Modelling of a Hydrogen Saturated Layer Within the Micropolar Approach

French vertical flow constructed wetlands (VFCW) treating raw wastewater have been developed successfully over the last 30 years. Nevertheless, the two-stage VFCWs require a total filtration area of 2–2.5 m2/P.E. Therefore, implementing a one-stage system in which treatment performances reach standard requirements is of interest. Biho-Filter® is one of the solutions developed in France by Epur Nature. Biho-Filter® is a vertical flow system with an unsaturated layer at the top and a saturated layer at the bottom. The aim of this study was to assess this new configuration and to optimize its design and operating conditions. The hydraulic functioning and pollutant removal efficiency of three different Biho-Filter® plants commissioned between 2011 and 2012 were studied. Outlet concentrations of the most efficient Biho-Filter® configuration are 70 mg/L, 15 mg/L, 15 mg/L and 25 mg/L for chemical oxygen demand (COD), 5-day biological oxygen demand (BOD5), total suspended solids (TSS) and total Kjeldahl nitrogen (TKN), respectively. Up to 60% of total nitrogen is removed. Nitrification efficiency is mainly influenced by the height of the unsaturated zone and the recirculation rate. The optimum recirculation rate was found to be 100%. Denitrification in the saturated zone works at best with an influent COD/NO3-N ratio at the inflet of this zone larger than 2 and a hydraulic retention time longer than 0.75 days.

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THE ADSORPTION GEOMETRY OF BENZOIC ACID ON Ni(110)

Surface Review and Letters ◽

10.1142/s0218625x99000093 ◽

1999 ◽

Vol 06 (01) ◽

pp. 53-75 ◽

Cited By ~ 21

Author(s):

M. NEUBER ◽

M. ZHARNIKOV ◽

J. WALZ ◽

M. GRUNZE

Keyword(s):

Benzoic Acid ◽

Photoelectron Spectroscopy ◽

Thermal Desorption Spectroscopy ◽

Adsorption Models ◽

X Ray ◽

Saturated Layer ◽

Adsorbate Layer ◽

Saturation Coverage ◽

Adsorption Geometry ◽

X Ray Absorption

The adsorption geometry of benzoic acid on Ni(110) was investigated by X-ray photoelectron spectroscopy, angle-resolved near edge X-ray absorption fine structure spectroscopy at the C1s and O1s excitation edges, and thermal desorption spectroscopy. At a substrate temperature of 360 K and saturation coverage the adsorbate forms a benzoate with molecules adsorbed on the surface via two equivalent oxygen atoms. For this dense adsorbate layer the molecular plane was found to be azimuthally rotated by about ± 30° with respect to the [Formula: see text] surface azimuth and tilted by ≈ 30° with respect to the surface normal. At about half the saturation coverage some rearrangement of molecules occurs in such a way that their planes become directed along the [001] surface direction, which is different from the adsorption geometry observed after annealing the saturated layer. At even smaller coverage the benzoate molecules appear to adsorb with their molecular planes nearly parallel to the surface. Semiempirical quantum-mechanical cluster calculations indicate that the carboxylate oxygens favor the highly coordinated sites in the [Formula: see text]-oriented troughs of the Ni(110) surface. Possible adsorption models are discussed.

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Physical Model for the Study of Mass and Energy Transfers in the Non-Saturated Layer of Soil Located Above a Solar Energy Storage

Solar Energy Applications to Dwellings ◽

10.1007/978-94-009-7924-6_50 ◽

1983 ◽

pp. 374-379

Author(s):

J. C. Benet ◽

G. Della-Valle ◽

P. Jouanna ◽

D. Koufogiannis ◽

C. Saix

Keyword(s):

Energy Storage ◽

Solar Energy ◽

Physical Model ◽

Solar Energy Storage ◽

Saturated Layer ◽

Energy Transfers

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Analysis of Surface Waves in an Elastic Medium with a Porous Saturated Layer

Radiophysics and Quantum Electronics ◽

10.1007/s11141-019-09988-5 ◽

2019 ◽

Vol 62 (6) ◽

pp. 420-438

Author(s):

A. V. Lebedev

Keyword(s):

Surface Waves ◽

Elastic Medium ◽

Saturated Layer

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Effects of a saturated layer and recirculation on nitrogen treatment performances of a single stage Vertical Flow Constructed Wetland (VFCW)

Water Science & Technology ◽

10.2166/wst.2013.359 ◽

2013 ◽

Vol 68 (7) ◽

pp. 1461-1467 ◽

Cited By ~ 14

Author(s):

S. Prigent ◽

J. Paing ◽

Y. Andres ◽

F. Chazarenc

Keyword(s):

Constructed Wetland ◽

Oxygen Demand ◽

Domestic Wastewater ◽

Single Stage ◽

Vertical Flow ◽

Saturated Layer ◽

Vertical Flow Constructed Wetland ◽

Hydraulic Load ◽

Nitrogen Concentrations ◽

Kjeldahl Nitrogen

Upgrades to enhance nitrogen removal were tested in a 2 year old pilot vertical flow constructed wetland in spring and summer periods. The effects of a saturated layer and of recirculation were tested in particular. Two pilots (L = 2 m, W = 1.25 m, H = 1.2 m), filled with expanded schist (Mayennite®), were designed with hydraulic saturated layers of 20 and 40 cm at the bottom. Each pilot was fed with raw domestic wastewater under field conditions according to a hydraulic load of 15–38 cm d−1 (i.e. 158–401 g COD (chemical oxygen demand) m−2 d−1) and to recirculation rates ranging from 0% up to 150%. The initial load during the first 2 years of operation resulted in an incomplete mineralized accumulated sludge leading to total suspended solids (TSS), COD and biochemical oxygen demand (BOD5) release. A 40 cm hydraulic saturated layer enabled an increase of 5–10% total nitrogen (TN) removal compared to a 20 cm saturated layer. Recirculation allowed the dilution of raw wastewater and enhanced nitrification in a single stage. A design of 1.8 m² pe−1 (48 cm d−1, 191 g COD m−2 d−1) with a 40 cm saturated layer and 100% recirculation enabled the French standard D4 (35 mg TSS L−1, 125 mg COD L−1, 25 mg BOD5 L−1), nitrogen concentrations below 20 mg TKN (total Kjeldahl nitrogen) L−1 and 50 mg TN L−1, to be met.

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The origin of resonance in the vertical component of earthquakes recorded on soft soil at Wainuiomata, New Zealand

Bulletin of the New Zealand Society for Earthquake Engineering ◽

10.5459/bnzsee.44.1.19-30 ◽

2011 ◽

Vol 44 (1) ◽

pp. 19-30

Author(s):

W. R. Stephenson

Keyword(s):

New Zealand ◽

Fundamental Mode ◽

Rayleigh Waves ◽

Soft Soil ◽

Vertical Component ◽

Soft Water ◽

Saturated Layer ◽

Water Saturated

Occasionally-observed resonances in the vertical components of earthquakes recorded at the Wainuiomata, New Zealand, soft site, are likely to be manifestations of the Airy phase of fundamental-mode Rayleigh waves which traverse the site. These packets of waves exist only when a soft, water-saturated layer of soil overlies a substrate with a much higher velocity. Other soft sites in Wellington also show the phenomenon, which may have implications for hazard estimates.

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Depth characterization of shallow aquifers with seismic reflection, Part I—The failure of NMO velocity analysis and quantitative error prediction

Geophysics ◽

10.1190/1.1451362 ◽

2002 ◽

Vol 67 (1) ◽

pp. 89-97 ◽

Cited By ~ 30

Author(s):

John H. Bradford

Keyword(s):

Layer Thickness ◽

Water Table ◽

Seismic Reflection ◽

Negative Impact ◽

Compressional Wave ◽

Unconsolidated Sediments ◽

Velocity Analysis ◽

Seismic Reflection Data ◽

Reflection Data ◽

Saturated Layer

As seismic reflection data become more prevalent as input for quantitative environmental and engineering studies, there is a growing need to assess and improve the accuracy of reflection processing methodologies. It is common for compressional‐wave velocities to increase by a factor of four or more where shallow, unconsolidated sediments change from a dry or partially water‐saturated regime to full saturation. While this degree of velocity contrast is rare in conventional seismology, it is a common scenario in shallow environments and leads to significant problems when trying to record and interpret reflections within about the first 30 m below the water table. The problem is compounded in shallow reflection studies where problems primarily associated with surface‐related noise limit the range of offsets we can use to record reflected energy. For offset‐to‐depth ratios typically required to record reflections originating in this zone, the assumptions of NMO velocity analysis are violated, leading to very large errors in depth and layer thickness estimates if the Dix equation is assumed valid. For a broad range of velocity profiles, saturated layer thickness will be overestimated by a minimum of 10% if the boundary of interest is <30 m below the water table. The error increases rapidly as the boundary shallows and can be very large (>100%) if the saturated layer is <10 m thick. This degree of error has a significant and negative impact if quantitative interpretations of aquifer geometry are used in aquifer evaluation such as predictive groundwater flow modeling or total resource estimates.

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Behavioral Analysis of Hydrogen in Metals under the Effect of H2S Corrosion Using a Layer-stripping Micro-hardness Technique

Materials Science ◽

10.5755/j01.ms.26.3.22103 ◽

2020 ◽

Vol 26 (3) ◽

pp. 287-294

Author(s):

Lei GU ◽

Jing WANG ◽

Xiaoyang LI

Keyword(s):

Hydrogen Sulfide ◽

Hydrogen Diffusion ◽

Hardness Test ◽

Micro Hardness ◽

Hydrogen Distribution ◽

Hydrogen In Metals ◽

H2s Corrosion ◽

Saturated Layer ◽

Structural Carbon ◽

Structural Carbon Steel

In order to study the distribution behavior of hydrogen in metals under the condition of H2S corrosion, a layer-stripping micro-hardness test was designed to analyze the hydrogen distribution along the depth of hydrogen-charged 45 high-quality structural carbon steel at three different hydrogen sulfide concentrations and four corrosion periods in this study. The results show that there is a terminal solid solubility of hydrogen in the metal for hydrogen sulfide solutions over various concentrations and corrosion periods. A hydrogen-saturated layer is produced by hydrogen diffusing through the metal from an unsaturated state to a fully saturated state. The hydrogen-saturated layer is not affected by the concentration of the corrosion, but its thickness increases as the corrosion period increases. In this way, we established a new hydrogen diffusion model in metals.

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