Performance of microbubble ozonation on treated tropical peat water: Effects on THM4 and HAA5 precursor formation based on DOM hydrophobicity fractions

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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Influence of disturbances and environmental changes on albedo in tropical peat ecosystems

Agricultural and Forest Meteorology ◽

10.1016/j.agrformet.2021.108348 ◽

2021 ◽

Vol 301-302 ◽

pp. 108348

Author(s):

Shinjiro Ohkubo ◽

Takashi Hirano ◽

Kitso Kusin

Keyword(s):

Environmental Changes ◽

Tropical Peat

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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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The Use of Subsidence to Estimate Carbon Loss from Deforested and Drained Tropical Peatlands in Indonesia

Forests ◽

10.3390/f12060732 ◽

2021 ◽

Vol 12 (6) ◽

pp. 732

Author(s):

Gusti Z. Anshari ◽

Evi Gusmayanti ◽

Nisa Novita

Keyword(s):

Water Table ◽

Carbon Emission ◽

Bottom Layer ◽

Groundwater Table ◽

Microbial Oxidation ◽

Tropical Peat ◽

Subsidence Rate ◽

Tier 1 ◽

Tropical Peatlands ◽

Physical Changes

Drainage is a major means of the conversion of tropical peat forests into agriculture. Accordingly, drained peat becomes a large source of carbon. However, the amount of carbon (C) loss from drained peats is not simply measured. The current C loss estimate is usually based on a single proxy of the groundwater table, spatially and temporarily dynamic. The relation between groundwater table and C emission is commonly not linear because of the complex natures of heterotrophic carbon emission. Peatland drainage or lowering groundwater table provides plenty of oxygen into the upper layer of peat above the water table, where microbial activity becomes active. Consequently, lowering the water table escalates subsidence that causes physical changes of organic matter (OM) and carbon emission due to microbial oxidation. This paper reviews peat bulk density (BD), total organic carbon (TOC) content, and subsidence rate of tropical peat forest and drained peat. Data of BD, TOC, and subsidence were derived from published and unpublished sources. We found that BD is generally higher in the top surface layer in drained peat than in the undrained peat. TOC values in both drained and undrained are lower in the top and higher in the bottom layer. To estimate carbon emission from the top layer (0–50 cm) in drained peats, we use BD value 0.12 to 0.15 g cm−3, TOC value of 50%, and a 60% conservatively oxidative correction factor. The average peat subsidence is 3.9 cm yr−1. The range of subsidence rate per year is between 2 and 6 cm, which results in estimated emission between 30 and 90 t CO2e ha−1 yr−1. This estimate is comparable to those of other studies and Tier 1 emission factor of the 2013 IPCC GHG Inventory on Wetlands. We argue that subsidence is a practical approach to estimate carbon emission from drained tropical peat is more applicable than the use of groundwater table.

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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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