ORCID Profile
0000-0002-8347-4281
Current Organisations
Instituto Português de Oncologia de Lisboa Francisco Gentil EPE
,
Institut Teknologi Sepuluh Nopember
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Publications
The effect of sodium silicate and sodium hydroxide on the strength of aggregates made from coal fly ash using the geopolymerisation method
Publisher: Wiley
Date: 23-08-2010
DOI: 10.1002/APJ.493
Pervaporation Membranes for Seawater Desalination Based on Geo–rGO–TiO2 Nanocomposites. Part 1: Microstructure Properties
Publisher: MDPI AG
Date: 08-12-2021
DOI: 10.3390/MEMBRANES11120966
Abstract: This is the first of two papers about the synthesis and microstructure properties of the Geo–rGO–TiO2 ternary nanocomposite, which was designed to suit the criteria of a pervaporation membrane for seawater desalination. The performance and capability of Geo–rGO–TiO2 as a seawater desalination pervaporation membrane are described in the second paper. A geopolymer made from alkali-activated metakaolin was utilized as a binder for the rGO-TiO2 nanocomposite. A modified Hummer’s method was used to synthesize graphene oxide (GO), and a hydrothermal procedure on GO produced reduced graphene oxide (rGO). The adopted approach yielded high-quality GO and rGO, based on Raman spectra results. The nanolayered structure of GO and rGO is revealed by Transmission Electron Microscopy (TEM) images. The Geo–rGO–TiO2 ternary nanocomposite was created by dispersing rGO nanosheets and TiO2 nanoparticles into geopolymer paste and stirring it for several minutes. The mixture was then cured in a sealed mold at 70 °C for one hour. After being demolded, the materials were kept for 28 days before being characterized. Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) measurements revealed that the geopolymer matrix efficiently bonded the rGO and TiO2, creating nanocomposites. Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Spectroscopy (EDS) was used to examine the morphology of the outer layer and cross-sections of nanocomposites, and the results displayed that rGO were stacked on the surface as well as in the bulk of the geopolymer and will potentially function as nanochannels with a width of around 0.36 nm, while TiO2 NPs covered the majority of the geopolymer matrix, assisting in anti-biofouling of the membranes. The pores structure of the Geo–rGO–TiO2 were classified as micro–meso pores using the Brunauer–Emmet–Teller (BET) method, indicating that they are appropriate for use as pervaporation membranes. The mechanical strength of the membranes was found to be adequate to withstand high water pressure during the pervaporation process. The addition of rGO and TiO2 NPs was found to improve the hyropobicity of the Geo–rGO–TiO2 nanocomposite, preventing excessive seawater penetration into the membrane during the pervaporation process. The results of this study elucidate that the Geo–rGO–TiO2 nanocomposite has a lot of potential for application as a pervaporation membrane for seawater desalination because all of the initial components are widely available and inexpensive.
Pervaporation Membranes for Seawater Desalination Based on Geo–rGO–TiO2 Nanocomposites: Part 2—Membranes Performances
Publisher: MDPI AG
Date: 26-10-2022
DOI: 10.3390/MEMBRANES12111046
Abstract: This is part 2 of the research on pervaporation membranes for seawater desalination based on Geo–rGO–TiO2 nanocomposite. The quality of the Geo–rGO–TiO2 pervaporation membranes (PV), as well as the suitability of the built pervaporation system, is thoroughly discussed. The four membranes described in detail in the first article were tested for their capabilities using the parameters turbidity, salinity, total suspended solids (TSS), and electrical conductivity (EC). The membranes’ flux permeate was measured as a function of temperature, and salt rejection was calculated using the electrical conductivity values of the feed and permeate. Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) techniques were used to investigate changes in the chemical composition and internal structure of the membranes after use in pervaporation systems. The morphology of the membrane’s surfaces was examined by means of scanning electron microscopy (SEM), and the elemental distribution was observed by using X-ray mapping and energy dispersive spectroscopy (EDS). The results showed that the pervaporation membrane of Geo–rGO–TiO2 (1, 3) achieved a permeate flux as high as 2.29 kg/m2·h with a salt rejection of around 91%. The results of the FTIR and XRD measurements did not show any changes in the functional group and chemical compositions of the membrane after the pervaporation process took place. Long-term pressure and temperature feed cause significant cracking in geopolymer and Geo–TiO2 (3) membranes. SEM results revealed that the surface of all membranes is leached out, and elemental distribution based on X-ray mapping and EDS observations revealed the addition of Na+ ions on the membrane surface. The study’s findings pave the way for more research and development of geopolymers as the basic material for inorganic membranes, particularly with the addition of rGO–TiO2 nanocomposites.
Combination of precipitated-calcium carbonate substitution and dilute-alkali fly ash treatment in a very high-volume fly ash cement paste
Publisher: Elsevier BV
Date: 02-2020
The modification of M41S materials: addition of metal clusters and nanoparticles
Publisher: Royal Society of Chemistry (RSC)
Date: 2010
DOI: 10.1039/B9NJ00626E
COVID-19 infection in adult patients with hematological malignancies: a European Hematology Association Survey (EPICOVIDEHA)
Publisher: Springer Science and Business Media LLC
Date: 14-10-2021
DOI: 10.1186/S13045-021-01177-0
Abstract: Patients with hematological malignancies (HM) are at high risk of mortality from SARS-CoV-2 disease 2019 (COVID-19). A better understanding of risk factors for adverse outcomes may improve clinical management in these patients. We therefore studied baseline characteristics of HM patients developing COVID-19 and analyzed predictors of mortality. The survey was supported by the Scientific Working Group Infection in Hematology of the European Hematology Association (EHA). Eligible for the analysis were adult patients with HM and laboratory-confirmed COVID-19 observed between March and December 2020. The study s le includes 3801 cases, represented by lymphoproliferative (mainly non-Hodgkin lymphoma n = 1084, myeloma n = 684 and chronic lymphoid leukemia n = 474) and myeloproliferative malignancies (mainly acute myeloid leukemia n = 497 and myelodysplastic syndromes n = 279). Severe/critical COVID-19 was observed in 63.8% of patients ( n = 2425). Overall, 2778 (73.1%) of the patients were hospitalized, 689 (18.1%) of whom were admitted to intensive care units (ICUs). Overall, 1185 patients (31.2%) died. The primary cause of death was COVID-19 in 688 patients (58.1%), HM in 173 patients (14.6%), and a combination of both COVID-19 and progressing HM in 155 patients (13.1%). Highest mortality was observed in acute myeloid leukemia (199/497, 40%) and myelodysplastic syndromes (118/279, 42.3%). The mortality rate significantly decreased between the first COVID-19 wave (March–May 2020) and the second wave (October–December 2020) (581/1427, 40.7% vs. 439/1773, 24.8%, p value 0.0001). In the multivariable analysis, age, active malignancy, chronic cardiac disease, liver disease, renal impairment, smoking history, and ICU stay correlated with mortality. Acute myeloid leukemia was a higher mortality risk than lymphoproliferative diseases. This survey confirms that COVID-19 patients with HM are at high risk of lethal complications. However, improved COVID-19 prevention has reduced mortality despite an increase in the number of reported cases.
Proximate composition of Xylocarpus moluccensis seeds and their oils
Publisher: Elsevier BV
Date: 2013
Recent development of mixed matrix membrane as a membrane bioreactor for wastewater treatment: A review
Publisher: Elsevier BV
Date: 12-2023
The Effect of Pb<sup>2+</sup> and Cd<sup>2+</sup> Addition to Mechanical Properties of Fly Ash Geopolymer Paste
Publisher: Trans Tech Publications, Ltd.
Date: 2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.841.178
Abstract: Immobilization of heavy metal ions using geopolymer paste is a promising way to solve the problem with heavy metal waste from industries. This research focused on the immobilization of Pb 2+ and Cd 2+ which are common heavy metal waste with distinctive cation size. The cations were immobilized by geopolymerization process to form geopolymer paste. The paste was prepared by using fly ash from a power plant in Cilacap, Indonesia, with SiO 2 /Al 2 O 3 ratio = 3 and S/L = 1.6. According to XRF analysis, the ash is type C fly ash and additional Al(OH) 3 was needed to achieve the SiO 2 /Al 2 O 3 ratio. A solution of Cd 2+ or Pb 2+ from their respective nitrate salts was added to the geopolymer mixture to make an immobilized Cd 2+ or Pb 2+ in a fly ash geopolymer matrix. Compressive strength tests showed that the maximum strength was achieved when 3855 ppm of Cd 2+ or 765 ppm of Pb 2+ was added to the geopolymer mixture. The change of strength is explained to be caused by the filling of geopolymer cavities that were formed during the geopolymerization process. Due to the smaller size of Cd 2+ than Pb 2+ , the strongest geopolymer paste was achieved at higher Cd 2+ concentration than Pb 2+ . X-ray diffraction analyses results show that the addition of Cd 2+ or Pb 2+ shift the position on hump to larger 2θ.
Light weight geopolymer paste made with sidoarjo mud (Lusi)
Publisher: Trans Tech Publications, Ltd.
Date: 08-2015
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.803.63
Abstract: This paper presents the efforts of how to use the solid form of Sidoarjo mud as a base material of lightweight-geopolymer paste. The mud, which is called Lusi was mixed with a class F fly ash. Some experimental results have shown that mixing mud with fly ash and alkali was potential to become a binder in concrete, instead of Portland cement. Alkaline solutions used in the mixture were NaOH of 12 M and 14 M and Na 2 SiO 3 combined in the ratio of 1:2.5 by weight. Aluminum powder was applied as a foaming agent. It showed that the strength of paste made with mixing Sidoarjo mud and fly ash was influenced by mud content. The effect of chemical admixture and curing temperature was observed as well. A steam curing method at 60°C was applied to the paste for three and six hours. Test results showed that the compressive strength of the paste varied with the concentration of alkaline solution, mud content, admixture and curing temperature. The maximum strength of the lightweight paste at 21 days was 2.8 MPa with the density of 722 kg/m 3 .
A dependence study: Molecular weight of polyethylene glycol (PEG) ON La0.7Sr0.3Co0.2Fe0.8O3−δ (LSCF 7328) hollow fiber membrane for oxygen permeation
Publisher: Elsevier BV
Date: 03-2023
Synthesis Of Zeolite X-carbon From Coal Bottom Ash For Hydrogen Storage Material
Publisher: International Association of Advanced Materials
Date: 08-2014
Tungsten Oxides-Containing Titanium Silicalite for Liquid Phase Epoxidation of 1-octene with Aqueous Hydrogen Peroxide
Publisher: Springer Science and Business Media LLC
Date: 04-11-2008
Comparative Study of Municipal Solid Waste Fuel and Refuse Derived Fuel in the Gasification Process Using Multi Stage Downdraft Gasifier
Publisher: Universitas Muhammadiyah Magelang
Date: 11-04-2021
DOI: 10.31603/AE.4625
Abstract: Municipal solid waste (MSW) is a type of general waste that includes households, traditional markets, commercial areas, and the rest from public facilities, schools, offices, roads, and so on. Refuse Derived Fuel (RDF) is obtained from the remnants of MSW which cannot be used anymore, which is flammable waste and is separated from parts that are difficult to burn through the process of chopping, sifting, and air classification. RDF has potential as an alternative energy source. In this study, RDF fuel was compared with MSW fuel both by proximate and calorific value, then the gasification process was carried out using a multi-stage downdraft gasifier to see gasification performance indicators such as syngas composition, LHV, cold gas efficiency, and tar concentration. The results showed that the gasification performance indicator for MSW biomass resulted in the syngas composition of CO = 19.08% v, H2 = 10.89% v, and CH4 = 1.54% v. The calorific value (Low Heating Value, LHV ) of syngas is 4,137 kJ/kg, cold gas efficiency is 70.14%, and tar content is 57.29 mg/Nm3. Meanwhile, RDF obtained the composition of CO gas: 18.68% v, H2: 9.5446% v, and CH4: 0% v. The maximum LHV syngas is 3365.08 kJ/kg, cold gas efficiency is 57.19 % and the smallest tar content is 80.24 mg/Nm3. When compared to RDF, MSW produces a better gasification performance indicator. However, RDF can still be used as an alternative energy source using the gasification process. The results of this study can be used to optimize the further RDF gasification process.
Mechanical Properties of MIRHA-Fly Ash Geopolymer Concrete
Publisher: Trans Tech Publications, Ltd.
Date: 08-2014
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.803.49
Abstract: This paper provides a report about the results of an investigation carried out to understand the effect of Microwave Incinerated Rice Husk Ash (MIRHA) on the mechanical properties of fly ash geopolymer concrete to access the concrete performance development. Fly ash (350kg/m 3 ) and MIRHA (0%, 3%, and 7%) were used as the source materials to replace cement, NaOH and Na 2 SiO 3 solutions used as the alkaline liquids for the medium of polymeric reaction. In addition, sugar was used as retarder, as well as three different types of curing regime (ambient, external exposure or oven curing regime). The concrete mixing procedure was adjusted to obtain the proper homogeneity of dry materials and wet ones. In this project, a number of mechanical tests have been conducted including the pull-out test, compressive strength test, flexural strength test, and modulus of elasticity test. It was then observed that the performance of mechanical properties of MIRHA-fly ash geopolymer concrete improved with the use of oven curing as the curing regime for the concrete s les.
The Fabrication of Solid Polymer Electrolyte from CS/PEO/NaClO4/Fly Ash Composite
Publisher: MDPI AG
Date: 08-11-2022
Abstract: Solid polymer electrolytes (SPEs) have been successfully fabricated from CS/PEO/NaClO4/Fly ash composite. Chitosan (CS), an organic polymer, was blended with polyethylene oxide (PEO) to enhance its electrochemical properties. However, SPEs based on CS/PEO composites have low conductivity. Fly ash (FA) has been studied to be used as a filler to increase the ionic conductivity of SPEs. In this study, polymer composites based on CS and PEO were developed with the addition of FA as a filler using the solution casting method. The interactions between CS, PEO, NaClO4, and fly ash were observed using FTIR. The SPE characterization using XRD and DSC showed a decrease in crystallinity after the addition of NaClO4 and FA. The SPE composite morphology and elemental distribution were investigated using SEM. SPE conductivity analysis using EIS showed the optimum results for SPE fabricated with a ratio of CS:PEO:NaClO4 = 3:2:7.5, which was 1.02 × 10−4 S cm−1 at 30 °C and increased to 2.13 × 10−3 S cm−1 at 60 °C. The addition of FA (5 wt.%) increased the conductivity to 3.20 × 10−4 S cm−1 at 30 °C and increased to 4.34 × 10−3 S cm−1 at 60 °C.
The Effects of Various Concentrations of NaOH on the Inter-Particle Gelation of a Fly Ash Geopolymer Aggregate
Publisher: MDPI AG
Date: 27-02-2021
DOI: 10.3390/MA14051111
Abstract: Aggregates can be categorized into natural and artificial aggregates. Preserving natural resources is crucial to ensuring the constant supply of natural aggregates. In order to preserve these natural resources, the production of artificial aggregates is beginning to gain the attention of researchers worldwide. One of the methods involves using geopolymer technology. On this basis, this current research focuses on the inter-particle effect on the properties of fly ash geopolymer aggregates with different molarities of sodium hydroxide (NaOH). The effects of synthesis parameters (6, 8, 10, 12, and 14 M) on the mechanical and microstructural properties of the fly ash geopolymer aggregate were studied. The fly ash geopolymer aggregate was palletized manually by using a hand to form a sphere-shaped aggregate where the ratio of NaOH/Na2SiO3 used was constant at 2.5. The results indicated that the NaOH molarity has a significant effect on the impact strength of a fly ash geopolymer aggregate. The highest aggregate impact value (AIV) was obtained for s les with 6 M NaOH molarity (26.95%), indicating the lowest strength among other molarities studied and the lowest density of 2150 kg/m3. The low concentration of sodium hydroxide in the alkali activator solution resulted in the dissolution of fly ash being limited thus, the inter-particle volume cannot be fully filled by the precipitated gels.
Morphological and Physical Study of La0.7Sr0.3Co0.2Fe0.8O3-δ (LSCF 7328) Flat Membranes Modified by Polyethylene Glycol (PEG)
Publisher: Penerbit UTM Press
Date: 21-11-2018
Abstract: The aim of this work is to study the effect of polyethylene glycol (PEG) on the modification of microstructure formation correlated with the mechanical strength properties of perovskite-based membrane in form of a flat sheet. LSCF 7328 flat membrane was potentially promoted as an oxygen separator and catalyst for partial oxidation of methane reaction at high temperature. In this study, the phase-inversion followed by sintering process was used as the membrane fabrication method using varied PEG concentration of 0.55, 1.00, and 3.00 wt% with different molecular weight, i.e., PEG 300, 600, 1500, and 4000 Da for each PEG concentration. The result of morphology observation shows that almost every membrane hasthe asymmetric structure with finger-like pores and thin dense layer. Increasing PEG concentration as well as molecular weight increases pore size and affects on porosity, pore's volume, and physical properties of membrane. The largest pore size, pore volume and porosity of the membrane after sintering were found in the addition of 3.00% PEG 4000 (Da) additive with the value of 110.45 μm, 81.34 ml.g-1 and 120.6%, respectively. In addition, the mechanical properties of membrane were tested using the Vickers micro hardness method with the greatest value found in the addition of 3.00% PEG 1500 (Da) additive with the value of 13.58 Hv and the lowest is 3.00% PEG 4000 (Da) with the value of 1.2 Hv.
Effect of Activators on Strength of Hybrid Alkaline Cement
Publisher: IOP Publishing
Date: 05-2017
Preparation of dense BaxSr1-xCo0.8Fe0.2O3 membranes: Effect of Ba2+ substituents and sintering method to the density, hardness and thermal expansion coefficient of the membranes
Publisher: International Association of Advanced Materials
Date: 07-2017
Study of microstructure modification on La0.7Sr0.3Co0.2Fe0.8O3-δ (LSCF 7328) asymmetric flat membrane
Publisher: Penerbit UTM Press
Date: 25-08-2019
DOI: 10.11113/MJFAS.V15N4.1425
Abstract: The LSCF 7328 (La0.7Sr0.3Co0.2Fe0.8O3-δ) asymmetric flat membranes were successfully prepared via a phase-inversion method followed by sintering at 1200 °C. In this study, a variety of poly(ethylene glycol) (PEGs) as the pore-forming agent, with 3 wt% composition and a wide ranges of molecular weight (Mw) (200 to 8000 Da) were used to tests its’ effect to the properties of LSCF membranes. The results show that the PEGs, as additives, were able to modify the pore morphology and mechanical properties of the LSCF 7328 membrane. The morphological evidence from SEM images showed that the LSCF membranes have an asymmetric configuration, comprised of sponge-like and finger-like pores which are integrated with a dense layer. The variation in average pore size is clearly seen, starting from 13.00 to 135.33 μm, following the increase in PEGs molecular weight. The LSCF membranes which were prepared using PEG additive have higher hardness (1.2 – 13.6 Hv) than the membrane with no PEG (0.2 Hv). In contrast, the porosity and pore volume of the membranes decrease with the increase of PEGs molecular weight. The decrease might be due to the formation of various closed macro-voids as the molecular weight of PEGs increases. Furthermore, the thermal expansion coefficient of the membrane with different PEGs molecular weight (ie. 400, 600, 4000 and 6000) Da posses no significant different, i.e. around 16 x 10-6 °C-1, although the membrane showed different morphology and mechanical properties.
Comprehensive Study of Morphological Modification of Dual-Layer Hollow Fiber Membrane
Publisher: Springer Science and Business Media LLC
Date: 31-07-2019
Photophysical properties of ammonium, pyrrolidinium, piperidinium, imidazolium, and pyridinium as a guide to prepare ionic-organic hybrid materials
Publisher: Elsevier BV
Date: 03-2022
Preparation of La0.7Sr0.3Co0.2Fe0.8O3-δ (LSCF 7328) by Combination of Mechanochemical and Solid State Reaction
Publisher: Trans Tech Publications, Ltd.
Date: 07-2017
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.744.399
Abstract: Structure evolution and morphology of La 0.7 Sr 0.3 Co 0.8 Fe 0.2 O 3- δ (LSCF 7328) were investigated during two different preparation methods namely mechanochemical and combination of mechanochemical-solid state. The result shows that no characteristic peak of perovskite oxide was found on the diffractogram of the product of sole mechanochemical method at 600 rpm and up to 12 h of high energy milling process. On the other hand, the manual grinding method that was followed by solid state calcination produces irregular particle size. Due to the result, the combination of both methods was proposed to obtain the fine structure formation and particle size distribution. Rietveld refinement was used to investigate the lattice distortion. It was found that unit cell remains unchanged at increasing milling time. Moreover, the combination method produces regular particle size at milling time of 0.5 h. At longer milling time, the more regular particle size is formed which comes from highly energy transfer of milling.
Artificial Lightweight Aggregates Made from Pozzolanic Material: A Review on the Method, Physical and Mechanical Properties, Thermal and Microstructure
Publisher: MDPI AG
Date: 31-05-2022
DOI: 10.3390/MA15113929
Abstract: As the demand for nonrenewable natural resources, such as aggregate, is increasing worldwide, new production of artificial aggregate should be developed. Artificial lightweight aggregate can bring advantages to the construction field due to its lower density, thus reducing the dead load applied to the structural elements. In addition, application of artificial lightweight aggregate in lightweight concrete will produce lower thermal conductivity. However, the production of artificial lightweight aggregate is still limited. Production of artificial lightweight aggregate incorporating waste materials or pozzolanic materials is advantageous and beneficial in terms of being environmentally friendly, as well as lowering carbon dioxide emissions. Moreover, additives, such as geopolymer, have been introduced as one of the alternative construction materials that have been proven to have excellent properties. Thus, this paper will review the production of artificial lightweight aggregate through various methods, including sintering, cold bonding, and autoclaving. The significant properties of artificial lightweight aggregate, including physical and mechanical properties, such as water absorption, crushing strength, and impact value, are reviewed. The properties of concrete, including thermal properties, that utilized artificial lightweight aggregate were also briefly reviewed to highlight the advantages of artificial lightweight aggregate.
Effect of Fe substitution on the partial oxidation of methane to syngas overLa0:7Sr0:3Co1
Publisher: The Scientific and Technological Research Council of Turkey (TUBITAK-ULAKBIM) - DIGITAL COMMONS JOURNALS
Date: 11-06-2019
DOI: 10.3906/KIM-1811-26
P84/ZCC Hollow Fiber Mixed Matrix Membrane with PDMS Coating to Enhance Air Separation Performance
Publisher: MDPI AG
Date: 28-09-2020
DOI: 10.3390/MEMBRANES10100267
Abstract: This research introduces zeolite carbon composite (ZCC) as a new filler on polymeric membranes based on the BTDA-TDI/MDI (P84) co-polyimide for the air separation process. The separation performance was further improved by a polydimethylsiloxane (PDMS) coating to cover up the surface defect. The incorporation of 1 wt% ZCC into P84 co-polyimide matrix enhanced the O2 permeability from 7.12 to 18.90 Barrer (2.65 times) and the O2/N2 selectivity from 4.11 to 4.92 Barrer (19.71% improvement). The PDMS coating on the membrane further improved the O2/N2 selectivity by up to 60%. The results showed that the incorporation of ZCC and PDMS coating onto the P84 co-polyimide membrane was able to increase the overall air separation performance.
Cd<sup>2</sup><sup>+ </sup>and Cr<sup>3+</sup> Cation Immobilization by Using Geopolymer Based on PT. IPMOMI Fly Ash
Publisher: Trans Tech Publications, Ltd.
Date: 2016
DOI: 10.4028/WWW.SCIENTIFIC.NET/MSF.841.186
Abstract: This study investigates the immobilization of Cd 2+ and Cr 3+ by using geopolymer paste based on PT. IPMOMI fly ash. The best composition of geopolimers paste was determined based on the highest magnitude of its 7 days compressive strength. Geopolymer pastes were prepared by varying SiO 2 /Al 2 O 3 and Na 2 O/SiO 2 molar ratio of the starting materials. X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were employed to examined these compositions. The molar ratio of SiO 2 /Al 2 O 3 6.46 was found to produce the highest compressive strength of the resulting geopolymer paste, i.e 25 MPa and increased to 33.17 MPa by adjusting the ratio of Na 2 O/SiO 2 to 0.65. Cd 2+ and Cr 3+ cations were added into geopolymers resin at the level of 1000 – 16000 ppm (mg/kg fly ash) and it was found to improve their compressive strength. The addition of 4000 ppm of Cd 2+ increased the compressive strength to 38.6 MPa while the inclusion of 6800 ppm of Cr 3+ reached 47.83 MPa. Further addition of cations reduced these values and the lowest compressive strength was observed on the addition of 16000 ppm of Cd 2+ and Cr 3+ , i.e 8.65 MPa and 4.39 MPa, respectively. Leaching test was conducted by using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) and the distribution of heavy metal cations were examined by using SEM-EDX. The results showed that geopolymer pastes were able to immobilize Cr 3+ at the studied level as there was no trace of Cr 3+ detected after 6.5 hours of leaching. Geopolymer pastes were also found to completely immobilize Cd 2+ at the level of 1000 ppm albeit the addition of 16000 ppm results in 6.26% leached out of this cation.
Influence of TiO2/TS-1 Calcination on Hydroxylation of Phenol
Publisher: The Institute for Research and Community Services (LPPM) ITB
Date: 04-2014
Related Organisations
Instituto Português De Oncologia De Lisboa Francisco Gentil EPE
Location: Portugal
Related Funding Activities
No related grants have been discovered for Raquel Rodrigues.