Water Quality Characteristics Research Articles

Reframing microplastics as a ligand for metals reveals that water quality characteristics govern the association of cadmium to polyethylene

Environmental characteristics including water quality and sediment properties alter the hazard that metals pose to aquatic systems by governing the speciation and partitioning of metals between water, sediment, and biotic ligands; however, alternate ligands are being introduced into aquatic systems through anthropogenic activity. Microplastics are a ligand on which metals interact through adsorption to the plastic surface. It remains unknown what factors determine the amount of metal bound to microplastic. Using a combination of laboratory experiments and machine learning, we tested a suite of eighteen environmental parameters (inclusive of both water and sediment) to understand how they influence association of cadmium to a representative microplastic, polyethylene. From this, we developed and tested a predictive model that outlines the characteristics that favour the association of cadmium to microplastic. Alkalinity, humification index of dissolved organic matter, and pH (all of which are water quality characteristics) were the three factors determining the proportion of cadmium adsorbed to plastics. These results align with other predictive models, such as the Biotic Ligand Model in demonstrating the governance of metal behaviour by water quality characteristics. To assess the relationship of the amount of cadmium bound to microplastic and cadmium uptake, an exposure was completed in which fathead minnows (Pimephales promelas) were acclimated to environments representing each of the potential outcomes of the model. The uptake of cadmium was not significantly different between groups, indicating that the stress of alterations to water quality may be a confounding factor in determining the exposure risk of microplastics and cadmium.

Impact of Conservation in the Futian Mangrove National Nature Reserve on Water Quality in the Last Twenty Years

Mangroves play a crucial role in improving the water quality of mangrove wetlands. However, current research faces challenges, such as the difficulty in quantifying the impact of mangroves on water quality and the unclear pathways of influence. This study utilized remote sensing imagery to investigate the long-term changes in mangrove forests in the Futian Mangrove National Nature Reserve and constructed a water quality index based on water quality data. Finally, structural equation modeling was employed to explore the pathways of influence and quantify the impact effects of mangroves, climate, and water quality. The study findings revealed several key points: (1) The mangrove forests in the Futian Mangrove National Nature Reserve exhibited a trend of expansion towards the ocean during this period. (2) The seasonal and annual characteristics of water quality in Shenzhen Bay indicated a significant improvement in water quality from 2000 to 2020. (3) Mangroves have significant direct and indirect impacts on water quality, which are more pronounced than the effects of climate factors. These findings not only offer insights for the environmental management and conservation of Shenzhen Bay but also provide support for future comprehensive studies on the response relationships between the morphology, species, and physiological characteristics of mangroves and water quality.

Kualitas Air dan Karakteristik Tanah Penduga Erodibilitas pada Sub-Sub DAS Amandit Kabupaten Hulu Sungai Selatan

Land management in, Amandit sub-sub watershed must comply with the principles of soil and water conservation to avoid erosion and sedimentation. The aim of this research was to assess water quality and soil characteristics that predict erosion in the upstream, middle and downstream areas. The purposive sampling method was used by taking soil and water samples in the upstream, middle and downstream parts. In the upstream section soil samples were taken with a slope of 15-25%, in the middle section with a slope of 8-15% and in the downstream section with a slope of 0-8%. Soil samples were taken at each of six points representing the upstream, middle, and downstream parts of the area. Water sampling was carried out in the soil sampling area by paying attention to the slope of the land. The results showed that the water quality (pH, DHL, SAR, and TSS) in the area was in accordance with the quality of water for irrigation. Soil erodibility values in the upper and middle areas did not show significant differences. In the upstream part, soil erodibility had very low criteria and the middle part had low criteria but were different from the downstream area (medium criteria).

Evolution Trend of Water Quality in the Inner Mongolia Section of the Yellow River from 2003 to 2020

The aim of this study was to comprehensively understand the water environment quality status and its change trend in the Inner Mongolia section of the Yellow River Basin. To analyze the water quality in recent years,the water quality data in the Yellow River basin from 2003 to 2020 were firstly collected from five typical monitoring stations．Various data analysis methods, including principal component analysis, cluster analysis, and a long short-term memory model, were used along with an improved comprehensive water quality identification index to explore the spatiotemporal characteristics of water quality in the Yellow River Basin. The results showed that the overall water quality in the basin has improved and stabilized over time. In terms of temporal variation, there was a distinction between the wet season and dry season, with a better status observed during the wet season due to increased agricultural irrigation and higher water volume. Spatially, the five monitoring sections could be divided into three categories based on strong natural factors that maintained their temporal characteristics during the wet season； however, significant differences were observed during the dry season due to urban water usage patterns. Analysis using LSTM models revealed that ammonia nitrogen will continue to decline and have a decreasing impact on the comprehensive water quality. These findings provide valuable insights for the comprehensive management of water quality in Inner Mongolia's Yellow River Basin.

Monitoring Water Diversity and Water Quality with Remote Sensing and Traits

Changes and disturbances to water diversity and quality are complex and multi-scale in space and time. Although in situ methods provide detailed point information on the condition of water bodies, they are of limited use for making area-based monitoring over time, as aquatic ecosystems are extremely dynamic. Remote sensing (RS) provides methods and data for the cost-effective, comprehensive, continuous and standardised monitoring of characteristics and changes in characteristics of water diversity and water quality from local and regional scales to the scale of entire continents. In order to apply and better understand RS techniques and their derived spectral indicators in monitoring water diversity and quality, this study defines five characteristics of water diversity and quality that can be monitored using RS. These are the diversity of water traits, the diversity of water genesis, the structural diversity of water, the taxonomic diversity of water and the functional diversity of water. It is essential to record the diversity of water traits to derive the other four characteristics of water diversity from RS. Furthermore, traits are the only and most important interface between in situ and RS monitoring approaches. The monitoring of these five characteristics of water diversity and water quality using RS technologies is presented in detail and discussed using numerous examples. Finally, current and future developments are presented to advance monitoring using RS and the trait approach in modelling, prediction and assessment as a basis for successful monitoring and management strategies.

Water quality dynamics and underlying controls in the Halton Region, Ontario.

We assessed the hydrochemistry of 15 watersheds in the Halton Region, southern Ontario, in high resolution (n > 500 samples across n > 40 streams) to characterize water quality dynamics and governing controls on major and trace element concentrations in this rapidly urbanizing region. In 2022, major water quality parameters were generally in line with historic monitoring data yet significantly different across catchments, e.g., in specific conductance, turbidity, phosphate and chloride, and trace element concentrations. Distinct hydrochemical signatures were observed between urban and rural creeks, with urban stream sections and sites near the river mouths close to Lake Ontario having consistently higher chloride (up to 700mg/L) and occasional enrichment in nutrients levels (up to 8 and 20mg/L phosphate and nitrate, respectively). Particularly upper reaches exhibited hydrochemical signatures that were reflective of the catchment surface lithologies, for instance through higher dissolved Ca to Mg ratios. Unlike for chloride and phosphate, provincial water quality guidelines for trace elements and heavy metals were seldom surpassed (on < 10 occasions for copper, zinc, cadmium, and uranium). Concentrations of other trace elements (e.g., platinum group elements or rare earth elements) were expectedly low (< 0.3µg/L) but showed spatiotemporal concentration patterns and concentration-discharge dynamics different from those of the major water quality parameters. Our results help improve the understanding of surface water conditions within Halton's regional Natural Heritage Systems and demonstrate how enhanced environmental monitoring can deliver actionable information for watershed decision-making.

Assessment of spatio-temporal variations in groundwater quality for the groundwater-dependent Maltese islands

Study regionMaltese islands Study focusThe Maltese islands are situated in the Mediterranean Sea, characterized by a semi-arid climate, and encounter increased levels of water stress. This study conducted a hydrochemical analysis of 35 groundwater samples to evaluate the suitability of the current groundwater for agricultural and domestic purposes. Additionally, three-dimensional numerical modeling was conducted to estimate long-term changes in groundwater levels and saline water distributions over 30 years, under the assumption that groundwater pumping will persist at the current rate. New hydrological insights for the regionSalinity factors that classify groundwater in this region can potentially be used for the irrigation of salt-tolerant crops. The output of the modeling calculations suggests that groundwater levels were expected to decrease significantly across most of the island, particularly around gallery areas. Descending the water table may compromise the discharge of coastal groundwater and potentially accelerate seawater intrusion into the inner island areas. Hydrochemical calculations indicated that an increase in salinity induced variations in saturation conditions, leading to a decrease in calcite and an increase in anhydrite, dolomite, and gypsum. The water quality characteristics and contamination evaluations conducted in this study are valuable for the development of long-term alternatives for water resource conservation in this region.

Water quality characterization of Lake Abaya, a water body under increasing anthropogenic pressure in Southern Ethiopia

Water quality characterization of Lake Abaya, a water body under increasing anthropogenic pressure in Southern Ethiopia

Analyzing the Vertical Recharge Mechanism of Groundwater Using Ion Characteristics and Water Quality Indexes in Lake Hulun

The water level of Lake Hulun has changed dramatically in recent years. The interannual interaction between groundwater and lake water is an important factor affecting Lake Hulun’s water level. Vertical recharge between groundwater and the lake is particularly important. Based on an analysis of differences between the hydrogeochemical and water quality characteristics of the spring water, the lake water, and the surrounding groundwater, the source and recharge mechanism of the spring water in the vertical recharge lake are determined. The results show that spring water is exposed at the bottom of Lake Hulun, and there are obvious differences between spring water and lake water in lake ice thickness, ion characteristics, and water quality characteristics. For example, the ice thickness at the spring site is only 6.8% of the average ice thickness of the lake, and there is a triangular area directly above the spring water area that is not covered by ice; the ion contents of the spring water at the lake bottom were less than 50% of those in the lake water; and the NH4+-N content of the spring water at the lake bottom was only 3.0% of the mean content of the lake water. In addition, the total nitrogen (TN), dissolved oxygen (DO), and NH4+-N contents of the spring water at the lake bottom all fall outside the range of contents of the surrounding groundwater. In general, the source of the spring water at the lake bottom is not recharged by the infiltration recharge of the phreatic aquifer but by the vertical recharge of the confined aquifer. Additionally, the Lake Hulun basin may be supplied with confined water through basalt channels while it is frozen. The vertical groundwater recharge mechanism may be that spring water at the lake bottom is first supplied by the deep, confined aquifer flowing through the fault zone to the loose-sediment phreatic aquifer under the lake, and finally interacts with the lake water through the phreatic aquifer.

High-proportions of tailwater discharge alter microbial community composition and assembly in receiving sediments

The tailwater from wastewater treatment plants serves as an important water resource in arid regions, alleviating the conflict between supply and demand. However, the effects of different tailwater discharge proportions on microbial community dynamics remain unclear. In this study, we investigated the effects of different tailwater discharge proportions on the water quality and microbial community characteristics of sediments in receiving water bodies under controlled conditions (WF-1, WF-2, WF-3, WF-4, and WF-5, containing 0% tailwater + 100% natural water, 25% tailwater + 75% natural water, 50% tailwater + 50% natural water, 75% tailwater + 25% natural water, and 100% tailwater + 0% natural water, respectively). Microbial co-occurrence networks and structural equation model were used to unveil the relationship between microbial communities and their shaping factors. Results showed that distinct microbial community compositions were found in the sediments with low- (< 50%) and high- (> 50%) proportions of tailwater. Specifically, WCHB1-41 and g_4-29–1, which are involved in organic degradation-related functions, were the key genera in the high-proportion cluster. A total of 21 taxa were more abundant in the low-proportion (< 50%) cluster than that in high-proportion (> 50%). Moreover, higher modularity was observed in the low-proportion. Total phosphorus directly affected while ammonia nitrogen indirectly affected the microbial community structure. Our findings support the distinct heterogeneity of microbial communities driven by tailwater discharge in receiving water bodies, and further confirmed that high-proportion tailwater depletes sensitive microbial communities, which may be avoided through scientific management.

Water Quality Characteristics and Water-Rock Interaction Mechanisms of Coal Mine Underground Reservoirs.

Constructing underground reservoirs in coal mines can effectively improve the recycling of mine water. Water-rock interactions within underground reservoirs have been demonstrated to improve water quality; however, the mechanisms underlying these water-rock interactions remain unclear, hindering the widespread applications of underground reservoirs. Thus, this study focused on the underground reservoir of the Shendong Daliuta coal mine. Through on-site sampling tests and single-mineral leaching experiments, combined with X-ray diffraction, X-ray fluorescence spectrometry, and scanning electron microscopy, the water quality characteristics of the inlet and outlet water samples from the coal mine underground reservoir were analyzed. Moreover, the physical and chemical properties of the collapsed rocks in the reservoir were investigated, with the aim of clarifying the mechanism underlying the water-rock interactions in coal mine underground reservoirs. The results revealed a significant self-purification effect of the coal mine underground reservoir. Compared with the inlet water sample, the outlet water sample featured substantially reduced amounts of solid-suspended substances, turbidity, total dissolved solids, and electrical conductivity, with the average removal rates of Fe and Mn approaching 98.73 and 92.12%, respectively. Along the flow direction of the inlet and outlet water of the coal mine underground reservoir, the concentrations of Na+ and Cl- presented an increasing trend, whereas the concentrations of Ca2+, Mg2+, and HCO3 - presented a decreasing trend. The concentration of K+ changed insignificantly, while the concentration of SO4 2- fluctuated unstably. The collapsed rocks in the Daliuta coal mine underground reservoir primarily comprised mudstone and sandstone with mineral components including quartz, orthoclase, albite, illite, kaolinite, glauconite, calcite, and pyrite. Among these, kaolinite exhibited the strongest adsorption capacity for Na+, Ca2+, and Mg2+ present in the mine water, while glauconite demonstrated the strongest dissolution capacity for Mg2+. Illite presented the strongest dissolution capacity for K+, while albite presented the strongest dissolution capacity for Na+. The water-rock interactions within the coal mine underground reservoir primarily included dissolution and adsorption processes, wherein mudstone and fine sandstone both played dominant roles in the adsorption of Ca2+, as well as in the dissolution of K+, Na+, and Mg2+. In particular, mudstone exhibited a stronger adsorption capacity than fine sandstone, whereas fine sandstone presented a stronger dissolution capacity than mudstone. Thus, our results offer theoretical guidance for understanding water quality purification mechanisms in coal mine underground reservoirs.

Moisture distribution change and quality characteristics of ultrasound enhanced heat pump drying on carrot

Abstract The study aims at investigating the impact of ultrasound enhancement on the water change and quality characteristics of dried carrots by heat pump drying (HPD). The results showed that ultrasound had obvious strengthening effect on the drying and dehydration process of HPD, but there was an attenuation effect of ultrasound in the propagation process of materials, and the magnetic resonance imaging results could visually demonstrate the change and migration of moisture inside carrot slices. Higher drying temperature and ultrasonic power could cause more micropores and higher content of polyphenols, flavonoids and niacin of carrot slices. Conversely, the elevated drying temperature reduced rehydration ratio. β-carotene content showed a trend of increasing first and then decreasing due to excessive temperature and ultrasonic power. Based on AHP-CRTITC method, the highest comprehensive score was attained at drying temperature of 60 °C and ultrasonic power of 80 W. Therefore, the reinforcement effect of ultrasound on HPD process could significantly enhance dehydration rate and improve product quality.

Water quality and stable isotope characteristics of Akaike, a temporary pond at the northern foot of Mt. Fuji, August 2021

Water quality and stable isotope characteristics of Akaike, a temporary pond at the northern foot of Mt. Fuji, August 2021

Numerical optimization of duration time for the gravitational sedimentation process of produced water in oilfield

Following water flooding, polymer flooding and alkali/surfactant/polymer (ASP) flooding have become the main measures to enhance oil recovery in mature oilfields. However, it is the fact that the development of mature oilfields has continuously entered the ultra-high water cut stage, the amount of produced water has increased year by year. The characteristics of water quality have become increasingly complex, posing challenges for green and efficient separation. Taking China's mature oilfield, Daqing Oilfield, as an example, gravitational sedimentation is a basic process for produced water treatment before filtration. The duration time has always been determined based on standardized design parameters, and the adjustment of duration time depends on experience. This paper distinguishes the characteristics of produced water, and the relationship between treatment performance and production conditions is comprehensively considered. The numerical simulation method is employed to optimize the duration time for gravitational sedimentation of produced water. For produced water with different characteristics of water flooding, polymer flooding and ASP flooding, the reasonable duration time for primary sedimentation is 5 h, 12 h and 14 h respectively, and the reasonable duration time for secondary sedimentation is 3 h, 8 h and 10 h respectively. This recommendation has been validated by experiments.

Effect of oxidized starch on the storage stability of frozen raw noodles: Water distribution, protein structure, and quality attributes.

Freezing is a popular method of food preservation with multiple advantages. However, it may change the internal composition and quality of food. This study aimed to investigate the effect of modified starch on the storage stability of frozen raw noodles (FRNs) under refrigerated storage conditions. Oxidized starch (OS), a modified starch, is widely used in the food industry. In the present study, texture and cooking loss rate analyses showed that the hardness and chewiness of FRNs with added OS increased and the cooking loss rate decreased during the frozen storage process. Low-field nuclear magnetic resonance characterization confirmed that the water-holding capacity of FRNs with OS was enhanced. When 6% OS was added, the maximum freezable water content of FRNs was lower than the minimum freezable water content (51%) of FRNs without OS during freezing. Fourier-transform infrared spectroscopy showed that after the addition of OS, the secondary structures beneficial for structural maintenance were increased, forming a denser protein network and improving the microstructure of FRNs. In summary, the water state, protein structure, and quality characteristics of FRNs were improved by the addition of OS within an appropriate range.

Wintertime diffusion of sedimentary phosphorus – implications for under-ice phosphorus removal from eutrophic lakes

PurposeMany eutrophic lakes are located in regions where lakes become ice-covered during the winter. This study aimed to find out if phosphorus (P) could be withdrawn from such lakes by utilizing the wintertime accumulation of P to the near-bottom water.MethodsData for water quality and sediment characteristics were collected from two eutrophic boreal lakes with tube samplers and sediment corers. Diffusion rates of P across the sediment-water interface (SWI) and within the active sediment layers, and potential export of P via wintertime withdrawal were calculated.ResultsIn the stratifying Lake Kymijärvi, P concentration in the near-bottom water reached 66 µg L−1 and P diffusion across SWI in the hypoxic area 5.4 mg m−2 d−1. In the shallow Lake Savijärvi, maximum P concentration was 78 µg L−1 but P diffusion rate only 0.34 mg m−2 d−1. In Kymijärvi, the concentrations of Fe and Mn in the sediment were high relative to P. In Savijärvi, sediment P was bound to clay minerals and calcium carbonates, while Fe was bound in sulfides.ConclusionIn Kymijärvi, a theoretical14.3% reduction in epilimnetic TP concentration could be achieved in 20 years with 20 L s−1 winter withdrawal. In Savijärvi, 10 L s−1 withdrawal could theoretically cause a 5.8% reduction in TP concentration in 5 years, but the low P diffusion rate across SWI, and the low discharge of the lake may limit P removal. In Kymijärvi, where summertime withdrawal is already applied, additional winter withdrawal could accelerate lake recovery.

A real-time simulation model of water quality with the impact of internal pollution for water source reservoir.

The water source reservoirs are the important urban water source in northern China. Although external pollution has been greatly improved, the internal pollutants in reservoirs continue to accumulate with the complex deposition and release processes, resulting in potential risks to water supply safety. To address the aforementioned issue, this paper proposed a simulation model of water quality named ECOlab EU1-WSR to simulate the spatio-temporal changes of water quality under the influence of internal pollution for the water source reservoirs. Based on the analysis of the water quality characteristics and the distribution of benthic vegetation in the reservoir, a three-dimensional hydrodynamic model was established based on MIKE3, the corresponding parameters and the related state variables were set, the ECOlab EU1-WSR model was established by secondly developing the original ECOlab EU1 template, and the real-time dynamic outputs of pollutant content in sediment were added to link the water quality index with sediment nutrition index for better revealing the impact of the internal pollution on the water quality. The performance of the model was evaluated by the case application on the water quality simulation of Daye reservoir and the optimization of the connection project between Daye reservoir and Xueye reservoir in Shandong Province China. The results showed that the model can accurately and simultaneously simulate the pollution in water and sediment by the comparative verification of hydrodynamics, water temperature, and water quality. Moreover, the model can effectively reflect the influence of the accumulation, deposition, and release of internal pollution on water quality by analyzing the correlation between the content of various pollution in water body and those in sediment, such as the total nitrogen and total phosphorus in the water body at the bottom of the water intake, were negatively correlated with the total nitrogen and total phosphorus in the sediments with correlation coefficients of 0.538 and 0.917, respectively. In addition, the optimal water inlet position and water flow rate of the connection project can be optimized and determined by using the model to effectively control water quality. The established model will be a useful tool for the design and management of a reservoir, the interconnection projects, and other water bodies by adaptively recoded.

Water function zone: A method to improve the accuracy of remote sensing retrieval of water bodies

In water monitoring, it is always a hot issue to exploring a method to improve the accuracy of remote sensing inversion. To this end, based on the actual investigation of the surrounding environment and water quality characteristics of the Fuyang river, this study has established five distinct water functional zones: reservoir (RS), village river (VR), industrial river (IR), artificial lake (AL), and urban river (UR), which are considered as subdivided datasets. Meanwhile, considering that lakes and reservoirs typically contain relatively stationary or slow-moving water bodies, while river channels are characterized by moving water bodies, three multi-type datasets have been constructed for comparison. These are based on the morphological and flow characteristics of different regions within the Fuyang river and include river channel (R), lake (L), and whole basin (W). Based on multi-spectral images of unmanned aerial vehicle (UAV) and measured water quality data, ten types of inversion models were to invert six kinds of water quality parameters, and compare and analyze the performance of the optimal inversion model of the corresponding data sets. The results show that the multivariate regression model is superior to the univariate regression model, and the mean coefficient of determination (R2) of the subdivided data set is 0.936, and the root mean square error (RMSE) and mean absolute error (MAE) appear decrease in different degrees compared with the W with 3.573 and 2.662, respectively. The mean ratio performance to interquartile (RPIQ) of the corresponding model in UR and VR are 3.963 and 2.748, respectively. Extremely Randomized Trees (ERT) model is more suitable for the inversion of multi-type data sets lacking obvious water quality characteristics and with complex components, while Categorical Boosting (CatBoost) model is more suitable for the inversion of subdivided data sets with obvious water quality characteristics. The current method has practical guiding significance for improving the application level of water monitoring technology in ecological environment protection and urban water resources protection.

Analysis of the water temperature and quality characteristics of the Daheiting Reservoir based on coupled hydrology–hydrodynamic–water quality simulations

To analyse the influence of nonpoint source pollution on the water quality in the Daheiting Reservoir, based on measured hydrological and water quality data, a coupled hydrological model for the Panjiakou-Daheiting interval basin and a two-dimensional vertical hydrodynamic and water quality model for the Daheiting Reservoir were constructed. The water quantity and water quality output results of the upstream hydrological model (Soil and Water Assessment Tool, SWAT) were input into the reservoir hydrodynamic-water quality model (CE-QUAL-W2) as boundary conditions. The annual distribution of pollutants in the reservoir was simulated and analysed. The results showed that nutrients such as nitrate nitrogen and phosphate in the reservoir area were stratified, and there were seasonal differences due to the water temperature, dissolved oxygen and upstream inflow. After lowering upstream pollution emissions, the water quality in the reservoir was improved significantly, and compared to that of reducing point source pollution, the effect of reducing nonpoint source pollution is more obvious.

Water quality characteristics and ecological risk evaluation of a landscaped river replenished by three reclaimed water sources in Qingdao, China.

The water crisis may be solved by utilizing reclaimed water. Three reclaimed water sources have restored the lower sections of the Licun River, forming a landscaped river. In this paper, the river's water quality was monitored for a year, and the ecological concerns were analyzed using luminescent bacteria, chlorella, and zebrafish. The results indicated that although basic water quality indicators like COD and ammonia fluctuated along the river, the classification of water quality was primarily affected by factors such as flow rate and water depth. Under experimental conditions, the toxic inhibitory effect of river water on luminescent bacteria, chlorella, and zebrafish was related to the treatment process of reclaimed water. It was found that the reclaimed water produced by the MBR, along with the UV disinfection process, showed no detectable toxicity. In contrast, the MBBR process, when combined with coagulation, sedimentation, filtration, ozonation, and chlorination, seemed to be the source of this toxicity. Along the river, the results of water quality assessments and ecological risk assessments were different, indicating that both should be conducted to evaluate rivers replenished with reclaimed water.