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Synthesis of tungsten oxide/ amino-functionalized sugarcane bagasse derived-carbon quantum dots (WO3/N-CQDs) composites for methylene blue removal

Nugraha MW, Zainal Abidin NH, Supandi, Sambudi NS

Chemosphere, 2021 Aug;277:130300.
PMID: 33774232 DOI: 10.1016/j.chemosphere.2021.130300

In this present study, the tungsten oxide/amino-functionalized sugarcane bagasse derived-carbon quantum dots (WO3/N-CQDs) composite has successfully been prepared through a simple mixing process. The WO3 was synthesized through a precipitation method, and CQDs were amino-functionalized using ethylenedinitrilotetraacetic acid (EDTA) and ethylenediamine (EDA) through one-pot hydrothermal method. It is revealed that N-CQDs incorporation into WO3 alters the bandgap energy, crystallinity, surface area, and photoluminescence (PL) properties. The produced composites exhibit higher monoclinic WO3 crystallinity, larger surface area, lower bandgap energy and quenched photoluminescence intensity. The as-prepared WO3/N-CQDs composites exhibit better adsorption and photocatalytic degradation performance of methylene blue (MB) than the pristine WO3. It shows that the combination of N-CQDs and WO3 enhanced visible light absorption, by lowering the bandgap energy of WO3 from 2.175 to 1.495 eV. The best performance composite is WO3/N-CQDs EDA 2.5% with an efficiency of 96.86%, removal rate constant of 0.02017/min, and chemical oxidation demand (COD) removal efficiency achieved 84.61%. Moreover, the WO3/N-CQDs EDA 2.5% shows a significant photocatalytic activity even at higher MB initial concentration with 92.93% removal for 50 ppm MB. Subsequently, the composite also has good stability after a sequential 3-times cycle of degradation with 86.85% removal. The increasing photocatalytic performance is affected by the quenching effect of PL and lower bandgap energy. The lower intensity of the PL indicates the reduced charge carrier recombination resulting in increased photocatalytic activity. The combination of N-CQDs and WO3 resulted in improved photodegradation, which shows its significant potential to be utilized for wastewater treatment.

Matched MeSH terms: Methylene Blue
Visible-Light Driven Effective Photocatalytic Degradation of Methylene Blue Dye Using Perforated Curly Zn0.1Ni0.9O Nanosheets

Karthikeyan V, Gnanamoorthy G, Varun Prasath P, Narayanan V, Sagadevan S, Umar A, et al.

J Nanosci Nanotechnol, 2020 Sep 01;20(9):5759-5764.
PMID: 32331175 DOI: 10.1166/jnn.2020.17898

Herein, we report the facile synthesis, characterization and visible-light-driven photocatalytic degradation of perforated curly Zn0.1Ni0.9O nanosheets synthesized by hydrothermal process. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies confirmed the cubic phase crystalline structure and growth of high density perforated curly Zn0.1Ni0.9O nanosheets, respectively. As a photocatalyst, using methylene blue (MB) as model pollutant, the synthesized nanosheets demonstrated a high degradation efficiency of ~76% in 60 min under visible light irradiation. The observed results suggest that the synthesized Zn0.1Ni0.9O nanosheets are attractive photocatalysts for the degradation of toxic organic waste in the water under visible light.

Matched MeSH terms: Methylene Blue
Fulltext Assessment of microleakage of few restorative materials after erosion by acidic solution

Suhaida Sabdi, Wan Zaripah Wan Bakar, Adam Husein

Archives of Orofacial Sciences, 2011;6(2):26-32.
MyJurnal

Some restorative materials are susceptible to erosion but whether it also causes microleakage is still questionable. The aim of this study was to assess the microleakage of few restorative materials after immersion in acidic solution. Standardized ‘U’ shaped cavity of 4mm diameter and 2mm depth were prepared on buccal or lingual surface of 52 human premolar and molar teeth. The teeth were divided into 4 groups which contains 13 samples and 3 controls for each and were restored either with Filtek Z250 (Group 1), Fuji IX (Group 2), Fuji II LC (Group 3), or Silverfill amalgam (Group 4).
All surfaces were painted with nail varnish leaving only 2mm of tooth structure surrounding the restoration before the study samples were immersed in acidic solution, lemon juice (pH 2.74) and control samples in deionised distilled water for 24 hours. Surface photos for erosion were taken before immersion in methylene blue for 7 days. After sectioning, the assessment of dye penetration was done using Leica Imaging System DMLM (Germany). Photos showed that Fuji IX demonstrated severe erosion but no obvious changes were seen on other materials. Kruskal-Wallis test indicated that microleakage between all four groups were statistically significant. The most significant difference was between Filtek Z250 and Fuji IX (p

Matched MeSH terms: Methylene Blue
Fulltext Arthroscopic mumford procedure utilizing the anteromedial and neviaser portals – a pilot cadaveric study on neurovascular structures at risk

Nasir Mohd Nizlan, Azfar Rizal Ahmad, Hisham Abdul Rashid, Paisal Hussin, Che Hamzah Fahrudin, Abdullah Arifaizad, et al.

Malaysian Journal of Medicine and Health Sciences, 2016;12(2):16-20.
MyJurnal

Introduction: Degenerative disorder involving the acromioclavicular
joint (ACJ) is quite common especially in the elderly.
One of the surgical modalities of treatment of this disorder is the
Mumford Procedure. Arthroscopic approach is preferred due to
its reduced morbidity and faster post-operative recovery. One
method utilizes the anteromedial and Neviaser portals, which
allow direct and better visualization of the ACJ from the
subacromial space. However, the dangers that may arise from
incision and insertion of instruments through these portals are
not fully understood. This cadaveric study was carried out to
investigate the dangers that can arise from utilization of these
portals and which structures are at risk during this procedure.
Methods: Arthroscopic Mumford procedures were performed
on 5 cadaver shoulders by a single surgeon utilizing the
anteromedial and Neviaser portals. After marking each portals
with methylene blue, dissection of nearby structures were
carried out immediately after each procedure was completed.
Important structures (subclavian artery as well as brachial plexus
and its branches) were identified and the nearest measurements
were made from each portal edges to these structures. Results:
The anteromedial portal was noted to be closest to the
suprascapular nerve (SSN) at 2.91 cm, while the Neviaser portal
was noted to be closest also to the SSN at 1.60 cm. The
suprascapular nerve was the structure most at risk during the
Mumford procedure. The anteromedial portal was noted to be
the most risky portal to utilize compared to the Neviaser portal.
Conclusion: Extra precaution needs to be given to the
anteromedial portal while performing an arthroscopic distal
clavicle resection in view of the risk of injuring the
suprascapular nerve of the affected limb.

Matched MeSH terms: Methylene Blue
Comparison of composite resin and porcelain inlays for restoration of noncarious cervical lesions: An In vitro study

Chee HT, Wan Bakar WZ, Ghani ZA, Amaechi BT

Dent Res J (Isfahan), 2018 6 21;15(3):215-219.
PMID: 29922341

Background: Composite resin (CR) currently is one of the most commonly used material in restoring noncarious cervical lesions (NCCL) due to its strength and esthetics color but has microleakage problem. The aim of this study is to compare in vitro the microleakage depth between CR and porcelain in restoring NCCL.
Materials and Methods: This an in vitro study was done by preparing cavities on the buccocervical surface of 62 extracted premolar teeth which randomly assigned to two groups (n = 31) where Group 1 was restored with nanocomposite and Group 2 was cemented with porcelain cervical inlays. They were then subjected to thermocycling before immersion in 2% methylene blue dye for 24 h. Dye penetration depths were measured using Leica imaging system For statistical analysis, independent t-test was used to analyze the results (P < 0.05).
Results: Porcelain cervical inlay restorations demonstrated statistically lesser microleakage depth for the cervical margins (P = 0.018) when compared to CR. Deeper microleakage depth at the cervical compared to coronal margins of CR (P = 0.006) but no significant difference of both margins for porcelain cervical inlays (P = 0.600).
Conclusion: Porcelain cervical inlays show lesser microleakage than CR which could be alternative treatment option in restoring NCCL with better marginal seal and esthetics.

Matched MeSH terms: Methylene Blue
Synthesis of Titanium Dioxide Microstructures via Sucrose Ester Microemulsion-Mediated Hydrothermal Method

Zakarya S, Kassim A, Lim H, Anwar N, Huang N

Sains Malaysiana, 2010;39.

Titanium dioxide particles were successfully prepared using microemulsion-mediated hydrothermal processing route, with sucrose ester as a stabilising agent. X-ray diffraction patterns revealed that the particles possessed anatase crystal phase. Scanning electron micrographs showed micron-sized spherical particles with rough and smooth surfaces, which eventually interconnected with one another. The formation mechanism of the titanium dioxide microstructures was postulated. The as-prepared particles were subjected to photocatalytic degradation of methylene blue, which exhibited higher photocatalytic activity compared to their commercial counterpart.

Matched MeSH terms: Methylene Blue
Synthesis of titanium dioxide nanoparticles via sucrose ester micelle-mediated hydrothermal processing route

Anwar N, Kassim A, Lim H, Zakarya S, Huang N

Sains Malaysiana, 2010;39:261-265.

Titanium dioxide nanoparticles were synthesized via low-temperature sucrose ester micelle-mediated hydrothermal processing route using titanium isopropoxide as the precursor. X-ray diffractometer revealed that the samples possessed a mixed crystalline phases consisting of anatase and brookite in which anatase was the main phase. Upon increasing the hydrothermal reaction temperature, the degree of crystallinity of the nanoparticles improved and their morphology transformed from bundles of needles to rods and to spheres. Photocatalytic behaviour of the as-synthesized nanoparticles was investigated by photodegradation of methylene blue solution in an ultraviolet A irradiating photoreactor. The as-synthesized nanoparticles exhibited higher photocatalytic performance as compared to the commercial counterpart.

Matched MeSH terms: Methylene Blue
Photocatalytic degradation of some charges aqueous phase pollutants using nafion and silica modified TiO2

Chowdhury M, Vohra M

Sains Malaysiana, 2016;45:477-487.

The present study investigated the use of modified titanium dioxide (TiO2) based photocatalytic degradation (PCD) process for the removal of some critical charged aqueous phase pollutants. First of all, the use of Nafion TiO2 (Nf-TiO2) and silica TiO2 (Si-TiO2) for the removal of aqueous phase ammonia (NH4+/NH3) species employing near UV lamp as energy source was studied. The use of Nf-TiO2 enhanced NH4+/NH3 PCD with optimum removal noted for 1 mL of Nafion solution coating per g of TiO2 and respective overall NH4+/NH3 removal was about 1.7 times higher compared to plain TiO2 at 6 h reaction time. Similarly the 0.5 mL silica solution coating per g TiO2 sample, also enhanced NH4+/NH3 removal with optimum efficiency similar to Nf-TiO2. The results from effect of ammonia concentration on to its PCD using Nf-TiO2 indicated that overall mass based NH4+/NH3 removal was higher at greater NH4+/NH3 amounts indicating high efficiency of Nf-TiO2. Similar trends were noted for Si-TiO2 as well. Furthermore, the results from modified TiO2 and mixed NH4+/NH3 and cyanide (CN-) systems indicated successful removal of co-pollutant CN- along with simultaneous degradation of NH4+/NH3 species at rates that were still higher than plain TiO2. Nevertheless application of Nf-TiO2 for the treatment of cationic dye methylene blue (MB) indicated slower MB removal compared to plain TiO2 though significant MB degradation using Nf-TiO2 could still be achieved at pH3. Additionally the results from solar radiation energized PCD process indicated positive role of solar radiation for the removal of NH4+/NH3 species under a varying set of conditions.

Matched MeSH terms: Methylene Blue
Fecl3-activated carbon developed from coconut leaves: characterization and application for methylene blue removal

Ali H. Jawad, Mohd Azlan Bin Mohd Ishak, Nur Nasulhah Kasim, Ramlah Abd Rashid

Sains Malaysiana, 2018;47:603-610.

In this study, coconut leaves were used as a starting material for the production of activated carbon by thermal
carbonization using FeCl3
-activation method. The characterization of coconut leaves-FeCl3
activated carbon (FAC) were
evaluated by bulk density, ash content, moisture content, point-of-zero charge (pHpzc) analysis, iodine test, scanning
electron microscopy (SEM), Fourier transform infrared (FTIR) and elemental (CHNS-O) analysis. The effect of the adsorbent
dosage (0.02-0.25 g), initial pH (3-11), initial dye concentrations (30-350 mg/L) and contact time (1-180 min) on the
adsorption of the methylene blue (MB) at 303 K was performed via batch experiments. The Pseudo-Second Order (PSO)
describes the kinetic model well whereas the Langmuir isotherm proved that adsorption behavior at equilibrium with
maximum adsorption capacity (qmax) of 66.00 mg/g.

Matched MeSH terms: Methylene Blue
Growth and optimization of carbon nanotubes in powder activated carbon for an efficient removal of methylene blue from aqueous solution

Alayan HM, Alsaadi MA, AlOmar MK, Hashim MA

Environ Technol, 2019 Jul;40(18):2400-2415.
PMID: 29451094 DOI: 10.1080/09593330.2018.1441911

This work demonstrated the synthesis of carbon nanotubes (CNTs) on powder activated carbon (PAC) impregnated with Ni-catalyst through chemical vapour deposition. The optimized effects of reaction temperature, time and feedstock flow rates on CNT growth were examined. Potassium permanganate (KMnO4) and potassium permanganate in acidic solution (KMnO4/H2SO4) were used to functionalize CNTs samples. A primary screening of methylene blue (MB) adsorption was conducted. The chemical, physical and morphological properties of the adsorbent with the highest removal efficiency were investigated using FESEM, EDX, TEM, BET surface area, RAMAN, TGA, FTIR, and zeta potential. The resulting carbon nanotube-loaded activated carbons possessed abundant pore structure and large surface area. The MB removal by the as-synthesized CNTs was more remarkable than that by the modified samples. Adsorption studies were carried out to evaluate the optimum conditions, kinetics and isotherms for MB adsorption process. The response surface methodology-central composite design (RSM-CCD) was used to optimize the adsorption process parameters, including pH, adsorbent dosage and contact time. The investigation of the adsorption behaviour demonstrated that the adsorption was well fitted with the pseudo-second-order model and Langmuir isotherm with the maximum monolayer adsorption capacity of 174.5 mg/g. Meanwhile, the adsorption of MB onto adsorbent was driven by the electrostatic attraction and π-π interaction. Moreover, the as-obtained CNT-PAC exhibited good reusability after four repeated operations. In view of these empirical findings, the low-cost CNT-PAC has potential for removal of MB from aqueous solution.

Matched MeSH terms: Methylene Blue
Studies of surface plasmon resonance of silver nanoparticles reduced by aqueous extract of shortleaf spikesedge and their catalytic activity

Isa N, Osman MS, Abdul Hamid H, Inderan V, Lockman Z

Int J Phytoremediation, 2023;25(5):658-669.
PMID: 35858487 DOI: 10.1080/15226514.2022.2099345

This study describes the synthesis of silver nanoparticles (AgNPs) using shortleaf spikesedge extract (SSE) to reduce AgNO3. Visual observation, in addition to analyses of UV-vis, EDX, XRD, FTIR, and TEM was employed to monitor the formation of AgNPs. The effects of SSE concentration, AgNO3 concentration, reaction time, pH, and temperature on the synthesis of AgNPs were studied based on the surface plasmon resonance (SPR) band. From the TEM image, highly-scattered AgNPs of quasi-spherical shape with an average particle size of 17.64 nm, were observed. For the catalytic study, the reduction of methylene blue (MB) was evaluated using two systems. A detailed batch study of the removal efficiency (%RE) and kinetics was done at an ambient temperature, various MB initial concentrations, and varying reaction time. Employing the electron relay effect in System 2, the batch study clearly highlighted the significant role of AgNPs in boosting the catalytic activity for MB removal. At 30-100 mg/L initial concentrations, MB was reduced by 100% in a very short reaction time between 1.5 and 5.0 mins. The kinetic data best fitted the pseudo-first-order model with a maximum reaction rate of 2.5715 min-1. These findings suggest the promising application of AgNPs in dye wastewater treatment.The SSE-driven AgNPs were prepared using unwanted dried biomass of shortleaf spikesedge extract (SSE) as a reducing as well as stabilizing agent. Employing the electron relay effect, the batch study clearly highlighted the significant role of SSE-driven AgNPs in boosting the catalytic activity for MB removal. At 30-100 mg/L initial concentrations, MB was reduced by 100% in a very short reaction time between 1.5 and 5.0 mins. In this sense, SSE-driven AgNPs acted as an electron relay point that behaves alternatively as acceptor and donor of electrons. The findings revealed the good catalytic performance of SSE-driven AgNPS, proving their viability for dye wastewater treatment.

Matched MeSH terms: Methylene Blue
Green synthesis of palm oil mill effluent-based graphenic adsorbent for the treatment of dye-contaminated wastewater

Teow YH, Nordin NI, Mohammad AW

Environ Sci Pollut Res Int, 2019 Nov;26(33):33747-33757.
PMID: 29754300 DOI: 10.1007/s11356-018-2189-6

Textile wastewater contains methylene blue (MB), a major coloring agent in textile industry. Activated carbon (AC) is the most widely used adsorbent in removing dyes from industrial wastewater. However, high production cost of AC is the major obstacle for its wide application in dye wastewater treatment. In this study, a sustainable approach in synthesizing graphenic adsorbent from palm oil mill effluent (POME), a potential carbonaceous source, has been explored. This new development in adsorption technique is considered as green synthesis as it does not require any binder during the synthesis process, and at the same time, it helps to solve the bottleneck of palm oil industry as POME is the main cause contributed to Malaysia's water pollution problem. The synthesized GSC was characterized through XRD, FESEM, and EDX. The adsorption performance of the synthesized GSC was evaluated by adsorption of MB. The effect of initial concentration of synthetic MB solution (1-20 mg/L) and weight of GSC (5-20 g) were investigated. A remarkable change in color of synthetic MB solution from blue to crystal clear was observed at the end of adsorption study. High efficiency of the synthesized GSC for dye-contaminated wastewater treatment is concluded.

Matched MeSH terms: Methylene Blue
Box-Behnken design with desirability function for methylene blue dye adsorption by microporous activated carbon from pomegranate peel using microwave assisted K2CO3 activation

Reghioua A, Jawad AH, Selvasembian R, ALOthman ZA, Wilson LD

Int J Phytoremediation, 2023;25(14):1988-2000.
PMID: 37291893 DOI: 10.1080/15226514.2023.2216304

This research aims to convert pomegranate peel (PP) into microporous activated carbon (PPAC) using a microwave assisted K2CO3 activation method. The optimum activation conditions were carried out with a 1:2 PP/K2CO3 impregnation ratio, radiation power 800 W, and 15 min irradiation time. The statistical Box-Behnken design (BBD) was employed as an effective tool for optimizing the factors that influence the adsorption performance and removal of methylene blue (MB) dye. The output data of BBD with a desirability function indicate a 94.8% removal of 100 mg/L MB at the following experimental conditions: PPAC dose of 0.08 g, solution pH of 7.45, process temperature of 32.1 °C, and a time of 30 min. The pseudo-second order (PSO) kinetic model accounted for the contact time for the adsorption of MB. At equilibrium conditions, the Freundlich adsorption isotherm describes the adsorption results, where the maximum adsorption capacity of PPAC for MB dye was 291.5 mg g-1. This study supports the utilization of biomass waste from pomegranate peels and conversion into renewable and sustainable adsorbent materials. As well, this work contributes to the management of waste biomass and water pollutant sequestration.

Matched MeSH terms: Methylene Blue
Ceria and titania incorporated silica based catalyst prepared from rice husk: adsorption and photocatalytic studies of methylene blue

Adam F, Muniandy L, Thankappan R

J Colloid Interface Sci, 2013 Sep 15;406:209-16.
PMID: 23800370 DOI: 10.1016/j.jcis.2013.05.066

Titania and ceria incorporated rice husk silica based catalyst was synthesized via sol-gel method using CTAB and glycerol as surface directing agents at room temperature and labeled as RHS-50Ti10Ce. The catalyst was used to study the adsorption and photodegradation of methylene blue (MB) under UV irradiation. The powder XRD pattern of RHS-50Ti10Ce was much broader (2θ=25-30°) than that of the parent RHS (2θ=22°). The catalyst exhibited type IV isotherm with H3 hysteresis loop, and the TEM images showed partially ordered pore arrangements. The TGA-DTG thermograms confirmed the complete removal of the templates after calcination at 500°C. RHS-50Ti10Ce exhibited excellent adsorption capability with more than 99% removal of MB from a 40 mg L(-1) solution in just 15 min. It also decolorized an 80 mg L(-1) MB solution under UV irradiation in 210 min, which was comparable with the commercialized pure anatase TiO2.

Matched MeSH terms: Methylene Blue/isolation & purification*
The effect of nanoparticles on gastrointestinal release from modified κ-carrageenan nanocomposite hydrogels

Hezaveh H, Muhamad II

Carbohydr Polym, 2012 Jun 5;89(1):138-45.
PMID: 24750615 DOI: 10.1016/j.carbpol.2012.02.062

In this article, silver and magnetite nanofillers were synthesized in modified κ-carrageenan hydrogels using the in situ method. The effect of metallic nanoparticles in gastro-intestinal tract (GIT) release of a model drug (methylene blue) has been investigated. The effect of nanoparticles loading and genipin cross-linking on GIT release of nanocomposite is also studied to finally provide the most suitable drug carrier system. In vitro release studies revealed that using metallic nanocomposites hydrogels in GIT studies can improve the drug release in intestine and minimize it in the stomach. It was found that cross-linking and nanofiller loading can significantly improve the targeted release. Therefore, applying metallic nanoparticles seems to be a promising strategy to develop GIT controlled drug delivery.

Matched MeSH terms: Methylene Blue/chemistry
Fulltext Synthesis and characterization of hybrid molecularly imprinted polymer (MIP) membranes for removal of methylene blue (MB)

Asman S, Yusof NA, Abdullah AH, Haron MJ

Molecules, 2012 Feb 15;17(2):1916-28.
PMID: 22337139 DOI: 10.3390/molecules17021916

This work reports the synthesis and characterization of a hybrid molecularly imprinted polymer (MIP) membrane for removal of methylene blue (MB) in an aqueous environment. MB-MIP powders were hybridized into a polymer membrane (cellulose acetate (CA) and polysulfone (PSf)) after it was ground and sieved (using 90 µm sieve). MB-MIP membranes were prepared using a phase inversion process. The MB-MIP membranes were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM). Parameters investigated for the removal of MB by using membrane MB-MIP include pH, effect of time, concentration of MB, and selectivity studies. Maximum sorption of MB by PSf-MB-MIP membranes and CA-MB-MIP membranes occurred at pH 10 and pH 12, respectively. The kinetic study showed that the sorption of MB by MB-MIP membranes (PSf-MB-MIP and CA-MB-MIP) followed a pseudo-second-order-model and the MB sorption isotherm can be described by a Freundlich isotherm model.

Matched MeSH terms: Methylene Blue/isolation & purification*
Citric acid modified kenaf core fibres for removal of methylene blue from aqueous solution

Sajab MS, Chia CH, Zakaria S, Jani SM, Ayob MK, Chee KL, et al.

Bioresour Technol, 2011 Aug;102(15):7237-43.
PMID: 21620692 DOI: 10.1016/j.biortech.2011.05.011

Chemically modified kenaf core fibres were prepared via esterification in the presence of citric acid (CA). The adsorption kinetics and isotherm studies were carried out under different conditions to examine the adsorption efficiency of CA-treated kenaf core fibres towards methylene blue (MB). The adsorption capacity of the kenaf core fibres increased significantly after the citric acid treatment. The values of the correlation coefficients indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The maximum adsorption capacity of the CA-treated kenaf core fibres was found to be 131.6mg/g at 60°C. Kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion, were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second-order model equation as compared to pseudo-first-order model. The adsorption of MB onto the CA-treated kenaf core fibres was spontaneous and endothermic.

Matched MeSH terms: Methylene Blue/isolation & purification*
Microwave-assisted preparation and adsorption performance of activated carbon from biodiesel industry solid reside: influence of operational parameters

Foo KY, Hameed BH

Bioresour Technol, 2012 Jan;103(1):398-404.
PMID: 22050840 DOI: 10.1016/j.biortech.2011.09.116

Preparation of activated carbon has been attempted using KOH as activating agent by microwave heating from biodiesel industry solid residue, oil palm empty fruit bunch (EFBAC). The significance of chemical impregnation ratio (IR), microwave power and activation time on the properties of activated carbon were investigated. The optimum condition has been identified at the IR of 1.0, microwave power of 600 W and activation time of 7 min. EFBAC was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and nitrogen adsorption isotherm. The surface chemistry was examined by zeta potential measurement, determination of surface acidity/basicity, while the adsorptive property was quantified using methylene blue as dye model compound. The optimum conditions resulted in activated carbon with a monolayer adsorption capacity of 395.30 mg/g and carbon yield of 73.78%, while the BET surface area and total pore volume were corresponding to 1372 m2/g and 0.76 cm3/g, respectively.

Matched MeSH terms: Methylene Blue/chemistry
Utilization of rice husks as a feedstock for preparation of activated carbon by microwave induced KOH and K2CO3 activation

Foo KY, Hameed BH

Bioresour Technol, 2011 Oct;102(20):9814-7.
PMID: 21871796 DOI: 10.1016/j.biortech.2011.07.102

Rice husk (RH), an abundant by-product of rice milling, was used for the preparation of activated carbon (RHAC) via KOH and K(2)CO(3) chemical activation. The activation process was performed at the microwave input power of 600 W for 7 min. RHACs were characterized by low temperature nitrogen adsorption/desorption, scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption behavior was examined using methylene blue as adsorbate. The K(2)CO(3)-activated sample showed higher yield and better pore structures and adsorption capacity development than the KOH-activated sample, with a BET surface area, total pore volume and monolayer adsorption capacity of 1165 m(2)/g, 0.78 cm(3)/g and 441.52 mg/g, respectively. The results revealed the feasibility of microwave heating for preparation of high surface area activated carbons from rice husks via K(2)CO(3) activation.

Matched MeSH terms: Methylene Blue/chemistry
Scavenging behaviour of meranti sawdust in the removal of methylene blue from aqueous solution

Ahmad A, Rafatullah M, Sulaiman O, Ibrahim MH, Hashim R

J Hazard Mater, 2009 Oct 15;170(1):357-65.
PMID: 19464117 DOI: 10.1016/j.jhazmat.2009.04.087

Meranti (Philippine mahogany) sawdust, an inexpensive material, showed strong scavenging behaviour through adsorption for the removal of methylene blue (MB) from aqueous solution. Batch studies were performed to evaluate and optimize the effects of various parameters such as contact time, pH, initial dye concentrations and adsorbent dosage. Langmuir, Freundlich and Temkin isotherms were used to analyze the equilibrium data at different temperatures. The experimental data fitted well with the Langmuir adsorption isotherm, indicating thereby the mono layer adsorption of the dye. The monolayer sorption capacity of meranti sawdust for MB was found to be 120.48, 117.64, 149.25 and 158.73 mg/g at 30, 40, 50 and 60 degrees C, respectively. Thermodynamic calculations showed that the MB adsorption process is endothermic and spontaneous in nature. Kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model. The results indicated that the meranti sawdust could be an alternative material in place of more costly adsorbents used for dye removal.

Matched MeSH terms: Methylene Blue/isolation & purification*

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