Flow rate dependent transport of Fluopyram in saturated sandy soil

2020 ◽  
Author(s):  
Mariana Vasconcelos Barroca ◽  
Gilboa Arye ◽  
Zeev Ronen
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Sandy Soil ◽  
Goodness Of Fit ◽  
Soil Column ◽  
Breakthrough Curves ◽  
Low Flow ◽  
Special Focus ◽  
Irreversible Adsorption ◽  
Pulse Input

<p>Velum<sup>®</sup> is a novel contact nematicide with Fluopyram (FL) as active ingredient. Knowledge on its adsorption and transport characteristics is essential for both agricultural and environmental considerations. The main objective of this study was to quantify the transport characteristics of FL in a sandy soil from a non-cultivated area in Arava region, Southern Israel, with a special focus on the behavior in soil after drip application. In this regard, soil column transport experiments under saturated water flow conditions were conducted. In addition to FL, the transport experiments were performed with a bromide tracer. Four factors were examined: (i) pulse concentration, (ii) water flux (ii) pulse size and (iv) interrupted flow. Equilibrium adsorption isotherms were measured by batch experiments. The established breakthrough curves (BTCs) were analyzed with the convection–dispersion equation (CDE) in its chemical equilibrium and non-equilibrium forms. In addition, the validity of a two-site kinetics model was evaluated. All models were examined with and without a term, assuming irreversible sorption. The bromide BTCs were adequately fitted by analytical solutions of the equilibrium CDE using the CXTFIT code, suggesting that physical equilibrium is prevailing. The FL BTCs were fitted with two-site sorption and two kinetic sites models using HYDRUS-1D code. The experimental mass balance analysis demonstrated that the bromide mass was fully recovered, while only part of total FL applied was recovered, in particular, at low flow rate. The comparison between non-interrupted and interrupted water flow demonstrated that at a given flow rate, during the pulse input, the two BTCs are identical. However, following the flow interruption (60 hours), when the flow resumed, a sharp decrease could be observed in FL concentration. Thereafter, the two BTCs are re-converged, exhibiting similar desorption behavior. Possible explanations for FL transport characteristics seems to be low kinetics desorption and/or irreversible adsorption. Additional quantitative insights from the numerical analysis will be presented and discussed based on the goodness of fit and optimized parameters of each model.   </p>

scholarly journals Effect of Flow Rate and Particle Concentration on the Transport and Deposition of Bare and Stabilized Zero-Valent Iron Nanoparticles in Sandy Soil

2019 ◽  
Vol 11 (23) ◽  
pp. 6608
Author(s):  
Ibrahim ◽  
Awad ◽  
Al-Farraj ◽  
Al-Turki
Keyword(s):  
Flow Rate ◽  
Sandy Soil ◽  
Particle Deposition ◽  
Particle Concentration ◽  
Soil Column ◽  
Relative Concentration ◽  
Methyl Cellulose ◽  
Maximum Flow ◽  
Breakthrough Curves ◽  
Zero Valent Iron

Efficient application of nanoscale zero-valent iron (nZVI) particles in remediation processes relies heavily on the ability to modify the surfaces of nZVI particles to enhance their stability and mobility in subsurface layers. We investigated the effect of sodium carboxy-methyl-cellulose (CMC) polymer stabilizer, pH, particle concentration, and flow rate on the transport of nZVI particles in sand columns. Breakthrough curves (BTCs) of nZVI particles indicated that the transport of nZVI particles was increased by the presence of CMC and by increasing the flow rate. The relative concentration (RC) of the eluted CMC–nZVI nanoparticles was larger at pH 9 as compared to RC at pH 7. This is mainly attributed to the increased nZVI particle stability at higher pH due to the increase in the electrostatic repulsion forces and the formation of larger energy barriers. nZVI particle deposition was larger at 0.1 cm min-1 flow due to the increased residence time, which increases the aggregation and settlement of particles. The amount of CMC–nZVI particles eluted from the sand columns was increased by 52% at the maximum flow rate of 1.0 cm min-1. Bare nZVI were mostly retained in the first millimeters of the soil column, and the amount eluted did not exceed 1.2% of the total amount added. Our results suggest that surface modification of nZVI particles was necessary to increase stability and enhance transport in sandy soil. Nevertheless, a proper flow rate, suitable for the intended remediation efforts, must be considered to minimize nZVI particle deposition and increase remediation efficiency.

The Effects of Low Flow Rate Gas Involvement on Oil-Water Flow in Horizontal Pipes

2011 ◽  
Vol 354-355 ◽  
pp. 41-44
Author(s):  
Hai Qin Wang ◽  
Lei Zhang ◽  
Yong Wang ◽  
De Xuan Li
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Flow Characteristics ◽  
Considerable Effect ◽  
Low Flow ◽  
Horizontal Pipes ◽  
Test Loop ◽  
Three Phase Flow ◽  
Oil Water ◽  
Low Flow Rate

The experiments were conducted in a horizontal multiphase flow test loop (50mm inner diameter, 40m long) to investigate the flow of oil/water and the influence of an involved gas phase with low flow rate in horizontal pipes, specifically including oil/water flow patterns, cross-section water holdup and pipe flow pressure gradient. The experimental results indicated that the involved gas with low flow rate had a considerable effect on oil/water flow characteristics, which shows the complexity of gas/oil/water three-phase flow. Thus, this effect could not be ignored in design and operation management of oil/gas gathering and transportation system.

201 Impact of Water Flow Rate on Finishing Pig Performance

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 68-69
Author(s):  
Hannah E Miller ◽  
Jorge Y Perez-Palencia ◽  
Crystal L Levesque ◽  
Robert C Thaler
Keyword(s):  
Body Weight ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Low Flow ◽  
Flow Rates ◽  
Finishing Pig ◽  
Daily Water ◽  
Pig Performance ◽  
High Treatment

Abstract A survey of South Dakota pork producers in 2019 demonstrated that water flow rate for nipple drinkers was highly variable among barns. Sixty-eight percent had water flow rates above the recommended rate of 500–1,000 mL/min (NSNG, 2010). The objective of this study was to determine the impact of water flow rate on finishing pig performance during the summer months. A total of 396 mixed-sex pigs, in two groups, were utilized in a 77-day trial (34.55 to103.8 kg BW) with 6 pigs/pen. Pens were assigned to one of three water flow rates (high, medium, low) based on the 3-hole diameters of the commercial water nipples used in the facility (2.0, 1.0, 0.80 mm; n = 22 pens/treatment). Daily water usage was recorded for each treatment along with room temperature, outside temperature, and relative humidity. Individual pen water flow rate was recorded every two weeks. At every diet phase change (26± 2.6 days), feed disappearance and individual pig body weight were recorded. Water flow rates averaged 1846±188, 906±214, 508±100 mL/min for high, medium, and low flow rates, respectively. Daily water disappearance for high, medium, and low treatments were 6.8, 2.3, 1.7±3.2 liters/pig, respectively. Final body weight (BW; 103.8±7.4 kg) did not differ. Daily gain (ADG) from 34.5±4.5 to 55.5±4.6 kg BW was greatest (P < 0.05) for high treatment. Daily intake (ADFI) and gain:feed (G:F) from 55.5±4.6 to 79.1±5.3 kg BW were greatest (P < 0.05) for high treatment. Cumulative ADFI was 2.27, 2.18, 2.16±0.16 kg (P < 0.05) in high, medium, and low flow ranges, respectively. There was no differences in cumulative ADG or G:F. Water flow rate had a significant impact on ADFI although there was minimal impact on gain and G:F. Water nipples should be regularly checked as part of normal barn maintenance to ensure adequate, but not excessive, water is available.

Displacement of Fluometuron and Diuron through Saturated Glass Beads and Soil

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 544-548 ◽  
Author(s):  
J. M. Davidson ◽  
P. W. Santelmann
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Glass Bead ◽  
Water Flow Rate ◽  
Soil Surface ◽  
Chloride Ion ◽  
Glass Beads ◽  
Low Flow ◽  
Flow Rates ◽  
Loam Soil

Solutions containing 3-(m-trifluromethylphenyl)-l,l-di-methylurea (fluometuron) or 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) were displaced through saturated 250-μ glass beads or through Norge loam soil at two water flow rates. The procedure used allowed uniform application of herbicide solutions to the soil surface and subsequent displacement of the herbicide through soil or glass bead columns at a constant water flow rate. Fluometuron was as mobile as the chloride ion at both high and low flow rates. The shape of the fluometuron distribution curves obtained at the two flow rates were distinctly different. The volume of water required to displace fluometuron through a material that adsorbed the herbicide was greater than that necessary to displace the fluometuron through materials giving a smaller amount of adsorption. More diuron was adsorbed by the glass bead system than fluometuron.

scholarly journals Parametric analysis on a simple design water reaction turbine for low-head low-flow Pico-hydro generation system

2021 ◽  
Vol 15 (3) ◽  
pp. 8356-8363
Author(s):  
Nurul Ashikin Mohd Rais ◽  
M. F. Basar
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Parametric Analysis ◽  
Water Flow Rate ◽  
Mass Conservation ◽  
Angular Speed ◽  
Low Flow ◽  
Pipe Diameter ◽  
Water Head ◽  
Low Head

This paper presents a parametric analysis of the outward flow reaction type turbine known as a Z-Blade turbine for low-head low-flow conditions. By applying the principles of mass conservation, momentum and energy, a nomogram was designed to investigate the theoretical performance characteristics. Based on the parametric analysis and the governing equations and experimental results, attempts have been made to prove that the mass flow rate, angular speed, centrifugal head, power output and efficiency respond dynamically to the water head, radius of the rotor, size of the PVC pipes and the nozzle exit area. A turbine with a 1” pipe diameter gives a higher performance compared to a 1/2” pipe diameter, and certainly the performances of both pipe sizes are improved when the supplied potential energy is increased. This innovative turbine has a maximum rotational speed at an optimum turbine diameter at 0.6m, accompanied by a point where there is a sudden reduction in the water flow rate, where previously the increment in the water flow rate was very high. This can shows from the outcome nomogram with 1” pipe diameter can perform 350 rpm speed with 1.48 L/sec water flow. The Z-Blade turbine has been examined and has shown good potential to be used for low-head (3m, 4m and 5m) and low-flow (less than 2.5 L/sec) conditions.

Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Test Protocol ◽  
Household Water ◽  
Medium Flow ◽  
Removal Efficiencies ◽  
Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

scholarly journals Effect of Water Flow on Underwater Wet Welded A36 Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 682
Author(s):  
Eko Surojo ◽  
Aziz Harya Gumilang ◽  
Triyono Triyono ◽  
Aditya Rio Prabowo ◽  
Eko Prasetya Budiana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Physical And Mechanical Properties ◽  
Shielded Metal Arc Welding ◽  
Effect Of Water ◽  
Bending Effect ◽  
Metal Arc Welding ◽  
A36 Steel

Underwater wet welding (UWW) combined with the shielded metal arc welding (SMAW) method has proven to be an effective way of permanently joining metals that can be performed in water. This research was conducted to determine the effect of water flow rate on the physical and mechanical properties (tensile, hardness, toughness, and bending effect) of underwater welded bead on A36 steel plate. The control variables used were a welding speed of 4 mm/s, a current of 120 A, electrode E7018 with a diameter of 4 mm, and freshwater. The results show that variations in water flow affected defects, microstructure, and mechanical properties of underwater welds. These defects include spatter, porosity, and undercut, which occur in all underwater welding results. The presence of flow and an increased flow rate causes differences in the microstructure, increased porosity on the weld metal, and undercut on the UWW specimen. An increase in water flow rate causes the acicular ferrite microstructure to appear greater, and the heat-affected zone (HAZ) will form finer grains. The best mechanical properties are achieved by welding with the highest flow rate, with a tensile strength of 534.1 MPa, 3.6% elongation, a Vickers microhardness in the HAZ area of 424 HV, and an impact strength of 1.47 J/mm2.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

scholarly journals Backflow effects on mass flow gain factor in a centrifugal pump

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042199886
Author(s):  
Wenzhe Kang ◽  
Lingjiu Zhou ◽  
Dianhai Liu ◽  
Zhengwei Wang
Keyword(s):  
Centrifugal Pump ◽  
Mass Flow ◽  
Flow Rate ◽  
Low Frequency ◽  
Gain Factor ◽  
Low Flow ◽  
Cavity Volume ◽  
Cavitating Flows ◽  
Inlet Tube ◽  
Low Flow Rate

Previous researches has shown that inlet backflow may occur in a centrifugal pump when running at low-flow-rate conditions and have nonnegligible effects on cavitation behaviors (e.g. mass flow gain factor) and cavitation stability (e.g. cavitation surge). To analyze the influences of backflow in impeller inlet, comparative studies of cavitating flows are carried out for two typical centrifugal pumps. A series of computational fluid dynamics (CFD) simulations were carried out for the cavitating flows in two pumps, based on the RANS (Reynolds-Averaged Naiver-Stokes) solver with the turbulence model of k- ω shear stress transport and homogeneous multiphase model. The cavity volume in Pump A (with less reversed flow in impeller inlet) decreases with the decreasing of flow rate, while the cavity volume in Pump B (with obvious inlet backflow) reach the minimum values at δ = 0.1285 and then increase as the flow rate decreases. For Pump A, the mass flow gain factors are negative and the absolute values increase with the decrease of cavitation number for all calculation conditions. For Pump B, the mass flow gain factors are negative for most conditions but positive for some conditions with low flow rate coefficients and low cavitation numbers, reaching the minimum value at condition of σ = 0.151 for most cases. The development of backflow in impeller inlet is found to be the essential reason for the great differences. For Pump B, the strong shearing between backflow and main flow lead to the cavitation in inlet tube. The cavity volume in the impeller decreases while that in the inlet tube increases with the decreasing of flow rate, which make the total cavity volume reaches the minimum value at δ = 0.1285 and then the mass flow gain factor become positive. Through the transient calculations for cavitating flows in two pumps, low-frequency fluctuations of pressure and flow rate are found in Pump B at some off-designed conditions (e.g. δ = 0.107, σ = 0.195). The relations among inlet pressure, inlet flow rate, cavity volume, and backflow are analyzed in detail to understand the periodic evolution of low-frequency fluctuations. Backflow is found to be the main reason which cause the positive value of mass flow gain factor at low-flow-rate conditions. Through the transient simulations of cavitating flow, backflow is considered as an important aspect closely related to the hydraulic stability of cavitating pumping system.

Sign in / Sign up

Export Citation Format

Share Document