scholarly journals Development of Biosorbent Derived from the Endocarp Waste of Gayo Coffee for Lead Removal in Liquid Wastewater—Effects of Chemical Activators

2021 ◽  
Vol 13 (6) ◽  
pp. 3050
Author(s):  
Mariana Mariana ◽  
Farid Mulana ◽  
Lisa Juniar ◽  
Dinda Fathira ◽  
Risna Safitri ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Removal Efficiency ◽  
Volume Ratio ◽  
Raw Material ◽  
Lead Removal ◽  
Positive Role ◽  
X Ray ◽  
And Performance ◽  
Enhanced Adsorption

This study reports the development of bio-based adsorbent by utilizing coffee endocarp (CE) waste as a raw material for lead (Pb) removal from liquid wastewater. The effect of NaOH and HCl as activation precursors on the characteristics and performance of the resulting adsorbents was investigated. The prepared adsorbents were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Surface Area Analyzer (SAA). The characterization results confirm the positive role of the activation by either NaOH or HCl in enhancing the surface properties of the resulting adsorbents. The chemical activations removed most of impurities leading to smoother surface, pore size enlargement and enhanced surface area to pore volume ratio, which result in an enhanced adsorption capacity and Pb removal efficiency. The raw adsorbent shows 57.7% of Pb removal efficiency and sorption capacity of 174.4 mg/g. On the other hand, after the chemical treatment using HCl and NaOH, the Pb removal efficiencies increased up to 63.9% and 89.86%, with adsorption capacity of 193 and 271.58 mg/g, respectively. Though both activated sorbents demonstrate better adsorption performance compared to the non-activated CE, overall results reveal that the NaOH-activated sorbent offers better characteristic and performance than the HCl-activated sorbent.

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.

scholarly journals Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Chemical Compositions ◽  
Ion Adsorption ◽  
X Ray ◽  
Wool Keratin

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

Removal of Remazol Red RR from Aqueous Solution by Glass Supported Films of Synthesized ZnO Nanoparticles

2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Mohammad Akter Hossain ◽  
Md. Nazmul Kayes ◽  
Md. Mufazzal Hossain
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
High Surface ◽  
Sol Gel ◽  
Volume Ratio ◽  
Textile Dye ◽  
Sunlight Irradiation ◽  
X Ray ◽  
Operating Variables ◽  
Remazol Red

The nanoparticles of ZnO (n-ZnO) have been synthesized by a sol-gel method and characterized by UV-visible and FTIR spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray spectrometry (EDX) and powder X-ray diffractometry (XRD). Precursor of n-ZnO particles were prepared via a non-aqueous route, which was calcined at 500oC. These particles were then deposited on a glass substrate for adsorption and photodegradation of a typical textile dye, Remazol Red R (RRR). Especially, the high surface to volume ratio of nanoparticles has appealed much attention to use these particles both as an adsorbent and a photocatalyst. A comparative study was carried out between n-ZnO and a commercially available ZnO (c-ZnO) to investigate the removal efficiency of RRR from its aqueous solution under different conditions. The removal efficiency has been optimized by varying several operating variables and the highest performance has been obtained with 0.115 g/slide of ZnO and 0.5 × 10-4 M aqueous solution of RRR under sunlight irradiation. It is important to note that the use of the films of ZnO in the presence of solar light makes it suitable for recycling and causes no secondary environmental pollution.

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

2021 ◽  
Author(s):  
Garven M Huntley ◽  
Rudy Lin Luck ◽  
Michael E Mullins ◽  
Nick K Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
Acid Modification ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

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.

scholarly journals Investigation of kinetics and adsorption isotherm for fluoride removal from aqueous solutions using mesoporous cerium–aluminum binary oxide nanomaterials

RSC Advances ◽  
2021 ◽  
Vol 11 (46) ◽  
pp. 28744-28760
Author(s):  
Rumman Zaidi ◽  
Saif Ullah Khan ◽  
I. H. Farooqi ◽  
Ameer Azam
Keyword(s):  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Removal Efficiency ◽  
Small Dose ◽  
Binary Oxide ◽  
Fluoride Removal ◽  
Maximum Adsorption Capacity

Mesoporous Ce–Al binary oxide nanomaterials prepared with a surface area of 110.32 m2 g−1 showed defluoridation capacity at pH 2.4, exhibited maximum adsorption capacity of 384.6 mg g−1 and a removal efficiency of 91.5% at a small dose of nanoadsorbent.

scholarly journals CuAl LDH/Rice Husk Biochar Composite for Enhanced Adsorptive Removal of Cationic Dye from Aqueous Solution

2020 ◽  
Vol 15 (2) ◽  
pp. 525-537 ◽  
Author(s):  
Neza Rahayu Palapa ◽  
Tarmizi Taher ◽  
Bakri Rio Rahayu ◽  
Risfidian Mohadi ◽  
Addy Rachmat ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Malachite Green ◽  
Rice Husk ◽  
Low Cost ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Cationic Dye ◽  
X Ray ◽  
Adsorptive Removal

The preparation of CuAl LDH and biochar (BC) composite derived from rice husk and its application as a low-cost adsorbent for enhanced adsorptive removal of malachite green has been studied. The composite was prepared by a one-step coprecipitation method and characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy - Energy Dispersive X-ray (SEM−EDX). The result indicated that CuAl LDH was successfully incorporated with the biochar that evidenced by the broadening of XRD peak at 2θ = 24° and the appearance of a new peak at 1095 cm−1 on the FTIR spectra. The BET surface area analysis revealed that CuAl/BC composite exhibited a larger surface area (200.9 m2/g) that the original CuAl LDH (46.2 m2/g). Surface morphological changes also confirmed by SEM image, which showed more aggregated particles. The result of the adsorption study indicated the composite material was efficient in removing malachite green with Langmuir maximum adsorption capacity of CuAl/BC reaching 470.96 mg/g, which is higher than the original CuAl LDH 59.523 mg/g. The thermodynamic analysis suggested that the adsorption of malachite green occurs spontaneously (ΔG < 0 at all tested temperature) and endothermic nature. Moreover, the CuAl/BC composite showed strong potential as a low-cost adsorbent for cationic dye removal since it showed not only a high adsorption capacity but also good reusability. Copyright © 2020 BCREC Group. All rights reserved

Impact of Impurities in Metallurgical Grade Silicon on Removal Efficiency of Vacuum Evaporation

2011 ◽  
Vol 287-290 ◽  
pp. 1521-1525
Author(s):  
Kui Xian Wei ◽  
Wen Hui Ma ◽  
Yang Zhou ◽  
Ke Qiang Xie ◽  
Bin Yang ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Raw Materials ◽  
Vacuum Evaporation ◽  
Raw Material ◽  
Vacuum Furnace ◽  
Metallurgical Grade Silicon ◽  
Quality Product ◽  
Grade Silicon ◽  
And Performance ◽  
Volatile Impurities

Vacuum evaporation is usually utilized to remove volatile impurities in metallurgical grade silicon to prepare solar grade silicon by metallurgical routes. Especially phosphorus needs to be removed by vacuum evaporation. And the removal efficiency of impurities strongly influenced the quality and performance of products. In this paper, the removal efficiency of impurities is studied by using different raw material. The results indicated that the content of impurities in raw material had deep effect on the removal efficiency of vacuum evaporation. The high quality product can be obtained by vacuum evaporation only once from raw materials with the lower content of impurities whereas it is not for high content of impurities in raw material. This is due to the vapor-liquid equilibrium in the vacuum furnace. The impurities can be removed effectively by vacuum evaporation many times.

Guanidine sulfate-assisted synthesis of hexagonal WO3 nanoparticles with enhanced adsorption properties

2015 ◽  
Vol 44 (16) ◽  
pp. 7419-7427 ◽  
Author(s):  
Wanjun Mu ◽  
Mei Li ◽  
Xingliang Li ◽  
Zongping Ma ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
Adsorption Properties ◽  
Large Specific Surface Area ◽  
Enhanced Adsorption

The hexagonal WO3 nanowires prepared with the assistance of C2H10N·H2SO4 possess a large specific surface area and numerous adsorption functional groups, consequently improving the Sr2+ adsorption capacity considerably.

Preparation and Performance Characterization of “Turnjujube-Like” CdSe Nanofibers

2014 ◽  
Vol 971-973 ◽  
pp. 123-126
Author(s):  
Yong Ping Luo ◽  
Zong Hu Xiao ◽  
Shun Jian Xu ◽  
Wei Zhong ◽  
Huan Wen Wu ◽  
...  
Keyword(s):  
Structure Characterization ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Cubic Crystal ◽  
X Ray ◽  
Zinc Blende ◽  
And Performance ◽  
First Time

It was reported for the first time that “Turnjujube-like” CdSe nanofibers have been assembled onto TiO2surface by electrochemical method of cyclic voltammetry, using CdSO4•8H2O and SeO2as raw material, can be used as a sensitizer of quantum dot-sensitized solar cell. CdSe morphology, structure characterization and optical properties are characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and ultraviolt-visible spectroscopy (UV–Vis), respectively. The experimental results show that the prepared “Turnjujube–like” CdSe nanofibers are zinc blende CdSe with cubic crystal system, and it have excellent light absorption within the wavelength range of 300–800 nm. It has a potential for the construction of QD-sensitized solar energy cell.

scholarly journals Removal of Cr (VI) by Biochar Derived from Six Kinds of Garden Wastes: Isotherms and Kinetics

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3243
Author(s):  
Qiao-Chu Zhang ◽  
Cheng-Chen Wang ◽  
Jin-Hua Cheng ◽  
Cheng-Liang Zhang ◽  
Jing-Jing Yao
Keyword(s):  
Adsorption Capacity ◽  
Removal Efficiency ◽  
Raw Materials ◽  
Great Influence ◽  
Populus Tomentosa ◽  
Raw Material ◽  
Sophora Japonica ◽  
Platycladus Orientalis ◽  
Different Temperatures ◽  
Garden Waste

Garden waste is one of the main components of urban solid waste which affects the urban environment. In this study, garden waste of Morus alba L. (SS), Ulmus pumila L. (BY), Salix matsudana Koidz (LS), Populus tomentosa (YS), Sophora japonica Linn (GH) and Platycladus orientalis (L.) Franco (CB) was pyrolyzed at 300 °C, 500 °C, 700 °C to obtain different types of biochar, coded as SSB300, SSB500, SSB700, BYB300, etc., which were tested for their Cr (VI) adsorption capacity. The results demonstrated that the removal efficiency of Cr by biochar pyrolyzed from multiple raw materials at different temperatures was variable, and the pH had a great influence on the adsorption capacity and removal efficiency. GHB700 had the best removal efficiency (89.44%) at a pH of 2 of the solution containing Cr (VI). The pseudo second-order kinetics model showed that Cr (VI) adsorption by biochar was chemisorption. The Langmuir model showed that the adsorption capacity of SSB300 was the largest (51.39 mg·g−1), BYB500 was 40.91 mg·g−1, GHB700, CBB700, LSB700, YSB700 were 36.85 mg·g−1, 36.54 mg·g−1, 34.53 mg·g−1 and 32.66 mg·g−1, respectively. This research, for the first time, used a variety of garden wastes to prepare biochar, and explored the corresponding raw material and pyrolysis temperature for the treatment of Cr (VI). It is hoped to provide a theoretical basis for the research and utilization of garden wastes and the production and application of biochar.

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