scholarly journals Kinetic and thermodynamic studies of polyvinyl chloride composite of manganese oxide nanosheets for the efficient removal of dye from water

2021 ◽  
Author(s):  
Tooba Saeed ◽  
Abdul Naeem ◽  
Tahira Mahmood ◽  
Afsar Khan ◽  
Zahoor Ahmad ◽  
...  
Keyword(s):  
Manganese Oxide ◽  
Surface Area ◽  
Polyvinyl Chloride ◽  
Point Of Zero Charge ◽  
Batch Adsorption ◽  
X Ray Diffraction ◽  
Efficient Removal ◽  
X Ray ◽  
Removal Capacity ◽  
The Fourier Transform

Abstract Manganese oxide nanosheets and manganese oxide composite with polyvinyl chloride (MnO2-PVC) were synthesized by the oxidation method for the efficient removal of congo red (CR). The Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray, surface area, point of zero charge and thermogravimetric analysis were performed to verify the newly synthesized adsorbents. After functionalizing the surface of MnO2 nanosheets with PVC, the PZC and SA were amplified from 4.10 and 214 m2g−1 to 5.01 and 226 m2g−1 respectively. The batch adsorption results showed that the removal capacity of CR on both the adsorbents decreased with the increase of pH and time, but increased with the increase of adsorbent dosage. However, due to the high stability, porosity and greater surface area, the PVC composite of MnO 2 was found to exhibit 15 times greater CR removal efficiency than its parent MnO 2 . Furthermore, the thermodynamic parameters specified that CR adsorption onto both the adsorbents was exothermic, spontaneous and film diffusion accompanied by the intraparticle diffusion is the rate controlling step. These results validate that MnO 2 composite with PVC is a useful, eco-friendly, competent candidate for dye removal from wastewater.

scholarly journals Polyvinyl chloride Waste as an Adsorbent for the Sorption ofPb2+from Aqueous Solution

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Donbebe Wankasi ◽  
Ezekiel Dixon Dikio
Keyword(s):  
Polyvinyl Chloride ◽  
High Surface ◽  
High Surface Area ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Controlled ◽  
The Fourier Transform ◽  
Morphological Image

The sorption of Pb2+from solution by polyvinyl chloride waste was investigated. The morphological features of the polymer sample were studied using the energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), and the Fourier transform infrared spectroscopy (FTIR). Equilibrium, kinetic, and thermodynamic batch adsorption experiments were carried out by the concentration, time, and temperature effects, respectively. The morphological image of the polymer showed irregular small size particles which indicated a high surface area and porosity that facilitated sorption. The adsorption studies recorded relatively rapid uptake of Pb2+by the polymer which was mainly diffusion controlled and followed a second order kinetic process. The thermodynamic studies suggested relatively low temperature (low energy) favoured sorption which was exothermic with a physisorption mechanism.

Safety and Efficacy of Pseudomonas Exopolymer in Sequestration of Iron From Aqueous Environments

2021 ◽  
pp. 256-272
Author(s):  
Moushumi Ghosh ◽  
Divya Sharma ◽  
Taranpreet Kaur
Keyword(s):  
Uronic Acid ◽  
Iron Removal ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Binding Characteristics ◽  
Edax Analysis ◽  
Removal Capacity ◽  
Aqueous Environments ◽  
The Fourier Transform

The present study reports the iron binding characteristics and safety of an exopolymer (EBP) of an environmental isolate of Pseudomonas sp. The EBP was predominantly polysaccharide in composition with pyruvic and uronic acid residues. A prevalence of carboxyl and hydroxyl groups was observed in the Fourier-transform infrared spectroscopy (FTIR) results, while scanning electron microscopy (SEM) revealed a porous structure in a linear fashion with large number of grooves. The purified EBP was stable for over two months and exhibited rapid binding of iron (25mg/L) within 10 minutes at ambient temperature. X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDAX) analysis of iron challenged EBP suggested the involvement of carboxyl groups in potentiating iron removal. Both Langmuir and Freundlich adsorption isotherms depicted high iron removal capacity in comparison to reported biomasses or biopolymers. Cytotoxic effects were not observed upon challenging various doses of EBP in RAW 264.7 cell lines implying a strong possibility of application of the EBP.

scholarly journals Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  
Keyword(s):  
Surface Area ◽  
Sulphuric Acid ◽  
Enzyme Immobilization ◽  
Morphological Changes ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
Kaolinite Clay ◽  
X Ray ◽  
Mineral Oxides ◽  
Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

scholarly journals Insights into Starch Coated Nanozero Valent Iron-Graphene Composite for Cr(VI) Removal from Aqueous Medium

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Prasanna Kumarathilaka ◽  
Vimukthi Jayaweera ◽  
Hasintha Wijesekara ◽  
I. R. M. Kottegoda ◽  
S. R. D. Rosa ◽  
...  
Keyword(s):  
Point Of Zero Charge ◽  
Inert Material ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Graphene Composite ◽  
Removal Capacity ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
First Time

Embedding nanoparticles into an inert material like graphene is a viable option since hybrid materials are more capable than those based on pure nanoparticulates for the removal of toxic pollutants. This study reports for the first time on Cr(VI) removal capacity of novel starch stabilized nanozero valent iron-graphene composite (NZVI-Gn) under different pHs, contact time, and initial concentrations. Starch coated NZVI-Gn composite was developed through borohydrate reduction method. The structure and surface of the composite were characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), and point of zero charge (pHpzc). The surface area and pHpzc of NZVI-Gn composite were reported as 525 m2 g−1 and 8.5, respectively. Highest Cr(VI) removal was achieved at pH 3, whereas 67.3% was removed within first few minutes and reached its equilibrium within 20 min obeying pseudo-second-order kinetic model, suggesting chemisorption as the rate limiting process. The partitioning of Cr(VI) at equilibrium is perfectly matched with Langmuir isotherm and maximum adsorption capacity of the NZVI-Gn composite is 143.28 mg g−1. Overall, these findings indicated that NZVI-Gn composite could be utilized as an efficient and magnetically separable adsorbent for removal of Cr(VI).

Hydrothermal Treatment of Coprecipitated YSZ Powders

2010 ◽  
Vol 660-661 ◽  
pp. 983-988 ◽  
Author(s):  
Alexander Rodrigo Arakaki ◽  
Walter Kenji Yoshito ◽  
Valter Ussui ◽  
Dolores Ribeiro Ricci Lazar
Keyword(s):  
Surface Area ◽  
Hydrothermal Treatment ◽  
Gas Adsorption ◽  
X Ray Diffraction ◽  
Electronic Microscopy ◽  
Immersion Method ◽  
Cubic Symmetry ◽  
X Ray ◽  
Granulometric Analysis ◽  
Symmetry Surface

Zirconia stabilized with 8.5 mol% yttria (YSZ) were synthesized by coprecipitation and resulting gels were hydrothermallly treated at 200°C and 220 PSI for 4, 8 and 16 hours. Products were oven dried at 70°C for 24 hours, isostatically pressed as pellets and sintered at 1500 °C for 1 hour. Powders were characterized for surface area with N2 gas adsorption, X-ray diffraction, laser diffraction granulometric analysis and scanning and transmission electronic microscopy. Density of ceramics was measured by an immersion method based on the Archimedes principle. Results showed that powders dried at 70°C are amorphous and after treatment has tetragonal/cubic symmetry. Surface area of powders presented a significant reduction after hydrothermal treatment. Ceramics prepared from hydrothermally treated powders have higher green density but sintered pellets are less dense when compared to that made with powders calcined at 800°C for 1 hour due to the agglomerate state of powders. Solvothermal treatment is a promising procedure to enhance density.

scholarly journals Characterization of Fly Ash Generated from Matla Power Station in Mpumalanga, South Africa

2012 ◽  
Vol 9 (4) ◽  
pp. 1788-1795 ◽  
Author(s):  
Olushola S. Ayanda ◽  
Olalekan S. Fatoki ◽  
Folahan A. Adekola ◽  
Bhekumusa J. Ximba
Keyword(s):  
Fly Ash ◽  
Inductively Coupled Plasma ◽  
Coal Fly Ash ◽  
Harmful Effect ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
Power Station ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

In this study, fly ash was obtained from Matla power station and the physicochemical properties investigated. The fly ash was characterized by x-ray fluorescence, x-ray diffraction, scanning electron microscopy, and inductively coupled plasma mass spectrometry. Surface area, particle size, ash and carbon contents, pH, and point of zero charge were also measured. The results showed that the fly ash is alkaline and consists mainly of mullite (Al6Si2O13) and quartz (SiO2). Highly toxic metals As, Sb, Cd, Cr, and Pb as well as metals that are essential to health in trace amounts were also present. The storage and disposal of coal fly ash can thus lead to the release of leached metals into soils, surface and ground waters, find way into the ecological systems and then cause harmful effect to man and its environments.

scholarly journals Synthesis of SnO2 Nanoparticles by High Potential Electrolysis

2017 ◽  
Vol 12 (2) ◽  
pp. 281 ◽  
Author(s):  
Fredy Kurniawan ◽  
Rahmi Rahmi
Keyword(s):  
Particle Size ◽  
Sno2 Nanoparticles ◽  
Particle Size Analysis ◽  
Reaction Engineering ◽  
High Potential ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanoparticles Synthesis ◽  
The Fourier Transform

SnO2 nanoparticles have been synthesized by high voltage electrolysis. Tin bare was used for anode and cathode. The effect of potentials and electrolyte were studied. The particles obtained after electrolysis was characterized using X-ray Diffraction (XRD). The diffractogram is in agreement with the standard diffraction pattern of SnO2 which is identified as tetragonal structure. The Fourier Transform Infrared (FTIR) spectrum indicates that there is a vibration of Sn–O asymmetric at 580 cm-1. The optimum potential for SnO2 nanoparticles synthesis is 60 V at 0.06 M HCl which shows the highest UV-Vis spectrum. The absorption peak of SnO2 nanoparticles by UV-Vis spectrophotometer appears at about 207 nm. The particle size analysis shows that the SnO2 nanoparticles obtained have the size distribution in a range of 25-150 nm with the highest volume at 83.11 nm. Copyright © 2017 BCREC Group. All rights reservedReceived: 15th November 2016; Revised: 26th February 2017; Accepted: 27th February 2017How to Cite: Rahmi, R., Kurniawan, F. (2017). Synthesis of SnO2 Nanoparticles by High Potential Electrolysis. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (2): 281-286 (doi:10.9767/bcrec.12.2.773.281-286)Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.2.773.281-286 

scholarly journals Synthesis and Characterization of Co-Mo/γ-Alumina Catalyst from local Kaolin clay for Hydrodesulfurization of Iraqi Naphtha

2021 ◽  
Vol 11 (1) ◽  
pp. 84-106
Author(s):  
Nada Sadoon Ahmed zeki ◽  
Sattar Jalil Hussein ◽  
Khalifa K. Aoyed ◽  
Saad Kareem Ibrahim ◽  
Ibtissam K. Mehawee
Keyword(s):  
Surface Area ◽  
Sulfur Removal ◽  
Sulfuric Acid Concentration ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mo Catalyst ◽  
Pressure Time ◽  
Al2o3 Catalyst

This work deals with the hydrodesulfurization of three types of naphtha feedstocks; mixednaphtha (WN), heavy naphtha (HN) & light naphtha (LN) with a sulfur content of 1642.1,1334.9 & 709 ppm respectively, obtained from Missan refinery using prepared Co-Mo/γ-Al2O3catalyst. The Iraqi white kaolin was used as a starting material for the preparation of γ-Al2O3support, transferring kaolin to meta-kaolin was studied through calcination at differenttemperatures and durations, kaolin structure was investigated using X-Ray diffractiontechniques.High purity 94.83%. Crystalline γ-Al2O3 with a surface area of 129.91 m2/gm, pore volume0.9002 cm3/g was synthesized by extraction of Iraqi kaolin with H2SO4 at different acid to clayweight ratios, acid concentrations & leaching time. Ethanol was used as precipitating agent; theresultant gel was dried and calcined at 70OC, 10 hrs & 900 OC, 2 hrs respectively.The effects of different parameters on the average crystallinity and extraction % ofsynthesized γ-Al2O3 were studied like; acid: clay ratio, sulfuric acid concentration, leachingtime, leaching temperature & kaolin conversion to metakaolin. Characterization of prepared γ-Al2O3 & Co-Mo catalyst were achieved by X-ray diffraction, FTIR-spectra, texture properties& BET surface area, BJH N2 adsorption porosity, AFM, SEM, crush strength & XRF tests. Co-Mo/ γ-Al2O3 catalyst with final loading 5.702 wt% and 21.45 wt% of Co and Mo oxidesrespectively was prepared by impregnation methods.The activity of prepared Co-Mo/γ-Al2O3 catalyst after moulding to be tested forhydrodesulfurization (HDS) of naphtha feedstock W.N, H.N & L.N was performed using apilot hydrotreating unit at petroleum research & development centre, at different operatingconditions. Effects of temperature, LHSV, pressure, time & pore size distribution were studied,the best percentage of sulfur removal is increased with decreasing LHSV to 2 hr-1 as a generaltrend to be 89.71, 99.72, 99.20 % at 310oC for the whole naphtha, heavy naphtha and lightnaphtha feedstocks respectively, at 34 bar pressure and 200/200 cm3/cm3 H2/HC ratio.

scholarly journals The Amounts of Water Adsorbed to the Surface of Clay Minerals at the Plastic Limit

2017 ◽  
Vol 64 (3-4) ◽  
pp. 155-162
Author(s):  
Aleksandra Gorączko ◽  
Andrzej Olchawa
Keyword(s):  
Surface Area ◽  
External Surface ◽  
Solid Phase ◽  
Water System ◽  
Basal Spacing ◽  
Plastic Limit ◽  
X Ray Diffraction ◽  
External Surface Area ◽  
X Ray ◽  
Water Layers

AbstractThe paper presents results of a study on the amount of water associated with the solid phase of the clay water system at the plastic limit. Two model monomineral clays, namely kaolinite, and montmorillonite, were used in the study. The latter was obtained by gravitational sedimentation of Na-bentonite (Wyoming).The calculated mean number of water molecule layers on the external surface of montmorillonite was 14.4, and water in interlayer spaces constituted 0.3 of the water mass at the plastic limit.The number of water layers on the external surface of kaolinite particles was 63, which was related to the higher density of the surface electrical charge of kaolinite compared to that of montmorillonite.The calculations were made on the basis of the external surface area of clays and the basal spacing at the plastic limit measured by an X-ray diffraction test. The external surface area of clays was estimated by measuring sorption at a relative humidity p/p0 = 0.5.

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