Now showing 1 - 4 of 4
  • Publication
    Crumb rubber geopolymer mortar at elevated temperature exposure
    ( 2022) ; ;
    Che Mohd Ruzaidi Ghazali
    ;
    ;
    Ramadhansyah Putra Jaya
    ;
    ;
    Mohammad A. Almadani
    ;
    Wysłocki, Jerzy J.
    ;
    Agata Śliwa
    ;
    Andre Victor Sandu
    Low calcium fly ash is used as the main material in the mixture and the crumb rubber was used in replacing fine aggregates in geopolymer mortar. Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) which were high alkaline solution were incorporated as the alkaline solution. The fly ash reacted with the alkaline solution forming alumino-silicate gel that binds the aggregate to produce a geopolymer mortar. The loading of crumb rubber in the fly ash based geopolymer mortar was set at 0%
  • Publication
    Hydroxyapatite incorporated metakaolin/sludge based geopolymer adsorbent for copper ions and ciprofloxacin removal : Synthesis, characterization and mechanisms
    ( 2024)
    Pilomeena Arokiasamy
    ;
    ; ;
    Andrei Victor Sandu
    ;
    Anna Fedrigo
    ;
    Ratna Ediati
    ;
    Shafiq Ishak
    ;
    Noor Haida Mohd Kaus
    The efficacy of copper Cu(II) adsorption is significantly affected by the presence of antibiotics, such as ciprofloxacin (CIP). Therefore, researchers are highly interested in conducting extensive investigations on the simultaneous adsorption of Cu(II) and CIP. However, most of the adsorbents exhibited low adsorption capacity of CIP with increasing Cu(II) concentration due to the competition for adsorption sites. Hence, the integration of various adsorbents into a single composite could be an effective way to increase the adsorption sites. Thus, this study aims to incorporate hydroxyapatite (Hap) into metakaolin/sludge based geopolymer adsorbent for simultaneous adsorption of Cu(II) and CIP. The effect of different filler loading of Hap (1–3 %) on the metakaolin/sludge geopolymerization and also on the removal efficiency of Cu(II) and CIP were studied in a single and binary system. Moreover, the effects of varied concentrations of Cu(II) (0–100 mg/L) on the removal efficiency of CIP were investigated. Characterization techniques such as x-ray diffraction (XRD), fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), brunauer-emmett-teller (BET) and neutron tomography imaging were employed to characterize the physicochemical properties of the synthesized geopolymer. It was found that the Hap content has a significant impact on the removal efficiency of CIP and Cu(II). The addition of 2 % Hap providing more nucleation site for the increasing geopolymerization (C-A-S-H) and silicoalumino phosphate gel (SAP) leading to the formation of highly cross-linked geopolymer network and abundant active sites which would favour the adsorption. Moreover, the removal efficiency of CIP by 2 % Hap-geopolymer increased (25.6 % to 61.51 %) with increasing Cu(II) concentration by the complexation and bridging effect between Cu(II) and CIP resulting in the formation of GMK25S1-2Hap-Cu(II)-CIP complexes. Therefore, the hybrid method of geopolymer and Hap is an exceptionally efficient approach for the treatment of wastewater that comprises Cu(II) and CIP.
  • 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
    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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