Following phytoremediation, the disposal of accumulating plants (phytoaccumulators) is challenging because the accumulated metals could leach back into the soil if not properly managed. Therefore, this study aims to use calcined clay (CC)-based geopolymer to stabilize Pb, Cu, and Zn in a phytoaccumulator (Sporobolus pyramidalis) ash (PA). Additionally, the effect of adding PA on the setting time, mechanical and heavy metals leaching properties of the geopolymers was investigated, to determine their environmental suitability and potential applications. Mixed proportions of CC (85-100%) and PA (5% - 15%) were used to produce geopolymers, using 8 M NaOH/Na2SiO3 (1:1) as an alkaline activator. The geopolymers were cured for 7 and 28 days at ambient temperatures. Thermograms showed the dehydroxylation of kaolinite at 450-650 °C. X-ray flourescene (XRF) analysis showed CC’s predominant oxides as SiO2 (53.1%) and Al2O3 (41.4%), while PA exhibited SiO2 (46.6%), CaO (13.8%), PbO (1.30%), ZnO (0.28%), and CuO (0.04%). Thermal treatment eliminated most FTIR bands associated with kaolinite, converting crystalline kaolinite into amorphous metakaolinite. Geopolymer setting time ranged from 75 min (100% CC) to 111 min (85% CC). Furthermore, elevated Cao content in the PA resulted in the geopolymer’s early strength development. However, the compressive strength decreased as PA quantity increased, with 95% CC-PA exhibiting maximum strength (22.5 ± 0.2 MPa) after 28 days. Further tests confirmed that 95% and 90% CC-PA geopolymer effectively stabilized Pb and Cu. Fabricated geopolymers met the ASTM (C62-17) Specification Standard for building brick, indicating their suitability as a waste-based construction material under controlled conditions.
Li, M.; Kuang, S.; Kang, Y.; Ma, H.; Dong, J., et al. (2022). Recent advances in application of iron- manganese oxide nanomaterials for removal of heavy metals in the aquatic environment. Science of The Total Environment, 819, 153157. https://doi.org/10.1016/j.scitotenv.2022.153157.
Zhang, Y.; Wang, Y.; Zang, H.; Yao, J.; Ma, H. (2023). Analysis of Heavy Metal Pollution in Soil along the Shuimo River by the Grey Relational Method and Factor Analysis. Metals, 13(5), 878. https://doi.org/10.3390/met13050878.
Ogunsola, S.S.; Oladipo, M.E.; Oladoye, P.O.; Kadhom, M. (2024). Carbon nanotubes for sustainable environmental remediation: A critical and comprehensive review. Nano-Structures & Nano-Objects, 37, 101099. https://doi.org/10.1016/j.nanoso.2024.10109.
Mishra, S.; Bharagava, R.N.; More, N.; Yadav, A.; Zainith, S., et al. (2019). Heavy Metal Contamination: An Alarming Threat to Environment and Human Health. In Environmental Biotechnology: For Sustainable Future (pp. 103–125). Springer Singapore.
Taylor, A.A.; Tsuji, J.S.; Garry, M.R.; McArdle, M.E.; Goodfellow, W.L., et al. (2020). Critical Review of Exposure and Effects: Implications for Setting Regulatory Health Criteria for Ingested Copper. Environmental Management, 65(1), 131–159. https://doi.org/10.1007/s00267-019-01234-y.
Goel, J.; Kadirvelu, K.; Rajagopal, C.; Kumar Garg, V. (2005). Removal of lead(II) by adsorption using treated granular activated carbon: Batch and column studies. Journal of Hazardous Materials, 125(1–3), 211–220. https://doi.org/10.1016/j.jhazmat.2005.05.032.
Kinuthia, G.K.; Ngure, V.; Beti, D.; Lugalia, R.; Wangila, A., et al. (2020). Levels of heavy metals in wastewater and soil samples from open drainage channels in Nairobi, Kenya: community health implication. Scientific Reports, 10(1), 8434. https://doi.org/10.1038/s41598-020-65359-5.
Yi, Y.M.; Sung, K. (2015). Influence of washing treatment on the qualities of heavy metal–contaminated soil. Ecological Engineering, 81, 89–92.
Ahmed, S.F.; Mofijur, M.; Nuzhat, S.; Chowdhury, A.T.; Rafa, N., et al. (2021). Recent developments in physical, biological, chemical, and hybrid treatment techniques for removing emerging contaminants from wastewater. Journal of Hazardous Materials, 416, 125912. https://doi.org/10.1016/j.jhazmat.2021.125912.
Rizwan, M.S.; Imtiaz, M.; Huang, G.; Chhajro, M.A.; Liu, Y., et al. (2016). Immobilization of Pb and Cu in polluted soil by superphosphate, multi-walled carbon nanotube, rice straw and its derived biochar. Environmental Science and Pollution Research, 23(15), 15532–15543. https://doi.org/10.1007/s11356-016-6695-0.
Yin, K.; Wang, Q.; Lv, M.; Chen, L. (2019). Microorganism remediation strategies towards heavy metals. Chemical Engineering Journal, 360, 1553–1563. https://doi.org/10.1016/j.cej.2018.10.226.
Singh, A.; Pal, D.B.; Mohammad, A.; Alhazmi, A.; Haque, S., et al. (2022). Biological remediation technologies for dyes and heavy metals in wastewater treatment: New insight. Bioresource Technology, 343, 126154. http://doi.org/10.1016/j.biortech.2021.126154.
Shi, L.; Li, J.; Palansooriya, K.N.; Chen, Y.; Hou, D., et al. (2023). Modeling phytoremediation of heavy metal contaminated soils through machine learning. Journal of Hazardous Materials, 441, 129904. https://doi.org/10.1016/j.jhazmat.2022.129904.
Bhayani, D.; Siddhapura, S.P.; Sindhav, S.R.; Jadeja, B.A. (2023). Potentiality of Weed Plants for Phytoremediation of Heavy Metal Polluted Soil. International Journal of Environment and Climate Change, 13(5), 400–412. https://doi.org/10.9734/ijecc/2023/v13i51785.
Njoku, K.L.; Nwani, S.O. (2022). Phytoremediation of heavy metals contaminated soil samples obtained from mechanic workshop and dumpsite using Amaranthus spinosus. Scientific African, 17, e01278. https://doi.org/10.1016/j.sciaf.2022.e01278.
Lin, H.; Liu, C.; Li, B.; Dong, Y. (2021). Trifolium repens L. regulated phytoremediation of heavy metal contaminated soil by promoting soil enzyme activities and beneficial rhizosphere associated microorganisms. Journal of Hazardous Materials, 402, 123829. https://doi.org/10.1016/j.jhazmat.2020.123829.
Bian, F.; Zhong, Z.; Zhang, X.; Yang, C.; Gai, X. (2020). Bamboo – An untapped plant resource for the phytoremediation of heavy metal contaminated soils. Chemosphere, 246, 125750. https://doi.org/10.1016/j.chemosphere.2019.125750.
Ogundiran, M.B.; Ikpeni, S.E. (2018). Metakaolin clay-derived geopolymer for recycling of waste cathode ray tube glass. African Journal of Pure and Applied Chemistry, 12(6), 42–49. https://doi.org/10.5897/AJPAC2018.0759.
Hammer, D.; Kayser, A.; Keller, C. (2003). Phytoextraction of Cd and Zn with Salix viminalis in field trials. Soil Use and Management, 19(3), 187–192. https://doi.org/10.1111/j.1475-2743.2003.tb00303.x.
Gomes, M.A. da C.; Hauser-Davis, R.A.; de Souza, A.N.; Vitória, A.P. (2016). Metal phytoremediation: General strategies, genetically modified plants and applications in metal nanoparticle contamination. Ecotoxicology and Environmental Safety, 134, 133–147. https://doi.org/10.1016/j.ecoenv.2016.08.024.
Mahar, A.; Wang, P.; Ali, A.; Awasthi, M.K.; Lahori, A.H.; et al. (2016). Challenges and opportunities in the phytoremediation of heavy metals contaminated soils: A review. Ecotoxicology and Environmental Safety, 126, 111–121. https://doi.org/10.1016/j.ecoenv.2015.12.023.
LeDuc, D. L.; Terry, N. (2005). Phytoremediation of toxic trace elements in soil and water. Journal of Industrial Microbiology & Biotechnology, 32(11–12), 514–520. https://doi.org/10.1007/s10295-005-0227-0.
Rezaei, A.; Hassani, H.; Hassani, S.; Jabbari, N.; Fard Mousavi, S. B.; et al. (2019). Evaluation of groundwater quality and heavy metal pollution indices in Bazman basin, southeastern Iran. Groundwater for Sustainable Development, 9, 100245. https://doi.org/10.1016/j.gsd.2019.100245.
Vu, T.H.; Gowripalan, N. (2018). Mechanisms of heavy metal immobilisation using geopolymerisation techniques – A review. Journal of Advanced Concrete Technology, 16(3), 124–135. https://doi.org/10.3151/jact.16.124.
Ogundiran, M.B.; Nugteren, H.W.; Witkamp, G.J. (2013). Immobilisation of lead smelting slag within spent aluminate—fly ash based geopolymers. Journal of Hazardous Materials, 248–249, 29–36. https://doi.org/10.1016/j.jhazmat.2012.12.040.
Duxson, P.; Fernández-Jiménez, A.; Provis, J.L.; Lukey, G.C.; Palomo, A.; et al. (2007). Geopolymer technology: the current state of the art. Journal of Materials Science, 42(9), 2917–2933. https://doi.org/10.1007/s10853-006-0637-z.
Guo, B.; Liu, B.; Yang, J.; Zhang, S. (2017). The mechanisms of heavy metal immobilization by cementitious material treatments and thermal treatments: A review. Journal of Environmental Management, 193, 410–422. https://doi.org/10.1016/j.jenvman.2017.02.026.
Zhang, J.; Provis, J.L.; Feng, D.; van Deventer, J.S.J. (2008). Geopolymers for immobilization of Cr6+, Cd2+, and Pb2+. Journal of Hazardous Materials, 157(2–3), 587–598. https://doi.org/10.1016/j.jhazmat.2008.01.053.
Perera, D.S.; Aly, Z.; Vance, E.R.; Mizumo, M. (2005). Immobilization of Pb in a Geopolymer Matrix. Journal of the American Ceramic Society, 88(9), 2586–2588. https://doi.org/10.1111/j.1551-2916.2005.00438.x.
Yunsheng, Z.; Wei, S.; Qianli, C.; Lin, C. (2007). Synthesis and heavy metal immobilization behaviors of slag based geopolymer. Journal of Hazardous Materials, 143(1–2), 206–213. https://doi.org/10.1016/j.jhazmat.2006.09.033.
Qian, G.; Delai Sun, D.; Hwa Tay, J. (2003). Characterization of mercury- and zinc-doped alkali-activated slag matrix. Cement and Concrete Research, 33(8), 1251–1256. https://doi.org/10.1016/S0008-8846(03)00045-0.
Van Jaarsveld, J.G.S.; Van Deventer, J.S.J.; Lorenzen, L. (1997). The potential use of geopolymeric materials to immobilise toxic metals: Part I. Theory and applications. Minerals Engineering, 10(7), 659–669. https://doi.org/10.1016/S0892-6875(97)00046-0.
Šesták, J.; Kočí, V.; Černý, R.; Kovařík, T. (2023). Thirty years since J. Davidovits introduced geopolymers considered now as hypo-crystalline materials within the mers-framework and the effect of oxygen binding: a review. Journal of Thermal Analysis and Calorimetry, 148(20), 10455–10463. https://doi.org/10.1007/s10973-023-12312-z.
Adeniyi, F.I.; Ogundiran, M.B.; Hemalatha, T.; Hanumantrai, B.B. (2020). Characterization of raw and thermally treated Nigerian kaolinite-containing clays using instrumental techniques. SN Applied Sciences, 2(5), 821. https://doi.org/10.1007/s42452-020-2610-x.
Davidovits, J. (1991). Geopolymers. Journal of Thermal Analysis, 37(8), 1633–1656. https://doi.org/10.1007/BF01912193.
Ogundiran, M. B.; Nugteren, H. W.; Witkamp, G. J. (2016). Geopolymerisation of fly ashes with waste aluminium anodising etching solutions. Journal of Environmental Management, 181, 118–123. https://doi.org/10.1016/j.jenvman.2016.06.017.
El-Eswed, B.I.; Yousef, R.I.; Alshaaer, M.; Hamadneh, I.; Al-Gharabli, S. I.; et al. (2015). Stabilization/solidification of heavy metals in kaolin/zeolite based geopolymers. International Journal of Mineral Processing, 137, 34–42. https://doi.org/10.1016/j.minpro.2015.03.002.
Phair, J.W.; van Deventer, J.S.J.; Smith, J.D. (2004). Effect of Al source and alkali activation on Pb and Cu immobilisation in fly-ash based “geopolymers.” Applied Geochemistry, 19(3), 423–434. https://doi.org/10.1016/S0883-2927(03)00151-3.
Nikolić, V.; Komljenović, M.; Marjanović, N.; Baščarević, Z.; Petrović, R. (2014). Lead immobilization by geopolymers based on mechanically activated fly ash. Ceramics International, 40(6), 8479–8488. https://doi.org/10.1016/j.ceramint.2014.01.059.
Palomo, A.; Palacios, M. (2003). Alkali-activated cementitious materials: Alternative matrices for the immobilisation of hazardous wastes. Cement and Concrete Research, 33(2), 289–295. https://doi.org/10.1016/S0008-8846(02)00964-X.
Pandey, B.; Kinrade, S.D.; Catalan, L.J.J (2012). Effects of carbonation on the leachability and compressive strength of cement-solidified and geopolymer-solidified synthetic metal wastes. Journal of Environmental Management, 101, 59–67. https://doi.org/10.1016/j.jenvman.2012.01.029.
Izquierdo, M.; Querol, X.; Davidovits, J.; Antenucci, D.; Nugteren, H.; et al. (2009). Coal fly ash-slag-based geopolymers: Microstructure and metal leaching. Journal of Hazardous Materials, 166(1), 561–566. https://doi.org/10.1016/j.jhazmat.2008.11.063.
Cheng, T.W.; Lee, M.L.; Ko, M.S.; Ueng, T.H.; Yang, S.F. (2012). The heavy metal adsorption characteristics on metakaolin-based geopolymer. Applied Clay Science, 56, 90–96. https://doi.org/10.1016/j.clay.2011.11.027.
Van Jaarsveld, J.G.S.; Van Deventer, J.S.J.; Schwartzman, A. (1999). The potential use of geopolymeric materials to immobilise toxic metals: Part II. Material and leaching characteristics. Minerals Engineering, 12(1), 75–91. https://doi.org/10.1016/S0892-6875(98)00121-6.
El-eswed, B.I. (2020). Chemical evaluation of immobilization of wastes containing Pb, Cd, Cu and Zn in alkali-activated materials: A critical review. Journal of Environmental Chemical Engineering, 8(5), 104194. https://doi.org/10.1016/j.jece.2020.104194.
Li, S.; Huang, X.; Muhammad, F.; Yu, L.; Xia, M.; et al. (2018). Waste solidification/stabilization of lead–zinc slag by utilizing fly ash based geopolymers. RSC Advances, 8(57), 32956–32965. https://doi.org/10.1039/C8RA06634E.
Waijarean, N.; MacKenzie, K.J.D.; Asavapisit, S.; Piyaphanuwat, R.; Jameson, G.N.L. (2017). Synthesis and properties of geopolymers based on water treatment residue and their immobilization of some heavy metals. Journal of Materials Science, 52(12), 7345–7359. https://doi.org/10.1007/s10853-017-0970-4.
El-Eswed, B.I.; Yousef, R.I.; Alshaaer, M.; Hamadneh, I.; Al-Gharabli, S.I.; et al. (2015). Stabilization/solidification of heavy metals in kaolin/zeolite based geopolymers. International Journal of Mineral Processing, 137, 34–42. https://doi.org/10.1016/j.minpro.2015.03.002.
Nikolići, I.; Đurović, D.; Tadić, M.; Blečić, D.; Radmilović, V. (2013). Immobilization of zinc from metallurgical waste and water solutions using geopolymerization technology. E3S Web of Conferences, 1, 41026. https://doi.org/10.1051/e3sconf/20130141026.
Singh, R.; Budarayavalasa, S. (2021). Solidification and stabilization of hazardous wastes using geopolymers as sustainable binders. Journal of Material Cycles and Waste Management, 23(5), 1699–1725. https://doi.org/10.1007/s10163-021-01245-0.
Guo, X.; Shi, H.; Xu, M. (2013). Static and dynamic leaching experiments of heavy metals from fly ash-based geopolymers. Journal of Wuhan University of Technology-Mater. Sci. Ed., 28(5), 938–943. https://doi.org/10.1007/s11595-013-0797-z.
Palacios, M.; Palomo, A. (2004). Alkali-activated fly ash matrices for lead immobilisation: a comparison of different leaching tests. Advances in Cement Research, 16(4), 137–144. https://doi.org/10.1680/adcr.2004.16.4.137.
Phillip, E.; Choo, T.F.; Khairuddin, N.W.A.; Abdel Rahman, R.O. (2023). On the Sustainable Utilization of Geopolymers for Safe Management of Radioactive Waste: A Review. Sustainability, 15(2), 1117. https://doi.org/10.3390/su15021117.
Petlitckaia, S.; Barré, Y.; Piallat, T.; Grauby, O.; Ferry, D.; et al. (2020). Functionalized geopolymer foams for cesium removal from liquid nuclear waste. Journal of Cleaner Production, 269, 122400. https://doi.org/10.1016/j.jclepro.2020.122400.
Srivastava, S.; Chaudhary, R.; Khale, D. (2008). Influence of pH, curing time and environmental stress on the immobilization of hazardous waste using activated fly ash. Journal of Hazardous Materials, 153(3), 1103–1109. https://doi.org/10.1016/j.jhazmat.2007.09.065.
Ogundiran, M.B., Osibanjo O. (2008). Heavy metal concentrations in soils and accumulation in plants growing in a deserted slag dumpsite in Nigeria. African Journal of Biotechnology, 7, 3053-3060.
Zhang, Z.; Wang, H.; Zhu, Y.; Reid, A.; Provis, J.L.; et al. (2014). Using fly ash to partially substitute metakaolin in geopolymer synthesis. Applied Clay Science, 88–89, 194–201. https://doi.org/10.1016/j.clay.2013.12.025.
Duxson, P.; Provis, J.L. (2008). Designing Precursors for Geopolymer Cements. Journal of the American Ceramic Society, 91(12), 3864–3869. https://doi.org/10.1111/j.1551-2916.2008.02787.x.
Ogundiran, M. B., & Kumar, S. (2015). Synthesis and characterisation of geopolymer from Nigerian Clay. Applied Clay Science, 108, 173–181. https://doi.org/10.1016/j.clay.2015.02.022.
Ogundiran, M.B.; Ikotun, O.J. (2014). Investigating the Suitability of Nigerian Calcined Kaolins as Raw Materials for Geopolymer Binders. Transactions of the Indian Ceramic Society, 73(2), 138–142. https://doi.org/10.1080/0371750X.2014.922430.
Ranjbar, N.; Kuenzel, C.; Spangenberg, J.; Mehrali, M. (2020). Hardening evolution of geopolymers from setting to equilibrium: A review. Cement and Concrete Composites, 114, 103729. https://doi.org/10.1016/j.cemconcomp.2020.103729.
Kaze, C.R.; Djobo, J.N.Y.; Nana, A.; Tchakoute, H.K.; Kamseu, E.; et al. (2018). Effect of silicate modulus on the setting, mechanical strength and microstructure of iron-rich aluminosilicate (laterite) based-geopolymer cured at room temperature. Ceramics International, 44(17), 21442–21450. https://doi.org/10.1016/j.ceramint.2018.08.205.
Their, J.M.; Ozakca, M. (2018). Developing geopolymer concrete by using cold-bonded fly ash aggregate, nano-silica, and steel fiber. Construction and Building Materials, 180, 12–22. https://doi.org/10.1016/j.conbuildmat.2018.05.274.
Malviya, R.; Chaudhary, R. (2006). Factors affecting hazardous waste solidification/stabilization: A review. Journal of Hazardous Materials, 137(1), 267–276. https://doi.org/10.1016/j.jhazmat.2006.01.065.
Chezom, D.; Chimi, K.; Choden, S.; Wangmo, T.; Shashi, D.; et al. (2013). Comparative Study of Different Leaching Procedures. International Journal of Engineering Research and General Science, 1(2).
Ayodele, O.B.; Sulaimon, A.A.; Alaba, P.A.; Tian, Z.Y. (2020). Influence of metakaolinization temperature on the structure and activity of metakaolin supported Ni catalyst in dry methane reforming. Journal of Environmental Chemical Engineering, 8(1), 103239. https://doi.org/10.1016/j.jece.2019.103239.
Barbosa, V.F.; MacKenzie, K.J.; Thaumaturgo, C. (2000). Synthesis and characterisation of materials based on inorganic polymers of alumina and silica: sodium polysialate polymers. International Journal of Inorganic Materials, 2(4), 309–317. https://doi.org/10.1016/S1466-6049(00)00041-6.
Ravisankar, R.; Naseerutheen, A.; Rajalakshmi, A.; Raja Annamalai, G.; Chandrasekaran, A. (2014). Application of thermogravimetry–differential thermal analysis (TG–DTA) technique to study the ancient potteries from Vellore dist, Tamilnadu, India. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 129, 201–208. https://doi.org/10.1016/j.saa.2014.02.095
Kim, B.; Lee, S. (2020). Review on characteristics of metakaolin-based geopolymer and fast setting. Journal of the Korean Ceramic Society, 57(4), 368–377. https://doi.org/10.1007/s43207-020-00043-y.
Silva, P. De; Sagoe-Crenstil, K.; Sirivivatnanon, V. (2007). Kinetics of geopolymerization: Role of Al2O3 and SiO2. Cement and Concrete Research, 37(4), 512–518. https://doi.org/10.1016/j.cemconres.2007.01.003.
Siyal, A.A.; Azizli, K.A.; Man, Z.; Ullah, H. (2016). Effects of Parameters on the Setting Time of Fly Ash Based Geopolymers Using Taguchi Method. Procedia Engineering, 148, 302–307. https://doi.org/10.1016/j.proeng.2016.06.624.
Dave, N.; Misra, A.K.; Srivastava, A.; Kaushik, S.K. (2017). Setting time and standard consistency of quaternary binders: The influence of cementitious material addition and mixing. International Journal of Sustainable Built Environment, 6(1), 30–36. https://doi.org/10.1016/j.ijsbe.2016.10.004.
Tian, X.; Xu, W.; Song, S.; Rao, F.; Xia, L. (2020). Effects of curing temperature on the compressive strength and microstructure of copper tailing-based geopolymers. Chemosphere, 253, 126754. https://doi.org/10.1016/j.chemosphere.2020.126754.
Diaz, E.I.; Allouche, E.N.; Eklund, S. (2010). Factors affecting the suitability of fly ash as source material for geopolymers. Fuel, 89(5), 992–996. https://doi.org/10.1016/j.fuel.2009.09.012.
Xu H.; Lukey G.C.; van Deventer, J.S.J. (2004). The Activation of Class C-, Class F-Fly Ash and Blast Furnace Slag Using Geopolymerisation. the proceedings of the Eighth CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag, and Natural Pozzolan, SP-221.
Wijaya, L.A.; Jaya Ekaputri, J.; Triwulan (2017). Factors influencing strength and setting time of fly ash based-geopolymer paste. MATEC Web of Conferences, 138, 01010. https://doi.org/10.1051/matecconf/201713801010.
Seo, J.; Park, S.; Yoon, H.N.; Lee, H.K. (2020). Effect of CaO incorporation on the microstructure and autogenous shrinkage of ternary blend Portland cement-slag-silica fume. Construction and Building Materials, 249, 118691. https://doi.org/10.1016/j.conbuildmat.2020.118691.
Elimbi, A.; Tchakoute, H.K.; Njopwouo, D. (2011). Effects of calcination temperature of kaolinite clays on the properties of geopolymer cements. Construction and Building Materials, 25(6), 2805–2812. http://doi.org/10.1016/j.conbuildmat.2010.12.055.
Standard Specification for building Brick (Solid Masonry Units Made from Clay or Shale). (accessed on 2 January 2024) Available online: https://www.astm.org/c0062-17.html.
Abbass, W.; Abbas, S.; Aslam, F.; Ahmed, A.; Ahmed, T.; et al. (2022). Manufacturing of Sustainable Untreated Coal Ash Masonry Units for Structural Applications. Materials, 15(11), 4003. https://doi.org/10.3390/ma15114003.
Oladele, O.L.; Adesanya, E.D.; Arbe, A.; Iturrospe, A.; Ogundiran, M.B. (2023). Mitigation of efflorescence, drying shrinkage and water demand of calcined clay-based geopolymers with biological waste ashes as activator and hardener. Applied Clay Science, 243, 107050. https://doi.org/10.1016/j.clay.2023.107050.
Chen, X.; Zhang, J.; Lu, M.; Chen, B.; Gao, S.; et al. (2022). Study on the effect of calcium and sulfur content on the properties of fly ash based geopolymer. Construction and Building Materials, 314, 125650. https://doi.org/10.1016/j.conbuildmat.2021.125650.
Mahmoodi, O.; Siad, H.; Lachemi, M.; Dadsetan, S.; Sahmaran, M. (2021). Development and characterization of binary recycled ceramic tile and brick wastes-based geopolymers at ambient and high temperatures. Construction and Building Materials, 301, 124138. https://doi.org/10.1016/j.conbuildmat.2021.124138.
Duxson, P.; Lukey, G.C.; Separovic, F.; van Deventer, J.S.J. (2005). Effect of Alkali Cations on Aluminum Incorporation in Geopolymeric Gels. Industrial & Engineering Chemistry Research, 44(4), 832–839. https://doi.org/10.1021/ie0494216.
SUBMITTED: 09 January 2024
ACCEPTED: 07 April 2024
PUBLISHED:
15 April 2024
SUBMITTED to ACCEPTED: 89 days
DOI:
https://doi.org/10.53623/tasp.v4i1.398