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

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.

Author(s):  
Garven M Huntley ◽  
Rudy Lin Luck ◽  
Michael E Mullins ◽  
Nick K Newberry

Four naturally occurring zeolites AZLB-Ca and AZLB-Na (Bowie, Arizona), NM-Ca (Winston, New Mexico), and NV-Na (Ash Meadows, Nevada) were studied to evaluate structural modifications after treatment with HCl acid. AZLB-Ca and AZLB-Na are chabazite-like species and become amorphous when boiled in concentrated HCl acid 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.


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

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.


2007 ◽  
Vol 534-536 ◽  
pp. 165-168 ◽  
Author(s):  
Luo Ji ◽  
Lin Tao ◽  
Zhi Meng Guo ◽  
Cheng Chang Jia

Vacuum carburization of nanometer tungsten powder was investigated in a simple designed apparatus. An X-Y recorder was used to plot differential thermal analysis (DTA) curves to determine the starting temperature of carburization of four samples with different specific surface area. The product was characterized by X-ray Diffraction (XRD) and small angle X-ray scattering (SAXS). The results show that finer tungsten powder has lower starting temperature of carburization. Tungsten powder, the BET surface area of which is 32.97m2/g, was completely carburized to tungsten carbide at 1050°C, even though the starting temperature was 890°C. The particle was found to grow sharply before carburization.


2018 ◽  
Vol 63 (1) ◽  
pp. 85-95 ◽  
Author(s):  
Harish Phattepur ◽  
Gowrishankar Bychapur Siddaiah ◽  
Nagaraju Ganganagappa

A sol-gel method was employed to synthesise pure titanium dioxide (TiO2) and surfactant assisted TiO2 nanoparticles (NPs). The effect of novel surfactant viz., Lauryl lactyl lactate on photocatalytic properties of TiO2 was studied. TiO2 NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis Diffuse Reflectance spectra (DRS), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Thermo gravimetric analysis (TGA), and Brunauer – Emmet - Teller (BET) surface area. Anatase phase of TiO2 was confirmed by X-Ray diffraction pattern and the crystallite size was between 9–19 nm. Addition of surfactant improved the BET surface area, surface defects, while the agglomeration of particles was reduced. DRS results revealed that the addition of surfactant to TiO2 sol induced a red shift of the absorption edge which resulted in the reduction of band gap from 3.23 to 3.21 eV. These physicochemical properties of TiO2 NPs were correlated with photocatalytic degradation of phenol. About 92% of phenol degradation was observed for surfactant assisted TiO2 NPs (SA-TiO2). Salicylic acid and caffeine were also degraded using SA-TiO2 NPs.


2016 ◽  
Vol 1141 ◽  
pp. 190-195
Author(s):  
Hitesh Saravaia ◽  
Hariom Gupta ◽  
Vaibhav Kulshreshtha

Barium Titanate (BaTiO3) nanostructures are synthesized by the molten salt-hydroxide reaction. The crystalline phase and chemical structure of the synthesized material are analyzed using powder x-ray diffraction (XRD) and FT-IR techniques, revealing the tetragonal BaTiO3 crystalline structure. Morphology and thermal stability of the material are characterized using TEM and TG-DTG analysis. BET surface area analysis shows significant active surface available for adsorption and its surface area value is found to be 14.8427 m2 g-1. The maximum adsorption of strontium metal is found to be 56.3 for the 1.2 g L-1 BaTiO3 adsorbent dose which reveals a remarkable separation property of the BaTiO3.


2021 ◽  
Author(s):  
Zohreh Razmara

Abstract A 2D heterometallic copper(II)–sodium(I) complex based on pyridine 2,6-dicarboxylato (dipic2-) formulated as [Cu(μ-dipic)2{Na2(µ-H2O)4}]n. 2nH2O (1) has been synthesized. Thermal stability of complex 1 was studied by thermo gravimetric analysis (TGA) and differential thermal analysis (DTA). Single-crystal X-ray diffraction (SC-XRD) analysis showed that the parallelepiped colorless crystal of complex 1 crystallizes in a monoclinic system with the space group P2/c . A highly dispersed truncated octahedral catalyst formulated as Cu-Na/Al2O3 (CNM) was prepared by thermal decomposition of complex 1. Besides, the reference catalyst of Cu-Na/Al2O3 (CNR) was prepared by impregnation conventional method. The catalysts were examined by FT-IR, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) surface area, and subjected to water-gas shift (WGS) reaction in the temperature range of 150-400 °C. The catalysts showed strong surface structure-activity dependence in WGS reaction. Improved catalytic performance during the water-gas shift reaction was observed for CNM compared to CNR due to its high dispersion, smaller particle size, and higher BET specific surface area.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
H. Ait Ahsaine ◽  
Z. Anfar ◽  
M. Zbair ◽  
M. Ezahri ◽  
N. El Alem

Zirconium oxide/activated carbon (Zr3O/AC) composite was synthesized to remove methylene blue (MB) and crystal violet (CV) from the aqueous medium. The Zr3O/AC sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analyses (EDS), Raman spectroscopy (RS), BET surface area, and Fourier transform infrared spectroscopy (FTIR). XRD profiles confirmed the successful synthesis of the zirconium oxide/activated carbon composite. SEM images showed multideveloped walls with irregular particle size with channel arrays. The nitrogen physisorption combines I and IV types with a calculated BET surface area of 1095 m2/g. Raman spectrum illustrated a disorder of both crystalline structure and the graphitic structure. The adsorption was better fitted to the pseudo-second-order (PSO) kinetic model. Langmuir model fitted better the experimental results of MB adsorption, whereas the CV was better consistent with the Freundlich model. The obtained results suggested that the MB and CV adsorption might be influenced by the mass transfer that involves multiple diffusion steps. The maximum adsorption capacities are 208.33 and 204.12 mg/g for MB and CV, respectively. The MB and CV removal mechanisms were proposed, and statistical optimization was performed using central composite design combined with the response surface methodology.


Author(s):  
Oluwadayo Francis Asokogene ◽  
Muhammad Abbas Ahmad Zaini ◽  
Misau Muhammad Idris ◽  
Surajudeen Abdulsalam ◽  
Aliyu El-Nafaty Usman

Abstract This study was aimed to evaluate the characteristics of chitosan from Pessu river crab shell and its derivatives as prospective adsorbent. The synthesized chitosan (CH) was modified with 10 % (w/v) oxalic acid (CHOx), while the composites (CHOx-ANL1, CHOx-ANL2 and CHOx-ANL3) were designated according to the amount of activated neem leave (ANL). The materials were characterized by Fourier transform infrared (FTIR), energy-dispersive X-ray (EDAX), X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), thermal gravimetric (TGA) and methylene blue dye adsorption. The FTIR spectra of chitosan samples show the characteristics of primary and secondary amine/amide groups. The SEM images exhibit a tight, porous and fractured surface, which is covered with activated neem leave for the composites. The BET surface area of chitosan materials is in the increasing order of, CH < CHOx-ANL1 < CHOx-ANL2 < CHOx < CHOx-ANL3. CHOx-ANL3 displays a higher surface area of 389 m2/g, and 70.9 % mesoporosity. Despite its lower surface area of 258 m2/g (65.4 % mesoporosity), CHOx-ANL1 exhibits a greater methylene blue adsorption of 90.8 mg/g at dye concentration of 300 mg/L. The possible removal mechanisms include ionic interaction between dye molecules and functional groups, and surface adsorption due to the textural properties of chitosan samples. Chitosan from Pessu river crab shell and its derivatives are promising adsorbent candidate for dyes and heavy metals removal from water.


2008 ◽  
Vol 368-372 ◽  
pp. 1130-1132
Author(s):  
Hong Zhi Wang ◽  
Qi Zhang ◽  
Yun Xin Gu ◽  
Yao Gang Li ◽  
Mei Fang Zhu

Ti0.6Cr0.4OxNy bimetallic metal oxynitride nano powder was synthesized by ammonolysis of the nanosized Cr2O3/TiO2 composite powder with n(Ti):n(Cr)=6:4 at 800oC for 8 h. The precursor and the resulting oxynitride were characterized by Auger electron spectroscope (AES), X-ray diffraction analysis (XRD), electron probe microanalysis (EPMA), transmission electron microscopy (TEM), and BET surface area techniques. The result indicated that the precursor was homogenous mixture of Cr2O3 and TiO2 with high BET surface area. The as-synthesized oxynitride powder contains only Ti0.6Cr0.4OxNy with cubic structure. The BET surface area of the oxynitride powder is 37.42 m2/g and the particle size is in the range of 20~30 nm.


2021 ◽  
Vol 14 ◽  
pp. 1-9
Author(s):  
Nur rahimah Said ◽  
Hazirah Syahirah Zakria ◽  
Siti Nor Atika Baharin ◽  
Nurul' Ain Jamion

Azo dyes are recognised as contaminants from the textile and printing industries that lead to human toxicity. Copper(II) activated carbon (CuAC) is an effective removal agent of dyes in these industries. The purpose of this study is to synthesise and characterise CuAC from date seeds. In addition, the efficiency of CuAC as a removal of Congo red (CR) in aqueous solution is also studied. Activated carbon (AC) was prepared from date seeds using phosphoric acid as activating agent, followed by activation process in a furnace at 500 ℃ for 2 hours. Copper(II) nitrate was used in the impregnation of AC to produce CuAC. The AC and CuAC were characterised using Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), BET surface area (SBET), Scanning Electron Microscope-Energy Dispersive X-Ray Spectroscopy (SEM-EDX), Atomic Absorption Spectroscopy (AAS) and X-Ray Diffraction (XRD). UV-VIS Spectroscopy was used to determine dye concentrations after treatment with removal agent of CuAC. The characterisation data proved that the CuAC has been successfully synthesised with 0.33% Cu(II) loaded onto AC and its surface area increased from 8.37 m2/g to 384.82 m2/g. The dye removal study was conducted at 10 ppm concentration of dye. Result revealed that 0.2 g of CuAC at pH 2 in 90 min removed 100% of CR dye.


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