Now showing 1 - 5 of 5
  • Publication
    Metakaolin/sludge based geopolymer adsorbent on high removal efficiency of Cu2+
    ( 2022)
    Pilomeena Arokiasamy
    ;
    ; ;
    Mohd Remy Rozainy Mohd Arif Zainol
    ;
    ;
    Marwan Kheimi
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    ;
    Rafiza Abdul Razak
    ;
    Activated carbon (AC) has received a lot of interest from researchers for the removal of heavy metals from wastewater due to its abundant porous structure. However, it was found unable to meet the required adsorption capacity due to its amorphous structure which restricts the fundamental studies and structural optimization for improved removal performance. In addition, AC is not applicable in large scale wastewater treatment due its expensive synthesis and difficulty in regeneration. Thus, the researchers are paying more attention in synthesis of low cost geopolymer based adsorbent for heavy metal removal due its excellent immobilization effect. However, limited studies have focused on the synthesis of geopolymer based adsorbent for heavy metal adsorption by utilizing industrial sludge. Thus, the aim of this research was to develop metakaolin (MK) based geopolymer adsorbent with incorporation of two types of industrial sludge (S1 and S3) that could be employed as an adsorbent for removing copper (Cu²⁺) from aqueous solution through the adsorption process. The effects of varied solid to liquid ratio (S/L) on the synthesis of metakaolin/sludge based geopolymer adsorbent and the removal efficiency of Cu²⁺ by the synthesis adsorbent were studied. The raw materials and synthesized geopolymer were characterized by using x-ray fluorescence (XRF), x-ray diffraction (XRD), scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and micro XRF. The concentration of Cu²⁺ before and after adsorption was determined by atomic absorption spectroscopy (AAS) and the removal efficiency was calculated. The experimental data indicated that the synthesized geopolymer at low S/L ratio has achieved the highest removal efficiency of Cu²⁺ about 99.62% and 99.37% at 25%:75% of MK/S1 and 25%:75% of MK/S3 respectively compared to pure MK based geopolymer with 98.56%. The best S/L ratio for MK/S1 and MK/S3 is 0.6 at which the reaction between the alkaline activator and the aluminosilicate materials has improved and enhanced the geopolymerization process. Finally, this work clearly indicated that industrial sludge can be utilized in developing low-cost adsorbent with high removal efficiency
  • Publication
    Self-Fluxing mechanism in geopolymerization for Low-Sintering temperature of ceramic
    ( 2021) ; ; ;
    Hasmaliza Mohamad
    ;
    ;
    Penphitcha Amonpattaratkit
    ;
    Joanna Gondro
    ;
    Wojciech Sochacki
    ;
    Norfadhilah Ibrahim
    Kaolin, theoretically known as having low reactivity during geopolymerization, was used as a source of aluminosilicate materials in this study. Due to this concern, it is challenging to directly produce kaolin geopolymers without pre-treatment. The addition of ground granulated blast furnace slag (GGBS) accelerated the geopolymerization process. Kaolin–GGBS geopolymer ceramic was prepared at a low sintering temperature due to the reaction of the chemical composition during the initial stage of geopolymerization. The objective of this work was to study the influence of the chemical composition towards sintering temperature of sintered kaolin–GGBS geopolymer. Kaolin–GGBS geopolymer was prepared with a ratio of solid to liquid 2:1 and cured at 60 °C for 14 days. The cured geopolymer was sintered at different temperatures: 800, 900, 1000, and 1100 °C. Sintering at 900 °C resulted in the highest compressive strength due to the formation of densified microstructure, while higher sintering temperature led to the formation of interconnected pores. The difference in the X-ray absorption near edge structure (XANES) spectra was related to the phases obtained from the X-ray diffraction analysis, such as akermanite and anothite. Thermal analysis indicated the stability of sintered kaolin–GGBS geopolymer when exposed to 1100 °C, proving that kaolin can be directly used without heat treatment in geopolymers. The geopolymerization process facilitates the stability of cured samples when directly sintered, as well as plays a significant role as a self-fluxing agent to reduce the sintering temperature when producing sintered kaolin–GGBS geopolymers.
  • Publication
    Assessment of the suitability of ceramic waste in geopolymer composites: an appraisal
    ( 2021)
    Ismail Luhar
    ;
    Salmabanu Luhar
    ;
    ;
    Marcin Nabiałek
    ;
    Andrei Victor Sandu
    ;
    Janusz Szmidla
    ;
    Anna Jurczyńska
    ;
    Rafiza Abdul Razak
    ;
    Ikmal Hakem A Aziz
    ;
    ;
    Laila Mardiah Deraman
    Currently, novel inorganic alumino-silicate materials, known as geopolymer composites, have emerged swiftly as an ecobenevolent alternative to contemporary ordinary Portland cement (OPC) building materials since they display superior physical and chemical attributes with a diverse range of possible potential applications. The said innovative geopolymer technology necessitates less energy and low carbon footprints as compared to OPC-based materials because of the incorporation of wastes and/or industrial byproducts as binders replacing OPC. The key constituents of ceramic are silica and alumina and, hence, have the potential to be employed as an aggregate to manufacture ceramic geopolymer concrete. The present manuscript presents a review of the performance of geopolymer composites incorporated with ceramic waste, concerning workability, strength, durability, and elevated resistance evaluation.
  • Publication
    Fundamental study on processing and characterization of kaolin-modified ground granulated blast furnace slag ceramic via geopolymerization process
    Kaolin which is theoretically known having low reactivity during geopolymerization will be used as a source of aluminosilicate materials in this study. Current research had pretreated the kaolin via thermal, mechanical and chemical treatment before geopolymerization. Due to this concern, it becomes a challenge to directly produce kaolin geopolymer without pre-treatment. Hence addition of ground granulated blast furnace slag (GGBS) will accelerate the geopolymerization process. Kaolin-GGBS geopolymer ceramic can be prepared at low sintering temperature due to the reaction of chemical composition during the initial stage of geopolymerization. The objective of this work is to study the influence of the chemical composition in raw materials, curing temperature and sintering temperature on the sintered kaolin-GGBS geopolymer. The ratio of solid-to-liquid chosen were 1:1, 1.5:1, and 2:1 to analyze the contribution of chemical composition. The effect of curing temperature will be a study based on four different temperature, which is, room temperature, 40 °C, 60 °C and 80 °C. The last parameter chosen was the sintering temperature varied at 800 °C, 900 °C, 1000 °C and 1100 °C. The optimum ratio of solid to liquid obtained was 2:1 (SL 2) with densified microstructure. The addition of GGBS to the kaolin geopolymer slurry did not only hasten the hardening process during geopolymerization, the presence of CaO, and MgO in GGBS had accelerated the formation of nepheline, gehlenite, akermanite, and albite phase after sintering. Elemental distribution from micro-XRF investigation proves the high concentration of Ca in a localized area and uniformly distribution of Si aligned with the phase of akermanite in SL 2. The curing temperature at 60 °C had resulted the highest compressive strength after the sintering process. This is due to the densified microstructure with open pores in the structure of sintered kaolin-GGBS geopolymer. It can be clearly seen the phase transformation from as-cured to sintered geopolymer. Transformation of the main crystalline phase which is kaolinite to nepheline phase due to reaction with alkali activator. Kaolin-GGBS geopolymer was prepared with a ratio of solid to liquid 2:1 and 60 °C of curing temperature were prepared for the last parameter varied, which are sintering temperature. Sintering at 900 °C had resulted in the highest compressive strength due to the formation of densified microstructure. The formation of akermanite phase had contributed to the densification. The sintering temperature exceeds than 900 °C had led to the formation of interconnected pores due to the decomposition and vapourisation of CaCO3. Meanwhile, sintering at 800 °C indicates an incomplete geopolymerization process. Thermal analysis shows the stability of sintered kaolin-GGBS geopolymer when being exposed to 1100 °C. Therefore, it proves that kaolin can be directly used without heat treatment in geopolymer. The geopolymerization process had facilitated the stability of as cured samples to be directly sintered besides playing a significant role as a self-fluxing agent to reduce the temperature in producing sintered kaolin-GGBS geopolymer.
  • Publication
    Metakaolin/sludge based geopolymer adsorbent on high removal efficiency of Cu2+
    ( 2022)
    Pilomeena Arokiasamy
    ;
    ; ;
    Mohd Remy Rozainy Mohd Arif Zainol
    ;
    ;
    Marwan Kheimi
    ;
    Jitrin Chaiprapa
    ;
    Andrei Victor Sandu
    ;
    Petrica Vizureanu
    ;
    ;
    Activated carbon (AC) has received a lot of interest from researchers for the removal of heavy metals from wastewater due to its abundant porous structure. However, it was found unable to meet the required adsorption capacity due to its amorphous structure which restricts the fundamental studies and structural optimization for improved removal performance. In addition, AC is not applicable in large scale wastewater treatment due its expensive synthesis and difficulty in regeneration. Thus, the researchers are paying more attention in synthesis of low cost geopolymer based adsorbent for heavy metal removal due its excellent immobilization effect. However, limited studies have focused on the synthesis of geopolymer based adsorbent for heavy metal adsorption by utilizing industrial sludge. Thus, the aim of this research was to develop metakaolin (MK) based geopolymer adsorbent with incorporation of two types of industrial sludge (S1 and S3) that could be employed as an adsorbent for removing copper (Cu2+) from aqueous solution through the adsorption process. The effects of varied solid to liquid ratio (S/L) on the synthesis of metakaolin/sludge based geopolymer adsorbent and the removal efficiency of Cu2+ by the synthesis adsorbent were studied. The raw materials and synthesized geopolymer were characterized by using x-ray fluorescence (XRF), x-ray diffraction (XRD), scanning electron microscope (SEM), fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and micro XRF. The concentration of Cu2+ before and after adsorption was determined by atomic absorption spectroscopy (AAS) and the removal efficiency was calculated. The experimental data indicated that the synthesized geopolymer at low S/L ratio has achieved the highest removal efficiency of Cu2+ about 99.62 % and 99.37 % at 25 %:75 % of MK/S1 and 25 %:75 % of MK/S3 respectively compared to pure MK based geopolymer with 98.56 %. The best S/
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