Water In Column Research Articles

The Link between Surface Visible Light Spectral Features and Water–Salt Transfer in Saline Soils—Investigation Based on Soil Column Laboratory Experiments

Monitoring soil salinity with remote sensing is difficult, but knowing the link between saline soil surface spectra, soil water, and salt transport processes might help in modeling for soil salinity monitoring. In this study, we used an indoor soil column experiment, an unmanned aerial vehicle multispectral sensor camera, and a soil moisture sensor to study the water and salt transport process in the soil column under different water addition conditions and investigate the relationship between the soil water and salt transport process and the spectral reflectance of the image on the soil surface. The observation results of the soil column show that the soil water and salt transportation process conforms to the basic transportation law of “salt moves together with water, and when water evaporates, salt is retained in the soil weight”. The salt accumulation phenomenon increases the image spectral reflectance of the surface layer of the soil column, while soil temperature has no effect on the reflectance. As the water percolates down, water and salt accumulate at the bottom of the soil column. The salinity index decreases instantly after the addition of brine and then tends to increase slowly. The experimental results indicate that this work can capture the relationship between the water and salt transport process and remote sensing spectra, which can provide theoretical basis and reference for soil water salinity monitoring.

The characteristics of nutrient distribution and influencing factors in the Chukchi Plateau and adjacent waters

The Arctic is one of the regions under the most dramatic climate change. Global warming has led to elevated freshwater inflow into the western Arctic Ocean and significantly altered nutrient structure and biogeochemical cycling. In this work, inorganic dissolved nutrients in the Chukchi Plateau (CP) and adjacent regions were investigated to further understand their characteristics and influencing factors. Results showed that relatively high nutrient concentrations occurred in the water masses with salinity >32 psu, especially there was a nutrient-rich layer influenced by Winter Pacific Water in the water column (15.10±1.96, 2.23±0.26, and 23.46±6.64 µmol/L for DIN, PO43– and Si(OH)4, respectively). Contrarily, lower nutrient concentrations occurred in the mixing water of the upper layer (1.76±1.04, 1.15±0.16 and 3.76±2.29 µmol/L for DIN, PO43– and Si(OH)4, respectively) with a low DIN/P ratio (1.44±0.59), suggesting DIN has become the potentially biological limiting factor. Furthermore, the freshening and deepening of the upper layer driven by the Beaufort Gyre has hindered the nutrient transport from underlying layer into the upper layer. A maximum chla was observed at 36‒75 m water depth, and the phytoplankton biomass decreased from the western to the eastern CP, accompanied by a decreased contribution of micro-sized chla but an increased contribution of small-sized chla (74.0±0.1%). The phytoplankton resource use efficiency for DIN was estimated as (3.2±4.6)×10-3, which was primarily influenced by the physicochemical parameters of water and also largely regulated by the size structure of phytoplankton.

Understanding the impacts of coastal deoxygenation in nitrogen dynamics: an observational analysis

Biological production and outgassing of greenhouse gasses (GHG) in Eastern Boundary Upwelling Systems (EBUS) are vital for fishing productivity and climate regulation. This study examines temporal variability of biogeochemical and oceanographic variables, focusing on dissolved oxygen (DO), nitrate, nitrogen deficit (N deficit), nitrous oxide (N2O) and air-sea N2O flux. This analysis is based on monthly observations from 2000 to 2023 in a region of intense seasonal coastal upwelling off central Chile (36°S). Strong correlations are estimated among N2O concentrations and N deficit in the 30–80 m layer, and N2O air-sea fluxes with the proportion of hypoxic water (4 < DO < 89 µmol L−1) in the water column, suggesting that N2O accumulation and its exchange are mainly associated with partial denitrification. Furthermore, we observe interannual variability in concentrations and inventories in the water column of DO, nitrate, N deficit, as well as air-sea N2O fluxes in both downwelling and upwelling seasons. These variabilities are not associated with El Niño-Southern Oscillation (ENSO) indices but are related to interannual differences in upwelling intensity. The time series reveals significant nitrate removal and N2O accumulation in both mid and bottom layers, occurring at rates of 1.5 µmol L−1 and 2.9 nmol L−1 per decade, respectively. Particularly significant is the increase over the past two decades of air-sea N2O fluxes at a rate of 2.9 µmol m−2 d−1 per decade. These observations suggest that changes in the EBUS, such as intensification of upwelling and the prevalence of hypoxic waters may have implications for N2O emissions and fixed nitrogen loss, potentially influencing coastal productivity and climate.

One-dimensional infiltration in a layered soil measured in the laboratory with the mini-disk infiltrometer

Abstract Layered soils can consist of a thin little permeable upper layer over a more permeable subsoil. There are not many experimental data on the influence of this upper layer on infiltration. The mini-disk infiltrometer set at a pressure head of –3 cm was used to compare infiltration of nearly 40 mm of water in homogeneous loam and clay soil columns with that in columns made by a thin layer (1 and 3 cm) of clay soil over the loam soil. For each run, the Horton infiltration model was fitted to the data and the soil sorptivity was also estimated by considering the complete infiltration run. For the two layered soils, the estimates of initial infiltration rate and decay constant were similar but a thicker upper layer induced 2.4 times smaller final infiltration rates. Depending on the infiltration parameter and the thickness of the upper layer, the layered soils were characterized by 2.2–6.3 times smaller values than the loam soil and 2.2–6.6 higher values than the clay soil. Sorptivity did not differ between the homogeneous clay soil and the layered soil with a thick upper layer and a thin layer was enough to induce a decrease of this hydrodynamic parameter by 2.5 times as compared with that of the homogeneous loam soil. Even a thin upper layer influences appreciably infiltration and hydrodynamic parameters. Layering effects vary with the thickness of the upper layer and the considered parameter. The applied experimental methodology could be used with other soils and soil combinations.

Optimization of oil recovery using heated low salinity water (HLSW) in the horizontal sand pack column during water flooding: radiotracer intervention

Water-flooding is a prevalent technique for secondary oil recovery that is capable to increase oil recovery by up to 45%. Due to its accessibility, affordability, and simplicity, water flooding is the most frequently used secondary oil recovery technique. However, the efficiency of conventional water flooding is limited by capillary forces which holds the residual crude oil in pore structures. Moreover, during water flooding operation, the injected fluid does not penetrate sufficiently due to low permeability or presence of channelling inside the sandstone reservoir. Therefore, in this study, thermal recovery was introduced to 100ppm (0.1g/L) low salinity water (LSW) in order to investigate the percentage of oil recovery during water flooding. A horizontal sand pack column was used for water flooding experiment and temperature and injections rate are the parameters to be optimised with respect to percentage of oil recovery. The column was initially packed with 125micrometer sieved sand to ensure constant homogeneity is achieved. Initially, formation water which comprised with NaCl, CaCl2 and MgSO4 was introduced inside the column together with light oil and was aged overnight. TAPIS oil with viscosity of 0.001382 Pa.s (1.382cP) was used as light-oil in this study. The injection rate was set to 1 mL/min, 2 mL/min, and 3 mL/min respectively whereas, the temperature of the LSW was heated at 50 °C, 70 °C, and 90 °C subsequently. Heated water was supplied continuously throughout the sand pack which was heated using water blanket to retain heat at 70°C (reservoir temperature). In conclusion, 3 mL/min and 70°C were identified as optimum parameters and the oil recovery experiment was proceeded with liquid radiotracer using Technecium-99m (Tc-99m) intervention and resulted with 73% of yield. Nevertheless, the radiotracer intervention only provides the Residence Time Distribution (RTD) model which describe the behaviour of the sand pack during water flooding process.

Interaction of cemented paste backfill (CPB) and circumneutral mine water during column experiments

Cemented paste backfill (CPB) is used as a support and filler material in underground mines. In underground conditions, before mine closure and flooding, surface and groundwaters with variable quality are in contact with CPB material, which may result in the leaching of harmful substances from the CPB. In this study, we used actual mine water from a gold mine to flush CPB in a laboratory test to simulate underground conditions and the environmental influence of CPB on groundwaters more realistically than before.Different CPB materials were treated with mine water in columns for nine months. The columns were drained and filled with new mine water batches four times during the experiment to simulate intermittent flushing underground. The dissolved elemental content, major cations, pH and oxidation-reduction potential (ORP) of the waters were measured, and the chemical results were analysed by performing geochemical modelling with the widely used geochemical code PHREEQC. X-ray tomography was also used to examine the internal structure of the CPB specimens.The results demonstrated that calcium and sulphate present in CPB parent materials leached into the mine water, which might cause a deterioration of CPB. In contrast, the concentrations of dissolved As, Sb and Ni decreased in the mine water when it was in contact with CPB materials. However, arsenic started to be re-released from the materials at the end of the nine-month experimental period. The geochemical modelling suggests that the removal of metals/metalloids from the mine water was driven by the surface complexation reactions on originally present and/or freshly precipitated metal (hydr)oxide minerals. A longer and modified testing period is needed to thoroughly examine the conditions under which these adsorbed elements start to release over time.

Development of Pairwise Force Smoothed Particle Hydrodynamics for Capillary Rise Modelling

This research conducted a series of numerical experiments employing the Pair-Wise Force Smoothed Particle Hydrodynamics (PF-SPH) model to simulate the capillary action of water in the soil column. Initially, analytical relationships were formulated to connect various PF-SPH model parameters to surface tensions, static contact angles, and pore radius. Subsequently, the model was utilized to investigate PF-SPH equations and develop a modified function between numerical and physical parameters that incorporate the pore radius variable. The findings of this research reveal that capillary rise profiles in a steady state condition and Soil Water Characteristic Curve (SWCC) profiles closely align with empirical data obtained from published laboratory experiments. In conclusion, we observed that the PF-SPH model could simulate the capillary rise of water through the soil column by adjusting parameters such as surface tension, contact angle, and soil particle properties.

Wastewater Treatment Using Poplar Plants: Processes

Phytoremediation is used to treat wastewater, wherein plants, microorganisms, and soil work together to remediate pollutants. We evaluated the plant processes that can affect metal mobilization during phytoremediation. The experimental columns were filled with silica sand and soil mixture spiked with redox-sensitive metal(loid)s—arsenic, manganese, and iron, and fitted with an ORP probe and oxygen sensors. Three columns were planted with poplars and three others were no-plant controls. Carbon-rich, synthetic food-processing wastewater was applied at 15.4 mm/day to the columns. Leachate water was analyzed every other week for water quality. Both soil and plant tissue samples were analyzed for metal concentrations, and soils were analyzed for microbial populations. Both treatments reduced 65–70% carbon. ORP ranged from −321 mV to 916 mV and affected metal mobilization. Oxic conditions in planted treatments yielded high ORP, oxygen concentration, and nitrates. Microbial communities were enhanced in both treatments, but the planted columns had more microbial abundance and evenness. Plants successfully accumulated metals in roots from soil with an accumulation factor of up to 40 for some metals and translocated to shoots from roots with a translocation factor of 10.62. The crop coefficient was 1.88, indicating accelerated loss of water in planted columns compared to control columns. The results demonstrated the benefits of plants in creating more oxic conditions, removing more wastewater from the rhizosphere, accumulating and translocating metals in the biomass, and enhancing rhizodegradation of pollutants by microbial population enhancement. Knowledge of the soil–plant–microbial processes is useful in designing engineered phytoremediation systems.

Engineering properties on salt rock as subgrade filler in dry salt lake: Water retention characteristics and water migration patterns

As a special road material, salt rock has high strength and stability in arid areas, and has broad application prospects in highway engineering construction in dry salt lake areas. To investigate the water retention characteristics of salt rock and its water migration patterns under the covering effect, and to ensure the long-term durability of salt rock subgrade, this study presents a comprehensive analysis of the effect of initial dry density on the water retention characteristics of fine-grained salt rock fillers. The soil–water characteristic curve model of salt rock was recommended. The capillary water migration patterns of salt rock were proved. The water migration patterns of salt rock under freeze–thaw cycles were clarified. The hydrothermal state of salt rock subgrade under the influence of pavement overburden was evaluated based on the field monitoring. The results indicated that the water retention capacity of fine-grained salt rock filler increases with the decrease of initial dry density during the high suction stage. The Fredlund & Xing model is recommended to address the soil–water characteristic curve of fine-grained salt rock. The capillary action of salt rock filler decreases with increasing compaction. The temperature gradient from the upper boundary to the bottom of the soil column under the effect of freeze–thaw cycles is significant. After five freeze–thaw cycles, the water in the soil column continued to migrate upwards under the covering effect and temperature gradient. The relative humidity and temperature of the salt rock subgrade both show a sinusoidal cyclical variation. When the temperature range of salt rock subgrade is −6°C–30 °C, the relative humidity of subgrade is significantly correlated with temperature. This study can provide theoretical support for the disaster prevention and control of salt rock subgrade covering effect in the Lop Nor area.

Estimating Unsaturated Hydraulic Conductivity in Unsaturated Soil Using Soil Moisture Sensors

Unsaturated hydraulic conductivity (K) is a measurement of soil water-retaining ability in unsaturated soil. The unsaturated hydraulic properties are necessary to predict the movement of water in unsaturated soil. The current study aims to create an alternative experimental device to estimate theKusing soil moisturesensors. The experimental set up was designed and fabricated in order to measure the volumetric water content using GS3 (Campbell) sensors at different heights. The data obtained from the sensors was validated using mass of moist sand column measured from electronic balance.TheKwas estimated with the help of retention and conductivity functions. The primary materials used in the study were solute-free water and sand. It was found that the reading from the sensors was in good match with the reading of the volumetric water content calculated from the mass of water in the sand column with a root mean square error of 0.0091. Soil water retention curve and hydraulic conductivity were plotted using Peters-Durner-Iden (PDI) model.The results were compared to the van Genuchten function. TheKprediction wasinitially equivalentfor both models, but the lateroverpredicts the falling rate of hydraulic conductivity with the increasing soil matric suction before underpredict after 200 cm matric suction on a sandy soil.PDI function was able to extrapolate the hydraulic conductivity film flow region of sandy soil.

Investigation of sustainable reactive distillation process to produce malonic acid from dimethyl malonate

The new energy battery is currently a hot research topic, leading to an increase in the demand for malonic acid (MA) as a raw material. The objective of the present work is to find a potential reactive distillation (RD) process to solve the problem of low conversion and high energy consumption in hydrolytic system. In the meantime, the RD technology still faces the problem of how to distribute water in the RD column. Aiming at the problem, four different RD processes are proposed: RD combined water separation process (RDWS), RD combined with MA concentration process (RDMC), RD combined methanol separation process (RDMS), and single RD process (SRD). Beforehand, reaction kinetic of dimethyl malonate (DM) hydrolysis was investigated using the ion exchange resin catalysts, and the developed RD model was verified via pilot-scale RD experiments. Finally, the proposed RD process is analyzed from the aspects of economic and environmental and compared with the traditional reaction + distillation (R + D) process. Consequently, the proposed SRD process is a better economy-saving and environment-friendly technology, and has certain directive significance for the industrial production of MA.

Industrial experience in using cyclic distillation columns for food grade alcohol purification

This study provides novel details about the industrial use of cyclic distillation in the production of food-grade alcohol, which confirmed the theoretical predictions of increasing separation efficiency. Increasing the profitability of the production of ethanol food grade is primarily associated with an increase in product quality and reduction of energy costs per unit of production. One of the ways to solve these problems is to improve the ethanol purification technology by using cyclic distillation, which allows reduction of energy costs and higher productivity by removing impurities at a higher concentration (leading also to waste reduction). The purification of ethanol from impurities (head and intermediate type) is carried out in hydro-selection columns. Critically, the volatility of most components depends on the actual ethanol concentration on the stage. This study investigated the distribution of ethanol on the trays depending on the water feed stage to the column and showed the optimal distribution of hydro-selective water in an industrial column to allow the highest possible separation efficiency of components during cyclic distillation. A cyclic distillation column with 15 Maleta trays was superior in separation capacity and performance as compared to a traditional column with 50 bubble cap trays.

Geochemical techniques to identify fluid sources in highly pressured casing-casing annuli (CCA)

The buildup of high pressure in the casing-casing annulus (CCA) threatens well integrity and can cause serious incidents in case of left untreated. Either, trapped water in the cement column or a dynamic water inflow represent potential fluid sources for the elevated CCA pressure. This study presents a sequential methodology to determine the provenance of CCA effluent as trigger for high pressure in newly drilled wells. Single fluid types, multicomponent mixing, and secondary fluid alteration processes were identified through inorganic geochemical techniques; in detail by monitoring the hydrochemical (major, minor, and trace elements) and stable isotopic (δ2H, δ18O) relationship between fluid candidates. As a proof-of-concept, geochemical signatures of CCA effluent from three wells were linked with potential source candidates, i.e., utilized drilling fluids (mud filtrate, supply water) from the prospect well site, groundwater from Lower - Upper Cretaceous aquifers, and Upper Jurassic - Upper Triassic formation waters from adjacent wells and fields. The detection of geochemical affinities of CCA water with groundwater from a Lower Cretaceous aquifer postulates one single lithological unit as source for active groundwater inflow. Nonreactive elements (Na+, Cl−) and environmental isotopes (δ2H, δ18O) were found to be most suited tools for primary fluid identification. The 2H/1H and 18O/16O ratios of supply water and mud filtrate are generally close to global meteoric water and Tertiary groundwater composition, while formation water from Mesozoic units (Cretaceous, Jurassic, and Triassic) can individually be distinguished through increasing ratios in δ18O and δ2H. Compositional anomalies in SO42− and K+, and extreme alkaline conditions for CCA water indicate the occurrence of secondary fluid alteration processes, likely caused by the contact of inflowing groundwater with alkaline minerals in the cement column or by fluid mixing with residuals of potassium chloride (KCl) additives from the drilling process. The geochemical techniques from this study facilitate the detection of high CCA pressure and fluid leakages sources. As a practical benefit, workover engineers are enabled to plan for potential remedial actions prior to moving the rig to affected well sites; thereby significantly reducing operational costs. Appropriate remedial solutions can be induced for safe well abandonment, plus to resume operation at the earliest time.

Modelling of removal of surfactants from liquid solutions in a bubble column

This paper proposes a theoretical model for the separation of a surfactant from water in a bubble column. The proposed model includes both mass balance and adsorption thermodynamics of surfactants on bubble surfaces in the liquid solution (e.i. surface equations of state and adsorption isotherms). This is very important because models, found in the literature, did not consider adsorption thermodynamics. The proposed model successfully predicted the experimental results. It was found that the separation efficacy was higher at a lower surfactant concentration in the liquid than that at a higher surfactant concentration; the reason is probably that available bubble surface areas for adsorption of the surfactant were higher at a lower surfactant concentration. A higher cross-sectional area of the column led to a better separation performance due to a larger amount of generated bubble surfaces. A low gas flow rate and low liquid fraction resulted in the best separation performance.

The transport of water in a cellulose foam

A novel experimental protocol and analysis technique is developed to determine whether water rise in a cellulose foam is by capillary flow alone, or is by capillary flow followed by diffusion. The literature is divided in the interpretation of the water rise versus time characteristic in the foam, and our study suggests that capillary flow dominates. The present study reveals that the foam can be idealised as a spectrum of individual capillary tubes; the probability density function of tube radius is obtained from a systematic set of siphon discharge experiments on inverted U-tubes made from the foam. We show that the capillary tube radii range from 0.1μm to 100μm, with two distinct peaks in probability density at 0.5μm and 10μm. The nature of the flow within the U-tube is confirmed by interrupting a siphon experiment and measuring the density profile along the length of the inverted U-tube by in-situ X-ray computed tomography. The probability density function is then used to predict the transient rise of water in a vertical column of dry foam.

The Effect of Magnetized Water with Certain Intensities on Salts Leaching Efficiency from Agricultural Soils

Two saline soils taken from two sites inside the Mosul city of (mrs1, mrs2), and two types of water, drinking water and well water, were exposed to two magnetic strengths (4000,2000) gauss, and three transparent cylinders with a diameter of 140 mm and a height of 500 mm were used. The leaching process continued until infiltration of 5 liters of water with twice repetition for each condition with stability of soil conditions (moisture, bulk density) and temperature difference in each experiment. The results showed a decrease in the electrical conductivity EC of the soil paste extract, which reached (75.7, 90.5) % for mrs2 soil, which is the most saline for Washing with an intensity of 4000 gauss for (drinking, well) water respectively. The percentage of salts in the leaching water increased, and the distribution and concentration of salts increased with the progression of water in the soil column, in addition to the decrease in the concentrations of salt ions such as sodium and sulfate by increasing Magnetization intensity and less leaching for a longer period of time, especially for well water.

Water and salt transport characteristics in a soil column in the presence of a low-permeable body

Soil water infiltration is an important factor affecting surface runoff, soil erosion, and soil solute transmission. Increasing soil infiltration reduces runoff and erosion. The presence of low-permeable body in soil can enhance soil infiltration capacity. However, different depths of low-permeable body have unknown effects on water infiltration and salt transfer. In this work, we evaluated the effects of low-permeable body with varied depths (control (CK), 0, 0.5, 1, and 1.5 cm) on silty loam soil water and salt movement using 15 soil columns (23 cm internal diameter, 50 cm length). Experimental results showed that low-permeable body increased infiltration rate and wetting front migration rate. Infiltration rate and wetting front propulsion rate decreased with the increase of the burial depth. Compared with the CK, when the depth of wetting front reached 20 cm, the infiltration time of 0, 0.5, 1, and 1.5 cm burial depth treatment was shortened by 72.24%, 56.29%, 44.61%, and 31.01%, respectively. Simultaneously, the existence of low-permeable body led to the increase of soil water content and salt content in the same soil layer, which indicated that the low-permeable body enhanced the soil holding capacity and reduced the salt leakage to the deep soil. Furthermore, the Philip’s model and the algebraic model were used to describe the infiltration process. Fitting results showed that the sorptivity in the Philip’s model increased with burial depth, while the comprehensive shape coefficient in the algebraic model decreased. Therefore, this study provides a reference for the application of low-permeable body in the improving soil infiltration capacity and controlling salt transport.

Determination of eugenitin in mouse blood by ultra-performance liquid chromatography-tandem mass spectrometry and its application to a pharmacokinetic study

Abstract Eugenitin is a non-volatile chromone derivative which is always found in dried flower buds of Syzygium aromaticum L. (Merr.) &amp; L.M. Perry. Until now, there were no reports about the pharmacokinetics of eugenitin in biological fluids. A UPLC-MS/MS method developed to determine eugenitin in mouse blood. The blood samples were prepared by protein precipitation with acetonitrile. Chrysin (internal standard, IS) and eugenitin were gradient eluted by mobile phase of acetonitrile and water (0.1% formic acid) in a BEH C18 column. The multiple reaction monitoring (MRM) of m/z 221.1→206.0 for eugenitin and m/z 255.1→152.9 for IS with an electrospray ionization (ESI) source was used for quantitative detection. The calibration curve ranged from 0.5 to 500 ng/mL (r &gt; 0.995). The accuracy ranged from 98 to 113%, the precision was less than 12%, and the matrix effect was between 86 and 94%, the recovery was better than 81%. The developed method was successfully used for pharmacokinetics of eugenitin in mice after intravenous (5 mg/kg) and oral (20 mg/kg) administration, and the absolute availability of eugenitin was 12%.

Optimization of fractional distillation column in crude oil refinery using artificial neural network

The paper outlines the methods, which improve the controlling process of separating methanol from water in the distillation column to produce crude oil products. Nowadays, many industries use PID controllers to control process variables like temperature, flow, pressure, level, which helps maintain good performances. However, PID controllers can have slightly bad performances in complicate control systems, such as in Multiple Input and Multiple Output (MIMO) systems; due to this, optimization methods of improving PID are considered. А tremendous amount of work has been done rеfіnіng, study in gаnd imprоvіng the PID controlling techniquesand methods. However, PID still faces challenges in a variety of common control problems. This article represents Nеural Nеtwork Algоritm bаsеd PID cоntrollеr, whіchіsusеdtоcоntrоlthе separating process of methanol from water in the distillation column, due to Nеuralnеtwork’s good generalization results. The Wood and Berry mathematical Model was chosen as the main control object.

A comprehensive study on the applicability of tea leaves and rice straw as novel sorbents for iron and manganese removal from running water in a fixed-bed column

A comprehensive study on the applicability of tea leaves and rice straw as novel sorbents for iron and manganese removal from running water in a fixed-bed column