scholarly journals In Situ Estimates of Variable Plant Resistance to Water Flux in Ilex opaca Ait.

1978 ◽  
Vol 61 (3) ◽  
pp. 311-313 ◽  
Author(s):  
Stephen W. Roberts ◽  
Kenneth R. Knoerr
Keyword(s):  
Plant Resistance ◽  
Water Flux ◽  
Ilex Opaca

Distributions of Ferrous Iron and Sulfide in an Anoxic Hypolimnion

1984 ◽  
Vol 41 (2) ◽  
pp. 286-293 ◽  
Author(s):  
Robert B. Cook
Keyword(s):  
Pore Water ◽  
Solubility Product ◽  
Iron Sulfide ◽  
Water Flux ◽  
Sediment Pore Water ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Anoxic Hypolimnion ◽  
Decomposition Of Organic Matter

In the anoxic hypolimnion of Lake 227, Experimental Lakes Area, northwestern Ontario, ΣH2S exhibits a mid-depth maximum, while Fe2+ increases with depth. At the mid-depth ΣH2S maximum and below, saturation with respect to amorphous FeS is reached, and the concentration of ΣH2S is limited by the high Fe2+ concentrations, in accord with the FeS solubility product. Values for pKsp[Formula: see text] for FeS determined from the ΣH2S maximum and below averaged 3.16 in 1979 and agree well with other in situ and laboratory measurements. In the top 10 cm of sediment, pore water ΣH2S and Fe2+ are in equilibrium with amorphous FeS. Analyses of cores confirms the existence of an iron sulfide phase. Fe2+, which is produced in the pore water from the decomposition of organic matter, increases to concentrations at which siderite may form, although the presence of siderite has not been verified. Comparison of calculated pore water fluxes of Fe2+ with the observed increase of Fe2+ in the anoxic hypolimnion reveals that about 90% of the observed flux originates at the sediment–water interface, while the remainder is derived from pore water flux.

Automated In Situ Measurement of Unsaturated Soil Water Flux

1988 ◽  
Vol 52 (5) ◽  
pp. 1215-1218 ◽  
Author(s):  
J.J.M. van Grinsven ◽  
H.W.G. Booltink ◽  
C. Dirksen ◽  
N. van Breemen ◽  
N. Bongers ◽  
...  
Keyword(s):  
Soil Water ◽  
Unsaturated Soil ◽  
Water Flux ◽  
In Situ Measurement ◽  
Soil Water Flux

Movement of Water Flux through Unsaturated Zones:A Transient Impact on in situ Potential Field

2018 ◽  
Vol 114 (07) ◽  
pp. 1414
Author(s):  
Rolland Andrade ◽  
D. Muralidharan ◽  
R. Rangarajan
Keyword(s):  
Potential Field ◽  
Water Flux

In situ measurement of snowmelt infiltration under various topsoil cap thicknesses on a reclaimed site

2013 ◽  
Vol 93 (4) ◽  
pp. 497-510 ◽  
Author(s):  
Andre F. Christensen ◽  
Hailong He ◽  
Miles F. Dyck ◽  
E. Lenore Turner ◽  
David S. Chanasyk ◽  
...  
Keyword(s):  
Effective Permittivity ◽  
Water Flux ◽  
Climatic Conditions ◽  
Time Domain Reflectometry ◽  
In Situ Measurement ◽  
Water Dynamics ◽  
Soil Freezing ◽  
Weather Data ◽  
Freezing And Thawing

Christensen, A. F., He, H., Dyck, M. F., Turner, L., Chanasyk, D. S., Naeth, M. A. and Nichol, C. 2013. In situ measurement of snowmelt infiltration under various topsoil cap thicknesses on a reclaimed site. Can. J. Soil Sci. 93: 497–510. Understanding the soil and climatic conditions affecting the partitioning of snowmelt to runoff and infiltration during spring snow ablation is a requisite for water resources management and environmental risk assessment in cold semi-arid regions. Soil freezing and thawing processes, snowmelt runoff or infiltration into seasonally frozen soils have been documented for natural, agricultural or forested systems but rarely studied in severely disturbed systems such as reclaimed lands. The objective of this study was to quantify the snowmelt infiltration/runoff on phosphogypsum (PG) tailings piles capped with varying thicknesses of topsoil (0.15, 0.3, and 0.46 m) at a phosphate fertilizer production facility in Alberta. There are currently no environmental regulations specifying topsoil capping thickness or characteristics for these types of tailings piles. Generally, the function of the topsoil cap is to facilitate plant growth and minimize the amount of drainage into the underlying PG. Experimental plots were established in 2006 to better understand the vegetation and water dynamics in this reconstructed soil. In 2011, time domain reflectometry (TDR) probes and temperature sensors were installed at various depths for continuous, simultaneous, and automated measurement of composite dielectric permittivity (ɛeff) and soil temperature, respectively. An on-site meteorological station was used to record routine weather data. Liquid water and ice content were calculated with TDR-measured effective permittivity (ɛeff) and a composite dielectric mixing model. Spatial and temporal change of total water content (ice and liquid) revealed that snowmelt infiltration into the topsoil cap increased with increasing topsoil depth and net soil water flux from the topsoil cap into the PG material was positive during the snowmelt period in the spring of 2011. Given the objective of the capping soil is to reduce drainage of water into the PG material it is recognized that a capping soil with a higher water-holding capacity could reduce the amount of meteoric water entering the tailings.

scholarly journals Major element concentrations in Mangrove Pore Water, Sepetiba Bay, Brazil

2012 ◽  
Vol 60 (1) ◽  
pp. 33-39
Author(s):  
Christian J. Sanders ◽  
Renato G. S. Barcellos ◽  
Emmanoel V. Silva-Filho
Keyword(s):  
Pore Water ◽  
Major Element ◽  
Sea Water ◽  
Water Flux ◽  
Mangrove Ecosystem ◽  
Major Elements ◽  
Atlantic Rain Forest ◽  
Molar Ratios ◽  
Element Concentrations

Concentrations of cations and anions of major elements (Na+, Ca2+, Mg2+, K+, Cl-, SO4 2-) were analyzed in the pore water of a mangrove habitat. Site specific major element concentrations were identified along a four piezometric well transect, which were placed in distinct geobotanic facies. Evapotranspiration was evident in the apicum station, given the high salinity and major element concentrations. The station landward of an apicum was where major element/Cl- ratios standard deviations are greatest, suggesting intense in situ diagenesis. Molar ratios in the most continental station (4) are significantly lower than the nearby freshwater source, indicating a strong influence of sea water flux into the outer reaches of the mangrove ecosystem and encroaching on the Atlantic rain forest. Indeed, the SO4 2-/Cl- and Ca2+/Cl- ratios suggest limited SO4 2- reduction and relatively high Ca2+/Cl- ratios indicate a region of recent saltwater contact.

One-step nanotopography construction by polyaniline polymerization for a superhydrophobic nanofibrous membrane towards direct contact membrane distillation

2019 ◽  
Vol 6 (8) ◽  
pp. 2553-2564 ◽  
Author(s):  
Lingling Zhong ◽  
Zhigao Zhu ◽  
Yu Han ◽  
Qiao Wang ◽  
Dongmei Liu ◽  
...  
Keyword(s):  
Direct Contact ◽  
Water Flux ◽  
High Water ◽  
Membrane Distillation ◽  
Nanofibrous Membrane ◽  
Direct Contact Membrane Distillation ◽  
One Step ◽  
Nanofibrous Membranes

In situ polymerization of aniline is used to prepare superhydrophobic PVDF nanofibrous membranes for direct contact membrane distillation with high water flux and long wetting times.

Bradykinin-induced elevations of hydraulic conductivity display spatial and temporal variations in frog capillaries

1993 ◽  
Vol 264 (5) ◽  
pp. H1575-H1581 ◽  
Author(s):  
D. A. Williams ◽  
V. H. Huxley
Keyword(s):  
Hydraulic Conductivity ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Water Flux ◽  
Temporal Variations ◽  
Time Dependent ◽  
Microvascular Networks ◽  
Microvascular Network

Bradykinin, a vasodilator, increases permeability to macromolecules in postcapillary venules. Recent studies indicate that vasodilators elevate water flux from frog mesenteric capillaries. Thus we hypothesized that bradykinin would also increase transcapillary water flux. Arteriolar (ac), true (tc), and venular (vc) capillaries were identified within the microvascular network of frog mesentery. Each capillary was cannulated in situ and perfused with control (frog Ringer and 10 mg/ml bovine serum albumin) and then bradykinin test (10(-7) M) solutions. Hydraulic conductivity (Lp) increased across the network (1.8, 5.3, and 11.0 x 10(-7) cm.s-1.cmH2O-1 for ac, tc, and vc, respectively). Bradykinin test Lp normalized to control (LpBKN/LPC) was elevated threefold (n = 37). Lp for ac (n = 12) was elevated 3.5-fold and oscillated with time. Lp for tc (n = 13) increased fivefold within the first 5 min of exposure and then dropped. Lp for vc (n = 12) was not different from control. Location- and time-dependent responses of Lp indicate that capillaries forming microvascular networks have individual responses to bradykinin.

Hydrophilic modification of PVDF membranes by in situ synthesis of nano-Ag with nano-ZrO2

2021 ◽  
Vol 10 (1) ◽  
pp. 538-546
Author(s):  
Yanjun Lu ◽  
Yuxuan Ma ◽  
Tong Yang ◽  
Jifeng Guo
Keyword(s):  
Polyvinylidene Fluoride ◽  
Pure Water ◽  
Water Flux ◽  
Inversion Method ◽  
Hydrophilic Modification ◽  
E Coli ◽  
Pure Water Flux ◽  
Modified Membrane ◽  
Phase Inversion Method

Abstract Modified polyvinylidene fluoride (PVDF) membranes were prepared by the phase inversion method via blending in situ formed nanosilver (Ag) and nanozirconium dioxide (ZrO2). Scanning electron microscopy of the membranes revealed that the surface pore size of the membranes was increased and distributed widely with the addition of modified nanosilver (Ag) and nanozirconium dioxide (ZrO2). The pores of the membrane were reduced due to excessive modification of the material when the content of zirconium dioxide was increased to 0.4%. XRD characterization showed that in situ synthesis of nanosilver (Ag) and nanozirconium dioxide (ZrO2) had been successfully blended in the membranes. The contact angle of the modified membrane ranged from 82.72° to 67.37°, which showed that the hydrophilic properties of the membrane were improved. The pure water flux of the modified membrane increased from 28.43 to 143.2 L/m2 h, indicating that the hydrophilicity of the modified membrane was enhanced significantly. The flux recovery rate of the modified membrane was obviously increased in the fouling experiment with BSA as the source of organic pollutants. The antimicrobial contamination of the membrane was greatly enhanced with the E. coli microbial contamination experiment.

scholarly journals Membrane Fouling and Performance of Flat Ceramic Membranes in the Application of Drinking Water Purification

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2606 ◽  
Author(s):  
Shujuan Meng ◽  
Minmin Zhang ◽  
Meng Yao ◽  
Zhuguo Qiu ◽  
Yubin Hong ◽  
...  
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Purification ◽  
Membrane Fouling ◽  
Membrane Surface ◽  
Water Flux ◽  
Ceramic Membranes ◽  
Surface Water Treatment ◽  
Drinking Water Purification

Membrane technologies have been widely applied in surface water treatment for drinking water purification. The main obstacles to the large scale application of membranes include membrane fouling, energy consumption and high investment. This study systematically investigated the performance of a hybrid system including in-situ coagulation and membrane module. The key parameters of a membrane system, including initial flux, operation mode (intermediate or continuous, time intervals, backwashing and aeration) was comprehensively investigated. In addition, the treatment performance in terms of turbidity, organic matter removal, membrane fouling and cleaning, and the effect of coagulants, were also studied. It was found that flat ceramic membranes with in-situ coagulation for surface water treatment performed much better without aeration and frequent backwashing, which gave interesting and important implications for future applications of a flat ceramic membrane, especially in drinking water purification. The hybrid system can achieve a high-water flux of 150 L/m2·h (LMH) for 8 h operation without aeration and backwash. The removal of turbidity, UV254 and COD can achieve 99%, 85% and 81%, respectively. The cake layer on the membrane surface formed from the coagulation flocs turned out to prevent the membrane to be exposed to organic pollutant immediately which minimized the fouling problem. In addition, the fouling layer on the membrane surface can be easily cleaned by air scouring and backwash at the end of experiments, with a water flux recovery of higher than 90%. These results in this study provided an alternative strategy for membrane fouling control and energy conservation.

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