Silica pretreatment for a RO brackish water source with high magnesium

2006 ◽  
Vol 6 (4) ◽  
pp. 179-187 ◽  
Author(s):  
S. Chen ◽  
T. Chang ◽  
C. Lin
Keyword(s):  
Brackish Water ◽  
Water Source ◽  
Xrd Analysis ◽  
Electrostatic Attraction ◽  
Magnesium Concentration ◽  
X Ray Diffraction ◽  
Silica Removal ◽  
Pros And Cons ◽  
The Impact ◽  
Amphoteric Properties

A brackish water source containing high magnesium concentration (333 mg/L as CaCO3) for reverse osmosis (RO) was studied for silica scaling. Threshold limit for RO recovery and required silica removal were firstly determined by a removal–saturation–recovery curve. Three different ratios of lime/soda ash combination were used to test the efficiency of silica removal as well as the impact of calcium and magnesium. Higher pH was more effective for silica removal due to electrostatic attraction since H3SiO−4 and H2SiO−24 were dominant when pH >9.9. The precipitation of Mg(OH)2(s) has assisted more for silica removal than that of CaCO3(s) and the ratio of 0.044 mg SiO2/mg Mg(OH)2(s) and 0.027 mg SiO2/mg CaCO3(s) were statistically determined. Moreover, the presence of high magnesium causes Mg(OH)2(s) to precipitate at lower pH (9.41) instead of formation of forsterite (Mg2SiO4(s)), which typically occurs at pH >12.3. Therefore, no forsterite was observed and was verified by X-ray diffraction (XRD) analysis. Consequently, adsorption is more dominant than chemical reaction in this study. Silica removal was also enhanced by coagulation. With the addition of coagulant (PACl), highest silica removal was achieved at pH of 10, but was decreased when the pH was over 10, due to the amphoteric properties of aluminum hydroxide to reduce the electrostatic attraction to silica at higher pH. Since both softening and coagulation were effective for silica removal, seven decision-making criteria were developed to compare the pros and cons of these two processes.

The Impact of Fly Ash after SNCR Treated with Tannin-Based Products on AAC Production

2019 ◽  
Vol 296 ◽  
pp. 173-179 ◽  
Author(s):  
Matěj Lédl ◽  
Lucie Galvánková ◽  
Rostislav Drochytka
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Bulk Density ◽  
Catalytic Reduction ◽  
Xrd Analysis ◽  
Gaseous Ammonia ◽  
X Ray Diffraction ◽  
Consistency Test ◽  
Effect Of Treatment ◽  
The Impact

This paper is focused on the effect of treatment of fly ash after selective non-catalytic reduction (SNCR) with tannin on autoclaved aerated concrete (AAC) production in order to reduce or stop ammonia leakage from the fresh mixture due to its alkalinity. A pure form of tannin and a tannin-based product „Farmatan“ were used as a treatment in dosage ranging from 0,5 g – 3 g of agent per 1 kg of fly ash. Efficient dosage was determined at 2 wt.% of fly ash by the speed of an indicator change due to gaseous ammonia diluted in water. The rheological properties of fresh mixtures were observed by consistency test in Viskomat showing that Farmatan causes delay of hydration. The results of bulk density and compressive strength testing revealed that Farmatan causes an increase of bulk density and at higher amount decreases the compressive strength because of thermal crack formation due to combined effect of delayed hydration and thixotropy. Using x-ray diffraction (XRD) analysis there were no differences in phase composition observed.

Fabrication and Characterization of Polypropylene/Ethylene-Octene Copolymer Blend Nanocomposites

2007 ◽  
Vol 29-30 ◽  
pp. 267-270 ◽  
Author(s):  
S.K. Samal ◽  
S. Mohanty ◽  
S.K. Nayak
Keyword(s):  
Loss Modulus ◽  
Clay Content ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Rheological Characterization ◽  
Maximum Increase ◽  
Cloisite 30B ◽  
Twin Screw ◽  
The Impact ◽  
Blend Nanocomposites

PP/EOC thermoplastic blend nanocomposites were prepared by melt intercalation technique using an intermeshing co-rotating twin screw extruder. The organoclay (Na+ MMT, Cloisite 20A, Cloisite 30B) content was varied between 0-5wt. % whereas the blend composition was kept constant (70PP: 30EOC) as optimized in our previous work. The effects of clays on the mechanical and rheological properties have been studied. Mechanical studies of PP/EOC nanocomposites reveal a significant increase in the impact strength upto a clay content of 3%. X-ray diffraction (XRD) analysis showed a significant increase in the interlayer gallery space with increase in clay loading. The rheological characterization made employing parallel plate rheometer revealed a maximum increase in storage modulus (G’) and loss modulus (G”) in case of modified clay indicating higher stiffness of the nanocomposites as compared to unmodified nanocomposites. Time Temperature superposition (TTS) was employed to generate various viscoelastic mastercurves.

scholarly journals Use of Chènevotte, a Valuable Co-Product of Industrial Hemp Fiber, as Adsorbent for Pollutant Removal. Part I: Chemical, Microscopic, Spectroscopic and Thermogravimetric Characterization of Raw and Modified Samples

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4574
Author(s):  
Chiara Mongioví ◽  
Dario Lacalamita ◽  
Nadia Morin-Crini ◽  
Xavier Gabrion ◽  
Aleksandra Ivanovska ◽  
...  
Keyword(s):  
Crystallinity Index ◽  
Xrd Analysis ◽  
Pollutant Removal ◽  
X Ray Diffraction ◽  
Hemp Fiber ◽  
X Ray ◽  
Agricultural Cooperative ◽  
Composition And Structure ◽  
Industrial Hemp ◽  
The Impact

FINEAU (2021–2024) is a trans-disciplinary research project involving French, Serbian, Italian, Portuguese and Romanian colleagues, a French agricultural cooperative and two surface-treatment industries, intending to propose chènevotte, a co-product of the hemp industry, as an adsorbent for the removal of pollutants from polycontaminated wastewater. The first objective of FINEAU was to prepare and characterize chènevotte-based materials. In this study, the impact of water washing and treatments (KOH, Na2CO3 and H3PO4) on the composition and structure of chènevotte (also called hemp shives) was evaluated using chemical analysis, X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray computed nanotomography (nano-CT), attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, solid state NMR spectroscopy and thermogravimetric analysis. The results showed that all these techniques are complementary and useful to characterize the structure and morphology of the samples. Before any chemical treatment, the presence of impurities with a compact unfibrillated structure on the surfaces of chènevotte samples was found. Data indicated an increase in the crystallinity index and significant changes in the chemical composition of each sample after treatment as well as in surface morphology and roughness. The most significant changes were observed in alkaline-treated samples, especially those treated with KOH.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

“New Normal”: Analisis Penerimaan Menggunakan Balance Score Card

2020 ◽  
Vol 3 (2) ◽  
pp. 396-402
Author(s):  
Maria Florentina Rumba ◽  
Margaretha P.N Rozady ◽  
Theresia W. Mado
Keyword(s):  
Higher Education ◽  
Higher Education Institutions ◽  
Normal Phase ◽  
Physical Contact ◽  
New Normal ◽  
Face To Face ◽  
Balance Score Card ◽  
Score Card ◽  
Pros And Cons ◽  
The Impact

Abstrak: Kebiasaan manusia berubah karena adanya wabah COVID-19, hal ini berpengaruh ketika manusia masuk ke dalam fase new normal. New normal diartikan sebagai keadaan yang tidak biasa dilakukan sebelumnya, yang kemudian dijadikan sebagai standar atau kebiasaan baru yang mesti dilakukan manusia untuk dirinya sendiri maupun untuk bersosialisasi dengan orang lain. Kebiasaan baru ini pun menimbulkan pro dan kontra seiring dengan dampak yang timbul. Lembaga pendidikan tinggi merupakan salah satu yang merasakan dampak penerapan new normal. Perkuliahan yang selama ini dilakukan secara online/daring, akan kembali dilakukan secara luring/tatap muka, dengan tetap menerapkan protokol COVID-19 seperti mengenakan masker, menjaga jarak, mengenakan sarung tangan, serta tidak melakukan kontak fisik seperti berjabat tangan. Masalah yang muncul bukan hanya kecemasan orang tua terhadap anak – anaknya, tetapi bagaimana lembaga pendidikan tinggi mengatur segala sumber daya yang dimiliki agar memenuhi standar penerapan new normal. penelitian ini bertujuan untuk mengetahui penerimaan  terhadap kondisi normal yang baru menggunakan Perspektif balance score card. Abstract: Human habits change because of the COVID-19 outbreak, this affects when humans enter the new normal phase. New normal is defined as a condition that is not normally done before, which is then used as a standard or new habits that must be done by humans for themselves or to socialize with others. This new habit also raises the pros and cons along with the impact arising with the new normal. Higher education institutions are the ones who feel the impact of implementing new normal. Lectures that have been conducted online / online will be re-done offline / face to face, while still applying the COVID-19 protocol such as wearing a mask, keeping a distance, wearing gloves, and not making physical contact such as shaking hands. The problem that arises is not only parents' anxiety about their children, but how higher education institutions regulate all available resources to meet new normal implementation standards. This study aims to determine acceptance of new normal conditions using the balance score card Perspective.

scholarly journals Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Population Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

A study on using expanded perlite with hydroxyapatite: Reinforced bio-composites

2021 ◽  
pp. 095441192199656
Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu
Keyword(s):  
Body Fluid ◽  
Xrd Analysis ◽  
Cold Isostatic Pressing ◽  
Expanded Perlite ◽  
X Ray Diffraction ◽  
Pressing Method ◽  
X Ray ◽  
Infra Red ◽  
Ft Ir

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.

scholarly journals The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikolaj Grabowski ◽  
Ewa Grzanka ◽  
Szymon Grzanka ◽  
Artur Lachowski ◽  
Julita Smalc-Koziorowska ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Temperatures ◽  
Point Defects ◽  
X Ray Diffraction ◽  
Helium Ions ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
The Impact ◽  
Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

scholarly journals An Insight into Chemistry and Structure of Colloidal 2D-WS2 Nanoflakes: Combined XPS and XRD Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1969
Author(s):  
Riccardo Scarfiello ◽  
Elisabetta Mazzotta ◽  
Davide Altamura ◽  
Concetta Nobile ◽  
Rosanna Mastria ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Crystal Habit ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Morphological Evaluation ◽  
Rational Understanding ◽  
Structural Inspection

The surface and structural characterization techniques of three atom-thick bi-dimensional 2D-WS2 colloidal nanocrystals cross the limit of bulk investigation, offering the possibility of simultaneous phase identification, structural-to-morphological evaluation, and surface chemical description. In the present study, we report a rational understanding based on X-ray photoelectron spectroscopy (XPS) and structural inspection of two kinds of dimensionally controllable 2D-WS2 colloidal nanoflakes (NFLs) generated with a surfactant assisted non-hydrolytic route. The qualitative and quantitative determination of 1T’ and 2H phases based on W 4f XPS signal components, together with the presence of two kinds of sulfur ions, S22− and S2−, based on S 2p signal and related to the formation of WS2 and WOxSy in a mixed oxygen-sulfur environment, are carefully reported and discussed for both nanocrystals breeds. The XPS results are used as an input for detailed X-ray Diffraction (XRD) analysis allowing for a clear discrimination of NFLs crystal habit, and an estimation of the exact number of atomic monolayers composing the 2D-WS2 nanocrystalline samples.

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