Effect of Alkali Concentration and Curing Temperature on the Leaching Behaviour of Heavy Metals: Geopolymer Matrix

IJEP 43(1): 31-40 : Vol. 43 Issue. 1 (January 2023)

Smita Badur Karmankar1, Rubina Chaudhary2* and Divya Khale2

1. IPS Academy, Institute of Engineering and Science, Indore, Madhya Pradesh – 452 012, India
2. Devi Ahilya University, School of Energy and Environmental Studies, Takshashila Campus, Indore, Madhya Pradesh – 452 001, India


The paper discusses the effect of alkali concentration and curing temperature on the leaching of the heavy metals in the geopolymer matrix. Leaching for all the metals Pb, Mn, Fe except Cu was found to be high for samples treated with 10 N NaOH as compared to the samples treated with 5 N NaOH. Whereas durability test results show that the geopolymer solidified/stabilized products withstand worst environmental conditions. All W/B ratios (0.11 to 1.0) passed 12 cycles of freezing thawing (FT) and heating thawing (HT). There was not very significant difference in the weight loss of all the samples for HT and FT. Strength of the samples cured at elevated temperature showed higher compressive strength as compared to the samples cured at room temperature. All the metals effectively fixed in the sample activated with 5 N NaOH cured for 7 days at room temperature as compared to other curing regimes.


Alkali concentration, Curing temperature, Geopolymer matrix, Leaching, Heavy metals, Treatment effectiveness


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