scholarly journals Characterization and Utilization of Sulphuric Acid and Bitter Leaf Extract Activated Carbon from Rice Husk for Zn(II) Adsorption

2021 ◽  
Vol 21 (2) ◽  
pp. 318
Author(s):  
Ilesanmi Osasona ◽  
Ujiro Bestow Kanuhor

The world is clamoring for green synthetic modes of scientific and technological operations. From this point of view, an attempt was made to prepare activated carbon from rice husk using aqueous bitter leaf extract and a mineral acid (H2SO4) separately. The surface characteristics and the adsorption properties of the activated carbons from both methods were compared. The effects of adsorption variables on the adsorption of Zn(II) by bitter leaf extract activated carbon (RHAC1) and H2SO4 activated carbon (RHAC2) were conducted through batch studies. The morphological characterization revealed RHAC1 to be fibrous, more porous and contained finer particles than the chemical-activated counterpart. The role of hydroxyl and carbonyl groups in the adsorption of Zn(II) was pivotal. The optimum pH values for the adsorption of Zn(II) by both samples was 7. The adsorption kinetics and equilibrium isotherm obeyed Elovich and Freundlich models respectively while the evaluated Langmuir qmax were 71.47 and 67.12 mg g–1 for RHAC1 and RHAC2 respectively. The thermodynamic parameters revealed that the process was endothermic and spontaneous at all evaluated temperatures. Therefore, bitter leaf aqueous extract, as an activating agent for carbon production, could serve as a better or close substitute for the less environment-friendly H2SO4.

RSC Advances ◽  
2015 ◽  
Vol 5 (41) ◽  
pp. 32626-32636 ◽  
Author(s):  
Yaxin Li ◽  
Xian Zhang ◽  
Ruiguang Yang ◽  
Guiying Li ◽  
Changwei Hu
Keyword(s):  

H3PO4promoted the decomposition of some species to form CO2and reacted with PBTRHR to form PH3.


2021 ◽  
Vol 1162 ◽  
pp. 65-73
Author(s):  
Rakhmawati Farma ◽  
Ona Lestari ◽  
Erman Taer ◽  
Apriwandi ◽  
Minarni ◽  
...  

Heavy metal such as Cu, Fe, and Zn are the most serious contributers to environmental problems. The removal of heavy metal from the environment is the research interest nowdays. The adsorption of Cu, Fe and Zn from wastewater was investigated with various activated carbons as adsorbents. The activated carbons were produced from oil palm leaves by using multi-activation methods. The H3PO4, NaOH, ZnCl2 and KOH were chosen as chemical activating agents. Batch adsorption experiment was used to test the ability of activated carbon to remove Cu, Fe, and Zn from wastewater. The surface characteristics of activated carbon were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption isotherms. The Activated carbons were able to purify wastewater with a maximum turbidity level of 2.83 NTU. The AC-H3PO4 activated carbon showed the highest absorbability of Cu metal as 91.540%, while the highest absorbabilities of Zn and Fe metals were indicated by AC-KOH activated carbon of 22.853% and 82.244% absorption respectively. Therefore, these results enable the oil palm leaves to become a high potential for activated carbon as removal the heavy metals.


2012 ◽  
Vol 60 (2) ◽  
pp. 185-189 ◽  
Author(s):  
Mohammad Arifur Rahman ◽  
S. M. Ruhul Amin ◽  
A. M. Shafiqul Alam

The possible utilization of rice husk activated carbon as an adsorbent for the removal of methylene blue dye from aqueous solutions has been investigated. In this study, activated carbons, prepared from low-cost rice husk by sulfuric acid and zinc chloride activation, were used as the adsorbent for the removal of methylene blue, a basic dye, from aqueous solutions. Effects of various experimental parameters, such as adsorbent dosage and particle size, initial dye concentration, pH and flow rate were investigated in column process. The maximum uptakes of methylene blue by activated rice husk carbon at optimized conditions (particle sizes: 140 ?m; Flow rate: 1.4 mL/min; pH: 10.0; initial volume of methylene blue: 50 mL and initial concentration of methylene blue: 4.0 mg/L etc.) were found to 97.15%. The results indicate that activated carbon of rice husk could be employed as low-cost alternatives to commercial activated carbon in waste water treatment for the removal of basic dyes. This low cost and effective removal method may provide a promising solution for the removal of crystal violet dye from wastewater.DOI: http://dx.doi.org/10.3329/dujs.v60i2.11491 Dhaka Univ. J. Sci. 60(2): 185-189, 2012 (July)


Author(s):  
Nduka Chidimma Adamma ◽  
Okereke Josephat Nwabueze ◽  
Peter, Chukwudi

This study evaluated the efficacy of activated carbon from rice husk, corn cob and coconut husk wastes in the reduction of microbial properties of grey water samples harvested from students’ hostels. Microscopic characterization, enumerations and identification of microbial isolates were carried out to determine the microbial community before and after the treatment with activated carbon.  Staphylococcus sp, Micrococcus sp, Bacillus sp, Salmonella sp, Saccharomyces sp and Penicillium sp were observed to be present in the grey water. Before treatment, Total Heterotrophic Count (THC) was 1.2 x 1011cfu/ml, Total Coliform Count (TCC), 6.4 x 106cfu/ml and Total Fungi Count (TFC) 2.2 x 1010cfu/ml. THC after the treatment ranged from 1.69 x 109 - 7.6 x 1010cfu/ml; TCC, 2.2 x 105 - 7.3 x 108cfu/ml and TFC 1.0 x 108 - 1.2 x 109cfu/ml. Reduction in the microbial load after treatment revealed that activated carbons from rice husk, corn cob and coconut husk can be used singly or in combined states for the treatment of wastewater.


2021 ◽  
Vol 1045 ◽  
pp. 59-66
Author(s):  
Dewa Ngakan Ketut Putra Negara ◽  
Tjokorda Gde Tirta Nindhia ◽  
Lusiana ◽  
I Made Widiyarta ◽  
I Made Astika ◽  
...  

The activation process is the final stage in the manufacturing of activated carbon that can be carried out physically or chemically. This paper focuses on characterizing the surface properties of activated carbons from Gigantochloa verticillata bamboo that are chemically activated at 750°C under different impregnation ratios (IRs) of 1:1, 2:1, and 3:1. The activated carbons produced were denoted as IR1-AC, IR2-AC, and IR3-AC for impregnation ratios of 1:1, 2:1, and 3:1, respectively. Characterizations include TGA, SEM, and adsorption isotherm tests. The results of the research show that variation of the impregnation ratio yielded fluctuated content of proximate elements and surface properties of activated carbons. The highest fixed carbon of 75.69% and the lowest ash of 13.10% were obtained by IR2-AC. The highest surface area of 511.10 m2/g and pore volume of 0.561 cc/g was obtained by IR3-AC and IR2-AC, respectively. The activated carbon pores are distributed in micropores and mesopores areas with average pore diameters of 1.245, 2.494, and 1.984 nm for IR1-AC, IR2-AC, and IR3-AC, respectively. The existence of the pores can be found on the surface morphology of activated carbons.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. G. Herawan ◽  
M. S. Hadi ◽  
Md. R. Ayob ◽  
A. Putra

Activated carbons can be produced from different precursors, including coals of different ranks, and lignocellulosic materials, by physical or chemical activation processes. The objective of this paper is to characterize oil-palm shells, as a biomass byproduct from palm-oil mills which were converted into activated carbons by nitrogen pyrolysis followed by CO2activation. The effects of no holding peak pyrolysis temperature on the physical characteristics of the activated carbons are studied. The BET surface area of the activated carbon is investigated using N2adsorption at 77 K with selected temperatures of 500, 600, and 700°C. These pyrolysis conditions for preparing the activated carbons are found to yield higher BET surface area at a pyrolysis temperature of 700°C compared to selected commercial activated carbon. The activated carbons thus result in well-developed porosities and predominantly microporosities. By using this activation method, significant improvement can be obtained in the surface characteristics of the activated carbons. Thus this study shows that the preparation time can be shortened while better results of activated carbon can be produced.


2020 ◽  
Vol 11 (3) ◽  
pp. 10265-10277

Activated carbons derived from rice husk pyrolysis (biochar) were prepared by chemical activation at different biochar/K2CO3 proportions in order to assess its capacity as adsorbent. The activated material was characterized by X-ray diffraction (DRX), Raman spectroscopy, scanning electron microscopy (SEM), the Brunauer, Emmet, and Teller (BET) method. The Barret, Joyner, and Halenda (BJH) method and functional density theory (DFT), presenting interesting texture properties, such as high surface area (BET 1850 m2 g-1) and microporosity, which allow its use as a sorbent phase in solid-phase extraction (SPE) of the main constituents of the aqueous pyrolysis phase. It was demonstrated that the activated carbon (RH-AC) adsorbs different compounds present in from rice husk pyrolysis wastewater through quantitative analysis by high-performance liquid chromatography with a diode-array detector (HPLC-DAD), presenting good linearity (R2 > 0.996) at 280 nm.


Neft i gaz ◽  
2020 ◽  
Vol 3-4 (117-1118) ◽  
pp. 169-179
Author(s):  
N.O. APPAZOV¹, ◽  
◽  
B.M. BAZARBAYEV¹, ◽  
N.I. AKYLBEKOV¹*, ◽  
R.U. ZHAPPARBERGENOV¹, ◽  
...  

Co-thermolysis of rice husk and straw with oil sludge was carried out in order to obtain a widely used adsorbent – activated carbon. Carbonization was carried out in a tubular furnace made of stainless steel at a temperature of 500°C and the activation of carbonization was carried out with water vapor at a temperature of 800°C. The influence of the ratio of the initial components of the raw material (husk / straw:oil sludge) on the properties of the product was studied. The ЭКОЛОГИЯ 172 НЕФТЬ И ГАЗ 2020. 3–4 (117–118) optimal ratio for co-thermolysis of the husk: oil sludge is 9:1 (by weight), respectively. The optimal condition for the production of activated carbon by co-thermolysis of rice straw and oil sludge is a carbonization temperature of 500°C with a duration of 100 min, activation of the carbonizate at a temperature of 850°C and with a ratio of water:carbonizate = 2:1. Indices such as iodine adsorption activity, total pore volume in water, mass fraction of moisture, and bulk density were studied. The microstructures of the obtained activated carbons were studied on a scanning scanning electron microscope. Activated carbon obtained by the joint processing of rice husk and oil sludge in a ratio of 9:1 corresponds to activated carbon brand DAK. The resulting product based on rice straw and oil sludge corresponds to the activated carbons BAU-MF, BAU-A and BAU-Ats.


Author(s):  
V. Sivanandan Achari ◽  
A. S. Rajalakshmi ◽  
S. Jayasree ◽  
Raichel Mary Lopez

In this study, a new series of coconut shell based granular activated carbons (GAC) are prepared by impregnating with zirconium ions as zirconyl chloride and activated under superheated steam. These carbons are designated with activation temperature/ conditions as GAC 383 (activated at 383K), GACO 383 (HNO3 oxidised), GACZR 1273 (ZrOCl2 activated at 1273K) and GACOZR 1273 (HNO3 oxidised, ZrOCl2 activated at 1273K). Surface characteristics of these carbons are evaluated using Boehm titration methods, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction techniques (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The pore volume and the respective specific surface area of each carbon are determined by BET, I plot, Langmuir, Freundlich, and Dubinin-Radushkevich isotherms using N2 adsorption data at 77K. Analysis shows that zirconium ion enhances the surface area and porosity of granular activated carbon. The adsorption characteristics of newly prepared GAC are tested by solid-liquid equilibria using phenol as adsorbate. Equilibrium phenol adsorption data fitted to standard isotherm models of Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) equations. Adsorption constants and parameters indicate that zirconium impregnated granular activated carbons are relatively more efficient for the removal of phenol than the native carbon used.


Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1339 ◽  
Author(s):  
Silvia Vita ◽  
Rico Ricotti ◽  
Andrea Dodero ◽  
Silvia Vicini ◽  
Per Borchardt ◽  
...  

Coatings have a fundamental role in covering the external surface of yachts by acting both as protective and aesthetic layers. In particular, fillers represent the essential layer from the point of view of mechanical properties and consist of a polymeric matrix, different extenders and additives, and dispersing agents, with the latter having the role to provide good extender-matrix compatibility. In the present work, the effects of dispersing agents with an ionic or steric action on the interactions between hollow glass microspheres and an epoxy-polyamide resin are evaluated. Un-crosslinked filler materials are studied via rheological tests, whereas the mechanical and morphological properties of the crosslinked samples are assessed. The results clearly indicate that steric dispersing agents provide a much greater compatibility effect compared to ionic ones, owing to their steric hindrance capability, thus leading to better-performing filler materials with a less-marked Payne effect, which is here proved to be an efficient tool to provide information concerning the extent of component interactions in nautical fillers. To the best of our knowledge, this work represents the first attempt to deeply understand the role of dispersing agents, which are until now empirically used in the preparation of fillers.


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