Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic rainwater.The dissolved salt poses an extra osmotic water pote...Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic rainwater.The dissolved salt poses an extra osmotic water potential being normally neglected in laboratory measurements and numerical analyses.However,ignorance of salinity may result in overestimation of stability,and the design may not be as conservative as thought.Therefore,this research aims to first experimentally examine the influence of pore water salinity on water retention curve and saturated permeability of natural dispersive loess under saline and desalinated conditions.Second,the measured parameters are used for stability analyses of a railway embankment in an area subjected to regional rainfall incident.Eventually,a numerical parametric study is carried out to explore the significance of different rainfall schemes,construction patterns,and anisotropic permeability on the factor of safety.Results reveal that desalinization suppresses the water retention capability,which in turn results in a tremendous declination of unsaturated hydraulic conductivity.Despite the natural saline embankment,rainfall can hardly infiltrate into the desalinated embankment due to the lower conductivity.Therefore,the factor of safety for natural saline conditions drops notably,while only marginal changes occur in the case of the desalinated embankment.展开更多
The effect of NaCl on soil strength was investigated in this project based on salinity concentrations of 0 g/L, 5 g/L, 20 g/L, and 50 g/L as well as varying water contents of 15%-20%. Laser particle size analyzer was ...The effect of NaCl on soil strength was investigated in this project based on salinity concentrations of 0 g/L, 5 g/L, 20 g/L, and 50 g/L as well as varying water contents of 15%-20%. Laser particle size analyzer was also performed to explain possible effects. From particle size analysis and strength tests, it is hypothesized that the strength of the soil is increased with the addition of certain salinity concentrations until there are reversed effects, which is between 20 g/L and 50 g/L from our study. The increase of strength is suggested to be the affect of a greater variety of particle sizes. Since NaCI plays a role in the particle size distribution, it also plays a role in the strength of soils. The degree of the effect of the water content also differs from concentrations, and could be due to the variation of hydration film thickness on particles, which is affected by the ions introduced from water.展开更多
In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the ...In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the effect of irrigation water salinity and nitrogen（N） application rate on soil salinity and cotton yield under drip irrigation during the 2011 and 2012 growing seasons. The experimental design was a 3×4 factorial with three irrigation water salinity levels（0.35, 4.61 and 8.04 dS/m） and four N application rates（0, 240, 360 and 480 kg N/hm2）. Results showed that soil water content increased as the salinity of the irrigation water increased, but decreased as the N application rate increased. Soil salinity increased as the salinity of the irrigation water increased. Specifically, soil salinity measured in 1：5 soil：water extracts was 218% higher in the 4.61 dS/m treatment and 347% higher in the 8.04 dS/m treatment than in the 0.35 dS/m treatment. Nitrogen fertilizer application had relatively little effect on soil salinity, increasing salinity by only 3%–9% compared with the unfertilized treatment. Cotton biomass, cotton yield and evapotranspiration（ET） decreased significantly in both years as the salinity of irrigation water increased, and increased as the N application rate increased regardless of irrigation water salinity; however, the positive effects of N application were reduced when the salinity of the irrigation water was 8.04 dS/m. Water use efficiency（WUE） was significantly higher by 11% in the 0.35 dS/m treatment than in the 8.04 dS/m treatment. There was no significant difference in WUE between the 0.35 dS/m treatment and the 4.61 dS/m treatment. The WUE was also significantly affected by the N application rate. The WUE was highest in the 480 kg N/hm2 treatment, being 31% higher than that in the 0 kg N/hm2 treatment and 12% higher than that in the 240 kg N/hm2 treatment. There was no significant difference between the 360 and 480 kg N/hm2 treatments. The N use efficiency（NUE） was significantly lower in the 8.04 dS/m treatment than in either the 4.61 dS/m or the 0.35 dS/m treatment. There was no significant difference in NUE between the latter two treatments. These results suggest that irrigation water with salinity 〈4.61 dS/m does not have an obvious negative effect on cotton production, WUE or NUE under the experimental conditions. Application of N fertilizer（0–360 kg N/hm2） could alleviate salt damage, promote cotton growth, and increase both cotton yield and water use efficiency.展开更多
Use of saline water in irrigated agriculture has become an important means for alleviating water scarcity in arid and semi-arid regions. The objective of this field experiment was to evaluate the effects of irrigation...Use of saline water in irrigated agriculture has become an important means for alleviating water scarcity in arid and semi-arid regions. The objective of this field experiment was to evaluate the effects of irrigation water salinity and N fertilization on soil physicochemical and biological properties related to nitrification and denitrification. A 3×2 factorial design was used with three levels of irrigation water salinity（0.35, 4.61 and 8.04 d S m-1） and two N rates（0 and 360 kg N ha^（-1））. The results indicated that irrigation water salinity and N fertilization had significant effects on many soil physicochemical properties including water content, salinity, p H, NH_4-N concentration, and NO_3-N concentration. The abundance（i.e., gene copy number） of ammonia-oxidizing archaea（AOA） was greater than that of ammonia-oxidizing bacteria（AOB） in all treatments. Irrigation water salinity had no significant effect on the abundance of AOA or AOB in unfertilized plots. However, saline irrigation water（i.e., the 4.61 and 8.04 d S m-1 treatments） reduced AOA abundance, AOB abundance and potential nitrification rate in N fertilized plots. Regardless of N application rate, saline irrigation water increased urease activity but reduced the activities of both nitrate reductase and nitrite reductase. Irrigation with saline irrigation water significantly reduced cotton biomass, N uptake and yield. Nitrogen application exacerbated the negative effect of saline water. These results suggest that brackish water and saline water irrigation could significantly reduce both the abundance of ammonia oxidizers and potential nitrification rates. The AOA may play a more important role than AOB in nitrification in desert soil.展开更多
In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resource...In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resources over the long term, it is crucial to understand the effects of salinity on crops and develop optimal water-salinity irrigation strategies for processing tomatoes. A two-year field experiment was conducted in 2018 and 2019 to explore the impact of water salinity levels(S1: 1 g L^(–1), S2: 3 g L^(–1), and S3: 5 g L^(–1)) and irrigation amounts(W1: 305 mm, W2: 485 mm, and W3: 611 mm) on the soil volumetric water content and soil salinity, as well as processing tomato growth, yield, and water use efficiency. The results showed that irrigation with low to moderately saline water(<3 g L^(–1)) enhanced plant wateruptake and utilization capacity, with the soil water content(SWC) reduced by 6.5–7.62% and 10.52–13.23% for the S1 and S2 levels, respectively, compared to the S3 level in 2018. Under S1 condition, the soil salt content(SSC) accumulation rate gradually declined with an increase in the irrigation amount. For example, W3 decreased by 85.00 and 77.94% compared with W1 and W2 in 2018, and by 82.60 and 73.68% in 2019, respectively. Leaching effects were observed at the W3 level under S1, which gradually diminished with increasing water salinity and duration. In 2019, the salt contents of soil under each of the treatments increased by 10.81–89.72% compared with the contents in 2018. The yield of processing tomatoes increased with an increasing irrigation amount and peaked in the S1W3 treatment for the two years, reaching 125,304.85 kg ha^(–1)in 2018 and 128,329.71 kg ha^(–1)in 2019. Notably, in the first year, the S2W3 treatment achieved relatively high yields, exhibiting only a 2.85% reduction compared to the S1W3 treatment. However, the yield of the S2W3 treatment declined significantly in two years, and it was 15.88% less than that of the S1W3 treatment. Structural equation modeling(SEM) revealed that soil environmental factors(SWC and SSC) directly influence yield while also exerting indirect impacts on the growth indicators of processing tomatoes(plant height, stem diameter, and leaf area index). The TOPSIS method identified S1W3, S1W2, and S2W2 as the top three treatments. The single-factor marginal effect function also revealed that irrigation water salinity contributed to the composite evaluation scores(CES) when it was below 0.96 g L^(–1). Using brackish water with a salinity of 3 g L^(–1)at an irrigation amount of 485 mm over one year ensured that processing tomatoes maintained high yields with a relatively high CES(0.709). However, using brackish water for more than one year proved unfeasible.展开更多
The formation mechanism of high salinity geothermal water is significant for utilizing geothermal resources and mineral resources.The high salinity in geothermal water may be derived from the geothermal mother fluid o...The formation mechanism of high salinity geothermal water is significant for utilizing geothermal resources and mineral resources.The high salinity in geothermal water may be derived from the geothermal mother fluid or from the evaporite dissolution.It is difficult to distinguish between these two sources because they may have similar hydrochemistry.In this paper,water chemistry and stable isotopes were used to explore the high salinity geothermal water in Yanchanghe geothermal field,central China.It is a lowtemperature hydrothermal system in the inland karst area.The thermal water is Cl-Na type with high salinity(TDS>8,400 mg/L).The modified silicon thermometer is more suitable and the reasonable result is about 58.8℃.The maximum circulation depth is 1.9 km.Using the temperature of hot and cold water to estimate the mixing ratio is 58%-81%.Saturation index(SI),Na/1000-K/100-Mg1/2 and Gibbs diagram suggest that the main source of salt in geothermal water is derived from the evaporite dissolution,which provides Cl-of 11,264-31,279 mg/L and Na+of 9,272-21,236 mg/L.We found the combination of temperature and hydrogeochemistry can be used to investigate the formation mechanism and mixing process of high-salinity geothermal water formed in a karst low-temperature hydrothermal system.展开更多
In recent years,controlling the salinity and composition of the injected water has become an emerging enhanced oil recovery(EOR)technique,often described as low salinity(LS)waterflooding.This work is done with the int...In recent years,controlling the salinity and composition of the injected water has become an emerging enhanced oil recovery(EOR)technique,often described as low salinity(LS)waterflooding.This work is done with the intention to contribute to the ongoing discussions about LS waterflooding mechanism(s).For this purpose,a series of different experiments were conducted.At first,the effect of salinity on the interfacial tension(IFT)and the contact angle was evaluated with a crude oil sample.Then to achieve more accurate results in observing oil/water interface,similar IFT experiments were also carried out on a synthetic oil containing asphaltenes.Thereafter,microscopic visualization using glass micromodel was performed on the interface of the synthetic oil sample and brines.Four brine solutions including Sea Water(SW),it's dilutions and formation water(FW)were used for various experiments.Finally,to investigate the presented mechanism by other authors,a series of Environmental Scanning Electron Microscopy(ESEM)analysis on the synthetic oil was carried out to understand better the phase behaviour after contacting both synthetic oil and water phases from the micromodel experiment.Based on the existing mechanism,there exists an optimal concentration beyond which dilution is no longer an effective process.展开更多
In arid and semi-arid irrigated croplands,the excessive accumulation of soluble salts in the root zone is an extensive problem that seriously limits crop yield and water productivity(WP).To avoid affects the yield pot...In arid and semi-arid irrigated croplands,the excessive accumulation of soluble salts in the root zone is an extensive problem that seriously limits crop yield and water productivity(WP).To avoid affects the yield potential of crops,the application of extra irrigation for leaching of excessive salts from the root zone was required.Quantitative knowledge of effects of the irrigation water salinity and leaching fraction(LF)on the relative yield(RY)and the unit water productivity of crop evapotranspiration(UWPET)and the unit water productivity of irrigation water(UWPI)were becoming gradually important.This article provided theoretical models for estimating the UWPs(UWPET and UWPI)and optimizing leaching fraction according to irrigation water salinity.In the present study,eight levels of irrigation water salinity(ECw=0.25,0.50,0.75,1,2,3,4,and 5 dS/m)and 39 levels of LF values ranging from 0.04 to 0.80 were set and tested to assessing their effects on the RY and UWPs for four typical crops(barley,bean,wheat,and maize)with different salt tolerance levels.Almost every curve determined between the UWPs and LFs for the four crops had an inflection point.It was indicated that the UWPET and UWPI could be maximized by optimizing the LF under different irrigation water salinities.Furthermore,the linear regression relationships were established to estimate the maximum values of UWPs and their corresponding optimal LFs for four crops by using the irrigation water salinity.Moreover,the theoretical models for estimating the UWPs were validated by data of wheat from previous literature,and the models could be suitable with acceptable relative errors when LFs ranging from 0.07 to 0.17.展开更多
Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to o...Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to obtain the crop water sensitivity index, the salinity sensitivity index, and other parameters. Using data collected during 35 years to calculate the 10-day mean precipitation and evaporation, the variation in soil salinity concentrations and in the yields of winter wheat and cotton were simulated for 49 irrigation scheduling that were combined from 7 irrigation schemes over 3 irrigation dates and 7 salinity concentrations of saline irrigation water (fresh water and 6 levels of saline water). Comparison of predicted results with irrigation data obtained from a large area of the field showed that the model was valid and reliable. Based on the analysis of the investment cost of the irrigation that employed deep tube wells or shallow tube wells, a saline water irrigation schedule and a corresponding strategy for groundwater development and utilization were proposed. For wheat or cotton, if the salinity concentration was higher than 7.0 g L-1 in groundwater, irrigation was needed with only fresh water; if about 5.0 g L-1, irrigation was required twice with fresh water and once with saline water; and if not higher than 3.0 g L-1, irrigation could be solely with saline water.展开更多
An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the ef...An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity,permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.展开更多
In order to explore the use of groundwater resources,field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China.Irrigation was conducted using four diff...In order to explore the use of groundwater resources,field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China.Irrigation was conducted using four different water salinity levels that were arranged in a split plot design.These four water salinity levels were s0,s3,s6 and s9(0.71,3,6 and 9 g/L,respectively).The soil salt content,soil bulk density,soil porosity,saturated hydraulic conductivity,plant height,leaf area index and yield of maize for seed production were measured for studying the effects of saline water irrigation on soil salt content distribution,soil physical properties and water use efficiency.It was observed that higher salinity level of irrigation water and long duration of saline water irrigation resulted in more salt accumulation.Compared to initial values,the soil salt accumulation in 0-100 cm soil layer after three years of experiments for s0,s3,s6 and s9 was 0.189 mg/cm3,0.654 mg/cm3,0.717 mg/cm3 and 1.135 mg/cm3,respectively.Both greater salt levels in the irrigation water and frequent saline water irrigation led to greater soil bulk density,but poorer soil porosity and less saturated hydraulic conductivity.The saturated hydraulic conductivity decreased with increase in soil bulk density,but increased with improvement in soil porosity.It was noted that the maize height,leaf area index and maize yield gradually decreased with increase in water salinity.The maize yield decreased over 25%and the water use efficiency also gradually declined when irrigated with water containing 6 g/L and 9 g/L salinity levels.However,maize yield following saline water irrigation with 3 g/L decreased less than 20%and the decline in water use efficiency was not significant during the three-year experiment period.The results demonstrate that irrigation with saline water at the level of 6 g/L and 9 g/L in the study area is not suitable,while saline water irrigation with 3 g/L would be acceptable for a short duration together with salt leaching through spring irrigation before sowing.展开更多
In this study, nineteen brine samples from the Qarhan Salt Lake(QSL) in western China were collected and analyzed for boron(B) and chlorine(Cl) concentrations, total dissolved solids(TDS), pH values and stable B isoto...In this study, nineteen brine samples from the Qarhan Salt Lake(QSL) in western China were collected and analyzed for boron(B) and chlorine(Cl) concentrations, total dissolved solids(TDS), pH values and stable B isotopic compositions. The B concentrations and δ^(11) B values of brines in the QSL range from 51.6 mg/L to138.4 mg/L, and from +9.32& to +13.08&, respectively. By comparison of B concentrations and TDS of brines in QSL with evaporation paths of brackish water, we found that B enrichment of brines primarily results from strong evaporation and concentration of Qarhan lake water. Combining with comparisons of B concentrations, TDS, p H values and δ^(11) B values of brines, previously elemental ratios(K/Cl, Mg/Cl, Ca/Cl, B/Cl) and δ^(11) B values of halite from a sediment core(ISL1 A), we observe good correlations between B concentrations and TDS, TDS and pH values, pH and δ^(11) B values of brines, which demonstrate that higher B concentrations and more positive δ^(11) B values of halite indicate higher salinity of the Qarhan paleolake water as well as drier paleoclimatic conditions. Based on this interpretation of the δ^(11) B values of halite in core ISL1 A, higher salinity of the Qarhan paleolake occurred during two intervals, around 46-34 ka and26-9 ka, which are almost coincident with the upper and lower halite-dominated salt layers in core ISL1 A,drier climate phases documented from the δ^(18) O record of carbonate in core ISL1 A and the paleomoisture record in monsoonal central Asia, and a higher solar insolation at 30°N. These results demonstrate that the δ^(11) B values of halite in the arid Qaidam Basin could be regarded as a new proxy for reconstructing the salinity record of paleolake water as well as paleoclimate conditions.展开更多
The low salinity water lenses（LSWLes） in the expansion area of the Changjiang diluted water（CDW） exist in a certain period of time in some years. The impact of realistic river runoff, ocean currents and weather co...The low salinity water lenses（LSWLes） in the expansion area of the Changjiang diluted water（CDW） exist in a certain period of time in some years. The impact of realistic river runoff, ocean currents and weather conditions need to be taken into account in the dynamical analysis of LSWL, which is in need of research. In this paper, the POM-σ-z model is used to set up the numerical model for the expansion of the CDW. Then LSWL in summer 1977 is simulated, and its dynamic mechanism driven by wind, tide, river runoff and the Taiwan Warm Current is also analyzed. The simulated results indicate that the isolated LSWL detaches itself from the CDW near the river mouth, and then moves towards the northeast region outside the Changjiang Estuary. Its maintaining period is from July 26 to August 11. Its formation and development is mainly driven by two factors. One is the strong southeasterly wind lasting for ten days. The other is the vertical tidal mixing during the transition from neap tide to spring tide.展开更多
Combining low salinity water (LSW) with surfactants has an enormous potential for enhancing oil recovery processes. However, there is no consensus about the mechanisms involved, in addition to the fact that several st...Combining low salinity water (LSW) with surfactants has an enormous potential for enhancing oil recovery processes. However, there is no consensus about the mechanisms involved, in addition to the fact that several studies have been conducted in model systems, while experiments with rocks and reservoir fluids are scarce. This study presents a core-flooding experiment of LSW injection, with and without surfactant, using the core and heavy oil samples obtained from a sandstone reservoir in southeastern Mexico. The effluents and the crude oil obtained at each stage were analyzed. The study was complemented by tomographic analysis. The results revealed that LSW injection and hybrid process with surfactants obtained an increase of 11.4 percentage points in recovery factor. Various phenomena were caused by LSW flooding, such as changes in wettability and pH, ion exchange, mineral dissolution, detachment of fines and modification of the hydrocarbon profile. In the surfactant flooding, the reduction of interfacial tension and alteration of wettability were the main mechanisms involved. The findings of this work also showed that the conditions believed to be necessary for enhanced oil recovery with LSW, such as the presence of kaolinite or high acid number oil, are not relevant.展开更多
A study comparative of rearing of the Pacific white shrimp （Litopenaeus vannamei） with the Nile tilapia （Oreochromis niloticus） in three earthen ponds （5,600 m^2） with the salinity ranged from 0.5-1.2 ppt and th...A study comparative of rearing of the Pacific white shrimp （Litopenaeus vannamei） with the Nile tilapia （Oreochromis niloticus） in three earthen ponds （5,600 m^2） with the salinity ranged from 0.5-1.2 ppt and three treatment ponds with salinity of 2-4 ppt by adding brine water into the ponds. Postlarvae 12 （PL12） of L. vannamei were stocked at density of 9 PL/m^2 and after one week the Nile tilapia fingerlings were stocked at density of I fish/m^2. Only pelleted feed were given to the fish during the 196-day rearing period. Shrimps were partially harvested by sieve net at day 80 and 120, and five days later PLI2 were stocked at the rate of 3 PL/m^2. After final harvesting at day 196, the production, body weight and survival from the treatment group were significantly higher （P 〈 0.05） than those of the control group. While the fish production body weight and survival rate from both groups were not significant differences （P 〉 0.051）. The ionic concentration of six major ions （CI, SO42, Ca^2＋, Na^＋, Mg^2＋ and K^＋）, salinity and hardness in the treatment ponds were significantly higher than those of the control ponds （P 〈 0.05）. Moreover, the ionic profiles of the treatment ponds were similar to seawater at the salinity of 2 ppt while only 1 ppt in the control ponds. Results from the study indicated that in order to achieve good growth and survival rate of L. vannamei, brine water should be added into grow-out ponds prior to stocking and during the rearing： period to obtain and maintain the salinity not less than 2 ppt.展开更多
High-entropy materials(HEMs),which are newly manufactured compounds that contain five or more metal cations,can be a platform with desired properties,including improved electrocatalytic performance owing to the inhere...High-entropy materials(HEMs),which are newly manufactured compounds that contain five or more metal cations,can be a platform with desired properties,including improved electrocatalytic performance owing to the inherent complexity.Here,a strain engineering methodology is proposed to design transition-metal-based HEM by Li manipulation(LiTM)with tunable lattice strain,thus tailoring the electronic structure and boosting electrocatalytic performance.As confirmed by the experiments and calculation results,tensile strain in the LiTM after Li manipulation can optimize the d-band center and increase the electrical conductivity.Accordingly,the asprepared LiTM-25 demonstrates optimized oxygen evolution reaction and hydrogen evolution reaction activity in alkaline saline water,requiring ultralow overpotentials of 265 and 42 mV at 10 mA cm−2,respectively.More strikingly,LiTM-25 retains 94.6%activity after 80 h of a durability test when assembled as an anion-exchange membrane water electrolyzer.Finally,in order to show the general efficacy of strain engineering,we incorporate Li into electrocatalysts with higher entropies as well.展开更多
The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific consideration...The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K<sup>+</sup>), Magnesium (Mg2<sup>+</sup>), Sulphur (S), CN ratio and Sodium (Na<sup>+</sup>) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels.展开更多
The properties of salinity in the South China Sea(SCS),a significant marginal sea connecting the Pacific and Indian Oceans,are greatly influenced by the transport of fresh water flux between the two oceans.However,the...The properties of salinity in the South China Sea(SCS),a significant marginal sea connecting the Pacific and Indian Oceans,are greatly influenced by the transport of fresh water flux between the two oceans.However,the long-term changes in the intermediate water in the SCS have not been thoroughly studied due to limited data,particularly in relation to its thermodynamic variations.This study utilized reanalysis data products to identify a 60-year trend of freshening in the intermediate waters of the northern South China Sea(NSCS),accompanied by an expansion of low-salinity water.The study also constructed salinity budget terms,including advection and entrainment processes,and conducted an analysis of the salinity budget to understand the impacts of external and internal dynamic processes on the freshening trend of the intermediate water in the NSCS.The analysis revealed that the freshening in the northwest Pacific Ocean and the intensification of intrusion through the Luzon Strait at intermediate levels are the primary drivers of the salinity changes in the NSCS.Additionally,a weakened trend in the intensity of vertical entrainment also contributes to the freshening in the NSCS.This study offers new insights into the understanding of regional deep sea changes in response to variations in both thermodynamics and oceanic dynamic processes.展开更多
In arid and semiarid regions such as Niger, irrigated agriculture leads to soil salinization, particularly through irrigation water salts, and has adverse effects on crop production such as vegetable crops including o...In arid and semiarid regions such as Niger, irrigated agriculture leads to soil salinization, particularly through irrigation water salts, and has adverse effects on crop production such as vegetable crops including onion. The main objective of this study, conducted in the experimental site of Djibo Hamani University of Tahoua in Niger, was to evaluate the effects of organic fertilizer on the growth and yield of onion crops irrigated with saline water. The experiment was performed in split-plot design to test tree type of fertilizer (chemical fertilizer, compost and millet glumes) and four (04) levels of irrigation water salinity in electrical conductivity values (ECw) (S0 = 0.28 dS/m as control, S1 = 2 dS/m, S2 = 4 dS/m and S3 = 6 dS/m). The growth parameters and bulb yield were evaluated during 4 months of onion cropping season. The results showed that the use of irrigation saline water significantly decreased the growth and bulb yield of onion crops. The yield in onion bulbs is 1.55 to 3.94 times higher with control (0.28 dS/m) than that with high saline water (ECw = 6 dS/m). Compared to control in irrigation water, the reduction in fresh onion bulb yield was 38.8, 52.6 and 63.5% respectively for ECw of 2, 4 and 6 dS/m. Furthermore, the application of organic fertilizers, particularly compost, improves salt-tolerance of onion crops in order to promote growth and bulb yield. Indeed, when irrigating onion crops with saline water (ECw of 2, 4 and 6 dS/m), the onion bulb yield is significantly higher under compost than under chemical fertilizer and glumes. At high irrigation saline water (ECw = 6 dS/m), the yield in onion bulbs is 1.9 and 2.1 times higher under compost than that under chemical fertilizer and glumes respectively. Thus, the compost is the promising organic amendment in a semiarid region of Tahoua in Niger to reduce the adverse effects of irrigation saline water on onion crop production.展开更多
Arsenic(As)contamination in the groundwater is a global issue,and its adverse effects on human life and the environment have been widely described,especially in Asian countries.Myanmar is a Southeast Asian country,wit...Arsenic(As)contamination in the groundwater is a global issue,and its adverse effects on human life and the environment have been widely described,especially in Asian countries.Myanmar is a Southeast Asian country,with an annual groundwater resource potential of 495 km3.A higher amount of As contamination(>50μm)has been reported in the Ayeyarwady region.Together with As,other toxic metals and substances,such as F,Fe,Mn,and saline water intrusions have been observed to contaminate groundwater in Myanmar.Evidence and verification of health-related assessment problems still need to be carried out.The most widely used As-removal technique in Myanmar is the gravel–sand filter method.Many drinking water tube wells and dug wells in Myanmar have been tested for As contamination,but As-removal methods need improvement.No law for the regulation and management of groundwater resources has yet been implemented in the country;thus,the groundwater abstraction process is disorganized.Here,we review the assessment of the As contamination process in Myanmar,their source,and their sustainability.A protection,security,and management of groundwater in Myanmar can be sustainably improved by increasing awareness with the help of non-governmental organizations(NGOs)and international sources.展开更多
基金the Iran’s National Elites Foundation and the Research Grant Office at Sharif University Technology for supporting this research by way of “Dr Kazemi-Ashtiani Award” and grant “G970902”,respectively。
文摘Natural soils contain a certain amount of salt in the form of dissolved ions or electrically charged atoms,originated from the long-term erosion by acidic rainwater.The dissolved salt poses an extra osmotic water potential being normally neglected in laboratory measurements and numerical analyses.However,ignorance of salinity may result in overestimation of stability,and the design may not be as conservative as thought.Therefore,this research aims to first experimentally examine the influence of pore water salinity on water retention curve and saturated permeability of natural dispersive loess under saline and desalinated conditions.Second,the measured parameters are used for stability analyses of a railway embankment in an area subjected to regional rainfall incident.Eventually,a numerical parametric study is carried out to explore the significance of different rainfall schemes,construction patterns,and anisotropic permeability on the factor of safety.Results reveal that desalinization suppresses the water retention capability,which in turn results in a tremendous declination of unsaturated hydraulic conductivity.Despite the natural saline embankment,rainfall can hardly infiltrate into the desalinated embankment due to the lower conductivity.Therefore,the factor of safety for natural saline conditions drops notably,while only marginal changes occur in the case of the desalinated embankment.
基金Acknowledgements： This work was supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, SEM, China, and also supported by the United States National Science Foundation. The authors thank Prof. SHEN H. H. and Prof. SHEN H. T. from Clarkson University for their unconditional support to this work.
文摘The effect of NaCl on soil strength was investigated in this project based on salinity concentrations of 0 g/L, 5 g/L, 20 g/L, and 50 g/L as well as varying water contents of 15%-20%. Laser particle size analyzer was also performed to explain possible effects. From particle size analysis and strength tests, it is hypothesized that the strength of the soil is increased with the addition of certain salinity concentrations until there are reversed effects, which is between 20 g/L and 50 g/L from our study. The increase of strength is suggested to be the affect of a greater variety of particle sizes. Since NaCI plays a role in the particle size distribution, it also plays a role in the strength of soils. The degree of the effect of the water content also differs from concentrations, and could be due to the variation of hydration film thickness on particles, which is affected by the ions introduced from water.
基金funded by the National Basic Research Program of China (2009CB825101)the National Natural Science Foundation of China (30960210)
文摘In arid and semi-arid regions, freshwater scarcity and high water salinity are serious and chronic problems for crop production and sustainable agriculture development. We conducted a field experiment to evaluate the effect of irrigation water salinity and nitrogen（N） application rate on soil salinity and cotton yield under drip irrigation during the 2011 and 2012 growing seasons. The experimental design was a 3×4 factorial with three irrigation water salinity levels（0.35, 4.61 and 8.04 dS/m） and four N application rates（0, 240, 360 and 480 kg N/hm2）. Results showed that soil water content increased as the salinity of the irrigation water increased, but decreased as the N application rate increased. Soil salinity increased as the salinity of the irrigation water increased. Specifically, soil salinity measured in 1：5 soil：water extracts was 218% higher in the 4.61 dS/m treatment and 347% higher in the 8.04 dS/m treatment than in the 0.35 dS/m treatment. Nitrogen fertilizer application had relatively little effect on soil salinity, increasing salinity by only 3%–9% compared with the unfertilized treatment. Cotton biomass, cotton yield and evapotranspiration（ET） decreased significantly in both years as the salinity of irrigation water increased, and increased as the N application rate increased regardless of irrigation water salinity; however, the positive effects of N application were reduced when the salinity of the irrigation water was 8.04 dS/m. Water use efficiency（WUE） was significantly higher by 11% in the 0.35 dS/m treatment than in the 8.04 dS/m treatment. There was no significant difference in WUE between the 0.35 dS/m treatment and the 4.61 dS/m treatment. The WUE was also significantly affected by the N application rate. The WUE was highest in the 480 kg N/hm2 treatment, being 31% higher than that in the 0 kg N/hm2 treatment and 12% higher than that in the 240 kg N/hm2 treatment. There was no significant difference between the 360 and 480 kg N/hm2 treatments. The N use efficiency（NUE） was significantly lower in the 8.04 dS/m treatment than in either the 4.61 dS/m or the 0.35 dS/m treatment. There was no significant difference in NUE between the latter two treatments. These results suggest that irrigation water with salinity 〈4.61 dS/m does not have an obvious negative effect on cotton production, WUE or NUE under the experimental conditions. Application of N fertilizer（0–360 kg N/hm2） could alleviate salt damage, promote cotton growth, and increase both cotton yield and water use efficiency.
基金funded by the National Natural Science Foundation of China (31360504)the Innovative Research Foundation for Excellent Young Scientists of Xinjiang Production and Construction Crops, China (2014CD002)
文摘Use of saline water in irrigated agriculture has become an important means for alleviating water scarcity in arid and semi-arid regions. The objective of this field experiment was to evaluate the effects of irrigation water salinity and N fertilization on soil physicochemical and biological properties related to nitrification and denitrification. A 3×2 factorial design was used with three levels of irrigation water salinity（0.35, 4.61 and 8.04 d S m-1） and two N rates（0 and 360 kg N ha^（-1））. The results indicated that irrigation water salinity and N fertilization had significant effects on many soil physicochemical properties including water content, salinity, p H, NH_4-N concentration, and NO_3-N concentration. The abundance（i.e., gene copy number） of ammonia-oxidizing archaea（AOA） was greater than that of ammonia-oxidizing bacteria（AOB） in all treatments. Irrigation water salinity had no significant effect on the abundance of AOA or AOB in unfertilized plots. However, saline irrigation water（i.e., the 4.61 and 8.04 d S m-1 treatments） reduced AOA abundance, AOB abundance and potential nitrification rate in N fertilized plots. Regardless of N application rate, saline irrigation water increased urease activity but reduced the activities of both nitrate reductase and nitrite reductase. Irrigation with saline irrigation water significantly reduced cotton biomass, N uptake and yield. Nitrogen application exacerbated the negative effect of saline water. These results suggest that brackish water and saline water irrigation could significantly reduce both the abundance of ammonia oxidizers and potential nitrification rates. The AOA may play a more important role than AOB in nitrification in desert soil.
基金funded by the National Key R&D Program of China (2022YFD1900405)。
文摘In recent years, the rational utilization of saline water resources for agricultural irrigation has emerged as an effective strategy to alleviate water scarcity. To safely and efficiently exploit saline water resources over the long term, it is crucial to understand the effects of salinity on crops and develop optimal water-salinity irrigation strategies for processing tomatoes. A two-year field experiment was conducted in 2018 and 2019 to explore the impact of water salinity levels(S1: 1 g L^(–1), S2: 3 g L^(–1), and S3: 5 g L^(–1)) and irrigation amounts(W1: 305 mm, W2: 485 mm, and W3: 611 mm) on the soil volumetric water content and soil salinity, as well as processing tomato growth, yield, and water use efficiency. The results showed that irrigation with low to moderately saline water(<3 g L^(–1)) enhanced plant wateruptake and utilization capacity, with the soil water content(SWC) reduced by 6.5–7.62% and 10.52–13.23% for the S1 and S2 levels, respectively, compared to the S3 level in 2018. Under S1 condition, the soil salt content(SSC) accumulation rate gradually declined with an increase in the irrigation amount. For example, W3 decreased by 85.00 and 77.94% compared with W1 and W2 in 2018, and by 82.60 and 73.68% in 2019, respectively. Leaching effects were observed at the W3 level under S1, which gradually diminished with increasing water salinity and duration. In 2019, the salt contents of soil under each of the treatments increased by 10.81–89.72% compared with the contents in 2018. The yield of processing tomatoes increased with an increasing irrigation amount and peaked in the S1W3 treatment for the two years, reaching 125,304.85 kg ha^(–1)in 2018 and 128,329.71 kg ha^(–1)in 2019. Notably, in the first year, the S2W3 treatment achieved relatively high yields, exhibiting only a 2.85% reduction compared to the S1W3 treatment. However, the yield of the S2W3 treatment declined significantly in two years, and it was 15.88% less than that of the S1W3 treatment. Structural equation modeling(SEM) revealed that soil environmental factors(SWC and SSC) directly influence yield while also exerting indirect impacts on the growth indicators of processing tomatoes(plant height, stem diameter, and leaf area index). The TOPSIS method identified S1W3, S1W2, and S2W2 as the top three treatments. The single-factor marginal effect function also revealed that irrigation water salinity contributed to the composite evaluation scores(CES) when it was below 0.96 g L^(–1). Using brackish water with a salinity of 3 g L^(–1)at an irrigation amount of 485 mm over one year ensured that processing tomatoes maintained high yields with a relatively high CES(0.709). However, using brackish water for more than one year proved unfeasible.
基金supported by the National Natural Science Foundation of China(Grant number:41440027)。
文摘The formation mechanism of high salinity geothermal water is significant for utilizing geothermal resources and mineral resources.The high salinity in geothermal water may be derived from the geothermal mother fluid or from the evaporite dissolution.It is difficult to distinguish between these two sources because they may have similar hydrochemistry.In this paper,water chemistry and stable isotopes were used to explore the high salinity geothermal water in Yanchanghe geothermal field,central China.It is a lowtemperature hydrothermal system in the inland karst area.The thermal water is Cl-Na type with high salinity(TDS>8,400 mg/L).The modified silicon thermometer is more suitable and the reasonable result is about 58.8℃.The maximum circulation depth is 1.9 km.Using the temperature of hot and cold water to estimate the mixing ratio is 58%-81%.Saturation index(SI),Na/1000-K/100-Mg1/2 and Gibbs diagram suggest that the main source of salt in geothermal water is derived from the evaporite dissolution,which provides Cl-of 11,264-31,279 mg/L and Na+of 9,272-21,236 mg/L.We found the combination of temperature and hydrogeochemistry can be used to investigate the formation mechanism and mixing process of high-salinity geothermal water formed in a karst low-temperature hydrothermal system.
文摘In recent years,controlling the salinity and composition of the injected water has become an emerging enhanced oil recovery(EOR)technique,often described as low salinity(LS)waterflooding.This work is done with the intention to contribute to the ongoing discussions about LS waterflooding mechanism(s).For this purpose,a series of different experiments were conducted.At first,the effect of salinity on the interfacial tension(IFT)and the contact angle was evaluated with a crude oil sample.Then to achieve more accurate results in observing oil/water interface,similar IFT experiments were also carried out on a synthetic oil containing asphaltenes.Thereafter,microscopic visualization using glass micromodel was performed on the interface of the synthetic oil sample and brines.Four brine solutions including Sea Water(SW),it's dilutions and formation water(FW)were used for various experiments.Finally,to investigate the presented mechanism by other authors,a series of Environmental Scanning Electron Microscopy(ESEM)analysis on the synthetic oil was carried out to understand better the phase behaviour after contacting both synthetic oil and water phases from the micromodel experiment.Based on the existing mechanism,there exists an optimal concentration beyond which dilution is no longer an effective process.
基金This research was financially supported by the National Natural Science Foundation of China(Grant Nos.41830754,U1706211,41977007,51679190,51979220)and National Key R&D Program of China(Grant Nos.2016YFC0501401)and Natural Science Foundation of Shaanxi Province(2018JQ5094).
文摘In arid and semi-arid irrigated croplands,the excessive accumulation of soluble salts in the root zone is an extensive problem that seriously limits crop yield and water productivity(WP).To avoid affects the yield potential of crops,the application of extra irrigation for leaching of excessive salts from the root zone was required.Quantitative knowledge of effects of the irrigation water salinity and leaching fraction(LF)on the relative yield(RY)and the unit water productivity of crop evapotranspiration(UWPET)and the unit water productivity of irrigation water(UWPI)were becoming gradually important.This article provided theoretical models for estimating the UWPs(UWPET and UWPI)and optimizing leaching fraction according to irrigation water salinity.In the present study,eight levels of irrigation water salinity(ECw=0.25,0.50,0.75,1,2,3,4,and 5 dS/m)and 39 levels of LF values ranging from 0.04 to 0.80 were set and tested to assessing their effects on the RY and UWPs for four typical crops(barley,bean,wheat,and maize)with different salt tolerance levels.Almost every curve determined between the UWPs and LFs for the four crops had an inflection point.It was indicated that the UWPET and UWPI could be maximized by optimizing the LF under different irrigation water salinities.Furthermore,the linear regression relationships were established to estimate the maximum values of UWPs and their corresponding optimal LFs for four crops by using the irrigation water salinity.Moreover,the theoretical models for estimating the UWPs were validated by data of wheat from previous literature,and the models could be suitable with acceptable relative errors when LFs ranging from 0.07 to 0.17.
基金Project supported by the National Natural Science Foundation of China (Nos. 50339030 and 90202001).
文摘Using a crop-water-salinity production function and a soil-water-salinity dynamic model, optimal irrigation scheduling was developed to maximize net return per irrigated area. Plot and field experiments were used to obtain the crop water sensitivity index, the salinity sensitivity index, and other parameters. Using data collected during 35 years to calculate the 10-day mean precipitation and evaporation, the variation in soil salinity concentrations and in the yields of winter wheat and cotton were simulated for 49 irrigation scheduling that were combined from 7 irrigation schemes over 3 irrigation dates and 7 salinity concentrations of saline irrigation water (fresh water and 6 levels of saline water). Comparison of predicted results with irrigation data obtained from a large area of the field showed that the model was valid and reliable. Based on the analysis of the investment cost of the irrigation that employed deep tube wells or shallow tube wells, a saline water irrigation schedule and a corresponding strategy for groundwater development and utilization were proposed. For wheat or cotton, if the salinity concentration was higher than 7.0 g L-1 in groundwater, irrigation was needed with only fresh water; if about 5.0 g L-1, irrigation was required twice with fresh water and once with saline water; and if not higher than 3.0 g L-1, irrigation could be solely with saline water.
基金the National Iranian South Oil Company (NISOC) for generously funding the project
文摘An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity,permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.
基金This research was financially supported by National Natural Science Foundation of China(51179166)Specialized Research Fund for the Doctoral Program of Higher Education of China(20123250110004)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘In order to explore the use of groundwater resources,field experiments were conducted for three consecutive years during 2012-2014 in the Shiyang River basin of Northwest China.Irrigation was conducted using four different water salinity levels that were arranged in a split plot design.These four water salinity levels were s0,s3,s6 and s9(0.71,3,6 and 9 g/L,respectively).The soil salt content,soil bulk density,soil porosity,saturated hydraulic conductivity,plant height,leaf area index and yield of maize for seed production were measured for studying the effects of saline water irrigation on soil salt content distribution,soil physical properties and water use efficiency.It was observed that higher salinity level of irrigation water and long duration of saline water irrigation resulted in more salt accumulation.Compared to initial values,the soil salt accumulation in 0-100 cm soil layer after three years of experiments for s0,s3,s6 and s9 was 0.189 mg/cm3,0.654 mg/cm3,0.717 mg/cm3 and 1.135 mg/cm3,respectively.Both greater salt levels in the irrigation water and frequent saline water irrigation led to greater soil bulk density,but poorer soil porosity and less saturated hydraulic conductivity.The saturated hydraulic conductivity decreased with increase in soil bulk density,but increased with improvement in soil porosity.It was noted that the maize height,leaf area index and maize yield gradually decreased with increase in water salinity.The maize yield decreased over 25%and the water use efficiency also gradually declined when irrigated with water containing 6 g/L and 9 g/L salinity levels.However,maize yield following saline water irrigation with 3 g/L decreased less than 20%and the decline in water use efficiency was not significant during the three-year experiment period.The results demonstrate that irrigation with saline water at the level of 6 g/L and 9 g/L in the study area is not suitable,while saline water irrigation with 3 g/L would be acceptable for a short duration together with salt leaching through spring irrigation before sowing.
基金financially supported by the National Natural Science Foundation of China(Grant Nos. 41872093, 41502096) Foundation of Qinghai Science & Technology Department (2016-ZJ-715) One-Thousand InnovativeTalent Project of Qinghai Province (Grant to QS Fan)
文摘In this study, nineteen brine samples from the Qarhan Salt Lake(QSL) in western China were collected and analyzed for boron(B) and chlorine(Cl) concentrations, total dissolved solids(TDS), pH values and stable B isotopic compositions. The B concentrations and δ^(11) B values of brines in the QSL range from 51.6 mg/L to138.4 mg/L, and from +9.32& to +13.08&, respectively. By comparison of B concentrations and TDS of brines in QSL with evaporation paths of brackish water, we found that B enrichment of brines primarily results from strong evaporation and concentration of Qarhan lake water. Combining with comparisons of B concentrations, TDS, p H values and δ^(11) B values of brines, previously elemental ratios(K/Cl, Mg/Cl, Ca/Cl, B/Cl) and δ^(11) B values of halite from a sediment core(ISL1 A), we observe good correlations between B concentrations and TDS, TDS and pH values, pH and δ^(11) B values of brines, which demonstrate that higher B concentrations and more positive δ^(11) B values of halite indicate higher salinity of the Qarhan paleolake water as well as drier paleoclimatic conditions. Based on this interpretation of the δ^(11) B values of halite in core ISL1 A, higher salinity of the Qarhan paleolake occurred during two intervals, around 46-34 ka and26-9 ka, which are almost coincident with the upper and lower halite-dominated salt layers in core ISL1 A,drier climate phases documented from the δ^(18) O record of carbonate in core ISL1 A and the paleomoisture record in monsoonal central Asia, and a higher solar insolation at 30°N. These results demonstrate that the δ^(11) B values of halite in the arid Qaidam Basin could be regarded as a new proxy for reconstructing the salinity record of paleolake water as well as paleoclimate conditions.
基金supported by the National Natural Science Foundation of China(Grant Nos.40906044,41076048 and 41376012)the Fundamental Research Funds for the Central Universities(Grant No.2011B05714)the Doctoral Starting up Foundation of College of Meteorology and Oceanography of the PLA University of Science and Technology,China
文摘The low salinity water lenses（LSWLes） in the expansion area of the Changjiang diluted water（CDW） exist in a certain period of time in some years. The impact of realistic river runoff, ocean currents and weather conditions need to be taken into account in the dynamical analysis of LSWL, which is in need of research. In this paper, the POM-σ-z model is used to set up the numerical model for the expansion of the CDW. Then LSWL in summer 1977 is simulated, and its dynamic mechanism driven by wind, tide, river runoff and the Taiwan Warm Current is also analyzed. The simulated results indicate that the isolated LSWL detaches itself from the CDW near the river mouth, and then moves towards the northeast region outside the Changjiang Estuary. Its maintaining period is from July 26 to August 11. Its formation and development is mainly driven by two factors. One is the strong southeasterly wind lasting for ten days. The other is the vertical tidal mixing during the transition from neap tide to spring tide.
文摘Combining low salinity water (LSW) with surfactants has an enormous potential for enhancing oil recovery processes. However, there is no consensus about the mechanisms involved, in addition to the fact that several studies have been conducted in model systems, while experiments with rocks and reservoir fluids are scarce. This study presents a core-flooding experiment of LSW injection, with and without surfactant, using the core and heavy oil samples obtained from a sandstone reservoir in southeastern Mexico. The effluents and the crude oil obtained at each stage were analyzed. The study was complemented by tomographic analysis. The results revealed that LSW injection and hybrid process with surfactants obtained an increase of 11.4 percentage points in recovery factor. Various phenomena were caused by LSW flooding, such as changes in wettability and pH, ion exchange, mineral dissolution, detachment of fines and modification of the hydrocarbon profile. In the surfactant flooding, the reduction of interfacial tension and alteration of wettability were the main mechanisms involved. The findings of this work also showed that the conditions believed to be necessary for enhanced oil recovery with LSW, such as the presence of kaolinite or high acid number oil, are not relevant.
文摘A study comparative of rearing of the Pacific white shrimp （Litopenaeus vannamei） with the Nile tilapia （Oreochromis niloticus） in three earthen ponds （5,600 m^2） with the salinity ranged from 0.5-1.2 ppt and three treatment ponds with salinity of 2-4 ppt by adding brine water into the ponds. Postlarvae 12 （PL12） of L. vannamei were stocked at density of 9 PL/m^2 and after one week the Nile tilapia fingerlings were stocked at density of I fish/m^2. Only pelleted feed were given to the fish during the 196-day rearing period. Shrimps were partially harvested by sieve net at day 80 and 120, and five days later PLI2 were stocked at the rate of 3 PL/m^2. After final harvesting at day 196, the production, body weight and survival from the treatment group were significantly higher （P 〈 0.05） than those of the control group. While the fish production body weight and survival rate from both groups were not significant differences （P 〉 0.051）. The ionic concentration of six major ions （CI, SO42, Ca^2＋, Na^＋, Mg^2＋ and K^＋）, salinity and hardness in the treatment ponds were significantly higher than those of the control ponds （P 〈 0.05）. Moreover, the ionic profiles of the treatment ponds were similar to seawater at the salinity of 2 ppt while only 1 ppt in the control ponds. Results from the study indicated that in order to achieve good growth and survival rate of L. vannamei, brine water should be added into grow-out ponds prior to stocking and during the rearing： period to obtain and maintain the salinity not less than 2 ppt.
基金support provided by the National Natural Science Foundation of China(Grant Nos.51972048,U23A20605)support provided by the Performance subsidy fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(Grant No.22567627H)the additional data in the revised manuscriptsupported by the National Key Research and Development Program of China(No.2022YFB3706300).
文摘High-entropy materials(HEMs),which are newly manufactured compounds that contain five or more metal cations,can be a platform with desired properties,including improved electrocatalytic performance owing to the inherent complexity.Here,a strain engineering methodology is proposed to design transition-metal-based HEM by Li manipulation(LiTM)with tunable lattice strain,thus tailoring the electronic structure and boosting electrocatalytic performance.As confirmed by the experiments and calculation results,tensile strain in the LiTM after Li manipulation can optimize the d-band center and increase the electrical conductivity.Accordingly,the asprepared LiTM-25 demonstrates optimized oxygen evolution reaction and hydrogen evolution reaction activity in alkaline saline water,requiring ultralow overpotentials of 265 and 42 mV at 10 mA cm−2,respectively.More strikingly,LiTM-25 retains 94.6%activity after 80 h of a durability test when assembled as an anion-exchange membrane water electrolyzer.Finally,in order to show the general efficacy of strain engineering,we incorporate Li into electrocatalysts with higher entropies as well.
文摘The necessity to saline and sodic waters is sometimes used for irrigating agricultural activities under certain circumstances, but it is important to note that the use of these waters comes with specific considerations and limitations. One way to decrease undesirable effects of sodic waters on the physical and chemical properties of soils is to apply organic and chemical amendments within the soil. This study aimed to assess the effectiveness of saline water on soil acidity, alkalinity and nutrients leaching in sandy loamy soil at Bella flower farm, in Rwamagana District, Rwanda. The water used was from the Muhazi Lake which is classified as Class I (Saline water quality). Column leaching experiments using treated soils were then conducted under saturated conditions. The soil under experimental was first analyzed for its textural classification, soil properties and is classified as sandy loamy soil. The t-test was taken at 1%, 5% and 10% levels of statistical significance compared to control soil. The results indicated that the application of saline water to soils caused an increase in some soil nutrients like increase of Phosphorus (P), Potassium (K<sup>+</sup>), Magnesium (Mg2<sup>+</sup>), Sulphur (S), CN ratio and Sodium (Na<sup>+</sup>) and decreased soil texture, physical and chemical properties and remained soil nutrients. Consequently, the intensive addition of saline water leachates to soil in PVC pipes led to decreased of soil EC through leaching and a raiser Soluble Sodium Percentage (SSP). The rate of saline water application affected the increase accumulation of SAR and Na% in the top soil layers. The study indicated that saline water is an inefficient amendment for sandy soil with saline water irrigation. The study recommends further studies with similar topic with saline water irrigation, as it accentuated the alkalinity levels.
基金National Natural Science Foundation of China(92158204,42076019)Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(31020004)Open Project of the State Key Laboratory of Tropical Oceanography(LTOZZ2001)。
文摘The properties of salinity in the South China Sea(SCS),a significant marginal sea connecting the Pacific and Indian Oceans,are greatly influenced by the transport of fresh water flux between the two oceans.However,the long-term changes in the intermediate water in the SCS have not been thoroughly studied due to limited data,particularly in relation to its thermodynamic variations.This study utilized reanalysis data products to identify a 60-year trend of freshening in the intermediate waters of the northern South China Sea(NSCS),accompanied by an expansion of low-salinity water.The study also constructed salinity budget terms,including advection and entrainment processes,and conducted an analysis of the salinity budget to understand the impacts of external and internal dynamic processes on the freshening trend of the intermediate water in the NSCS.The analysis revealed that the freshening in the northwest Pacific Ocean and the intensification of intrusion through the Luzon Strait at intermediate levels are the primary drivers of the salinity changes in the NSCS.Additionally,a weakened trend in the intensity of vertical entrainment also contributes to the freshening in the NSCS.This study offers new insights into the understanding of regional deep sea changes in response to variations in both thermodynamics and oceanic dynamic processes.
文摘In arid and semiarid regions such as Niger, irrigated agriculture leads to soil salinization, particularly through irrigation water salts, and has adverse effects on crop production such as vegetable crops including onion. The main objective of this study, conducted in the experimental site of Djibo Hamani University of Tahoua in Niger, was to evaluate the effects of organic fertilizer on the growth and yield of onion crops irrigated with saline water. The experiment was performed in split-plot design to test tree type of fertilizer (chemical fertilizer, compost and millet glumes) and four (04) levels of irrigation water salinity in electrical conductivity values (ECw) (S0 = 0.28 dS/m as control, S1 = 2 dS/m, S2 = 4 dS/m and S3 = 6 dS/m). The growth parameters and bulb yield were evaluated during 4 months of onion cropping season. The results showed that the use of irrigation saline water significantly decreased the growth and bulb yield of onion crops. The yield in onion bulbs is 1.55 to 3.94 times higher with control (0.28 dS/m) than that with high saline water (ECw = 6 dS/m). Compared to control in irrigation water, the reduction in fresh onion bulb yield was 38.8, 52.6 and 63.5% respectively for ECw of 2, 4 and 6 dS/m. Furthermore, the application of organic fertilizers, particularly compost, improves salt-tolerance of onion crops in order to promote growth and bulb yield. Indeed, when irrigating onion crops with saline water (ECw of 2, 4 and 6 dS/m), the onion bulb yield is significantly higher under compost than under chemical fertilizer and glumes. At high irrigation saline water (ECw = 6 dS/m), the yield in onion bulbs is 1.9 and 2.1 times higher under compost than that under chemical fertilizer and glumes respectively. Thus, the compost is the promising organic amendment in a semiarid region of Tahoua in Niger to reduce the adverse effects of irrigation saline water on onion crop production.
基金the Korea Ministry of Environment through the strategic EcoSSSoil Project(grant numbers 2019002820004)the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(grant numbers 2019R1I1A2A01057002 and 2019R1A6A1A03033167).
文摘Arsenic(As)contamination in the groundwater is a global issue,and its adverse effects on human life and the environment have been widely described,especially in Asian countries.Myanmar is a Southeast Asian country,with an annual groundwater resource potential of 495 km3.A higher amount of As contamination(>50μm)has been reported in the Ayeyarwady region.Together with As,other toxic metals and substances,such as F,Fe,Mn,and saline water intrusions have been observed to contaminate groundwater in Myanmar.Evidence and verification of health-related assessment problems still need to be carried out.The most widely used As-removal technique in Myanmar is the gravel–sand filter method.Many drinking water tube wells and dug wells in Myanmar have been tested for As contamination,but As-removal methods need improvement.No law for the regulation and management of groundwater resources has yet been implemented in the country;thus,the groundwater abstraction process is disorganized.Here,we review the assessment of the As contamination process in Myanmar,their source,and their sustainability.A protection,security,and management of groundwater in Myanmar can be sustainably improved by increasing awareness with the help of non-governmental organizations(NGOs)and international sources.
