scholarly journals Utilization of Rice Husk Ash in the Preparation of Graphene-Oxide-Based Mesoporous Nanocomposites with Excellent Adsorption Performance

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1214
Author(s):  
Tzong-Horng Liou ◽  
Yuan Hao Liou

Rice husk is an agricultural biomass waste. Burning rice husks in an oxygenic atmosphere releases thermal energy and produces ash that is rich in silica. Rice husk ash (RHA) can be used as a sustainable source of silica for producing high-value-added products. In this study, mesostructural graphene oxide (GO)/SBA-15, a graphene-based hybrid material, was synthesized from RHA. The materials are inspected by Fourier transform infrared spectrometer, Raman spectrometer, field-emission scanning electron microscopy, transmission electron microscopy, surface area analyzer, and X-ray diffraction analyzer. Studies have revealed that GO/SBA-15 possesses various oxygen functional groups that are helpful for dye adsorption. The material consisted of high pore volume of 0.901 cm3/g, wide pores of diameter 11.67 nm, and high surface area of 499 m2/g. Analysis of the methylene blue (MB) adsorption behavior of GO/SBA-15 composites revealed that their adsorption capacity depended on the gelation pH, GO content, adsorbent dosage, and initial dye (MB) concentration. The highest adsorption capacity of GO/SBA-15 was 632.9 mg/g. Furthermore, the adsorption isotherms and kinetics of GO/SBA-15 were investigated. This study demonstrated the great advantage of treated RHA and the potential of this material for use in organic dye adsorption.

2020 ◽  
Vol 20 (5) ◽  
pp. 2867-2877
Author(s):  
Tzong-Horng Liou ◽  
Pie-Ying Wang

Rice husk is an agricultural waste that provides an alternative renewable source of bioenergy. Burning rice husk can produce rice husk ash. The rice husk ash is a potential resource of low-cost precursor for synthesizing high value-added materials. This paper reports the synthesis of SBA-15 mesoporous silica from recycled rice husk ash waste. Next, graphene oxide/ordered mesoporous carbon (GO/CMK-3) nanocomposite was synthesized using the SBA-15 template. The composite was investigated by X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectrometer, Raman spectrometer and surface area analyzer. Experimental results confirmed that GO/CMK-3 composite possessed high surface area (936 m2/g), large pore volume (1.077 cm3/g), and uniform pore size (4.35 nm). The mesopore structure was not destroyed by the introduction of GO. Methylene blue was employed as an adsorbate to evaluate the adsorption capacity of GO/CMK-3 composite. The GO/CMK-3 revealed much higher adsorption capacity levels than did pure CMK-3 and SBA-15. The adsorption capacity decreased with increasing solution temperature, and increasing initial concentration of dye. The thermodynamic observation indicated that the total adsorption process was spontaneous and exothermic. The conversion of rice husk ash waste into GO/CMK-3 composites can be regarded as an economically beneficial by-product for reducing environmental pollution.


2014 ◽  
Vol 625 ◽  
pp. 498-502
Author(s):  
Samah B. Daffalla ◽  
Hilmi Mukhtar ◽  
Maizatul S. Shaharun

In this research, the development of three (3) low-cost adsorbent materials from abundant waste rice husk was achieved via thermal treatment. The physiochemical properties of the developed adsorbents were evaluated. Their adsorption behaviours in batch system were evaluated for the removal of phenol from aqueous solutions by varying the pH (2 to 10). It was found that, the rice husk ash burned a 400oC for 1hr ‘RHA400,1’ has the highest surface area (201.36 m2.g-1) followed by RHA300,4(87.08 m2.g-1) and RHA600,1(43.22 m2.g-1), respectively. RHA400,1had shown the highest removal efficiency followed by RHA300,4and RHA600,1, towards phenol due to high surface area and porosity. The maximum uptake of phenol was found at pH 4. The adsorption kinetics was well described by both pseudo-second order and the Elovich models.


2014 ◽  
Vol 798-799 ◽  
pp. 727-731 ◽  
Author(s):  
Angela M. Gutierrez ◽  
Dachamir Hotza ◽  
Gabriel B. Dutra ◽  
André L. Nogueira ◽  
César V. Franco ◽  
...  

In this work, silver nanoparticles were incorporated in four different concentrations into rice husk ash (RHA) to promote an antimicrobial effect. The suspension was magnetic stirred and dried at 80°C for 24 h. The samples were characterized by scanning electron microscopy (SEM), specific surface area and zeta potential measurements. Microbiological analyses were conducted test the efficiency of the material in the elimination of the bacteria Escherichia coli. SEM results revealed a homogeneous dispersion of silver nanoparticles on the substrate, surface area values similar to those found in the literature and effective antimicrobial activity at low silver concentration.


2021 ◽  
Vol 10 (2) ◽  
Author(s):  
Miyuki Miyazaki ◽  
Takeshi Shiono

Rice husk (RH) is a biomass resource that contains about 20 mass% silica. In Southeast Asia countries, RH is used as fuel for thermal power plants, and it produces a large amount of ash (Rice Husk Ash: RHA), as industrial waste. Furthermore, our research group has reported that consolidated zeolite A could be prepared from RHA as a raw material. Zeolite A has hydrophilic micropore in the structure and is used for adsorption and a builder for detergent. From processing point of view, the remaining carbon must be removed before synthesizing of zeolite A. However, the utility of carbon in RHA has not been studied sufficiently. In the present study, therefore, the possibility of usage of both silica and carbon in RHA as a raw material was investigated for the high value-added application of RHA. Before the synthesis of zeolite, activation treatment of carbon was carried out for RHA under specific conditions to make the carbon become porous. The specific surface area was measured by BET for activated RHA. Additionally, hydrothermal treatments were attempted after adjusting the composition of raw materials for the preparation of composites of carbon and zeolite. For the obtained specimens, XRD analysis and SEM were conducted as characterizations to confirm crystalline phases and microstructures respectively. Activation treatment made the specific surface area of RHA larger. As the activation time and temperature increased, silica was crystallized to cristobalite and the reactivity was decreased. The crystalline phase of zeolite A was recognized in the specimens with an appropriate composition. Furthermore, the homogenous zeolite A particles with a size smaller than 1 μm were also observed. Therefore, activated carbon-zeolite composites could be synthesized from RHA.


Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1540
Author(s):  
Muhammad Ahmad ◽  
Tehseen Nawaz ◽  
Mohammad Mujahid Alam ◽  
Yasir Abbas ◽  
Shafqat Ali ◽  
...  

The development of excellent drug adsorbents and clarifying the interaction mechanisms between adsorbents and adsorbates are greatly desired for a clean environment. Herein, we report that a reduced graphene oxide modified sheeted polyphosphazene (rGO/poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol)) defined as PZS on rGO was used to remove the tetracycline (TC) drug from an aqueous solution. Compared to PZS microspheres, the adsorption capacity of sheeted PZS@rGO exhibited a high adsorption capacity of 496 mg/g. The adsorption equilibrium data well obeyed the Langmuir isotherm model, and the kinetics isotherm was fitted to the pseudo-second-order model. Thermodynamic analysis showed that the adsorption of TC was an exothermic, spontaneous process. Furthermore, we highlighted the importance of the surface modification of PZS by the introduction of rGO, which tremendously increased the surface area necessary for high adsorption. Along with high surface area, electrostatic attractions, H-bonding, π-π stacking and Lewis acid-base interactions were involved in the high adsorption capacity of PZS@rGO. Furthermore, we also proposed the mechanism of TC adsorption via PZS@rGO.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  

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.


RSC Advances ◽  
2014 ◽  
Vol 4 (85) ◽  
pp. 45244-45250 ◽  
Author(s):  
Yun Meng ◽  
Liyuan Zhang ◽  
Liyuan Chai ◽  
Wanting Yu ◽  
Ting Wang ◽  
...  

PmPD nanobelts with high adsorption performance have been synthesized by using CTAP as oxidants.


2016 ◽  
Vol 75 (2) ◽  
pp. 350-357
Author(s):  
Graham Dawson ◽  
Wei Chen ◽  
Luhua Lu ◽  
Kai Dai

The adsorption properties of two nanomorphologies of trititanate, nanotubes (TiNT) and plates (TiNP), prepared by the hydrothermal reaction of concentrated NaOH with different phases of TiO2, were examined. It was found that the capacity for both morphologies towards methylene blue (MB), an ideal pollutant, was extremely high, with the TiNP having a capacity of 130 mg/g, higher than the TiNT, whose capacity was 120 mg/g at 10 mg/L MB concentration. At capacity, the well-dispersed powders deposit on the floor of the reaction vessel. The two morphologies had very different structural and adsorption properties. TiNT with high surface area and pore volume exhibited exothermic monolayer adsorption of MB. TiNP with low surface area and pore volume yielded a higher adsorption capacity through endothermic multilayer adsorption governed by pore diffusion. TiNP exhibited a higher negative surface charge of −23 mV, compared to −12 mV for TiNT. The adsorption process appears to be an electrostatic interaction, with the cationic dye attracted more strongly to the nanoplates, resulting in a higher adsorption capacity and different adsorption modes. We believe this simple, low cost production of high capacity nanostructured adsorbent material has potential uses in wastewater treatment.


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