scholarly journals Characterization and Modification of Clay for Removal of Drinking Water Hardness

2021 ◽  
Vol 18 (3) ◽  
pp. 318-331
Author(s):  
Asanthi Ireshika Rukshani Wickramasuriya ◽  
Ruwan Chandima Wickramasinghe Arachchige ◽  
Iresha Renuke Menike Kottegoda

Hardness in drinking water is a major problem in domestic usage. It is important to use drinking water within the tolerance limits of hardness. Clay samples obtained from two different areas in Sri Lanka were analysed, modified, and optimized with a view to suppress the hardness in drinking water. Characterization of clay was carried out using XRD (X-ray diffraction spectroscopy), FTIR (Fourier transformed infrared spectroscopy), and SEM (Scanning electron microscope). Variation of the adsorption capacity of clay was analysed at different firing temperatures of the clay samples. XRD analysis revealed that both clay types are consisting of Kaolinite as the main constituent. The hardness adsorption efficiency and the retention of hardness adsorption in prolonged cycles has been observed when the clay is heated at different temperatures. In addition, the water hardness adsorption efficiency was enhanced by the cationic modification using sodium chloride. The results further reveals that the Freundlich isotherm is best fit for Ca2+ adsorption on both Biyagama and Deniyaya clay whereas that for the Mg2+ adsorption is Langmuir isotherm. The present study is useful to develop low-cost clay-based materials to minimize water hardness.

2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
E. K. K. Baldin ◽  
C. F. Malfatti ◽  
V. Rodói ◽  
R. N. Brandalise

The objective of this study was to evaluate the influence of sterilization on a hybrid coating obtained from a sol composed of alkoxysilane tetraethoxysilane (TEOS) and organoalkoxysilane methyltriethoxysilane (MTES) containing 10% (mass) of hydroxyapatite particles. The coating was obtained by dip coating, by applying two layers (protective/bioactive), which were cured at different temperatures (450°C and 60°C). The effects of sterilization on the superficial, electrochemical, bioactive, and mechanical properties of the coating were evaluated by performing different sterilization processes, namely, steam autoclave, hydrogen peroxide plasma, and ethylene oxide. Subsequently, the coating was characterized by using scanning electron microscopy (SEM/FEG), and FTIR measurements were performed to characterize the chemical structure. The bioactivity and degradability of the coating were analyzed by mass variation after immersion in SBF and X-ray diffraction (XRD) analysis. The electrochemical behavior was assessed by open circuit potential (OCP) and potentiodynamic polarization curves and the mechanical behavior by wear resistance. Results showed that all sterilization processes caused significant morphological changes in the hybrid coating. The autoclaved sample presented the highest structural chemical changes, and, consequently, the highest degradability, even though it had a superior bioactive behavior in relation to the other samples. In addition, the sterilization processes influenced the electrochemical behavior of the hybrid coating and altered the mechanical resistance to abrasion, thus presenting lower wear performance in relation to the nonsterilized sample.


2018 ◽  
Vol 30 (8) ◽  
pp. 918-926 ◽  
Author(s):  
Rakhi Nangia ◽  
Neeraj K Shukla ◽  
Ambika Sharma

In this work, polymer blend films based on polyvinyl alcohol (PVA)/poly(ethylene glycol) (PEG) were prepared by solution casting technique. X-ray diffraction (XRD) analysis was performed to investigate the structural details of the polymer blend. XRD pattern confirms the polycrystalline nature of the films. Sandwich structures of the type Ag-PVA/PEG-Ag were formed to study the dielectric and conduction properties in the frequency range 300 Hz–3 MHz and at different temperatures varying from 298 K to 420 K. Experimental results show that both dielectric constant ( ε′) and dielectric loss ( ε″) values were strong functions of frequency and temperature. The AC conductivity ( σAC) was found to obey the power law Aωs and correlated barrier hopping as the conduction mechanism. The imaginary part of electric modulus shows peak shifting corresponding to relaxation mechanisms. Electric modulus study was also found to support the dielectric permittivity data.


2019 ◽  
Vol 48 (5) ◽  
pp. 464-471
Author(s):  
Fatma Abdelghaffar ◽  
Rehab A. Abdelghaffar ◽  
Safia A. Mahmoud ◽  
Badria M. Youssef

Purpose This paper aims to improve the adsorption capacity of sugarcane bagasse (SCB) as a low-cost, attractive and effective adsorbent for dye removal from wastewater. Design/methodology/approach SCB is a cellulosic material; it was chemically modified with compounds containing cationic groups. The adsorption efficiency of unmodified and modified SCB was investigated with anionic dyes by studying various factors that affect modified SCB and adsorption. Findings X-ray diffraction, FT-IR spectra and nitrogen content were used to confirm the effect of existence of quaternary ammonium groups on modified SCB. The morphological structure of the modified and unmodified SCB has been demonstrated using electronic scanning microscopy. Research limitations/implications The modified SCB was chemically treated by Quat 188, which is commercially available in the solution of 3-chloro-2-hydroxypropyltrimethyl ammonium chloride. Practical implications Grafting cationic function groups on the surface of sugarcane by cationization treatment enhances its adsorption efficiency for anionic dyes. Originality/value The main value of this research was indicating a clear difference in the appearance of unmodified and modified SCB surfaces. Furthermore, it can be determined that the modified SCB absorbs more of the dyes.


2014 ◽  
Vol 605 ◽  
pp. 31-34
Author(s):  
Girolamo Costanza ◽  
R. Donnini ◽  
Saulius Kaciulis ◽  
Giorgio Maddaluno ◽  
Roberto Montanari

W is a promising material to use as protection for thermal shields in future nuclear fusion reactors, however the joining to other metals is really challenging. For realizing such joints plasma spraying (PS) has been used for its simplicity, the possibility to cover complex and extended surfaces and the relatively low cost. An appropriate interlayer must be optimized to increase the adhesion of W on the substrates and to provide a soft interface for better thermo-mechanical compatibility.The present work demonstrates that high-temperature X-ray diffraction (HT-XRD) permits to quickly assess the reliability and quality of the coating-interlayer-substrate system by measuring the strain of coating. This is very useful to orientate the work for optimizing the structure and composition of the interlayer and the parameters of deposition process.


2021 ◽  
Vol 33 (6) ◽  
pp. 1304-1308
Author(s):  
Debasish Mondal ◽  
Dipankar Mahata ◽  
Kamala Mandy Hansda ◽  
Sourav Mondal ◽  
Ajit Das

Recently non-harmful nanomaterials have acquired critical significant attention in wastewater treatment containing organic pollutants especially toxic and hazardous dyes. In this regard, a low cost and eco friendly method has been investigated for the green synthesis of alumina nanoparticles (Al2O3 NPs). The alumina nanoparticles were synthesized using an aqueous extract of Psidium guajava leaf as a potential stabilizing agent. The UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) techniques were used to characterize the synthesized nanoparticles. The absorption at 281 nm confirmed the formation of alumina nanoparticles. The FTIR spectra and XRD analysis confirmed the presence of various functional groups and crystalline structures of Al2O3 NPs during the synthesis. The spectrum clearly indicates the organic moieties in Psidium guajava extract are responsible for the biosynthesis of Al2O3 NPs. The suface morphology of Al2O3 NPs was confirmed by SEM and EDS studies. Besides this, the removal of methylene blue through adsorption and kinetic study was also reported.


2019 ◽  
Vol 9 (2) ◽  
pp. 102-115
Author(s):  
Hanane Essebaai ◽  
Ilham Ismi ◽  
Ahmed Lebkiri ◽  
Said Marzak ◽  
El Housseine Rifi

Highly efficient low-cost adsorbent was applied for copper (II) ions uptake from aqueous solution. Characteristics of natural adsorbent were established using scanning X-ray diffraction (XRD), X-ray fluorescence, electron microscope (SEM) and Fourier Transform Infra-Red (FTIR). Various physicochemical parameters such as contact time, initial copper(II) ions concentration, adsorbent dosage, pH of copper (II) ions solution and temperature were investigated. The result showed that the adsorption of copper (II) ions by natural clay was favorable at pH=5,5. The adsorption was found to increase with increase in initial copper (II) ions concentration, and contact time. Equilibrium adsorption data were fitted using three isotherms and kinetic data tested with four kinetic models. Freundlich isotherm best described the adsorption of copper (II) ions onto utilised clay, the maximum monolayer adsorption capacity (qmax) was 8 mg/g. Pseudo-second-order model best described the kinetics of the adsorption process. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were determined. It was found that copper (II) ions adsorption was spontaneous (ΔG°<0) and endothermic (ΔH°>0).


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1129
Author(s):  
Luyara de Almeida Cavalcante ◽  
Laís Sibaldo Ribeiro ◽  
Mitsuo Lopes Takeno ◽  
Pedro Tupa Pandava Aum ◽  
Yanne Katiussy Pereira Gurgel Aum ◽  
...  

The present work demonstrates the production of chlorapatite (ClAp) through thermal decomposition of chemically treated fish scales, originating from an Amazon fish species (Arapaima gigas). The scales were treated with hydrochloric acid (HCl) solution for deproteinization. Afterwards, the solution was neutralized by sodium hydroxide (NaOH) treatment to obtain an apatite-rich slurry. The heat treatment was carried out at different temperatures including 600 °C, 800 °C, and 1000 °C. The powders obtained were characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). The XRD analysis and FTIR spectra confirmed the incorporation of chlorine into the apatite structure. The FTIR results showed absorption bands relative to the OH–, PO43− functional groups which are a characteristic of chlorapatite. Moreover, the intensity of the OH–Cl elongation could be observed. Chlorapatite Ca5(PO4)3Cl, NaCl, and NaCaPO4 phases were identified, achieving up to 87.4 wt% for ClAp. The SEM observations show that with increasing temperature, the ClAp obtained consists of slightly larger, more crystalline grains. Furthermore, the grains ranged in size, between 1-5 μm and ClAp1000 sample recorded crystallinity of 84.27%. ClAp and NaCaPO4 can be used in electronics as phosphor materials due to their luminescence and biomedical applications.


MRS Advances ◽  
2020 ◽  
Vol 5 (26) ◽  
pp. 1357-1366
Author(s):  
E.S Akpan ◽  
M. Dauda ◽  
L.S Kuburi ◽  
D.O Obada

AbstractIn this study, biological hydroxyapatite (HAp) was synthesized from catfish (Pangasius hypophthalmus) bones. First, the as-received catfish bones were de-proteinized in open air, and then converted to HAp by a solid state heat treatment method at a temperature of 900 °C for a holding time of 2 h in a muffle furnace. X-ray diffraction (XRD) analysis confirmed that HAp with high crystallinity of 99.9% was formed matching the structural properties of flouro-apatite with crystallite sizes of approximately 37.1 nm. The morphology of the HAp prepared showed irregularly shaped particles and revealed the appearance of open pores with a less agglomerated structure and a Ca/P ratio of about 1.58. The specific mechanical properties: hardness, compressive strength and fracture toughness of the catfish derived scaffolds were recorded as 480 MPa, 1.92 MPa, and 5.72 Mpa.m1/2, respectively. The fracture toughness of the HAp derived scaffolds suggests that the produced biomaterial is promising for biomedical applications. These findings are useful for the production and application of the HAp powders prepared from catfish bones, and further suggests a possible low-cost route for producing inexpensive ceramics using natural catfish bones.


2017 ◽  
Vol 64 (5) ◽  
pp. 508-514 ◽  
Author(s):  
M. Adam Khan ◽  
S. Sundarrajan ◽  
S. Natarajan

Purpose The aim of this paper is to study the hot corrosion behaviour of super 304H stainless steel for marine applications. Design/methodology/approach The investigation was carried out with three different combinations of salt mixture (Na2SO4, NaCl and V2O5) at two different temperatures (800 and 900°C). Findings The spalling and growth of oxide layer was observed more with the presence of V2O5 in the salt mixture at 900°C during experimentation than what was observed in 800°C. The mass change per unit area is calculated to study the corrosion kinetics and also the influence of salt mixture. Further, the samples are analysed through materials characterisation techniques using optical image, scanning electron microscope (SEM), energy dispersive X-ray (EDAX) and X-ray diffraction (XRD) analysis. The presence of V2O5 in the salt mixture was the most important influencing species for accelerating hot corrosion. Originality/value SEM, EDAX and XRD analysis confirmed the formation of Fe2O3 and Cr2O3 at 900°C showing contribution in corrosion protection.


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