Search Results (314)

Groundwater is crucial for domestic, agricultural, and ecological uses, particularly in the lower reaches of arid basins, where its quality often limits availability. A total of 26 phreatic groundwater samples were collected from a typical endorheic watershed on the Tibetan Plateau to assess the hydrochemical characteristics of phreatic groundwater in the lower reaches of arid inland watersheds. The hydrochemical characteristics, quality, and formation mechanisms of groundwater were analyzed using the Entropy-Weight Water Quality Index (EWQI), irrigation water quality indexes (such as sodium adsorption ratio, soluble sodium percentage, and permeability index), hydrochemical diagrams, and correlation analysis. The findings indicate that phreatic groundwater in the lower reaches is slightly alkaline, with a substantial TDS variation from 252.58 to 1810.41 mg/L. Groundwater is predominantly characterized by fresh hydrochemical facies of HCO₃-Ca and HCO₃-Na types, with a few saline Cl-Na types present. The concentrations of NO₃⁻, NO₂⁻ and NH₄⁺, in groundwater range from 0.32 to 100.00 mg/L, 0.00 to 0.48 mg/L, and 0.00 to 0.20 mg/L, respectively, and 3.59%, 26.92%, and 7.69% of the samples exceeding the permissible drinking limits recommended by Chinese guideline and World Health Organization. Groundwater is classified as fresh at 80.8% of sampling sites and brackish at 19.2%. Approximately 96.2% of the sampled groundwaters is rated as excellent to medium quality according to EWQI assessments, suitable for domestic use, while 3.8% is of extremely poor quality and should be avoided for direct consumption. Groundwater from all sampling sites is suitable for agricultural irrigation and does not pose permeability hazards to the soil. Most groundwaters are suitable for long-term irrigation in terms of sodium hazards, with only 3.8% and 7.7% of samples falling into the “Permissible to Doubtful” and “Doubtful to Unsuitable” categories, respectively. Salinity poses the primary threat in long-term irrigation, with 38.5%, 53.8%, and 7.7% of sampled groundwaters exhibiting moderate, high, and very high salinity risks, respectively. Groundwater chemistry is primarily governed by water-rock interaction and evaporation, with additional impacts from agricultural inputs of nitrogen contaminants and chemicals. Agricultural practices contribute to elevated groundwater salinity in the study area, while natural evaporation drives salinity accumulation in the lower parts. In managing and utilizing groundwater resources in the study area and similar arid regions globally, attention should be paid to salinity caused by agricultural activities and natural evaporation, as well as nitrogen pollution from farming. Full article

Groundwater serves as a vital water source in Zhanjiang City. This study analyzed the chemical components of 35 samples to understand the hydrochemical characteristics and evolution mechanism of groundwater in Zhanjiang City. A comprehensive analysis was conducted using statistical methods, including the use of Piper trilinear diagrams, the Gibbs method, ion ratios, and other techniques, to investigate the sources and control factors of the main ions in groundwater in the area. The findings reveal that all the groundwater is freshwater, with the main cations and anions being Na⁺ and HCO₃⁻, respectively. Shallow water is mainly of the Cl•SO₄ mixed cation type, followed by the HCO₃•ClNa•Ca type. Middle and deep pore water is mainly of the HCO₃Na type, followed by the HCO₃Na•Mg type and HCO₃Na•Ca type. The hydrochemical classifications of pore and fissure water are Cl•HCO₃Mg•Na type and Cl•HCO₃Na type water. The primary hydrogeochemical process is water–rock interaction, particularly the dissolution of silicate minerals. Additionally, evaporation and concentration contribute significantly to the chemical composition of shallow water, and ion exchange is also an important hydrogeochemical process affecting middle and deep pore water. Shallow water commonly contains nitrates, with 37.5% of shallow water showing contamination with NO₃⁻. This study aims to provide insights into the development and utilization of local water resources. Full article

The degradation of groundwater quality due to mining activities is a major public concern globally. This study employed a combination of methods (multivariate statistics, Self-organizing mapping, and PHREEQC hydrogeochemical simulation) to uncover the hydrochemical characteristics and processes of mine water in the Kailuan mining area. Self-organizing mapping (SOM) clustering divided the mine water into three groups, TDS values gradually increased from the first to the third group, and the hydrogeochemical type of mine water gradually changed from Na-HCO₃ and CaMg-HCO₃ to CaMg-SO₄, Na-Cl, and mixed types. Principal component analysis (PCA) revealed that water–rock action and evaporation concentration were major ion concentration factors. According to the molar ion concentration ratio method, the main ions in mine water in Kailuan mining area originate from silicate and sulfate, and a small amount from carbonate rock weathering, and they are influenced by cation exchange. As a result of the PHReactor EQuilibrium Code (PHREEQC) simulation results, it can be concluded that better hydrodynamic conditions in mines are primarily controlled by carbonate dissolution. Mine water with poorer hydrodynamic conditions is mainly controlled by sulfate and carbonate dissolution, with sulfate dissolution having a greater effect. The results of this study provide an important scientific basis for the safe mining of mines and the protection of groundwater resources. Full article

Lake Kotokel, the largest lake on the eastern shore of Lake Baikal, has historically served as an important fishery and recreational resource. However, it underwent an ecological crisis and a Haff disease outbreak in 2008–2009. Hydraulic engineering interventions were subsequently implemented, and the lake was closed to tourism and fishing for an extended period. This study provides the first comprehensive analysis of Lake Kotokel’s water level fluctuations from 1985 to 2022 and evaluates hydrochemical data collected between 2015 and 2024. A comparative assessment of the seasonal variability in Lake Kotokel’s condition during 2023–2024 and 2008–2009 was conducted using various water quality indices, including the Russian Specific Combinatorial Water Pollution Index (SCWPI) and Basic Anthropogenic Load Index (ALI), as well as the international National Sanitation Foundation Water Quality Index (NSF-WQI) and Canadian Council of Ministers of the Environment Water Quality Index (CCME-WQI). Trophic state indices, such as Carlson’s Trophic State Index (CTSI) and the Trophic Index (TRIX), were also applied. The analysis revealed a seasonal decline in water quality, transitioning from pure (“excellent”) and “light eutrophic” index classifications in spring to polluted (“marginal”) and “hypertrophic” index classifications in summer and autumn. This study demonstrated that a combination of unfavorable factors, including significant lake-level fluctuations, prolonged high temperatures during the vegetative period, and the discharge of fracture-vein waters, led to a sharp decline in water quality and an increase in the lake’s trophic status. Elevated levels of iron, manganese, COD, pH, and ammonium detected in water samples in 2024, alongside incidents of fry mortality in spring and summer and intense algal blooms, raise concerns as they may signal a potential recurrence of Haff disease in the lake. Full article

Groundwater is a vital and invaluable resource on our planet, serving as a critical water supply for human life, industrial activities, and agricultural production. It plays a pivotal role in sustaining human existence and driving societal progress. In this study, we conducted a comprehensive analysis of the hydrochemical characteristics and controlling factors of groundwater in the Upper Weihe River (UWR) using statistical analysis, Piper diagrams, Gibbs diagrams, correlation analysis, and ion ratio analysis. To evaluate the suitability of the regional groundwater for potable use, we employed the entropy weight water quality index (EWQI). Additionally, the sodium adsorption ratio (SAR) and percentage of soluble sodium (Na%) were utilized to evaluate the groundwater’s adaptability to irrigation. Furthermore, this study also assessed the health risks faced by adults and children in the UWR. The findings indicate that the main cations and anions in groundwater are Ca²⁺ and HCO₃⁻, respectively. The hydrochemical types are predominantly HCO₃-Ca, Cl-Ca, and mixed types. The composition of groundwater is primarily influenced by the dissolution of silicate and carbonate minerals, with cation exchange also playing a significant role in shaping its hydrochemical characteristics. The water quality assessment indicates that the majority of groundwater in UWR is classified as “excellent” or “good”, rendering it suitable for human consumption. However, 7.17% of the water samples were of poor quality and unsuitable for drinking; these were primarily located in a few areas in the northern and western parts of the study area. Regarding irrigation, 94.83% of the groundwater is deemed very suitable; however, a small fraction is not appropriate for such use. Additionally, non-carcinogenic risks are generally higher across most parts of the study area for both children and adults, with children exhibiting significantly higher risks than adults. These findings offer crucial insights regarding the sustainable management and environmental conservation of groundwater resources in the UWR. Full article

This study investigated the spatial and temporal variations of macrobenthos community structure in the Yuqu River Basin during the dry and wet seasons due to environmental factors. This study quantified the independent and interactive contributions of hydrophysical, hydrochemical, and climatic factors to the community structure through a variance decomposition analysis (VPA). The study findings indicate that during May (the dry season), factors such as water depth, flow velocity, dissolved oxygen, and air temperature exhibit relatively minor fluctuations, rendering the aquatic environment more stable than in the rainy season. This stability is particularly conducive to the maintenance of the macrobenthic community structure and species diversity, which is especially evident in aquatic insects with nesting habits, such as those belonging to the Trichoptera order (including genera like Glossosoma, Glossosomatidae, and Georodes). In contrast, during August (the rainy season), substantial precipitation alters the thermal conditions of the river, increases flow velocity, raises water levels, and introduces a significant influx of organic matter through sedimentation. This distinctive ecological environment fosters unique adaptive strategies among macrobenthic organisms. Notwithstanding a notable decline in species diversity during this particular phase, there is a concurrent increase in the abundance of individual organisms, which is indicative of the populations’ remarkable capacity to swiftly adapt to environmental heterogeneity. Research has demonstrated that macrobenthic communities within the Yuqu River Basin adopt pronounced adaptive tactics that vary significantly between seasons. During the dry season, these macrobenthic fauna rely heavily on the stability of their physical habitat. In stark contrast, they are compelled to navigate and cope with the more intricate and dynamic changes in hydrological and chemical conditions that characterize the rainy season. The presented results uncover the sensitive responsiveness of the macrobenthic fauna to seasonal hydrological and environmental fluctuations in high-altitude river systems and their adaptive strategies under diverse ecological stressors. Arthropods, in particular, exhibit a marked sensitivity to seasonal hydrological and environmental changes. This study delves into the biodiversity of high-altitude river ecosystems, analyzing the ecological environment and the distribution patterns and seasonal variation characteristics of macrobenthic communities. This study aims to examine how diverse seasons and hydroclimatic conditions modulate the composition of macrobenthic assemblages within the tributaries and principal channels of high-altitude river systems, thereby establishing a foundational reference for future water ecosystem assessments in such regions. Full article

In recent years, deep–penetrating geochemical exploration techniques have played a crucial role in the detection of concealed minerals. These methods effectively detect deep−seated anomalies and have been tested in various landscape–covered areas, yielding remarkable results. This study focuses on the covered areas of the southern margin of the Kuqa Basin, utilizing deep–penetrating geochemical methods for systematic sampling to explore concealed potassium salt. This study examines the chemical composition of several underground brine samples, revealing salinity levels ranging from 9.41 to 26.16 g/L and potassium concentrations of between 0.04 and 0.22 g/L. The hydrochemical coefficients indicate a high nNa⁺/nCl⁻ value, with low K⁺ × 10³/Cl⁻ values. The average nNa⁺/nCl⁻ ratio is approximately 0.97, and the Br⁻ × 10³/C1⁻ value is about 0.07. The brine samples fall within the halite phase region of the Quaternary system Na⁺, K⁺, Mg²⁺//C1⁻–H₂O at 25 °C, concentrated at the high Na terminal, suggesting halite dissolution. In the metastable phase diagram of the Na⁺, K⁺, Mg²⁺//C1⁻, SO₄²⁻–H₂O five−element water system, all the brine samples were cast in the glauberite phase area, which may indicate that the shallow underground brine is still in the initial stage of potassium salt deposition. The underground brine mainly dissolved and filtered the stone salt in the formation during the process of runoff underground and then was squeezed by the strong active structure and discharged to the surface along the formation fault or fissure channel. The deep–penetration geochemical survey of the fracture reveals that certain profile points show significantly higher potassium and other salt contents than others, indicating a potassium anomaly. This suggests the potential ascent and migration of potassium–rich brine along deep fracture segments, providing preliminary evidence of potassium richness in the Kuqa Basin’s depths and offering significant guidance for key exploration areas in potassium salt prospecting. Full article

Groundwater is a significant source of water, and evaluating its hydrochemical attributes, quality, and associated health risks holds paramount importance in guaranteeing safe water access for the population and fostering sustainable socio-economic progress. Situated within a semi-arid region, the Dianbu area (DBA) features numerous greenhouses interspersed amongst open farmlands. An examination revealed a discernible decline in the overall water chemistry environment in this area. This study extensively examined the fundamental water chemistry characteristics of groundwater and surface water samples through a statistical analysis, Piper’s trilinear diagram, ion ratios, and other analytical methods. The assessment of irrigation water quality was conducted using the entropy weight water quality index (EWQI), sodium adsorption ratio (SAR), percentage of soluble sodium (Na%), among other relevant indicators. The findings demonstrate multiple key aspects: 1. Water cations are chiefly composed of Ca²⁺ and Na⁺, while groundwater anions are notably NO₃⁻ and SO₄²⁻ dominant, defining the water type as NO₃-SO₄-Ca. Conversely, surface water primarily displays HCO₃⁻ and SO₄²⁻ anions, aligning it with an HCO₃-SO₄-Ca water type. 2. The extensive agricultural activities in the region, coupled with the excessive utilization of pesticides, chemical fertilizers, as well as the discharge of domestic sewage, contribute to heightened NO₃⁻ concentrations in groundwater. 3. The water quality assessments indicate that approximately 53% of agricultural water quality meets irrigation standards based on EWQI, with SAR results suggesting around 65.52% suitability for irrigation and Na% findings indicating approximately 55.88% viability for this purpose. Proper water selection tailored to specific conditions is advised to mitigate potential soil salinization risks associated with long-term irrational irrigation practices. Full article

Anhui Province is rich in geothermal water resources, making the study of its hydrochemical evolution and genetic models essential for scientific development and sustainable utilization. This study combines hydrochemical and hydrogen–oxygen isotopic data from different regions of Anhui Province to analyze the hydrogeochemical evolution characteristics and recharge mechanisms of basin-type and mountainous-type geothermal waters. The results show that basin-type geothermal water is predominantly of the Cl–Na type, with water–rock interactions mainly including halite dissolution, gypsum dissolution, dedolomitization, and silicate hydrolysis. The groundwater system is relatively closed off, with slow flow rates. In contrast, mountainous geothermal water is mainly of the HCO₃–Na·Ca, SO₄–Na·Ca, and SO₄–Na types, with water–rock interactions primarily involving calcite dissolution, dolomite dissolution, and gypsum dissolution. Enhanced precipitation infiltration due to fault structures leads to stronger recharge and an open-system characteristic. The genetic models of the two types of geothermal water reveal the structural and recharge mechanisms of thermal reservoirs under different geological settings, highlighting the significant control of geological background on geothermal water formation. Full article

During the process of managed aquifer recharge (MAR), when the aerobic surface water is recharged into the reductive aquifer, the redox environment changes along the water pathway. MAR practice can reshape the initial groundwater bacterial community, and further induce variations in the bacteria-mediated hydrochemical reactions. In this study, laboratory-scale column experiments were conducted to simulate the processes of aerobic/anaerobic recharge to aquifer. The results showed that the concentration of DO during the aerobic recharge was higher than that of the anaerobic recharge, and ORP showed a similar trend. Active nitrogen transformation was observed during the simulated MAR processes. In the early stages of both the aerobic and anaerobic recharges, nitrate reduction occurred due to denitrification and DNRA. However, in the late stages, nitrification might happen in the aerobic column, and nitrate reduction remained the major process in the anaerobic column. For the bacterial community, Massilia, Ralstonia, Legionella, and Curvibacter predominated under the aerobic recharge. Comparatively, Cedecea, Cupriavidus, and Ralstonia maintained high relative abundances under the anaerobic recharge. Our study provides essential information about the characteristics of bacterial-mediated hydrochemical reactions during the MAR process. The result would enhance understanding of MAR activities and provide valuable insights into the groundwater resources’ sustainable development and management. Full article

This study explores the effects of varying exposure times of microelement fertilization on hydrochemical parameters, plant growth, and nutrient content in an aquaponic system cultivating Capsicum annuum L. (pepper) with Cyprinus carpio (Common carp L.). It also investigates the potential of visible–near-infrared (VIS-NIR) spectroscopy to differentiate between treated plants based on their spectral characteristics. The findings aim to enhance the understanding of microelement dynamics in aquaponics and optimize the use of VIS-NIR spectroscopy for nutrient and stress detection in crops. The effects of microelement exposure on the growth and health of Cyprinus carpio (Common carp L.) in an aquaponic system are investigated, demonstrating a 100% survival rate and optimal growth performance. The findings suggest that microelement treatments, when applied within safe limits, can enhance system productivity without compromising fish health. Concerning hydrochemical parameters, conductivity remained stable, with values ranging from 271.66 to 297.66 μS/cm, while pH and dissolved oxygen levels were within optimal ranges for aquaponic systems. Ammonia nitrogen levels decreased significantly in treated variants, suggesting improved water quality, while nitrate and orthophosphate reductions indicated an enhanced plant nutrient uptake. The findings underscore the importance of managing water chemistry to maintain a balanced and productive aquaponic system. The increase in root length observed in treatments 2 and 6 suggests that certain microelement exposure times may enhance root development, with treatment 6 showing the longest roots (58.33 cm). Despite this, treatment 2 had a lower biomass (61.2 g), indicating that root growth did not necessarily translate into increased plant weight, possibly due to energy being directed towards root development over fruit production. In contrast, treatment 6 showed both the greatest root length and the highest weight (133.4 g), suggesting a positive correlation between root development and fruit biomass. Yield data revealed that treatment 4 produced the highest yield (0.144 g), suggesting an optimal exposure time before nutrient imbalances negatively impact growth. These results highlight the complexity of microelement exposure in aquaponic systems, emphasizing the importance of fine-tuning exposure times to balance root growth, biomass, and yield for optimal plant development. The spectral characteristics of the visible–near-infrared region of pepper plants treated with microelements revealed subtle differences, particularly in the green (534–555 nm) and red edge (680–750 nm) regions. SIMCA models successfully classified control and treated plants with a misclassification rate of only 1.6%, highlighting the effectiveness of the spectral data for plant differentiation. Key wavelengths for distinguishing plant classes were 468 nm, 537 nm, 687 nm, 728 nm, and 969 nm, which were closely related to plant pigment content and nutrient status. These findings suggest that spectral analysis can be a valuable tool for the non-destructive assessment of plant health and nutrient status. Full article

Groundwater resources play a critical role in meeting the agricultural, industrial, and domestic water demands of Tangshan, a key industrial city in China. However, with the acceleration of urbanization and the overextraction of groundwater, issues related to groundwater quality have become increasingly apparent. Notably, groundwater hardness has steadily increased over the years, posing risks to human health and elevating industrial water treatment costs. This study analyzed the spatial distribution characteristics and causes of groundwater hardness using 214 groundwater quality samples collected in 2022 from the plain area of Tangshan City, employing inverse distance weighting (IDW), Gibbs diagrams, ion ratios, mineral saturation indices, and Pearson correlation analysis. The results indicate that, in horizontal distribution, high-hardness groundwater is predominantly concentrated in the southern coastal plain area, with hardness gradually decreasing from south to north. Vertically, shallow groundwater in the coastal plain exhibits significantly higher hardness than deep groundwater, with a non-compliance rate of 94.12%, while deep groundwater hardness remains markedly lower. Mid-depth groundwater (60–300 m) in the alluvial plain exhibits elevated hardness, primarily attributed to mineral dissolution and agricultural irrigation return flow. The spatial distribution pattern of groundwater hardness across the study area is predominantly governed by hydrogeochemical processes and hydrochemical environmental factors, with cation exchange adsorption and evaporation–concentration processes identified as the dominant influences. The analysis of ion sources indicates that Ca²⁺ and Mg²⁺, the primary contributors to groundwater hardness in the area, are mainly derived from the weathering and dissolution of carbonate minerals, sulfate minerals, and cation exchange processes. Therefore, an in-depth investigation into the spatial distribution and driving factors of groundwater hardness in Tangshan can provide a scientific basis for regional water resource management, pollution control, and water quality optimization. Such research also supports the development of sustainable groundwater management and optimization strategies. Full article

With rapid urbanization, intensified agricultural activities, and industrialization, groundwater resources are increasingly threatened by pollution. Industrial wastewater discharge and the extensive use of agricultural fertilizers in particular, have had substantial impacts on groundwater quality. This study examines 18 groundwater samples collected from the main urban area of Yibin City to assess hydrochemical characteristics, spatial distribution, source attribution, water quality, and human health risks. Statistical analysis reveals significant exceedances in TDS, NO₃⁻, Mn, and As levels in groundwater, with elevated concentrations of B as well. Isotopic analysis identifies atmospheric rainfall as the primary recharge source for groundwater in the area, with water–rock interactions and limestone dissolution playing key roles in shaping its chemical composition. Applying the Entropy-Weighted Water Quality Index (EWQI) for a comprehensive water quality assessment, the study found that 94.44% of groundwater samples were rated as “good”, indicating relatively high overall water quality. Deterministic health risk assessments indicate that 72.22% of the groundwater samples have non-carcinogenic health risks below the threshold of 1, while 66.67% have carcinogenic health risks below 1.00 × 10⁻⁴. Monte Carlo simulations produced similar results, reinforcing the reliability of the health risk assessment. Although the study area’s groundwater quality is generally good, a significant human health risk persists, underscoring the need to ensure the safety of drinking and household water for local residents. This study provides a valuable reference for the rational management and remediation of groundwater resources. Full article

The sand–gravel brine deposit in the Mahai Basin is a newly discovered large-scale potassium–bearing brine deposit. The potassium–bearing brine is primarily found at depths exceeding 150 m within the porous alluvial and fluvial sand–gravel reservoir of the Middle to Lower Pleistocene. This deposit is characterized by a relatively shallow water table, moderate–to–strong aquifer productivity, high salinity, and a KCl content that meets the conditions for exploitation, with the advantage of reduced salt crystallization during well mining, making it a potential reserve base for potash development. A geochemical analysis of the sand–gravel brine revealed consistent trends for the major ions K⁺, Na⁺, Mg²⁺, Cl⁻, and SO₄²⁻ along the east–west axis of the alluvial fan, while Ca²⁺ showed an opposite trend compared to Mg²⁺. Along the exploration lines from north to south, the concentrations of the main ions gradually increase. The brine is enriched in Na⁺ and Cl⁻ ions, while SO₄²⁻ and HCO₃⁻ are depleted. In the K⁺-Na⁺-Mg²⁺/Cl⁻-H₂O (25 °C) quaternary phase diagram, the brine falls within the halite stability field, with the hydrochemical type classified as chloride type. The brine coefficient characteristics indicate a multi-source origin involving residual evaporation, salt rock leaching, and metamorphic sedimentary brine. Comparison studies of the ionic composition and isotopic signatures (δD, δ¹⁸O, δ³⁷Cl, and δ⁷Li) of deep sand–gravel brines in the study area with interstitial and confined brines in the southern depression suggest similar geochemical characteristics between them. The genetic analysis of the deposit proposes that during the basin tectonic evolution, the potassium-rich interstitial and confined brines originally located in the southern depression of the Mahai Basin were displaced under compressional forces and migrated northward as the depositional center shifted, eventually backfilling into the loose alluvial and fluvial sand and gravel reservoirs at the front of the Saishiteng Mountains, forming the deep sand–gravel brine deposits in the foreland. Full article

Lakes in cold zones have common characteristics of long frozen periods and fragile water ecosystems. More and more lakes in cold zones have been experiencing water quality deterioration due to eutrophication with climate change and human activities. Lake Hulun is located in the cold zone of northern China, in which Cyanobacterial blooms frequently occur. The excessive nutrient input with inflowing river water and the change in lake hydrodynamic condition might be the main factors affecting this. To obtain a better understanding of the effects, the input loads of nutrients from the inflowing rivers were analyzed. A field test of freezing concentration combined with microbial activity regulation was carried out at a river–lake confluence. The results showed the following: (1) Lake Hulun receives a large amount of nitrogen and phosphorus pollutants from river runoff every year, and the water quality of these river is inferior Grade V, which greatly increases the difficulty in ecological purification of cold zone lakes. (2) The microbial activity control technology has a high purification rate for water during the unfrozen period. The order of purification rates for each hydrochemical index was TP > TN > COD > NH₄⁺-N, and the purification rates of TN and COD were between 35% and 36%. Compared with the water before purification, the water quality grade improved from Grade V to Grade III. (3) The composite technology of freezing concentration–microbial activity regulation has a general water purification rate during the frozen period. Under the low-temperature condition, the TN and COD nutrient fluxes in the water were reduced by 9.38% and 9.36%, respectively. After purification, the water quality grade of the ice body was above Grade II, and the water under the ice layer was above Grade IV, which was one grade higher than the water quality grade of the original lake water. This water treatment and purification process is a green, low-energy consumption, and low-cost technology. This study can provide reference for the integration and demonstration of lake water ecological governance and water resources security technology in cold and arid regions. It is beneficial to the sustainable development of the lake. Full article