Use of biochar to manage soil salts and water: Effects and mechanisms

Magnesium hydroxide (Mg(OH)2) thin films were deposited by the drop-dry deposition (DDD) method using an aqueous solution containing Mg(NO3)2 and NaOH. DDD was performed by dropping the solution on a substrate, heating-drying, and rinsing in water. Effects of different deposition conditions on the surface morphology and optical properties of Mg(OH)2 thin films were researched. Films with a thickness of 1−2 μm were successfully deposited, and the Raman peaks of Mg(OH)2 were observed for them. Their transmittance in the visible range was 95% or more, and the bandgap was about 5.8 eV. It was found that the thin films have resistivity of the order of 105 Ωcm. Thus, the transparent and semiconducting Mg(OH)2 thin films were successfully prepared by DDD.

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In situ SAXS analysis of the water effects on the thickness evolution of nanocellulose within bamboo fiber

Wood Science and Technology ◽

10.1007/s00226-020-01260-8 ◽

2021 ◽

Author(s):

Ziyu Ba ◽

Guowei Chen ◽

Hongyun Luo ◽

Jun Luo

Keyword(s):

Bamboo Fiber ◽

Water Effects ◽

Saxs Analysis

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Cooking of short, medium and long-grain rice in limited and excess water: Effects on microstructural characteristics and gastro-small intestinal starch digestion in vitro

LWT ◽

10.1016/j.lwt.2021.111379 ◽

2021 ◽

Vol 146 ◽

pp. 111379

Author(s):

Masatsugu Tamura ◽

Chisato Kumagai ◽

Lovedeep Kaur ◽

Yukiharu Ogawa ◽

Jaspreet Singh

Keyword(s):

Starch Digestion ◽

Microstructural Characteristics ◽

Excess Water ◽

Water Effects ◽

Small Intestinal

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Model Based Assessment of the Reflection Behavior of Tidal Waves at Bathymetric Changes in Estuaries

Water ◽

10.3390/w13040489 ◽

2021 ◽

Vol 13 (4) ◽

pp. 489

Author(s):

Vanessa Sohrt ◽

Sebastian S.V. Hein ◽

Edgar Nehlsen ◽

Thomas Strotmann ◽

Peter Fröhle

Keyword(s):

Cross Sectional ◽

High Agreement ◽

Tidal Waves ◽

Level Data ◽

Water Level Data ◽

Abrupt Changes ◽

Water Effects ◽

Potential Impact ◽

Tidal Constituents ◽

Harmonic Components

Estuaries are often modified by human activities. Adjustments in the morphology of an estuary have a potential impact on the hydrodynamics and on the reflection behavior of the tide. The influence of such system changes on the complex tidal regime with a large number of superimposed tidal constituents is not fully understood yet. The reflection properties of estuaries that are characterized by abrupt changes in geometry are systematically investigated on the basis of simplified estuary model approaches to improve the understanding of the oscillation and reflection behavior of tidal waves in estuaries. The reflection coefficients at abrupt cross-sectional changes are determined by two different methods, i.e., an analytical energy-based approach and a hydrodynamic numerical (HN) model. Comparisons indicate a high agreement of the results of the different methods when evaluating the reflection coefficient. The tidal constituents are reflected at partial and total reflectors and amplified by shoaling depending on the water depths, the height of the bottom step and the horizontal constriction. A harmonic analysis of simulated water level data partly shows the formation and amplification of higher harmonic components as a result of shallow water effects. The interaction with reflectors results in an increasing amplification of the tidal constituents and the tide.

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Pyrite (FeS2)-supported ultrafiltration system for removal of mercury (II) from water

Emergent Materials ◽

10.1007/s42247-021-00282-7 ◽

2021 ◽

Author(s):

Dong Suk Han ◽

Kawsher M. D. Solayman ◽

Ho Kyong Shon ◽

Ahmed Abdel-Wahab

Keyword(s):

Membrane Filter ◽

Pyrite Surface ◽

Ph Change ◽

Filtration Process ◽

Sem Images ◽

Flux Decline ◽

Cake Layer ◽

Water Effects ◽

Almost All ◽

Over Time

AbstractThis study investigated the Hg(II) removal efficiencies of the reactive adsorbent membrane (RAM) hybrid filtration process, a removal process that produces stable final residuals. The reaction mechanism between Hg(II) and pyrite and the rejection of the solids over time were characterized with respect to flux decline, pH change, and Hg and Fe concentration in permeate water. Effects of the presence of anions (Cl−, SO42−, NO3−) or humic acid (HA) on the rejection of the Hg(II)-contacted pyrite were studied. The presence of both HA and Hg(II) increased the rate of flux decline due to the formation of irreversible gel-like compact cake layers as shown in the experimental data and modeling related to the flux decline and the SEM images. Stability experiments of the final residuals retained on the membrane using a thiosulfate solution (Na2S2O3) show that the Hg(II)-laden solids were very stable due to little or no detection of Hg(II) in the permeate water. Experiment on the possibility of continuously removing Hg(II) by reusing the Hg/pyrite-laden membrane shows that almost all Hg(II) was adsorbed onto the pyrite surface regardless of the presence of salts or HA, and the Hg(II)-contacted pyrite residuals were completely rejected by the DE/UF system. Therefore, a membrane filter containing pyrite-Hg(II) could provide another reactive cake layer capable of further removal of Hg(II) without post-chemical treatment for reuse.

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