concentration 1.05 mg/L). Fe and Zn were the dominant metal concentration observed in all the 3 size fractions of suspended solids. Industrial activities and seawater influx dominate in the downstream, whereas weathering and agricultural inputs are significant in the upstream of the river. Particulate and colloidal fractions are the major contributors for the metal transport in the midstream and downstream of the river. The outcome of this study offer a thorough understanding of the seasonal elemental distribution at different size fractions, geochemical behaviour and the pollution status of the Miri River. With this knowledge, sustainable management strategies can be developed for this crucial water resource to the benefit of Miri community.