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Deng T, Fisonga M, Ke H, Li L, Wang J, Deng Y. Mixing uniformity effect on leaching behaviour of cement-based solidified contaminated clay. Sci Total Environ 2024; 908:167957. [PMID: 37866593 DOI: 10.1016/j.scitotenv.2023.167957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 10/24/2023]
Abstract
Mixing uniformity is essential for the quality control of the contaminated clay's solidification. To investigate the effect of the mixing uniformity on the leaching behaviour of the cement-based solidified contaminated clay, this study proposed a quantitative method to characterize the mixing uniformity and investigated the leaching behaviour by the leaching toxicity tests and semi-dynamic leaching tests. X-ray computed tomography (X-CT) was employed to reveal the internal mesoscopic structure. In this case, Pb2+ was selected as a tagged pollutant because of the widespread attention at heavy metal-contaminated sites. The leaching toxicity indicates the significant Pb2+ concentration deviation among the parallel specimens and non-association with the mixing uniformity. However, the Pb2+ cumulative leaching mass and observed diffusion coefficient by the semi-dynamic leaching tests both decrease with the mixing uniformity. X-CT image analysis reveals that the high cement zones wrap the low cement zones with different dimensions in the heterogeneous solidified matrix. Moreover, the specimen pretreatment method in the existing leaching toxicity standards may be inadequate because of the overall encapsulation destruction by the crushing process and representativeness uncertainty when sampling. However, for semi-dynamic leaching, the Pb2+ migration depends on the uniformity, reflecting the continuous distribution of high cement zones.
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Affiliation(s)
- Tingting Deng
- Institute of Geotechnical Engineering, School of Transportation, Southeast University, Nanjing 211189, China
| | - Marsheal Fisonga
- Institute of Geotechnical Engineering, School of Transportation, Southeast University, Nanjing 211189, China
| | - Han Ke
- School of Civil Engineering, Zhejiang University, Hangzhou 310058, China
| | - Ling Li
- CECEP DADI Environmental Remediation Co., Ltd., Beijing 100085, China
| | - Jianwei Wang
- CECEP DADI Environmental Remediation Co., Ltd., Beijing 100085, China
| | - Yongfeng Deng
- Institute of Geotechnical Engineering, School of Transportation, Southeast University, Nanjing 211189, China.
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Duduković N, Slijepčević N, Tomašević Pilipović D, Kerkez Đ, Leovac Maćerak A, Dubovina M, Krčmar D. Integrated application of green zero-valent iron and electrokinetic remediation of metal-polluted sediment. Environ Geochem Health 2023; 45:5943-5960. [PMID: 37198355 DOI: 10.1007/s10653-023-01609-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/04/2023] [Indexed: 05/19/2023]
Abstract
In recent years, more focus has been placed on integrated metal removal processes. Electrokinetic (EK) treatment is superior to other technologies because it can be applied to a variety of mediums. Green nanoparticles, on the other hand, have the potential to significantly reduce pollutant concentrations in a short period of time. In this study, we investigated the possibility of combining green zero-valent iron (nZVI) with EK on Cd and Zn-contaminated sediment. For green synthesis, extracts of dry leaves of mulberry (ML-nZVI) and oak (OL-nZVI) were used, both abundantly present in the Republic of Serbia. The results show that, despite the fact that their availability was greatly reduced, the metals were concentrated and stabilized to a significant extent in the middle of the EK cell (z/L 0.5) after all treatments. When the results were compared, OL-nZVI proved to be a more effective nanomaterial even with smaller doses of OL-nZVI, which is important in terms of achieving better economic benefits. This study identified green nano zero-valent iron as a powerful tool for metal removal when combined with electrokinetic (EK) treatment, which improves green nZVI longevity and migration. This study of the combined green nZVI-EK remediation treatment, in particular, will have an impact on future research in this field, given the achieved efficiency.
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Affiliation(s)
- Nataša Duduković
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Serbia.
| | - Nataša Slijepčević
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Serbia
| | - Dragana Tomašević Pilipović
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Serbia
| | - Đurđa Kerkez
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Serbia
| | - Anita Leovac Maćerak
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Serbia
| | - Miloš Dubovina
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Serbia
| | - Dejan Krčmar
- Department of Chemistry, Biochemistry and Environmental Protection, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 3, Novi Sad, 21000, Serbia
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Popov N, Rončević S, Duduković N, Krčmar D, Mihaljev Ž, Živkov Baloš M, Đorđievski S. Ex situ remediation of sediment from Serbia using a combination of electrokinetic and stabilization/solidification with accelerated carbonation treatments. Environ Sci Pollut Res Int 2021; 28:14969-14982. [PMID: 33222071 DOI: 10.1007/s11356-020-11621-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 11/09/2020] [Indexed: 06/11/2023]
Abstract
The application of three simple and cost-effective technologies for ex situ remediation of the sediment of Begej River in Serbia is presented in this paper. In the first step, conventional electrokinetic treatment (EK) was carried out to reduce the amount of contaminated sediment and enhance the accumulation of metals. Subsequently, stabilization/solidification (S/S) treatment was applied to the remaining portion of polluted sediment to immobilize the accumulated metals. At the same time, the influence of accelerated carbonation on the effectiveness of the treatment was evaluated. The immobilizing agents used in this study included bio ash produced by combustion of wheat and soy straw mixture and bio ash derived from molasses incineration. After the treatments, the risk assessment was performed by using the sequential extraction procedure (SEP) and TCLP and DIN 3841-4 S4 leaching tests. The results obtained after the EK treatment revealed a reduction in the amount of polluted sediment to a half. Leaching tests and SEP performed on S/S mixtures after a 28-day maturation period indicated that accelerated carbonation decreased the mobility of critical metals, especially in wheat and soy straw mixtures. Moreover, based on the leaching tests, all prepared mixtures were categorized as non-hazardous and safe for disposal according to the relevant Serbian regulations. The newly developed method that combines EK and S/S treatments with the addition of accelerated carbonation produced reduced volumes of stabilized sediment which is safe for disposal.
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Affiliation(s)
- Nenad Popov
- Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
- Scientific Veterinary Institute "Novi Sad", Rumenački put 20, Novi Sad, 21000, Serbia
| | - Srđan Rončević
- Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
| | - Nataša Duduković
- Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia.
| | - Dejan Krčmar
- Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, University of Novi Sad, Trg Dositeja Obradovića 3, Novi Sad, 21000, Serbia
| | - Željko Mihaljev
- Scientific Veterinary Institute "Novi Sad", Rumenački put 20, Novi Sad, 21000, Serbia
| | - Milica Živkov Baloš
- Scientific Veterinary Institute "Novi Sad", Rumenački put 20, Novi Sad, 21000, Serbia
| | - Stefan Đorđievski
- Mining and Metallurgy Institute Bor, Zeleni Bulevar 35, Bor, 19210, Serbia
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