Formation of Water Quality of Surface Water Bodies Used in the Material Processing

In the process of production or processing of materials by various methods,there is a need for a large volume of water of the required quality.Today in many regions of the world,there is an acute problem of providing industry with water of a required quality.Its solution is an urgent and difficult task.The water quality of surface water bodies is formed by a combination of a large number of both natural and anthropogenic factors,and is often significantly heterogeneous not only in the water area,but also in depth.As a rule,the water supply of large industrial enterprises is located along the river network.Mergers are the most important nodes of river systems.Understanding the mechanism of transport of pollutants at the confluence of rivers is critical for assessing water quality.In recent years,thanks to the data of satellite images,the interest of researchers in the phenomenon of mixing the waters of merging rivers has increased.The nature of the merger is influenced by the formation of transverse circulation.Within the framework of this work,a study of vorticity,as well as the width of the mixing zone,depending on the distance from the confluence,the speeds of the merging rivers and the angle of confluence was carried out.Since the consumer properties of water are largely determined by its chemical and physical indicators,the intensity of mixing,determined largely by the nature of the secondary circulation,is of fundamental importance for assessing the distribution of hydrochemical indicators of water quality in the mixing zone.These characteristics are important not only for organizing water intake for drinking and technical purposes with the best consumer properties,but also for organizing an effective monitoring system for confluence zones.

Sacrificial piles as a countermeasure against local scour around underwater pipelines

Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed an experimental method to reduce local scour around pipelines with a steady flow of clear water by installing cylindrical and cubical sacrificial piles.Three sizes of sacrificial piles were examined in a linear arrangement.Sacrificial piles were installed on the upstream side of the pipeline at three distances.Maximum scour depth reduction rates below the pipeline were computed.The results showed that sacrificial piles could protect a pipeline from local scour.A portion of scoured sediment around the sacrificial piles was deposited beneath the pipeline.This sediment accumulation reduced the scour depth beneath the pipeline.Analysis of the experimental results demonstrated that the size of piles(d),the spacing between piles,and the distance between the pipe and piles(Xp)were the variables that reduced the maximum scour beneath the pipeline with a diameter of D.For the piles with d=0.40D and 0.64D,X_(p)=4OD was the optimal distance to install a group of piles,and cubical piles could mitigate scour more effectively than cylindrical piles under similar conditions.For the piles with d=D,the greatest reduction in scour depth was achieved at X_(p)=50D with any desired spacings between piles,and cylindrical piles in this dimension could protect the pipeline against scour more effectively than cubical piles.

Formation mechanism of hydrochemical and quality evaluation of shallow groundwater in the Upper Kebir sub-basin,Northeast Algeria

This study investigates the hydrochemical formation mechanism of shallow groundwater in the Upper Kebir upstream sub-basin(Northeastern Algeria).The objective is to evaluate water quality suitability for domestic purposes through the application of water quality index(WQI).A total of 24 water points(wells and borewells)evenly distributed in the basin were collected and analyzed in the laboratory for determining the major ions and other geochemical parameters in the groundwater.The groundwater hydrochemical types were identified as Cl–Na and Cl–HCO_(3)^(–)Na,with the dominant major ions were found in the order of Na^(+)>Ca^(2+)>Mg^(2+)for cations,and Cl^(−)>SO_(4)^(2−)>HCO_(3)^(–)>NO_(3)^(−)for anions.Results suggest that weathering,dissolution of carbonate,sulfate,salt rocks,and anthropogenic activities were the major contributors to ion content in the groundwater.The Water Quality Index(WQI)was calculated to assess the water quality of potable water.Approximately 50%of the sampled sites exhibited good water quality.However,the study highlights significant NO_(3)contamination in the study area,with 50%of samples exceeding permissible limits.Therefore,effective treatment measures are crucial for the safe consumption of groundwater.

Optimization of the Algorithm for Increasing Injection Rate in Water Injection Wells for Pressure Optimization in P Oilfield

In today’s society, with the continuous growth of energy demand, Bohai Oilfield, as an important offshore oil resource base in China, is facing increasingly severe challenges while contributing to national energy security. In order to improve the quality of water injection in the oilfield and gradually achieve efficient and stable production, Bohai Oilfield has launched a water injection well pressure optimization project, focusing on improving the efficiency and quality of water injection in the water injection wells, in order to achieve the optimal water injection plan. In practical work, P Oilfield continues to promote the development of water injection well pressure optimization projects, emphasizing practical exploration and continuous optimization of work plans. However, during the project implementation process, there were some problems, one of which was that the statistics of cumulative injection volume were not scientific enough, resulting in a more comprehensive and accurate presentation of the actual results of pressure optimization work. In the context of continuous improvement work, after careful analysis and research, P Oilfield has decided to optimize the cumulative injection rate algorithm to guide the oilfield’s water injection work in a more refined way, ensuring sufficient and good water injection, and enhancing the oilfield’s production efficiency and comprehensive competitiveness.

Spatio-temporal variation of water conservation and its impact factors on the southern slope of Qilian Mountains

The ecology of Qilian Mountains has been seriously threatened by uncontrolled grazing and wasteland reclamation. This study examined the ecological changes on the southern slope of Qilian Mountains in China from the perspective of water conservation by classifying different clusters of water conservation functional areas to efficiently use limited human resources to tackle the water conservation protection problem. In this study, we used Integrate Valuation of Ecosystem Services and Tradeoffs(InVEST) model to estimate water conservation and analyzed the factors that influence the function. The results of this study include:(1) from 2000 to 2015, the water conservation of the southern slope of Qilian Mountains generally showed an increasing trend, and the total water conservation in 2015 increased by 42.18% compared with that in 2000.(2) Rainfall, fractional vegetation cover(FVC), and evapotranspiration have the most significant influence on the water conservation of the study area. Among them, water conservation is positively correlated with rainfall and FVC(P<0.05) and negatively correlated with evapotranspiration(P<0.05).(3) The importance level of water conservation functional areas gradually increases from northwest to southeast, and the region surrounding Menyuan Hui Autonomous County in the southeast of the southern slope of Qilian Mountains is the core water conservation functional area. And(4) the study area was divided into five clusters(Cluster Ⅰ–Cluster Ⅴ) of water conservation, with the areas of Clusters Ⅰ through Ⅴ accounting for 0.58%, 13.74%, 41.23%, 32.43%, and 12.01% of the whole study area, respectively.

A thermodynamic-based model for modeling thermo-elastoplastic behaviors of saturated clayey soils considering bound water dehydration

The non-isothermal deformation of soft mudrocks or clay soils is one of the most critical issues in energy and environmental related geotechnics.Clay-related geomaterials hold complex microstructure and mineral composition,which brings difficulty in investigating their thermo-mechanical behaviors.Previous studies pay little attention to the difference between a thermal plastic strain and the strain from clay dehydration.In this study,a new constitutive model is proposed for describing the thermoelastoplastic behaviors of clayey soils under water-saturated condition.The effect of temperature variation and mechanical loading on elastoplastic strains and dehydration are investigated.The thermodynamics laws and the unconventional plasticity are applied to quantify the thermo-mechanical behavior.The irreversible strain is captured by using Cam-Clay plasticity and subloading yield surface concept.The dehydration strain is described by utilizing a novel method based on generalized thermodynamics approach and Helmholtz free energy function.The internal variables,and the first and second laws of thermodynamics are applied in the model.The hardening rule is established by implementing the laws of physical conservation,energy dissipation,and plastic flow.The proposed model is validated using specially designed thermal consolidation tests on laboratory prepared heavily consolidated clayey soils and some published data of clayey soils with different geological origins.

Research Progress and Prospects for the Evolution Process and Treatment Technology of Urban Black and Smelly Water

Water is an important material resource for human survival,and with the increasing development of society,the amount of urban industrial wastewater and domestic sewage is gradually increasing.However,wastewater collection and treatment facilities lag behind,so that a large number of wastewater enters urban water,making urban water become gradually black and smelly.In order to provide a good living environment for human beings,a large number of scholars actively explore the treatment technology of black and smelly water.In this paper,the evolution process of black and smelly water was introduced firstly,and then the treatment technology of black and smelly water was summarized.Finally,the prospects for the development of the treatment technology were put forward.

The critical rate of horizontal wells in bottom-water reservoirs with an impermeable barrier

Barrier impacts on water cut and critical rate of horizontal wells in bottom water-drive reservoirs have been recognized but not investigated quantitatively. Considering the existence of impermeable barriers in oil formations, this paper developed a horizontal well flow model and obtained mathematical equations for the critical rate when water cresting forms in bottom-water reservoirs. The result shows that the barrier increases the critical rate and delays water breakthrough. Further study of the barrier size and location shows that increases in the barrier size and the distance between the barrier and oil-water contact lead to higher critical rates. The critical rate gradually approaches a constant as the barrier size increases. The case study shows the method presented here can be used to predict the critical rate in a bottom-water reservoir and applied to investigate the water cresting behavior of horizontal wells.

Apparent permeability variation of underground water aquifer induced by an earthquake:A case of the Zhouzhi well and the 2008 Wenchuan earthquake

t Taking the M2 wave as calibration signals, we extract the phase shifts of the water level relative to the Earth tide in the Zhouzhi well by utilizing the cross-correlation function. And we further obtain the apparent permeability variation in the aquifer of the Zhouzhi well in 2008. Comparison with the commonly used tidal analysis software Baytap-G shows that phase shifts obtained by cross-correlation function are more stable. The resulting apparent permeability of the Zhouzhi well aquifer fluctuates with time, indicating it is a dynamically controlled parameter. The 2008 Wenchuan earthquake caused the apparent permeability increasing drastically, which is interpreted as the combination effects of effective stress changes and the barriers removing in the flow channel due to seismic wave pressure pulse. After the Wenchuan earthquake, the effective stress began to recover and the impurities deposited gradually, causing the apparent permeability to decrease a month later and almost recover to the pre-earthquake level in six months.

Study on the mechanism of isotope fractionation in soil water during the evaporation process under equilibrium condition

In this study, with the method of vacuum extraction, two evaporative processes of soil water and free water under equilibrium condition were simulated. For each sample,water vapor was condensed by liquid nitrogen and was collected in four time intervals. From the analysis of hydrogen and oxygen isotopic compositions of the water collected at different times, it was discovered that the isotope fractionation of soil water also follows the mode, which is just the same as the evaporative process of free water. The relationship between the stable hydrogen and oxygen isotopes in residual water showed that the simulative evaporation line was close to the global meteoric water line (GMWL) under the equilibrium condition at about 20℃. Comparison of the two types of evaporative processes indicated that the isotope fractionation and evaporation velocity of soil water were only slightly modified by the Van der Waals force.

Variability in Quantity and Salinity of Produced Water from an Oil Production in South Kuwait

Produced water (PW) is the largest waste stream in the oil and gas industry. Water remains trapped for millions of years in the reservoir with oil and gas. When a hydrocarbon reservoir is infiltrated by a production well, the produced fluids commonly contain water. The understanding of this water’s constituents and volumes is vital for the sustainable continuity of production operations, as PW has a number of negative impacts on the infrastructure integrity of the operation. On the other hand, PW can be an alternative source of irrigation water as well as of industrial salt. Interestingly, both the quantity as well as the quality of PW do not remain constant but can vary, both progressively and erratically, even over short periods of time. This paper discusses such a situation of variable PW in an oil and gas operation in the State of Kuwait.

Hydrochemistry of the Mixed Dead Sea-Red Sea Water under Different Impoundment Scenarios as a Time Dependent State

The expected water mixing process between Red/Dead Sea water during the proposed conveyance projects is the main target of this research. The project will ensue transporting Red Sea water to recover and maintain certain level of the Dead Sea, mostly will reach -395 m. It is found that, the two different water bodies with different EC values or different densities (salinities) are relatively divided by stable plane. This plane is defined as the BARZACH PLANE. In this study, the mixing process occurred between the Red Sea with the Dead Sea waters, located at 20% - 24% of the Dead Sea column depth based on the Barzach Plane level. During a laboratory experimental work, it is found that the mixed Red/Dead Sea water evaporates in a high rate until certain level where the solution attains oversaturated conditions with different dissolved solids. At this stage, a thin layer of solids suddenly formed and floated at the surface of the dense brine. The salinity of the captured water is so dense that floated salt layer cannot be dissolved. In addition, the formed floated salt layer at the surface prevents the below captured water to evaporate and at this stage, stalactites start to form until the excess dissolved solids are not oversaturated with any mineral.

Model for Periodic Analysis of the Quantity of Water Evaporated during Thermo-processing of Clay Designated for Production of Oven Refractory

A model has been derived for periodic analysis of the quantity of water evaporated during thermo-processing of clay designated for production of oven refractory. The model;γ = exp〔〔lnt/2.9206〕1.3〕 shows that the quantity of evaporated water during the drying process is dependent on the drying time, with the evaporating surface being constant. It was found that the validity of the model is rooted on the expression lnγ = (lnt/Logβ)N where both sides of the equation are correspondingly almost equal. The maximum deviation of the model-predicted quantity of evaporated water from the corresponding experimental value is less than 19% which is quite within the acceptable deviation range of experimental results. Water evaporation rate as obtained from experiment and derived model were evaluated to be 0.0536 and 0.0337g mins -1 respectively.

Total Indicative Dose Determination in Water from the North Riviera Well Field of SODECI in Abidjan, Cote d’Ivoire

The Uranium-238 (238U), Thorium-232 (232Th) families and Potassium-40 (40K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (SODECI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection Institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of 238U, 232Th and 40K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclides238U, 232Th, and 40K vary for the seven boreholes from 0.150 to 0.166 mSv/yr with an average of 0.161 ± 0.034 mSv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 mSv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 mSv/yr. But all remain below the UNSCEAR reference dose of 0.29 mSv/yr.

Adaptability of Development Methods for Offshore Gas Cap Edge Water Reservoirs under Different Permeability Levels

The BZ 34-1 oilfield is a typical gas cap edge water reservoir in the Bohai oilfield. The main characteristics of the oilfield were multi-phase sand body stacking and the sand body was composed of three parts: gas cap, oil reservoir, and edge water. The actual production site results show that the permeability difference of multi-layer sand bodies has a serious impact on the development effect. This article establishes a typical reservoir model numerical model based on the total recovery degree of the reservoir and the recovery degree of each layer, and analyzes the impact of permeability gradient. As the permeability gradient increases, the total recovery degree of all four well patterns decreases, and the total recovery degree gradually decreases. The recovery degree of low permeability layers gradually decreases, and the recovery degree of high permeability layers gradually increases. As the permeability gradient increases, the degree of recovery gradually decreases under different water contents. As the permeability gradient increases, the reduction rate of remaining oil saturation in low permeability layers is slower, while the reduction rate of remaining oil saturation in high permeability layers was faster. By analyzing the impact of permeability gradient on the development effect of oil fields, we could further deepen our understanding of gas cap edge water reservoirs and guide the development of this type of oil field.

Analysis on the Characteristics of the Coseismic Response of Water Levels Recorded in Three Wells in Hainan,China to the Two Sumatra-Andaman Strong Earthquakes

The characteristics of seismic water level fluctuations of the two Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 on December 26,2004 and March 29,2005 recorded at Jiaji well,Qionghai,Hainan were analyzed,the features of the infrequent "step" changes of well water level after the two earthquakes were also analyzed and the mechanism of the "step change" of well water level was discussed.Then the high-sample-rate digital observation data of seismically-induced water level fluctuations of the Sumatra-Andaman strong earthquakes with magnitude 8.7 and 8.5 recorded at Nanbin well,Sanya and Tanniu well,Wenchang were analyzed.The results suggest that the dominant period of the seismic well water level fluctuation in all three wells was comparatively accordant,the amplitudes of seismic water level fluctuation of the same earthquake in different wells were clearly different,the time duration of seismic water level fluctuations of different earthquakes at the same well was also clearly different.

Ecological water demand of natural vegetation in the lower Tarim River

We have appraised the relationships between soil moisture, groundwater depth, and plant species diversity in the lower reaches of the Tarim River in western China, by analyzing field data from 25 monitoring wells across eight study sites and 25 permanent vegetation survey plots. It is noted that groundwater depth, soil moisture and plant species diversity are closely related. It has been proven that the critical phreatic water depth is five meters in the lower reaches of the Tarim River. We acquired the mean phreatic evaporation of different groundwater levels every month by averaging the two results of phreatic evaporation using the Qunk and Averyanov formulas. Based on different vegetation types and acreage with different groundwater depth, the total ecological water demand （EWD） of natural vegetation in 2005 was 2.4×10^8 m^3 in the lower reaches of the Tarim River. Analyzing the monthly EWD, we found that the EWD in the growth season （from April to September） is 81% of the year＇s total EWD. The EWD in May, June and July was 47% of the year＇s total EWD, which indicates the best time for dispensing artificial water. This research aims at realizing the sustainable development of water resources and provides a scientific basis for water resource management and sound collocation of the Tarim River Basin.

Understanding Surface Water-Groundwater Conversion Relationship and Associated Hydrogeochemistry Evolution in the Upper Reaches of Luan River Basin, North China

Luan River is the main water source in Beijing-Tianjin-Hebei region,northern China,where the groundwater system is vulnerable and pollution issue is serious.It is significant for regional groundwater resources protection to identify the hydrogeochemistry evolution and affecting factors along flow direction occurred in the upper reaches,especially the surface water-groundwater(SWGW)conversion relationship.In this study,recharge,conversion and geochemistry evolution of SW and GW were elucidated based on physical-hydrochemical indicators and stable isotopes in 36 GW samples and 20 SW samples,which were collected in July 2019 and July 2020.The factor analysis was further utilized to determine the main factors responsible for regional hydrogeochemical evolution.Results indicate that GW recharged SW in plateau area,and SW and GW recharged each other in typical Alpine valley area.The hydrochemical types are HCO3-Ca·Mg and HCO3-Ca,and the hydrochemical evolution is dominated by weathering of silicate and carbonate minerals.The cation exchange adsorption has minor impact on groundwater hydrochemistry.The rise of SO42-and NO3-contents in groundwater is related to industrial and agricultural activities.The main controlling factors of SW hydrochemical components included recharge from groundwater,industrial and mining activities,explaining 90.04%of data variance.However,water-rock interaction,agricultural and domestic sewage are responsible for GW quality,accounting for 83.38%.

The Impact of Soil Freezing/Thawing Processes on Water and Energy Balances

A frozen soil parameterization coupling of thermal and hydrological processes is used to investigate how frozen soil processes affect water and energy balances in seasonal frozen soil. Simulation results of soil liquid water content and temperature using soil model with and without the inclusion of freezing and thawing processes are evaluated against observations at the Rosemount field station. By comparing the simulated water and heat fluxes of the two cases, the role of phase change processes in the water and energy balances is analyzed. Soil freezing induces upward water flow towards the freezing front and increases soil water content in the upper soil layer. In particular, soil ice obviously prevents and delays the infiltration during rain at Rosemount. In addition, soil freezingthawing processes alter the partitioning of surface energy fluxes and lead the soil to release more sensible heat into the atmosphere during freezing periods.

An Incursion of Off-Equatorial Subsurface Cold Water and Its Role in Triggering the “Double Dip” La Nia Event of 2011

Based on Global Ocean Data Assimilation System （GODAS） and NCEP reanalysis data, atmospheric and oceanic pro- cesses possibly responsible for the onset of the 2011/12 La Nifia event, which followed the 2010/11 La Nifia even--referred to as a ＂double dip＂ La Nifia--are investigated. The key mechanisms involved in activating the 2011/12 La Nifia are illus- trated by these datasets. Results show that neutral conditions were already evident in the equatorial eastern Pacific during the decaying phase of the 2010/11 La Nifia. However, isothermal analyses show obviously cold water still persisting at the surface and at subsurface depths in off-equatorial regions throughout early 2011, being most pronounced in the tropical South Pacific. The negative SST anomalies in the tropical South Pacific acted to strengthen a southern wind across the equator. The subsurface cold water in the tropical South Pacific then spread northward and broke into the equatorial region at the thermo- cline depth. This incursion process of off-equatorial subsurface cold water successfully interrupted the eastern propagation of warm water along the equator, which had previously accumulated at subsurface depths in the warm pool during the 2010/11 La Nifia event. Furthermore, the incursion process strengthened as a result of the off-equatorial effects, mostly in the tropical South Pacific. The negative SST anomalies then reappeared in the central basin in summer 2011, and acted to trigger local coupled air-sea interactions to produce atmospheric-oceanic anomalies that developed and evolved with the second cooling in the fall of 2011.