Impact of pH on Selectivity Adsorption by Cement and the Retention and Release of Lead and Cadmium in Single and Double-Component Systems in Cement-based Stabilization/Solidification

Document Type : Original Research

Authors
V. Ouhadi 1
A. Aleefar 2
D. Saaedifar 3
S. Omid Naeini 3
1 Prof. Bu Ali Sina University; Adjunct Prof., University of Tehran
2 School of Civil Engineering, University of Tehran
3 School of Civil Eng., University of Tehran
10.22034/23.6.5
Abstract
The presence of heavy metal contaminants in clays causes changes in soil properties, which increases the risk of contaminant transport into the clay layer. Various techniques have been developed recently to remediate contaminated soil. These methods include electrokinetics, biological treatment, and immobilization. Among them, cement-based stabilization/solidification technique is very common. Generally, cement-based systems are frequently used because of their affordability and great durability. This method uses the two mechanisms of chemical stabilization and physical solidification to retain heavy metals and decrease the mobility of contaminants. Even though several researches have been performed to address the different aspects of cement-based solidification/stabilization, there has been a lack of research on the stabilization/solidification of heavy metals in the presence of two different heavy metal ions. Therefore, the objective of this study is to determine to what extent the pH variations affect lead and cadmium retention and release in single and double-component cement-based stabilization/solidification systems. To accomplish the aforementioned objective, first, the retention capacity of lead and cadmium, in cement-based S/S of contaminated bentonite in single and double-component heavy metal systems is investigated. The effect of pH on the stabilization/solidification process was determined by conducting a series of XRD tests in order to investigate and differentiate the stabilization and solidification mechanisms. In the next step, the amount of released cadmium and lead ions during the TCLP test was determined in single and double-component systems in order to investigate the effect of pH and the simultaneous presence of lead and cadmium in the release of these heavy metals. According to the achieved results, the maximum retention capacities of lead and cadmium occur in the pH ranges of 8.5 to 11 and 10 to 12, respectively. Furthermore, retention in the double-component system is always lower than that of the single-component system, assuming a similar initial concentration. In addition, XRD results illustrate that the intensity of the peaks of cadmium and lead chemical compounds has increased for the samples their pHs take place in the safe zones. This indicates an increase in the contribution of the stabilization mechanism. According to the results of this paper, at a similar contaminant concentration, the intensity of the C-S-H peak increases with an increase in cement percentages. This indicates progress in the contribution of the solidification mechanism in the retention of heavy metals. Still, the release of these heavy metals is always lower than the maximum allowable value reported by the US EPA in the above-mentioned pH ranges. Moreover, the results of this research show that the amount of released cadmium and lead in the double-component system is more than that of the single-component system, assuming similar initial concentrations. Based on the definition of the safe zone, in the defined pH range, the contaminant is retained during the TCLP test mainly by chemical stabilization (precipitation). In fact, in the above range, an increase in the amount of cement has not shown a significant effect on the amount of heavy metal desorption. This finding is supported by the results of retention tests.

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1. Rui, D., Wu, Z., Ji, M., Liu, J., Wang, S. and Ito, Y., 2019. Remediation of Cd-and Pb-contaminated clay soils through combined freeze-thaw and soil washing. Journal of Hazardous Materials, 369, pp.87-95.
2. Jaishankar, M., Tseten, T., Anbalagan, N., Mathew, B.B. and Beeregowda, K.N., 2014. Toxicity, mechanism and health effects of some heavy metals. Interdisciplinary Toxicology, 7(2), pp.60-72.
3. He, Z., Shentu, J., Yang, X., Baligar, V.C., Zhang, T. and Stoffella, P.J., 2015. Heavy metal contamination of soils: sources, Journal of Environmental Indicators. 9:17-18, 2015.
4. Hutton, M., 1983. Sources of cadmium in the environment. Ecotoxicology and Environmental Safety, 7(1), pp.9-24.
5. Goering, P.L., Waalkes, M.P. and Klaassen, C.D., 1995. Toxicology of cadmium. Toxicology of metals (pp. 189-214). Springer, Berlin, Heidelberg.
6. Muthu, M., Santhanam, M. and Kumar, M., 2018. Pb removal in pervious concrete filter: Effects of accelerated carbonation and hydraulic retention time. Construction and Building Materials, 174, pp.224-232.
7. Mao, L., Guo, H. and Zhang, W., 2018. Addition of waste glass for improving the immobilization of heavy metals during the use of electroplating sludge in the production of clay bricks. Construction and Building Materials, 163, pp.875-879.
8. Xia, M., Muhammad, F., Zeng, L., Li, S., Huang, X., Jiao, B., Shiau, Y. and Li, D., 2019. Solidification/stabilization of lead-zinc smelting slag in composite based geopolymer. Journal of Cleaner Production, 209, pp.1206-1215.
9. Liu, L., Li, W., Song, W. and Guo, M., 2018. Remediation techniques for heavy metal-contaminated soils: Principles and applicability. Science of the Total Environment, 633, pp.206-219.
10. Niu, M., Li, G., Wang, Y., Li, Q., Han, L. and Song, Z., 2018. Comparative study of immobilization and mechanical properties of sulfoaluminate cement and ordinary Portland cement with different heavy metals. Construction and Building Materials, 193, pp.332-343.
11. Chen, Q.Y., Tyrer, M., Hills, C.D., Yang, X.M. and Carey, P., 2009. Immobilisation of heavy metal in cement-based solidification/stabilisation: A review. Waste Management, 29(1), pp.390-403.
12. Amiri, M. and Ouhadi, V., 2018. Evaluation of Micro and Nano-Structure of Cement Hydration Process in Solidification and Stabilization of Zn Heavy Metal Contaminant at the Presence of Clayey Soil. Modares Civil Engineering Journal. 1-15. (In Persian)
13. Tajudin, S.A., Azmi, M.M. and Nabila, A.T.A., 2016, July. Stabilization/solidification remediation method for contaminated soil: a review. In IOP conference series: Materials Science and Engineering (Vol. 136, No. 1, p. 012043). IOP Publishing.
14. Shi, C. and Spence, R., 2004. Designing of cement-based formula for solidification/stabilization of hazardous, radioactive, and mixed wastes. Critical Reviews in Environmental Science and Technology, 34(4), pp.391-417.
15. Ouhadi, V.R., Yong, R.N. and Deiranlou, M., 2021. Enhancement of cement-based solidification/stabilization of a lead-contaminated smectite clay. Journal of Hazardous Materials, 403, p.123969.
16. Wang, Y.S., Dai, J.G., Wang, L., Tsang, D.C. and Poon, C.S., 2018. Influence of lead on stabilization/solidification by ordinary Portland cement and magnesium phosphate cement. Chemosphere, 190, pp.90-96.
17. Li, Y., Min, X., Ke, Y., Fei, J., Liu, D. and Tang, C., 2019. Immobilization potential and immobilization mechanism of arsenic in cemented paste backfill. Minerals Engineering, 138, pp.101-107.
18. Contessi, S., Calgaro, L., Dalconi, M.C., Bonetto, A., Bellotto, M.P., Ferrari, G., Marcomini, A. and Artioli, G., 2020. Stabilization of lead contaminated soil with traditional and alternative binders. Journal of Hazardous Materials, 382, p.120990.
19. Ouhadi, V.R., Yong, R.N., Rafiee, F. and Goodarzi, A.R., 2011. Impact of carbonate and heavy metals on micro-structural variations of clayey soils. Applied Clay Science, 52(3), pp.228-234.
20. Ouhadi, V. and Deiranlou, M., 2021. Impact of fly ash on the process of cement-based solidification of heavy metal contaminated bentonite. Sharif Journal of Civil Engineering, 37(1.1), pp.85-94. (In Persian)
21. de Rojas Gómez, M. S., & Rojas, M. F. 2013. Natural pozzolans in eco-efficient concrete. In Eco-efficient concrete (pp. 83-104). Woodhead Publishing.
22. USEPA, 2009. Technology performance review: Selecting and using solidification/stabilization treatment for site remediation.
23. Nikolić, V., Komljenović, M., Džunuzović, N. and Miladinović, Z., 2018. The influence of Pb addition on the properties of fly ash-based geopolymers. Journal of Hazardous Materials, 350, pp.98-107.
24. Ouhadi, V.R. and Zare Shahriari, E., 2020. Effect of bentonite initial pH on selectivity of heavy metals in single and composite systems. Modares Civil Engineering Journal, 20(2), pp.1-11. (In Persian)
25. Paria, S. and Yuet, P.K., 2006. Solidification–stabilization of organic and inorganic contaminants using portland cement: a literature review. Environmental Reviews, 14(4), pp.217-255.
26. Yong, R.N., Nakano, M. and Pusch, R., 2012. Environmental soil properties and behaviour. CRC Press.
27. Du, H., Chen, W., Cai, P., Rong, X., Feng, X. and Huang, Q., 2016. Competitive adsorption of Pb and Cd on bacteria–montmorillonite composite. Environmental pollution, 218, pp.168-175.
28. Ouhadi, V.R. and Amiri, M., 2020. Microstructural Evaluation of Stabilization and Solidification of Heavy Metals by Cement at the Presence of Nano Montmorillonite. Amirkabir Journal of Civil Engineering, 52(1), pp.107-122. (In Persian).
29. Ouhadi, V.R., Amiri, M. and Ouhadi, M.H., 2015. Micro-structural evaluation of lead heavy metal retention in stabilization and solidification with bentonite and cement. Journal of Engineering Geology, 9(1), pp.2575-2592.
30. American Society for Testing and Materials, 2016. Annual Book of ASTM Standards. Soil and Rock; Building Stones, Philadelphia.
31. Macht, F., Eusterhues, K., Pronk, G.J., Totsche, K.U., 2011. Specific surface area of clay minerals: Comparison between atomic force microscopy measurements and bulk-gas (N2) and -liquid (EGME) adsorption methods. Applied Clay Science. 53 (1), 20–26.
32. Ouhadi, V.R. and Deiranlou, M. 2017. Development and validation of the modified barium chloride method for CEC measurement and determination of accurate exchangeable calcium cation concentration in carbonated clayey soils, Modares Civil Engineering journal, 17 (3), pp. 21-34. (In Persian).
Modares Civil Engineering journal
Volume 23, Issue 6
November and December 2023
Pages 68-81