The Influence of Dosing Modes of Coagulate on Arsenic Removal

Three different dosing modes, including one single dosing mode and two sequential dosing modes, were applied in high-arsenic contaminated water treatment. The results illustrated that the As (V) soluble and the As (V) nonspecifically sorbed were the insignificant species from Fe-As (V) samples in the sequential dosing mode, while they were higher in the single dosing mode. However, it could be further concluded that the mobility of the Fe-As (V) in sequential dosing mode was greater than that in single dosing mode. Besides, the main arsenic speciation governing the arsenic-borne coagulates was the As (V) associated with poorly crystalline hydrous oxides of Fe in sequential or single dosing mode. Moreover, the particle size distribution analysis indicated that the sequential dosing mode was more prevalent in neutralizing and adsorbing the As (V) compared with the single dosing mode. In the FT-IR spectra, the presence of arsenic was highlighted by a well resolved band at 825–829 cm−1. The positions of the As–O stretching vibration bands were shifted gradually as the dosing mode changed from the single to the sequential. This result could be related to the distribution of arsenic speciation in different dosing modes.

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UKURAN PARTIKEL DAN KONFORMASI KRISTAL ZEOLIT-A HASIL SINTESIS DENGAN PENAMBAHAN TETRAPROPILAMMONIUM HIDROKSIDA (TPAOH)

REAKTOR ◽

10.14710/reaktor.15.2.132-138 ◽

2014 ◽

Vol 15 (2) ◽

pp. 132 ◽

Cited By ~ 1

Author(s):

Nurul - Widiastuti ◽

Farhanah Thalib ◽

Didik Prasetyoko ◽

Hamzah Fansuri

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Electrostatic Interactions ◽

Distribution Analysis ◽

Zeolite A ◽

Zeolite Framework ◽

Tetrapropylammonium Hydroxide ◽

Ft Ir ◽

Average Size

Abstract PARTICLE SIZE AND CRYSTAL CONFORMATION OF SYNTHESIZED ZEOLITE-A WITH TETRAPROPYLAMMONIUM HYDROXIDE (TPAOH) ADDITION. The aims of this research is to study the effect of tetrapropylammonium hydroxide (TPAOH) concentration in the synthesis of zeolite A to its physical characteristics such as crystallinity, crystal conformation and average crystal size. The zeolite A was synthesized with composition 3.165 Na2O : 1.000 Al2O3 : 1.926 SiO2 : 128 H2O : x TPAOH where x was 0; 0.0385; 0.0577; 0.0770; 0.1540 and 4.1602. The zeolite was crystalized under hydrothermal condition in a stainless steel autoclave at 100°C for 5 hours. The resulting crystal was washed with distilled water until pH 8 and then dried in an oven at 80oC for 24 hours. FT-IR and XRD analysis results show that the synthesized zeolite A at x = 4.1602 has the lowest crystallinity. It is estimated due to the mass of TPAOH was four times higger than the mass of zeolite framework components (Si and Al). SEM and PSD (Particle Size Distribution) analysis results show that TPAOH concentration affected the crystal conformation and the average size of zeolite A particles. The formation of chained crystal conformation was caused by the electrostatic interactions between TPA+ and negatively charge of zeolite framework. In addition, the particel size of the synthesized zeolite A at x = 0.1540 was 2.024 µm which was smaller than the particel size of the synthesized zeolite A without TPAOH, which was 3.534 µm. Keywords: average size of particles; crystal conformation; TPAOH; zeolite A Abstrak Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi TPAOH (Tetrapropilamonium hidroksida) dalam sintesis zeolit A terhadap sifat fisikanya yang meliputi kekristalan, konformasi kristal dan ukuran rata-rata kristal yang terbentuk. Pada penelitian ini zeolit A disintesis dengan komposisi 3,165 Na2O : 1 Al2O3 : 1,926 SiO2 :128 H2O: x TPAOH. Konsentrasi TPAOH divariasikan dengan nilai x adalah 0; 0,0385; 0,0577; 0,0770; 0,1540 dan 4,1602. Metode hidrotermal digunakan dalam penelitian ini dengan kondisi suhu hidrotermal 100°C dan waktu kristalisasi selama 5 jam dengan pH pencucian 8. Hasil karakterisasi menggunakan FT-IR (Fourier Transform – Infrared Spectroscopy) dan XRD (X-Ray Diffraction) menunjukkan bahwa zeolit A yang disintesis dengan x = 4,1602 memiliki kekristalan terendah. Hal ini diperkirakan terjadi karena masa TPAOH yang digunakan empat kali lebih besar daripada masa penyusun zeolit (Si dan Al). Berdasarkan hasil karakterisasi menggunakan SEM (Scanning Electron Microscopy) dan PSD (Particle Size Distribution), dapat diketahui bahwa TPAOH berpengaruh terhadap konformasi kristal dan rata-rata ukuran kristalnya. Terbentuknya konformasi kristal seperti rantai disebabkan oleh adanya interaksi elektrostatik antara muatan positif pada TPA+ dan muatan negatif dari kerangka zeolit. Zeolit A yang disintesis dengan x = 0,1540 memiliki ukuran partikel rata-rata 2,024 µm yang lebih kecil dari daripada zeolit A tanpa TPAOH yaitu sebesar 3,534 µm. Kata kunci : ukuran partakel rata-rata; konformasi kristal; TPAOH; zeolite A

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PIPERINE-LOADED CHITOSAN NANOPARTICLES: PREPARATION AND CHARACTERIZATION

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/59/4/15523 ◽

2021 ◽

Vol 59 (4) ◽

pp. 480

Author(s):

Tran Thi Y Nhi ◽

Cong Duc Trinh ◽

Thien Do Truong ◽

Tuan Le Quang ◽

Hanh Bich Pham ◽

...

Keyword(s):

Particle Size ◽

Plasma Cholesterol ◽

Chitosan Nanoparticles ◽

Black Pepper ◽

Plasma Cholesterol Level ◽

Distribution Analysis ◽

Transmission Electron ◽

Ft Ir ◽

The Mean ◽

Ft Ir Spectroscopy

Abstract – HCTN7. Plasma cholesterol level plays an important role in atherosclerosis and cardiovascular diseases. Piperine, an alkaloid form of black pepper is known to reduce cholesterol uptake. In this paper, piperine-loaded chitosan nanoparticles (CTS-PIP NPs) were prepared by ionic gelation method. Molecular interactions among the components were confirmed by FT-IR spectroscopy. Transmission electron microscopy (TEM) images revealed spherical-shaped nanoparticles with diameter of <100 nm. CTS-PIP NPs displayed positive ζ-potential(ZP) of about 31.6 mV. Dynamic light scattering (DLS) particle size (PS) distribution analysis indicated the mean particle size of CTS-PIP NPs was 245.9 nm, polydispersity index of 31%

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Arsenic Removal by Precipitation with Calcium Phosphate Hydroxyapatite

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.506.413 ◽

2012 ◽

Vol 506 ◽

pp. 413-416 ◽

Cited By ~ 5

Author(s):

W. Dungkaew ◽

K.J. Haller ◽

A.E. Flood ◽

J.F. Scamehorn

Keyword(s):

Calcium Phosphate ◽

Water Sample ◽

Removal Efficiency ◽

Arsenic Removal ◽

Arsenic Speciation ◽

Arsenic Concentration ◽

Contaminated Water ◽

Low Levels ◽

Removal Of Arsenic ◽

Key Parameter

The removal of arsenic from synthetic arsenic contaminated water sample by precipitating arsenic (in the form of arsenate oxyanion) with calcium phosphate hydroxyapatite, HAp, was studied under conditions that induce arsenate incorporated calcium phosphate hydroxyapatite, Ca (P/As)HAp, to form. Arsenate is able to substitute for a fraction of the phosphate in HAp host material as it forms. Consequently, arsenic is successfully removed from the contaminated water achieving up to 99% arsenic removal from 25 ppm initial arsenic concentration. The Ca:(P+As) and P:As mole ratios were found to play an important role in arsenic removal efficiency. Higher Ca:(P+As) and P:As mole ratios give higher arsenic removal efficiency. Surprisingly, the pH of the initial anion solution, a key parameter in arsenic speciation, was found to not have a significant effect on arsenic removal by this process. The advantage of this process is that the precipitation can occur rapidly at relatively low levels of arsenic contamination, implying an easy and inexpensive process for arsenic removal can be developed based on this approach.

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Isolasi Dan Karakterisasi Bentonit Alam Menjadi Nanopartikel Monmorillonit

Jurnal Katalisator ◽

10.22216/jk.v3i1.2729 ◽

2018 ◽

Vol 3 (1) ◽

pp. 12 ◽

Cited By ~ 1

Author(s):

Zaimahwati Zaimahwati ◽

Yuniati Yuniati ◽

Ramzi Jalal ◽

Syahman Zhafiri ◽

Yuli Yetri

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Particle Size ◽

Surface Morphology ◽

Average Diameter ◽

Particle Size Analyzer ◽

Ft Ir ◽

Scanning Electron ◽

Sedimentation Processes

Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara. Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes. The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.

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Double-pathway arsenic removal and immobilization from high arsenic-bearing wastewater by using nature pyrite as in situ Fe and S donator

Chemical Engineering Journal ◽

10.1016/j.cej.2020.128303 ◽

2021 ◽

Vol 410 ◽

pp. 128303

Author(s):

Yongkui Li ◽

Xianjin Qi ◽

Guohua Li ◽

Hua Wang

Keyword(s):

Arsenic Removal ◽

High Arsenic

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Functional Properties and Molecular Degradation of Schizostachyum Brachycladum Bamboo Cellulose Nanofibre in PLA-Chitosan Bionanocomposites

Molecules ◽

10.3390/molecules26072008 ◽

2021 ◽

Vol 26 (7) ◽

pp. 2008

Author(s):

Samsul Rizal ◽

N. I. Saharudin ◽

N. G. Olaiya ◽

H. P. S. Abdul Khalil ◽

M. K. Mohamad Haafiz ◽

...

Keyword(s):

Electron Microscopy ◽

Particle Size ◽

Moisture Content ◽

Polymeric Materials ◽

Particle Size Analysis ◽

Size Analysis ◽

Thickness Swelling ◽

Compression Moulding ◽

Ft Ir ◽

Degradation Properties

The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.

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A Simple Dissolved Metals Mixing Route to Prepare Nanostructured Mg0.8Zn0.2TiO3 Solid Solution

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1112.47 ◽

2015 ◽

Vol 1112 ◽

pp. 47-52 ◽

Cited By ~ 4

Author(s):

Frida Ulfah Ermawati ◽

Suasmoro Suasmoro ◽

Suminar Pratapa

Keyword(s):

Solid Solution ◽

Particle Size ◽

Rietveld Analysis ◽

Dissolved Metals ◽

Intermediate Phases ◽

Particle Size Analyzer ◽

Ft Ir ◽

Xrd Patterns ◽

Zn Ions

A study of liquid mixing route to synthesize high purity Mg0.8Zn0.2TiO3 nanopowder, a candidate dielectric ceramics, has been successfully performed. Formation of the phases on the dried powder was studied using TG/DTA, XRD and FT-IR data. Rietveld analysis on the collected XRD patterns confirmed the formation of solid solution in the system. Such solid solution can be obtained from the powder calcined at 500 °C, but calcination at 550 °C gave rise to the most optimum molar purity up to 98.5% without intermediate phases. The role of Zn ions on the formation of solid solution was also discussed. Homogeneity of particle size distribution and nano-crystallinity of the system was verified from the particle size analyzer data, TEM image and the Rietveld analysis output.

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Arsenic Speciation: Reduction of Arsenic(V) to Arsenic(III) by Fulvic Acid

Environmental Chemistry ◽

10.1071/en05095 ◽

2006 ◽

Vol 3 (2) ◽

pp. 137 ◽

Cited By ~ 17

Author(s):

Tsanangurayi Tongesayi ◽

Ronald B. Smart

Keyword(s):

Fulvic Acid ◽

Arsenic Removal ◽

Research Effort ◽

Arsenic Speciation ◽

Inorganic Arsenic ◽

Stripping Voltammetry ◽

Reduction Reaction ◽

Cathodic Stripping Voltammetry ◽

Suwannee River Fulvic Acid ◽

Removal Technologies

Environmental Context.Most technologies for arsenic removal from water are based on the oxidation of the more toxic and more mobile arsenic(iii) to the less toxic and less mobile arsenic(v). As a result, research effort has been focussed on the oxidation of arsenic(iii) to arsenic(v). It is equally important to explore environmental factors that enhance the reduction of arsenic(v) to arsenic(iii). An understanding of the redox cycling of arsenic could result in the development of cheaper and more efficient arsenic removal technologies, especially for impoverished communities severely threatened by arsenic contamination. Abstract.The objective of this study was to investigate the reduction of inorganic arsenic(v) with Suwannee River fulvic acid (FA) in aqueous solutions where pH, [FA], [As(v)], [As(iii)], and [Fe(iii)] were independently varied. Samples of inorganic As(v) were incubated with FA in both light and dark at constant temperature. Sterilisation techniques were employed to ensure abiotic conditions. Aliquots from the incubated samples were taken at various time intervals and analysed for As(iii) using square-wave cathodic-stripping voltammetry at a hanging mercury drop electrode. The study demonstrated the following important aspects of As speciation: (1) FA can significantly reduce As(v) to As(iii); (2) reduction of As(v) to As(iii) is a function of time; (3) both dark and light conditions promote reduction of As(v) to As(iii); (4) Fe(iii) speeds up the reduction reaction; and (5) oxidation of As(iii) to As(v) is promoted at pH 2 more than at pH 6.

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