Abstract Water pollution caused by heavy metals and dyes has emerged as a pressing global issue due to their adverse effects on human health and ecosystems. In this study, magnetic zeolite nanocomposite (Fe3O4–NaA) was employed as an efficient magnetic adsorbent to remove cadmium (Cd), lead (Pb), malachite green (MG), and methylene blue (MB) from aqueous solutions. The Fe3O4–NaA adsorbent was synthesized and characterized through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analysis. The results confirmed nanostructure, high surface area, and high adsorption capacity of this adsorbent. The point of zero charge (pHpzc) of the Fe3O4–NaA was determined to be 6.2, demonstrating its versatility for various pH ranges. Process optimization was conducted using a central composite design (CCD) matrix combined with response surface methodology (RSM) to evaluate the influence of key factors, including solution pH, Fe3O4–NaA nanocomposite amount, ultrasonic time, and initial analyte concentration. The optimal conditions (Fe3O4–NaA nanocomposite amount of 0.04 g, pH of 7, initial analyte concentration of 17 mg L-1, and ultrasound time of 16 min) resulted in removal efficiencies ranging from 91.11% to 96.09%. Reusability tests revealed that the Fe3O4–NaA adsorbent retained high performance over 5 adsorption/desorption cycles, with hydrochloric acid identified as the most effective eluent for regeneration. The efficacy of Fe3O4–NaA nanocomposite was further validated using real water samples, where it successfully removed contaminants with high efficiency. These findings highlight the potential of Fe3O4–NaA nanocomposites as cost-effective and environmentally-friendly adsorbents for the remediation of contaminated water.
Groundwater is one of the most important sources of drinking water for human populations. Rapid urbanization, industrialization, and agricultural activities have significantly affected groundwater quality in many regions. This study focuses on the assessment of groundwater quality by evaluating various physicochemical parameters to determine its suitability for domestic and agricultural purposes. Groundwater contamination occurs when harmful substances such as industrial chemicals, fertilizers, pesticides, sewage, and landfill leachate enter underground aquifers. These pollutants alter the natural characteristics of water and reduce its quality. Once groundwater becomes polluted, it is very difficult to restore due to the slow movement of water beneath the Earth's surface. In this study, groundwater samples were collected from six different locations in Tamil Nadu. The collected samples were analyzed for physical and chemical parameters such as colour, odour, temperature, turbidity, total hardness, chloride, fluoride, and residual chlorine. These parameters help determine water quality and suitability for drinking purposes. The results showed variations in groundwater quality among sampling locations. Some samples showed higher hardness and chloride levels due to mineral dissolution and environmental conditions. However, most parameters were within acceptable limits. Regular monitoring of groundwater quality is necessary to ensure safe water supply and protect water resources for future generations.
Ghorban Zeidvand, Gholam Reza Hashemzadeh khorasgani, A. Alirezaei
The purpose of the present article is to develop a dynamic model for water consumption management in the Khuzestan Plain. Data collection was conducted through both library-based and field-based methods, employing a field analysis approach. Data analysis was performed using Vensim software. One of the prominent approaches in water resource allocation is the use of system dynamics methodology. Predicting behavioral changes in water resource systems under the influence of scenario-based and integrated policy interventions can support the optimal utilization of these resources. The system dynamics approach to water resource management in the agricultural sector of the Khuzestan Plain suggests short-, medium-, and long-term water consumption management strategies after examining current conditions. Under drought conditions, a shift in cropping patterns should be prioritized by planning authorities in responsible organizations. Accordingly, in recent years, a substantial portion of the land previously allocated to sugar beet and rapeseed—crops known for high water consumption—should be reduced. In collaboration with agricultural cooperatives, farmers should be encouraged to increase wheat cultivation. Changing cropping patterns across various cities can improve water demand in the agricultural sector. Given the rainfall levels in the province, farmers can replace high-water-demand crops with wheat to optimize water savings. Altering the cropping pattern not only increases wheat production in the province but also curbs excessive water use in this sector. In the industrial sector, the system dynamics approach to water resource management in the Khuzestan Plain identifies the direct use of potable water by industries as a major challenge for responsible organizations. Many of these industries have been established at high costs, yet initial planning for their water supply was inadequate. As a result, citizens frequently face shortages of drinking water. In the domestic sector, applying the system dynamics approach to water resource management in the Khuzestan Plain suggests that appropriate management and planning—along with promoting a water-saving culture—can largely alleviate citizens’ deprivation from potable water. For instance, public education and awareness campaigns regarding efficient water use, planting drought-resistant and climate-compatible vegetation, detecting and repairing leaks in faucets and plumbing fixtures, utilizing unused water sources, employing water-retaining irrigation gels, reducing shower time, avoiding car washing with water hoses, and preventing the hosing down of streets and sidewalks can significantly minimize household water consumption.
Azam Kadirkhodjaev, D. Andreev, Botir Akramov
et al.
A shallow quaternary sedimentary aquifer within the river alluvial deposits of eastern Uzbekistan is increasingly vulnerable to the impacts of climate change and anthropogenic activities. Despite its essential role in supplying water for domestic, agricultural, and industrial purposes, the aquifer system remains poorly understood. This study employed a three-dimensional MODFLOW-based groundwater flow model to assess climate change impacts on water budget components under the SSP5-8.5 scenario for 2020–2099. Model calibration yielded RMSE values between 0.25 and 0.51 m, indicating satisfactory performance. Simulations revealed that lateral inflows from upstream and side-valley alluvial deposits contribute over 84% of total inflow, while direct recharge from precipitation (averaging 120 mm/year, 24.7% of annual rainfall) and riverbed leakage together account for only 11.4%. Recharge occurs predominantly from November to April, with no recharge from June to August. Under future scenarios, winter recharge may increase by up to 22.7%, while summer recharge could decline by up to 100%. Groundwater storage is projected to decrease by 7.3% to 58.3% compared to 2010–2020, indicating the aquifer’s vulnerability to prolonged dry periods. These findings emphasize the urgent need for adaptive water management strategies and long-term monitoring to ensure sustainable groundwater use under changing climate conditions.
Maryam Movaseghi Gilani, Mohammad Ali Afshar Kazemi, Mohamad Ali Keramati
<p><strong>Introduction:</strong> In this study, the country's water resources management system has been modeled using a system dynamics approach. After simulation, optimal water resources, social power of governance, government financial resources, and the rate of water migration have been determined based on the decision variables of household, agricultural, and industrial water tariffs. The optimal combined results suggest an 11%, 200%, and 200% increase in water tariffs for household, agricultural, and industrial sectors, respectively, over the next 5 years.</p>
<p><strong>Methods:</strong> Initially, this study modeled and simulated the variables and feedback loops involved in water resources management using system dynamics tools. For optimization, two methods, genetic algorithm and the Simulation-optimization capability in the Vensim software, were employed. In the genetic algorithm, an initial population of 30 individuals and crossover and mutation probabilities of 83% and 17% were considered. The selection criterion for each chromosome is based on the roulette wheel method.</p>
<p><strong>Findings: </strong>The results indicate that optimization using the genetic algorithm results in an 89% increase in water resources behind dams compared to the baseline conditions, whereas the Vensim software output shows an 84% improvement. Overall, the genetic algorithm improves the objective function by 2% compared to the Vensim software's optimization output. Additionally, after optimization, the best tariff policy for enhancing the objective function is a further increase in agricultural and industrial water tariffs compared to household tariffs.</p>
M. Nageeb Rashed, A. A. Moneam Gad, N. Magdy Fathy
Abstract The utilization of waste resources to synthesize functional materials is crucial for achieving environmentally sustainable development. In this context, the current investigation aims to develop a new material using waste chicken and camel bones as adsorbents for the removal of Pb2+ and Cd2 from polluted water. The Hydroxyapatite (HA) adsorbents of chicken (HB) and camel (CB) bones were prepared via chemical treatment with NaOH, HNO3, H2O2, and ethanol, and also those followed by carbonization. The physicochemical and microscopic characteristics of the adsorbents were analyzed via SEM, XRD, FT-IR, and BET surface area analyses. Adsorption studies of Pb2+ and Cd2+ were performed in a batch style that included initial metal concentration, pH, pHpzc, solution temperature, contact time, and adsorbent dose. The results revealed that the bone chemically activated with 0.1 M NaOH had greater adsorption of Cd2+ ion (99.7% for HB and 99.89% for CB) and Pb2+ ions (99.85% for HB and 99.79% for CB) than the other activators did. Adsorption isotherms, adsorption kinetics, and thermodynamic models have been used to confirm the fit conditions that improve the adsorption technique. Maximum adsorption removal percentages for Pb2+ and Cd2+ were obtained under constant operation conditions (initial metal concentration 10 ppm, pH 6, adsorbent dose 0.05 g, contact time 30 min and solution temperature 328 K. Adsorption of Pb2+ and Cd2+ obeyed a pseudo-second-order model and fit well with the Langmuir isotherm.The metals adsorption using the prepared adsorbent was a spontaneous and exothermic process. Overall, the prepared adsorbents from chicken and camel bone waste are highly effective and promising as low-cost materials for the remediation of heavy metals-contaminated waters.
Water supply for domestic and industrial purposes, Environmental sciences
Abstract This work aims to investigate the photocatalytic degradation of imidacloprid (IM) via copper(II) sulfide (CuS) attached to a titanium dioxide (CuS@TiO2) composite catalyst under solar-simulated light and to evaluate its efficiency compared with that of pure titanium dioxide (TiO2) and other TiO2 sensitizers. The CuS@TiO2 composite demonstrated superior photocatalytic performance, achieving up to 96% degradation of IM under UV–visible irradiation and up to 70% under visible light alone. The primary objective was to determine the optimal parameters for maximum degradation efficiency, with the highest efficiency observed at pH 7.5, which is attributed to the balanced surface charge that would enhance IM adsorption. Additionally, this study examines the effects of the IM concentration and photocatalyst loading. Higher concentrations of IM reduce the efficiency due to competition for active sites, even though the quantum yields increase. The optimum photocatalyst loading was between 0.15 and 0.20 g, at which a peak removal efficiency of 93% was noted. The study also confirmed the complete mineralization of IM through high-performance liquid chromatography (HPLC), total organic carbon (TOC), and UV–visible spectroscopy analyses, which revealed significant reductions in organic carbon and its conversion to by-products that are much less harmful by-products, such as carbon dioxide (CO2) and chloride ions (Cl−). During five cycles of reuse, the CuS@TiO2 catalyst maintained a degradation efficiency of 91–96%, highlighting its robustness and long-term potential. These findings suggest that the CuS@TiO2 composite is a promising, environmentally friendly, and effective alternative for large-scale environmental remediation.
Beaches play an important role in the survival of the world. They serve the purpose of water supply for domestic, industrial, agricultural, and power generation. Beaches are also used for the disposal of industrial and sewage waste, putting rivers under tremendous pressure due to human activities. This research assesses heavy metal contamination in sediments, shrimps (Parapenaeopsis atlantica) and periwinkles (Tympanotonus fuscatus) from Esuk Ibeno Beach, Akwa Ibom State, Nigeria, to ascertain their potential human health risks to consumers. Shrimp samples and periwinkle samples (at low tide) were obtained with the help of local fishermen from Esuk Ibeno beach. Sediment samples were collected at the same location as the periwinkles. Concentrations of chromium (Cr), iron (Fe), nickel (Ni), copper (Cu), lead (Pb), and cadmium (Cd) were analyzed using atomic absorption spectrometry. The sediments indicated heavy metal concentrations of Cr (0.24-0.32 mg/kg), Fe (25.0-41.4 mg/kg), Ni (0.27-0.38 mg/kg), Cu (0.05-0.11 mg/kg) Pb (0.03-0.09 mg/kg), and Cd (0.01-0.02 mg/kg), all below the quality standards of marine sediments. In the biota, Fe concentrations in shrimps (8.80±0.25 mg/kg) and periwinkles (0.90±0.03 mg/kg) exceeded the FAO/WHO limit of 0.5 mg/kg, while Cr, Ni, Cu, Pb and Cd were within the permissible limits. Biomagnification was apparent for Cr (1.00) and Cd (2.00) in the periwinkles. Dietary exposure assessments showed ingestion rates for adults and children, with the Expdiet values for Cr, Fe, Ni, Cu, Pb and Cd being lower than the oral reference dose (RfD). The target hazard quotient (THQ) values were less than 1 for all metals, indicating that there were no significant health risks. The cumulative hazard indices for shrimps (1.56×10-2 in adults; 1.61×10-2 in children) and periwinkles (1.11×10-2 in adults; 1.15×10-3 in children) suggest potential long-term risks of bioaccumulation. Incremental lifetime cancer risk (ILCR) for all investigated metals were 1.0×10-6 and 1.0×10-4. This indicates that the consumption of Parapenaeopsis atlantica and Tympanostus fuscatus from the Esuk Ibeno beach was within the acceptable range. This study indicates a great impact of anthropogenic activities on Esuk Ibeno Beach and calls for sustainable industrial waste management to prevent environmental and public health hazards.
The environmental situation in the country, domestic and foreign experience of biologisation of agriculture indicate the need to develop and implement post-industrial bioconversion technologies and their integrated use. Currently, the problem of treating concentrated wastewater, which also includes livestock farm wastewater, is becoming increasingly important in addressing environmental issues. The use of livestock wastewater on irrigation fields and composting does not allow for the full range of organic matter available in them. On the other hand, the current methods of treating and disinfecting these wastewaters do not provide the required degree of purification. Insufficiently purified wastewater (the degree of purification during aerobic treatment is 55–60% in terms of biochemical oxygen consumption), emergency discharges from manure storage facilities, storm water discharges from the complex’s territories, and excessive irrigation rates all cause soil and water pollution, which is why improved purification technologies are needed. The most promising from an environmental point of view is a comprehensive technology for the purification of concentrated wastewater from livestock farms and complexes using anaerobic (methane) fermentation at the preliminary stage of purification followed by aerobic purification, as well as the use of a biofilter and hydroponic installation. The research was conducted on the manure wastewater of a dairy cattle farm. For their purifica tion, a plant consisting of an anaerobic-aerobic fer menter, a biofilter, a block of containers, heat supply and aeration systems was used. The liquid fraction of manure effluents was subjected to biological purification on a mock-up sample of the technological line after settling in the block of containers. Methane fermentation of the effluent was carried out in a methane tank. The fermentation exposure was 5 days at a temperature regime (process temperature 40...45 °C). The fermented effluent entered the aeration tank, where it was aerated with compressed air for 2,5 days. The pre-purified effluent was subjected to further purification on a biofilter, then – on hydroponic equipment, the crop was barley, the seeding rate was 5 kg/m2, the duration of growing hydroponic green fodder was 7 days. As a result of the purification of livestock farm wastewater using biological treatment using anaerobic and aerobic aeration and a biofilter, as well as hydroponic equipment, the pH value decreased from 8,61 to 7,6, the COD decreased from 3282 mg/l to 746 mg/l, the BOD5 decreased from 2177 mg/l to 96 mg/l, the nitrogen content decreased from 955 mg/l to 152 mg/l), the phosphorus content decreased from 180 mg/l to 7 mg/l. As a result of the use of the biofilter, the suspended solids content decreased from 1520 mg/l to 70 mg/l. The purified wastewater from the livestock farm after growing hydroponic green fodder can be used for technical purposes and cannot be used for direct discharge into water bodies. It was established that the obtained feed corresponds in chemical composition to the GZK, which was grown on an artificially prepared base solution, and the optimal duration of cultivation is 7 days at an optimal seeding rate – 5 kg/m2. The obtained research results give grounds to conclude that it is expedient to use combined technologies that include the processes of microbiological non-sterile fermentation and phytopurification. The resulting biomass can be used as hydroponic green fodder. Key words: waste disposal, microbiological fermentation, phytoremediation, hydroponic green fodder, livestock effluents.
The Danube-Black Sea Hydrographic Space, spanning 6,500 km² or 19.2% of Moldova, includes the river basins of Ialpug, Cogâlnic, Sărata, and Hadjider. This region faces considerable challenges due to its limited water resources and its predominantly agrarian and rural character. This study examines the distinctive aspects of water use in Danube-Black Sea Hydrographical Space, assessing its role in Moldova’s overall water supply and the factors affecting its efficiency. The research employs statistical, deductive, comparative, and cartographic methods, utilizing data from the Moldovan Water Agency, the Inspectorate of Environmental Protection, the National Bu- reau of Statistics, and the Moldova Water-Canal Association, in addition to watershed management plans and relevant analytical studies. The Danube-Black Sea Hydrographical Space contributes minimally to the water supply of the Republic of Moldova, with over 85% of water sourced from groundwater due to the poor quality of surface water. Water use in the region is primarily agri- cultural (58%), with 30% allocated for domestic purposes and only 3% for industrial use. While there has been an increase in water use for technological and domestic needs, agricultural water use shows fluctuating trends. The region’s strained water resources call for improved management strategies to address its hydrological characteristics and the impacts of climate change, ensuring sustainable water use and supporting local economic and environmental needs.
The development of civilization and the preservation of environmental ecosystems are strongly dependent on water resources. Typically, an insufficient supply of surface water resources for domestic, industrial, and agricultural needs is supplemented with groundwater resources. However, groundwater is a natural resource that must accumulate over many years and cannot be recovered after a short period of recharge. Therefore, the long-term management of groundwater resources is an important issue for sustainable development. The accurate prediction of groundwater levels is the first step in evaluating total water resources and their allocation. However, in the process of data collection, data may be lost due to various factors. Filling in missing data is a main problem that any research field must address. It is well known that to maintain data integrity, one effective approach is missing value imputation (MVI). In addition, it has been demonstrated that machine learning may be a better tool. Therefore, the main purpose of this study was to utilize a generative adversarial network (GAN) that consists of a generative model and a discriminative model for imputation. Although the GAN could not capture the groundwater level endpoints in every section, the overall simulation performance was still excellent to some extent. Our results show that the GAN can improve the accuracy of water resource evaluations. In the current study, two interdisciplinary deep learning methods, univariate and Seq2val (sequence-to-value), were used for groundwater level estimation. In addition to addressing the significance of the parameter conditions, the advantages and disadvantages of these two models in hydrological simulations were also discussed and compared. Regarding parameter selection, the simulation results for univariate analysis were better than those for Seq2val analysis. Finally, univariate was employed to examine the limits of the models in long-term water level simulations. Our results suggest that the accuracy of CNNs is better, while LSTM is better for the simulation of multistep prediction. Therefore, the interdisciplinary deep learning approach may be beneficial for providing a better evaluation of water resources.
The unsatisfactory ecological state of water resources indicates, first of all, the problems of pollution and depletion of water resources and their relevance today. The lack of an optimal principle of management and responsibility for the state of surface sources of drinking water supply has led to the fact that industrial facilities, which, depending on their technological processes, determine the state of the surface source of drinking water, are located in the territory of the same regions, and the production and consumption of drinking water from of this source occurs on the territory of other regions, which complicates the settlement of control issues at the regional level. Therefore, solving the task of preparing drinking water of the required quality at drinking water treatment stations is a strategically important task in the conditions of a significant anthropogenic factor. This issue has become especially relevant in recent years on the territory of Ukraine in connection with the armed conflict, which has turned into a full-scale armed conflict on the territory of Ukraine. Today, these issues concern the south-eastern regions especially acutely. Meanwhile, it should be noted that the long-term operation of water supply systems without a capital replacement of communications, the lack of modernization of treatment facilities, or their absence at all, the consequences of irresponsible economic activity that led to the pollution of surface water became the prerequisite for a difficult situation with water supply of standardized quality. Of particular concern in connection with chemical and bacteriological pollution is the state of water supply for the rural population, which in most cases uses water from underground water sources for drinking purposes. A quarter of the villages and towns of Ukraine use the services of centralized domestic drinking water supply, and more than 60% of the population of most regions in Ukraine consume water from wells, the nitrate content of which is 1.5–30 times higher than the standard level. So, taking into account the fact that fresh water resources on Earth are distributed extremely unevenly, and arid or partially arid regions of the world include 40% of the landmass, which use only 2% of the world's water reserves, the issue of the introduction of modern water supply systems and the modernization of existing ones with the use of modern technologies is gaining more and more importance. According to the conclusions of scientists and the analysis of statistical data, it is possible to predict the development of the economy of Ukraine based on the introduction of hydrogen energy. But regardless of today's realities and a number of obstacles in the development of Ukraine, it is worth paying attention to urgent problems in the country that require urgent solutions, on which national security depends. Taking into account the fact that renewable energy sources are currently widely implemented in Ukraine and the world, and taking into account the problem of water supply as a global problem and local problems of a regional scale in the territory of Ukraine, it will be relevant in the future to use the indicated capacities to obtain certain volumes of suitable water, in accordance with sanitary standards, for use by the population. The proposed approach of using the capacities of renewable sources of electric energy for the needs of the functioning of systems for obtaining water suitable, in accordance with sanitary standards, for use by the population. The introduction of renewable energy sources into the system of obtaining water suitable, in accordance with sanitary standards, for use by the population should provide an opportunity to expand the functional capabilities of existing installations and increase their efficiency. This approach also aims to attract the attention of investors and reduce the ecological burden on the environment.
Nawaf Bin Darwish, Abdulrahman AlAlawi, Hamad AlRomaih
et al.
In membrane filtration technology, membrane fouling is the primary obstacle to optimizing efficiency and results in a short membrane lifetime and high operating costs. By incorporating nanomaterials into the membrane synthesis process, a mixed-matrix membrane with significantly enhanced characteristics and performance may be obtained. Graphene oxide (GO), aluminum oxide (Al2O3), tin oxide (SnO2), and titanium oxide (TiO2) were incorporated into a polyethersulfone (PESU) membrane. The water permeability of the modified membranes showed improvements when compared with the pure membrane. It increased from 65 L/m2 h bar for the pristine membrane (PES-1) to 143.6, 83.68, 92.12, 75.43 L/m2 h bar for Al2O3 (PES-2), TiO2 (PES-3), SnO2 (PES-4), and GO (PES-5) membranes, respectively. It was discovered that the membrane's surface hydrophilicity was significantly and directly affected by the incorporation of nanoparticles. Fouling parameters include Rr (Reversible fouling ratio), Rir (irreversible fouling ratio), Rt (total fouling ratio), and Frr (flux recovery ratio) and were measured to determine the membrane's fouling tendency. The results showed that the membrane's propensity for fouling could be reduced when nanoparticles were incorporated into it. The experimental results are best explained by the cake layer and both standard and intermediate blocking mechanism models, as determined by the traditional single fouling models.
HIGHLIGHTS
Ultrafiltration membranes were incorporated with different nanomaterials.;
Different fouling models were fitted to the experimental data.;
The fouling parameters were measured to determine the membrane fouling tendency.;
Water flux improved as a result of pore formation and hydrophilicity enhancement.;
Abstract Considering the recent significant drop in the groundwater level (GWL) in most of world regions, the importance of an accurate method to estimate GWL (in order to obtain a better insight into groundwater conditions) has been emphasized by researchers. In this study, artificial neural network (ANN) and support vector regression (SVR) models were initially employed to model the GWL of the Aspas aquifer. Secondly, in order to improve the accuracy of the models, two preprocessing tools, wavelet transform (WT) and complementary ensemble empirical mode decomposition (CEEMD), were combined with former methods which generated four hybrid models including W-ANN, W-SVR, CEEMD-ANN, and CEEMD-SVR. After these methods were implemented, models outcomes were obtained and analyzed. Finally, the results of each model were compared with the unit hydrograph of Aspas aquifer groundwater based on different statistical indexes to assess which modeling technique provides more accurate GWL estimation. The evaluation of the models results indicated that the ANN model outperformed the SVR model. Moreover, it was found that combining these two models with the preprocessing tools WT and CEEMD improved their performances. Coefficient of determination (R 2) which indicates model accuracy was increased from 0.927 in the ANN model to 0.938 and 0.998 in the W-ANN and CEEMD-ANN models, respectively. It was also improved from 0.919 in the SVR model to 0.949 and 0.948 in the W-SVR and CEEMD-SVR models, respectively. According to these results, the hybrid CEEMD-ANN model is found to be the most accurate method to predict the GWL in aquifers, especially the Aspas aquifer.
Abstract Management and protection of regional water resources requires an understanding of the hydrological characteristics and water quality changes. In this study, we combined isotopic, geochemical and hydrometric measurements to investigate hydrological characteristics and water quality changes during the interactions between surface water and groundwater in mountain river valley. Our results showed that the stable isotope values in most of the groundwater and river water samples were located above the middle of the local meteoric water line in a mountain river valley. The hydrochemical types of most of the groundwater and river water samples were Ca–Mg–HCO3 and were primarily dominated by rock weathering. The hydrochemical compositions of groundwater and river water were mainly affected by carbonate dissolution and cation exchange, but influences of saltwater intrusion and human activity were found at the lakeside. Precipitation was the main factor affecting the changes in hydrological processes at these groundwater and river water sites and they were also affected by meltwater, soil water and the interaction between groundwater and surface water. The water level of the river increased, and the recharge of the groundwater by river water increased in river valley during the rainy season, which led to an increase runoff path in groundwater. The interaction between the river water and groundwater was affected by the rainfall frequency and intensity, the recharge time of the soil water and the pressure of the river on both sides of the river channels. Additionally, our results indicated that the flow of groundwater into the river will lead to water quality deterioration. The increasing pressure of the river on the groundwater will cause the deterioration of groundwater quality, which will also be affected by saltwater intrusion and human activity. Our results detailed the hydrological characteristics, water quality changes and main influencing factors of the interaction between surface water and groundwater of river valley in mountain, which will be beneficial to promote the reasonable protection of water resources under climate change in the future.
Dissolved organic carbon (DOC) is indicative of water quality in drinking source water and has an impact on drinking water treatment. Exploring occurrence of DOC in drinking source water is of great significance for the drinking water safety in Beijing. This study elucidated spatial-temporal DOC dynamics in the Miyun section of Chaobai River in Beijing of China and identified sources of DOC based on DOC fluorescent spectral characteristics. Results showed that the average riverine DOC concentration was 30.60 mg/L. DOC concentrations in the Miyun section of the Chaobai River were 30.40, 30.24, and 31.09 mg/L in spring, summer and autumn, respectively. DOC concentrations at the three segments of the Miyun section of the Chaobai River (the Chaohe River, the Baihe River and the Chaobai River) were 29.93, 30.29 and 32.57 mg/L, respectively. Land use contributed to DOC variations rather than season and river segment. Significant increases in DOC concentration were observed in river water flowing through farmland and urban areas, and DOC concentration presented the highest after flowing through the farmland area. The results of FI, HIX and BIX showed that DOC mainly came from endogenous sources such as aquatic biological activities, and was less affected by terrestrial inputs. Special attentions ought to be paid on prevention and control of endogenous DOC inputs.
River, lake, and water-supply engineering (General), Water supply for domestic and industrial purposes
In order to solve the problem of providing the population with high-quality drinking water, preference is given to the use of groundwater deposits, which differ from surface sources in better quality and are more protected from man-made influences and climate change. Thirty-seven existing groundwater deposits are used for drinking and technical water supply in Lviv region. The distribution of groundwater in the region is very uneven, and in the Eastern Carpathians they are almost non-existent. The main factors of groundwater pollution in most of Ukraine are municipal sewage, livestock effluents, unorganized warehouses for storage of industrial waste, fertilizers and pesticides and other local objects that affect the state of groundwater. The gradual reduction of mineral fertilizer and pesticide usage has led to some improvement in the quality of groundwater, but for some agro-industrial areas the presence of residual pesticides and nitrogen compounds in groundwater remains a relevant problem. This year, there was an increase in the use of mineral fertilizers compared to last year. The aim of this work was to study the compliance of the maximum allowable concentrations of hydrochemical parameters of the wells of the Stryi water intake and to determine the potential impact of anthropogenic factors on water quality. The compliance with the sanitary and hygienic requirements of the hydrochemical parameters of water in the wells of the Stryi water intake was analyzed. The regularities of their changes as well as the presence of wells that have a potentially unstable chemical composition and are prone to deterioration of water quality were determined. The results of studies of related to the impact of self-treatment processes in the river Stryi on the quality of water intake in the city of Stryi showed that the drinking water from artesian wells is of high quality and now there are no negative effects of river water in the Stryi basin on groundwater deposits. The quality of river water is satisfactory for its use in domestic and drinking water supply and for recreational purposes.