CHITOSAN-ASSISTED SOIL WASHING: INFLUENCE OF CONCENTRATION AND LIQUID-TO-SOLID RATIO ON HEAVY METAL REMOVAL
DOI:
https://doi.org/10.29302/Pangeea25.07Keywords:
chitosan, soil washing, sustainable remediation, heavy metal removalAbstract
The process of mining has led to metal contamination of soils, which is an environmental concern in Romania, and especially in the Apuseni Mountains region, where considerable extractive activity has been conducted that has left behind large amounts of tailings and waste materials. The purpose of this study was to investigate the effect of chitosan-based washing solutions on the removal of copper (Cu) and lead (Pb) from contaminated soil collected from the Larga de Sus mining site (Alba County, Romania). Soil washing was conducted using chitosan solutions with various chitosan content (0%, 2% and 5% w/v) and at a liquid-to-solid ratios (mL:g) of 5:1 and 8:1. The washing process was done using a mechanical stirrer for up to 40 hours, and the concentration of metals was measured by Atomic Absorption Spectrometry (AAS). Results demonstrated that both chitosan concentration and washing solution volume strongly influenced metal removal efficiency. The maximum rate of metal removal was obtained using the 2% chitosan solution and an 8:1 liquid-to-solid ratio, resulting in the removal of Cu and Pb by 74.5% and 79.6%, respectively. Copper concentration after soil washing dropped below the Romanian regulatory intervention limit while Pb concentration remained slightly over that limit. Overall, the results indicate that chitosan is a natural, green, and effective chelating agent for soil remediation, with a potential for large scale and field applications to remediate heavy metal contaminated sites.
References
1. Szanto (Prodan) M.; Micle V.; Prodan C.V. Study of Soil Quality in Copsa Mică Area with the Aim of their Remediation. ProEnvironment 2011, 4, 251 – 255.
2. Stancu P.T.. Studii geochimice şi transformări mineralogice rezultate în urma proceselor secundare de exploatare minieră şi tehnologii de remediere a zonelor poluate cu metale grele şi/sau rare în zona Zlatna. Teză, Bucure ti, 2013.
3. Boro M.; Smical I.; Micle V.; Lichtscheild-Schultz I. Heavy metal pollution of soil from Baia-Mare-Case Study: Cuprom Industrial Area. Scientific Papers. Series E. Land Reclamation, Earth Observation & Surveying 2015, IV, 99-106.
4. Khalid S.; Shahid M.; Niazi N.K.; Murtaza B.; Bibi I.; Dumat C. A comparison of technologies for remediation of heavy metal contaminated soils. Journal of Geochemical Exploration 2017, 182, 247-268. https://doi.org/10.1016/j.gexplo.2016.11.021
5. Lestan D.; Luo C.; Li X. The use of chelating agents in the remediation of metal-contaminated soils: A review. Environmental Pollution 2008, 153, 3-13. https://doi.org/10.1016/j.envpol.2007.11.015
6. Gămăneci G.; Căpăţână C.. Studiul poluării solului cu metale grele a solului din zona Rovinari. Analele Universităţii “Constantin Brâncuşi” din Târgu Jiu, Seria Inginerie 2011, 3, 309-318.
7. Mathew A.M. Phytoremediation of Heavy Metal Contaminated Soil. Thesis, Faculty of the Graduate College of the Oklahoma State University, 2005.
8. Dermont G.; Bergeron M.; Mercier G.; Richer-Lafl`eche M. Soil washing for metal removal: A review of physical/chemical technologies and field applications. Journal of Hazardous Materials 2008, 152, 1–31. https://doi.org/10.1016/j.jhazmat.2007.10.043
9. Begum Z.A.; Rahman I.M.M.; Sawai H.; Hasegawa H. Chemical-Induced Washing Remediation of Metal-Contaminated Soils. Environmental Remediation Technologies for Metal-Contaminated Soils 2016, pp. 197-218. https://doi.org/10.1007/978-4-431-55759-3_9
10. Zhu H.; Yuan X.; Zeng G.; Jiang M.; Liang J.; Zhang C.; Yin J.; Huang H.; Liu Z.; Jiang H. Ecological risk assessment of heavy metals in sediments of Xiawan Port based on modified potential ecological risk index. Transactions of Nonferrous Metals Society of China 2012, 22, 1470 1477. 10.1016/S1003-6326(11)61343-5
11. Wang P.; Li J.; Wang H. Engineering Properties of Heavy Metal Contaminated Soil Affected by EDTA Washing. Electronic Journal of Geotechnical Engineering 2013,18, 3809-3918.
12. Jiang W.; Tao T.; Liao Z. Removal of Heavy Metal from Contaminated Soil with Chelating Agents. Open Journal of Soil Science 2011, 1, 70-76. 10.4236/ojss.2011.12010
13. Meng F.; Yuan G.; Wei J.; Bi D.; Ok Y.S.; Wang H. Humic substances as a washing agent for Cd-contaminated soils. Chemosphere 2017, 181, 461- 467. https://doi.org/10.1016/j.chemosphere.2017.04.127
14. Yang T.; Hodson M.E. Investigating the use of synthetic humic-like acid as a soil washing treatment for metal contaminated soil. Science of the Total Environment 2019, 647, 290–300. https://doi.org/10.1016/j.scitotenv.2018.07.457
15. Keri A.A.; Avram S.; Rusu T. Characteristics Regarding the Geomorphological Change of Land at the Larga de Sus Mine, the Zlatna Mining Perimeter, the County of Alba, ProEnvironment 2010, 3, 318 – 321.
16. Damian G.E.; Micle V.; Sur I.M. Mobilisation of Cu and Pb from multi-metal contaminated soils by dissolved humic substances extracted from Leonardite and factors affecting the process. Journal of Soils and Sediments 2019, 19(7), 2869-2881. https://doi.org/10.1007/s11368-019-02291-w
17. Castro S.P.; Paulin E.G. Is Chitosan a New Panacea? Areas of Application. In: The Complex World of Polysaccharides, Rijeka, October 2012, 3-46.
18. Sur I.M.; Micle V.; Gabor T. Heavy metals removal by bioleaching using Thiobacillus ferrooxidans. Romanian Biotechnological Letters 2018, 23, 13409-13416.
19. Order No. 756 of November 3, 1997 for the Approval of the Regulation on Environmental Pollution Assessment. Eminent: Ministry of Waters, Forests and Environmental Protection. (Published in: Official Gazette No 303 bis of 6 November 1997). http://legislatie.just.ro/Public/Detalii DocumentAfis/151788 (in romanian).
20. Li Y.; Lei M.; Chen T.; Yang J.; Zhou X.; Wang Y. Optimized EDTA washing procedure to decontaminate heavymetals from soils in iron and steel works sites. Asian Journal of Chemistry 2013, 25, 37–41. 10.14233/ajchem.2013.12229
21. Soleimani M.; Hajabbasi M.A.; Afyuni M.; Akbar S. Comparison of Natural Humic Substances and Synthetic Ethylenediaminetetraacetic Acid and Nitrilotriacetic Acid as Washing Agents of a Heavy Metal–Polluted Soil. Journal of Environmental Quality 2010, 39, 855–862. 10.2134/jeq2009.0292
22. Kulikowska D.; Gusiatin Z.M.; Bulkowska K.; Klik B. Feasibility of using humic substances fromcompost to remove heavymetals (Cd, Cu, Ni, Pb, Zn) from contaminated soil aged for different periods of time. Journal of Hazardous Materials 2015, 300, 882–891. https://doi.org/10.1016/j.jhazmat.2015.08.022
