Water Removal Rate Research Articles

An Interactive Analysis of Influencing Factors on the Separation Performance of the Screw Press

In order to optimize the separation performance of the screw press and enable its water removal rate and production to meet the production requirements, the influencing rule of the interactive effect of multi-factor parameters on its separation performance was studied by numerical simulation and experimental means. The internal flow field of the screw press was simulated by Fluent software. The rotation speed of the screw axis, back pressure of the slag outlet, and initial water content were taken as influencing factors, and the water removal rate and production were taken as objective functions. The Box–Behnken method was used to analyze the influencing rules of the interactive factors on the water removal rate and production. The results show that the significant factors affecting the water removal rate of the screw press are in the following order: initial water content > back pressure > rotation speed. The significant factors affecting screw press production are in the following order: rotation speed > back pressure > initial water content. The optimal combination of process parameters for the screw press is an initial water content of 55%, a screw axis rotation speed of 30 r/min, and a 5 kPa back pressure at the slag outlet. The water removal rate of 48.9% and production of 234.2 kg/d were obtained.

Study of Physico-Chemical Properties of Dough and Wood Oven-Baked Pizza Base: The Effect of Leavening Time

The research objective was to investigate the morpho-rheological, chemical, and structural changes of dough and Neapolitan pizza TSG as the leavening time varies and to evaluate their effects on the digestibility of starch and on the formation of acrylamide during baking. Pizza dough leavening was monitored for 48 h at 22 °C/80% RH, and the analyses were conducted at selected leavening times (0, 4, 8, 16, 24, and 48 h). It was observed that in 30 h the volume tripled and the viscoelastic dough relaxed in the first 4 h, as evidenced by the lower value of the relaxation percentage "a" and the higher rate of decay "b", associated with a high value of the compression work, indicating the presence of a very strong gluten mesh. In the following hours, the dough lost elasticity, and in fact, the G' modulus decreased due to the weakening of the weak interactions between the gluten proteins and the starch. This suggests that a long leavening improved the extensibility of the pizza disc, facilitating the action of the pizza maker. Thermal (TGA and DSC) and morphological (SEM) analyses evidenced the highest water removal rate from the dough, a wider starch gelatinization temperature range, a ∆H of 0.975 ± 0.013 J/g, and a more open and weak gluten structure in dough balls leavened for 16 h. As the leavening time increased, both dough and pizza base samples showed an increase in reducing sugars and free amino groups, while the rapidly digestible starch decreased in the dough following the metabolism of the yeasts and increased in the pizza base due to the starch gelatinization that occurs during baking, which makes it much more susceptible to α-amylase. Finally, the levels of acrylamide remained at the same values despite the higher availability of reducing sugars and its precursors during leavening.

Changes in blood pressure and arterial stiffness monitored using the cardio-ankle vascular index during hemodialysis.

During hemodialysis (HD), blood pressure (BP) changes are frequently observed. However, the mechanism of BP changes during HD has not been fully clarified. The cardio-ankle vascular index (CAVI) reflects the arterial stiffness of the arterial tree from the origin of the aorta to the ankle independent from BP during measurement. Additionally, CAVI reflects functional stiffness in addition to structural stiffness. We aimed to clarify the role of CAVI in regulating the BP system during HD. We included 10 patients undergoing 4-hour HD (total 57 HD sessions). Changes in the CAVI and various hemodynamic parameters were evaluated during each session. During HD, BP decreased and CAVI significantly increased (CAVI, median [interquartile range]; 9.1 [8.4-9.8] [0min] to 9.6 [9.2-10.2] [240min], p < 0.05). Changes in CAVI from 0min to 240min were significantly correlated with water removal rate (WRR) (r = -0.42, p = 0.002). Changes in CAVI at each measurement point were negatively correlated with ΔBP (Δsystolic BPeach MP, r = -0.23, p < 0.0001; Δdiastolic BPeach MP, r = -0.12, p = 0.029). Whereas one patient exhibited a simultaneous decrease in BP and CAVI during the initial 60min of HD. Arterial stiffness monitored with CAVI generally increased during HD. CAVI elevation is associated with decreased WWR and BP. An increase in CAVI during HD may reflect the contraction of smooth muscle cells and play an important role in BP maintenance. Hence, measuring CAVI during HD may distinguish the cause of BP changes.

Photothermally enhanced hollow gold nanopigment for water evaporation and sterilization achieved via a photothermal effect

Humidity management in indoor environments, achieved through the application of antimicrobial coatings, is an important and significant component that influences human behavior in such environments. Recently, nanotechnology has been widely used for humidity management in the construction industry, by improving and functionalizing existing materials. However, when a humidity control material or novel nanocoating agent was applied, the water removal rate from the walls, particularly the painted surface, was not good. Therefore, in this study, a photothermally enhanced hollow gold nanopigment was prepared as an indoor humidity controller with sterilization capabilities. The photothermal effect of metal nanoparticles caused by the localized surface plasmon resonance (LSPR) is essentially a light-heat conversion mechanism, in which heat is created around nanoparticles (NPs) owing to their light absorption. In this study, hollow gold nanoparticles (HAuNPs) were synthesized, and they demonstrated a comparatively high photothermal performance under near-infrared light (NIR) irradiation. Subsequently, they were blended with paint to test their suitability for pigment and heat-generation performance. In a water evaporation test, under NIR irradiation, water droplets (10 μL) on the surface of the HAuNPs@paint_8 wt% evaporated entirely after 180 s, with evaporation rates of 400 g/m2·h. In a photothermal sterilization test performed with Escherichia coli on a wetted painted surface, colony growth was noticeably reduced by approximately 99%. These findings demonstrate that the HAuNP nanopigment can be used in applications in which a particularly high temperature must be maintained continuously to prevent bacterial development and manage humidity.

Non-thermal treatments for the control of endogenous formaldehyde from Auricularia auricula and their effects on its nutritional characteristics

To control endogenous formaldehyde (EFA) from Auricularia auricula and preserve its nutritional properties, we selected various non-thermal treatments and evaluated their effects on the removal of EFA, inhibition of γ-glutamyl transpeptidase and l -cysteine sulfoxide lyase activities, and bioactive ingredients (i.e., principal nutrients, including vitamins and taste substances). The results showed that single and co-non-thermal treatments (US-EW, IPL-EW) reduced the EFA content of A. auricula to varying degrees. Correlation and principal component analyses showed that synergistic treatment with ultrasound and electrolyzed water (US-EW) significantly reduced EFA (removal rate = 40.54%), with relatively small losses of other chemical components. The second best was treatment with intense pulsed light and electrolyzed water (IPL-EW) (removal rate = 36.27%). We constructed and validated a kinetic model for EFA removal using the US–EW treatment, and fitted a second-order kinetic equation. The optimal process parameters were as follows: ultrasound (US) frequency: 50 kHz, US power: 100 W, and available chlorine concentration of EW: 35 mg/L. These results were verified and can serve as a reliable technical reference to improve safety during the processing and preservation of edible fungi. • US-EW has the highest removal rate of EFA (40.54%). • The removal of EFA via US-EW confirmed the second-order reaction kinetic. • The optimal processing parameters for US-EW removal of EFA have been obtained. • US-EW causes the least loss in nutritional quality of A. auricula .

Study on city tail water treatment in constructed wetland with straw biochar substrate modified by freeze–thaw cycles

The preparation of biochar is one of the important directions to realize the high-value resource utilization of straw. Constructed wetland (CW) has low cost and high efficiency in treating city tail water. In order to improve the purification rate of CW with straw biochar for city tail water, freeze–thaw cycles (FTCs) modification of straw biochar and the application of FTCs-modified biochar in CW were studied. The relatively optimal modification condition of biochar was eight FTCs. The adsorption of CO 2 on eight FTCs-modified biochar was increased by more than 20%. Biochar modified by eight FTCs was used as the CW substrate to promote denitrification, and the nitrate nitrogen (NO 3 − N) mean removal rate of city tail water was exceeded 85%. The eight FTCs-modified biochar reduced the impact on the electrical conductivity of city tail water. The carbon sequestration rate of eight FTCs-modified biochar reached 55.6%. The research results will be helpful to realize the straw carbon sequestration, improve the performance of biochar and the treatment effect of CW on city tail water. • The modification effect of biochar was the best when the number of FTCs was 8 times. • Eight FTCs modified biochar promoted nitrification in CW with plants. • TP removal rate increment exceeded 15% in CW with FTCs-modified biochar and plants. • The FTCs reduced the soluble components of biochar, so the EC was reduced.

Biodrying with the hot-air aeration system for kitchen food waste.

Biodrying is a promising method that produces bio-stabilized output with minimum pretreatment requirements. In this study, a hot-air supply system was added to the traditional biodrying process for kitchen waste, which showed significant reduction in moisture content in 5 days (maximum reduction of 37.45%). A series of experiments was conducted to optimize the hot-air biodrying system utilizing different aeration rates, temperatures, and mixing ratios of feedstock to bulking agents. The results showed that a 65°C aeration temperature led to the highest water removal rate and low volatile solids consumption rate, with the biodrying index reaching 4.9g water per gram of volatile solids. On the other hand, evaluation of the overall biodrying efficiency based on the weight loss and bio-stabilization showed that intermittent aeration temperature at 55°C performed best, offering suitable conditions for water evaporation and bio-degradation. In combination with a flow rate of 0.8L/kg*min and 1:1 mixing ratio, these conditions resulted in the maximum volatile solids consumption of 26.26% in 5 days. The volatile solids consumption and 34.47% water removal rate of the trial had contributed to a total of 64.13% weight loss. The weight loss was even higher than that of a conventional biodrying system which was conducted for more than 14 days.

Numerical and experimental investigation of desiccant cooling system using metal organic framework materials

• Modelling of stationary desiccant wheel coated with different metal organic framework adsorbent materials (MIL-100(Fe), MIL101(Cr), CPO-27(Ni), Aluminium fumarate). • Develop new equilibrium equations from the isotherms related to these MOFs. • New experimental data and numerical data for stationary honeycomb desiccant wheel coated with Aluminium Fumarate was generated. • MOF materials coating process and performance comparisons with different humidifier air speeds. Evaporative cooling consumes fraction of the electricity required by the vapour compression refrigeration system but is only effective in dry weather conditions. A promising method for controlling the incoming air humidity is to use a desiccant wheel before the evaporative cooler. Currently, most desiccant cooling systems employ conventional materials like silica gel or zeolites which have low water uptake. Metal Organic Framework (MOF) materials are new class of meso -porous material with high water adsorption capabilities (∼1.5 kg/kgads). Using numerical modelling and experimental testing, this paper investigates the use of four MOF materials namely CPO27(NI), MIL100(Fe), MIL-101(Cr), Aluminium Fumarate and silica gel on the performance of a stationary desiccant heat exchanger (honeycomb Aluminium structure coated with MOF desiccant material) in terms of the Coefficient of performance (COP) and moisture removal rate. Numerical results showed that Aluminium fumarate produced the highest COP of 0.65 with water removal rate of 12.65 g/kg dry air and MIL-101(Cr) produced the highest moisture removal of 15.99 g/kg dry air but with COP of 0.44 compared to silica gel and other MOF materials used. Experimental tests were carried out using honeycomb structure coated with Aluminium fumarate as the stationary desiccant wheel and results were compared to numerical modelling showing good agreement with maximum deviation of 13%. Experimental and modelling results showed that the rate of moisture removal increases with the increase of air inlet humidity and with the decrease of incoming air speed. Also, results showed that the highest moisture removal occur after the first 2 min from starting the dehumidification process highlighting the advantage of using MOF materials.

Establishment of electrochemical treatment method to dye wastewater and its application to real samples

It is of great significance to study the treatment of organic dye pollution. In this work, a method of electrochemical treatment for reactive blue 19 dye (RB19) wastewater system was established, and it was applied to the actual dye wastewater treatment. The effects of applied voltage, electrolyte concentration, electrode spacing, and initial concentration on the removal effect of RB19 have been studied in detail. The results show that the removal rate of RB19 can reach 82.6% and the chemical oxygen demand (CODcr) removal rate is 54.3% under optimal conditions. The removal of RB19 in the system is mainly the oxidation of hydroxyl free radicals. The possible degradation pathway is inferred by ion chromatography: hydroxyl free radicals attack the chromophoric group of RB19 to make it fall off, and then decompose it into ring-opening. The product is finally oxidized to CO2 and water. The kinetic fitting is in accordance with the zero-order reaction kinetics. At the same time, using the established electrochemical system to treat the actual dye wastewater has also achieved good results. After 3 hours of treatment, the CODcr removal rate of the raw water is 44.8%, and the CODcr removal of the effluent can reach 89.5%. The degradation process conforms to the zero-order reaction kinetics. The result is consistent with the electrochemical treatment of RB19.

Preparation of a demulsifier for oily wastewater using thorn fir bark as raw materials via a hydrothermal and solvent-free amination route.

In current work, a TB-EDA demulsifier for disposing oily wastewater was prepared using thorn fir bark (TB) as starting materials via a hydrothermal and solvent-free amination route. Field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectrometer (EDS), and Fourier transform infrared spectroscope (FT-IR) were employed to characterize the TB-EDA demulsifier. Three-phase contact angle (CA), interfacial activity, formation of interfacial film (FIF), coalescence time of droplets (CTD), dynamic interfacial tension (IFT), and Zeta potential were carried out to study the possible demulsification mechanism. Bottle test was performed to investigate the effect of the TB-EDA dosage, salinity, and pH value on the demulsification performance at room temperature. Light transmittance (DL) and oil removal rate (DR) of separated water were 94.7% and 97.2%, respectively, with 100mg/L of TB-EDA demulsifier in oily wastewater at room temperature. In addition, the TB-EDA demulsifier has an excellent salt tolerance even at the salinity of 50,000mg/L. The corresponding DL and DR could reach 99.8% and 99.9%, respectively.

Mathematical Models to Describe the Foam Mat Drying Process of Cumbeba Pulp (Tacinga inamoena) and Product Quality

The present study investigated the mathematical modeling foam-mat drying kinetics of cumbeba pulp and the effect of drying conditions on the color and contents of ascorbic acid, flavonoids, and phenolic compounds of the powder pulps obtained. Foam-mat drying was carried out in a forced air circulation oven at temperatures of 50, 60, and 70 °C, testing foam-mat thicknesses of 0.5, 1.0, and 1.5 cm. The increase in the water removal rate is a result of the increase in air temperature and the decrease in the thickness of the foam layer. Among the empirical and semi-empirical mathematical models, the Midilli model was the one that best represented the drying curves in all conditions evaluated. Effective water diffusivity ranged from 1.037 × 10−9 to 6.103 × 10−9 m2 s−1, with activation energy of 25.212, 33.397, and 36.609 kJ mol−1 for foam thicknesses of 0.5, 1.0, and 1.5 cm, respectively. Cumbeba powders showed light orangish colors and, as the drying temperature increased from 50 to 70 °C, for all thicknesses, the lightness value (L*) decreased and the values of redness (+a*) and yellowness (+b*) increased. Foam-mat drying at higher temperatures (60 and 70 °C) improved the retention of ascorbic acid and flavonoids, but reduced the content of phenolic compounds, while the increase in thickness, especially for flavonoids and phenolic compounds, caused reduction in their contents. The foam-mat drying method allowed obtaining a good-quality cumbeba pulp powder.

Efficient degradation of semi-coking wastewater in three-dimensional electro-Fenton by CuFe2O4 heterocatalyst.

Semi-coking wastewater contains a rich source of toxic and refractory compounds. Three-dimensional electro-Fenton (3D/EF) process used CuFe2O4 as heterocatalyst and activated carbon (AC) as particle electrode was constructed for degrading semi-coking wastewater greenly and efficiently. CuFe2O4 nanoparticles were prepared by coprecipitation method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy disperse spectroscopy (EDS). Factors like dosage of CuFe2O4, applied voltage, dosage of AC and pH, which effect COD removal rate of semi-coking waste water were studied. The results showed that COD removal rate reached to 80.9% by 3D/EF process at the optimum condition: 4V, 0.3g of CuFe2O4, 1g of AC and pH = 3. Trapping experiment suggesting that hydroxyl radical (•OH) is the main active radical. The surface composition and chemical states of the fresh and used CuFe2O4 were analyzed by XPS indicating that Fe, Cu, and O species are involved into the 3D/EF process. Additionally, anode oxidation and the adsorption and catalysis of AC are also contributed to the bleaching of semi-coking waste water. The possible mechanisms of 3D/EF for degrading semi-coking waste water by CuFe2O4 heterocatalyst were proposed.

Role of a physisorbed collecting agent in flotation of pyrite

The article addresses the role of products of interaction between xanthate and iron ions in flotation of pyrite at different pH values. It is shown that derivatives of butyl xanthate and iron chloride feature a high spreading rate at the gas-liquid interface and can contribute to removal of the kinetic constraint of the particle-bubble attachment. The effect on the rate of water removal from the interlayer between a mineral particle and a gas bubble depends on the ratio of concentrations and on pH values of the solution. The mechanism of physisorption of a collecting agent is used to explain the suppression of pyrite flotation in a pH-neutral medium and the increased floatability of pyrite in the alkaline range of pH.

Diethylenetriamine modified biological waste for disposing oily wastewater

Oily wastewater produced in the process of oil extraction has a potential threat to the environment. In this paper, diethylenetriamine was used to modify rice straw powder (RSP) by a solvent-free strategy, and the obtained product (AM-RSP) was utilized to dispose oily wastewater. AM-RSP was characterized by Field emission scanning electron microscope (FE-SEM), energy dispersive spectrometer (EDS), Fourier transform infrared spectroscope (FT-IR) and BET. The factors affecting the demulsification performance (DP) such as dosage, salinity and pH value were detailly investigated. The results indicated that light transmittance (ET) and oil removal rate (ER) of separated water could reach 93.5% and 96.5%, respectively, within 40 min with 150 mg/L of AM-RSP at room temperature. Also, AM-RSP had a good salt resistance. In addition, three-phase contact angle (TCA), formation of interfacial film, interfacial activity, dynamic interfacial tension (IFT), coalescence time of droplets and zeta potential were adopted to probe the demulsification mechanism.

Screening and Demulsification Mechanism of Fluorinated Demulsifier Based on Molecular Dynamics Simulation.

In order to solve the problem of demulsification difficulties in Liaohe Oilfield, 24 kinds of demulsifiers were screened by using the interface generation energy (IFE) module in the molecular dynamics simulation software Materials Studio to determine the ability of demulsifier molecules to reduce the total energy of the oil–water interface after entering the oil–water interface. Neural network analysis (NNA) and genetic function approximation (GFA) were used as technical means to predict the demulsification effect of the Liaohe crude oil demulsifier. The simulation results show that the SDJ9927 demulsifier with ethylene oxide (EO) and propylene oxide (PO) values of 21 (EO) and 44 (PO) reduced the total energy and interfacial tension of the oil–water interface to the greatest extent, and the interfacial formation energy reached −640.48 Kcal/mol. NNA predicted that the water removal amount of the SDJ9927 demulsifier was 7.21 mL, with an overall error of less than 1.83. GFA predicted that the water removal amount of the SDJ9927 demulsifier was 7.41mL, with an overall error of less than 0.9. The predicted results are consistent with the experimental screening results. SDJ9927 had the highest water removal rate and the best demulsification effect. NNA and GFA had high correlation coefficients, and their R2s were 0.802 and 0.861, respectively. The higher R2 was, the more accurate the prediction accuracy was. Finally, the demulsification mechanism of the interfacial film breaking due to the collision of fluorinated polyether demulsifiers was studied. It was found that the carbon–fluorine chain had high surface activity and high stability, which could protect the carbon–carbon bond in the demulsifier molecules to ensure that there was no re-emulsion due to the stirring external force.

A 3D Janus stainless steel mesh bed with high efficiency and flux for on-demand oil-in-water and water-in-oil emulsion separation

Janus materials with asymmetric wettability have attracted wide attention in oil/water separation due to the ability to remove water or oil on demand. In this work, a Janus stainless steel mesh (SSM) combining superhydrophilicity and high hydrophobicity was prepared through in-situ growth of polydopamine (PDA) and SiO2, phase interface deposition of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (PFOTS) on one side and floating deposition of polydopamine/polyethyleneimine (PDA/PEI) on the other side. Relying on the unidirectional water transportation ability, the Janus SSM could efficiently separate light/heavy oil/water mixtures on demand with a water removal rate of 7000 L·m−2·h−1 and an oil removal rate of 46,000 L·m−2·h−1. Based on this, a three-dimensional (3D) Janus SSM bed was designed by controllable assembling single piece of Janus SSM and 20 pieces of superhydrophilic SSM with in situ grown PDA@SiO2 nanoparticles (PDA@SiO2 SSM). The 3D Janus SSM bed showed excellent emulsion separation ability due to its long irregular permeation channels to make emulsified liquid droplets continuously collide, agglomerate and demulsificate. For oil-in-water emulsion, the separation efficiency could reach 99.31% and the flux was higher than 2864 L·m−2·h−1. For water-in-oil emulsion, the separation efficiency was over 99.68% and the permeation flux could reach 7072 L·m−2·h−1. With these excellent performances, the 3D Janus SSM bed was believed to be able to bring important contributions to the modern industrial oil/water separation process.

Modelling and simulation of food waste bio-drying

Bio-drying of food waste is an attractive aerobic treatment method for moisture removal and producing refuse-derived fuel (RDF) beneficial for waste utilization as an energy source. Understanding the mechanism of process and interaction of key variables is necessary for optimizing the parameters to improve the water removal rate. In the present study, an attempt was made to develop mass and energy balances using the first principles to predict the variation of key variables namely concentration of degradable matter, moisture, oxygen concentration, and temperature based on process kinetics. The simulation of the developed first-order ordinary differential equations combined for three horizontal layers of the waste pile was carried out using Simulink software in MATLAB R2020b interface. The predicted output was compared with experimental data of the pilot-scale plant for food waste with different municipal solid waste components including paper and plastic and with literature data for food waste with a bulking agent (BA). A good prediction of bio-drying performance was achieved using the proposed model and the experimental data.

Effects of Water Removal from Palm Oil Reactant by Electrolysis on the Fuel Properties of Biodiesel

Biodiesel, which is composed of mono-alkyl esters of long carbon-chained fatty acids, is used as an alternative fuel to petro-diesel. The water content of the reactant mixture of feedstock oil influences the extent of transesterification and thus the fuel characteristics. Lower water content in feedstock oil is generally suggested for successful transesterification. This experimental study removed water from the reactant mixture of feedstock palm oil and methanol during transesterification using various systems composed of either electrodes or molecular sieves with rotary vibration. The effect of input electrical energy, number of electrodes, vibration modes, and operating time on the amount of water removed from the reactant mixture and the fuel properties of the final biodiesel product were analyzed and compared with those achieved using molecular sieves. The results show that the biodiesel—after water was removed during transesterification—appeared to have increased kinematic viscosity, cetane index, distillation temperature, and acid value, while the heating value, flash point, ignition point, and water content decreased with an increase in the input electrical energy of the electrodes responsible for electrolyzing water away. Electrolysis by the double-pair electrodes was more effective at reducing acid value and water content than that performed by the single-pair electrodes under the same input electrical energy. The biodiesel was found to have the lowest water content (0.0304 wt.%) and the highest water-removal rate (0.011 wt.%) when water was removed during transesterification by the double-pair electrodes with an input electrical energy of 9 J/(g palm oil). The water-removal rate of the rotary-vibrating molecular sieves was 11.24 times that of the single-pair electrodes. The biodiesel was found to have increased kinematic viscosity with higher input electrical energy, reaching 5.15 mm2/s when the double-pair electrodes with an input electrical energy of 11 J/(g palm oil) were used. Longer carbon-chained fatty acids, ranging from C20 to C24, amounted to 0.74 wt.% of the biodiesel produced using the double-pair electrodes, which was greater than that seen for the single-pair electrodes. However, the molecular sieve method consumed more energy than the double-pair electrodes did to remove the same amount of water from the palm oil reactant mixture via transesterification.

Choice of Pipe Material Influences Drain Spacing and System Cost in Subsurface Drainage Design

HighlightsFor 3- or 4-row regular-perforated pipes, the effective radius ranged from 0.3 to 0.9 cm (average 0.6 cm).For 8-row regular-perforated pipes, the effective radius was 1.9 cm.The effective radius of sock-wrapped pipes ranged from 5.7 to 6.0 cm (average 5.9 cm).The 8-row sand-slot pipes had a lower initial system cost than the sock-wrapped pipes.The 8-row regular-perforated pipes had a lower initial system cost than the 4-row regular-perforated pipes.Abstract. Knitted-sock envelopes are applied in agricultural subsurface drainage to prevent sediment clogging of the drain pipes. In the United States and Canada, sand-slot pipes are sometimes used as a cheaper alternative to sock-wrapped pipes. However, their initial system cost has not been compared. The main objective of this study was to evaluate the effect of pipe material on drain spacing and initial system cost. First, the theoretical effective radius of each pipe material was estimated. Then, the drain spacing was calculated for each pipe material in a drainage design, such that each pipe would provide the same design drainage rate (i.e., same water removal rate). The results showed that the effective radius of sock-wrapped pipes (average 5.9 cm) was much greater than that of 4-row (average 0.4 cm) and 8-row perforated sand-slot pipes (average 1.6 cm). Rows refer to number of longitudinal rows of perforations. The sock-wrapped pipes considerably increased the effective radius of the pipe by reducing the entrance head loss. Furthermore, the sock-wrapped pipes allowed for a wider drain spacing (ranging from 0.8 to 5.4 m wider) in soil with risk of drain sedimentation, thereby reducing the total length of the lateral drain pipe needed for drainage design compared to both 4- and 8-row sand-slot pipes. The 8-row regular-perforated pipes allowed for a wider optimum drain spacing, thereby reducing the initial system cost in soil without a drain sedimentation issue compared to 4-row regular-perforated pipes. In conclusion, even though the sock-wrapped pipe reduced the total length of the lateral drain pipe, the 8-row sand-slot pipe had a lower initial system cost compared to the sock-wrapped pipe, when designed at the same design drainage rate and drain depth. Keywords: Drain spacing, Effective radius, Entrance resistance, Geotextile, Knitted sock, Perforation.

In situ investigation of water on MXene interfaces

A continuum of water populations can exist in nanoscale layered materials, which impacts transport phenomena relevant for separation, adsorption, and charge storage processes. Quantification and direct interrogation of water structure and organization are important in order to design materials with molecular-level control for emerging energy and water applications. Through combining molecular simulations with ambient-pressure X-ray photoelectron spectroscopy, X-ray diffraction, and diffuse reflectance infrared Fourier transform spectroscopy, we directly probe hydration mechanisms at confined and nonconfined regions in nanolayered transition-metal carbide materials. Hydrophobic (K+) cations decrease water mobility within the confined interlayer and accelerate water removal at nonconfined surfaces. Hydrophilic cations (Li+) increase water mobility within the confined interlayer and decrease water-removal rates at nonconfined surfaces. Solutes, rather than the surface terminating groups, are shown to be more impactful on the kinetics of water adsorption and desorption. Calculations from grand canonical molecular dynamics demonstrate that hydrophilic cations (Li+) actively aid in water adsorption at MXene interfaces. In contrast, hydrophobic cations (K+) weakly interact with water, leading to higher degrees of water ordering (orientation) and faster removal at elevated temperatures.