1
|
Shi Y, Liu Q, Wu G, Zhao S, Li Y, You S, Huang G. Removal and reduction mechanism of Cr (VI) in Leersia hexandra Swartz constructed wetland-microbial fuel cell coupling system. Ecotoxicol Environ Saf 2024; 277:116373. [PMID: 38653023 DOI: 10.1016/j.ecoenv.2024.116373] [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: 12/24/2023] [Revised: 03/29/2024] [Accepted: 04/20/2024] [Indexed: 04/25/2024]
Abstract
Cr (VI) is extremely harmful to both the environment and human health, and it can linger in the environment for a very long period. In this research, the Leersia hexandra Swartz constructed wetland-microbial fuel cell (CW-MFC) system was constructed to purify Cr (VI) wastewater. By comparing with the constructed wetland (CW) system, the system electricity generation, pollutants removal, Cr enrichment, and morphological transformation of the system were discussed. The results demonstrated that the L. hexandra CW-MFC system promoted removal of pollutants and production of electricity of the system. The maximum voltage of the system was 499 mV, the COD and Cr (VI) removal efficiency was 93.73% and 97.00%. At the same time, it enhanced the substrate and L. hexandra ability to absorb Cr and change it morphologically transformation. Additionally, the results of XPS and XANES showed that the majority of the Cr in the L. hexandra and substrate was present as Cr (III). In the L. hexandra CW-MFC system, Geobacter also functioned as the primary metal catabolic reducing and electrogenic bacteria. As a result, L. hexandra CW-MFC system possesses the added benefit of removing Cr (VI) while producing energy compared to the traditional CW system.
Collapse
Affiliation(s)
- Yucui Shi
- School of Chemical Engineering and Environment, Weifang University of Science and Technology, Weifang 262700, China; Shandong Engineering Research Center of Green and High-value Marine Fine Chemical, Weifang 262700, China; Weifang Key Laboratory of Chemical Wastewater Pollution Control and Resource Reuse, Weifang 262700, China
| | - Qing Liu
- School of Chemical Engineering and Environment, Weifang University of Science and Technology, Weifang 262700, China; Shandong Engineering Research Center of Green and High-value Marine Fine Chemical, Weifang 262700, China; Weifang Key Laboratory of Chemical Wastewater Pollution Control and Resource Reuse, Weifang 262700, China
| | - Guowei Wu
- Shouguang Hospital of Traditional Chinese Medicine, Weifang 262700, China
| | - Shasha Zhao
- School of Chemical Engineering and Environment, Weifang University of Science and Technology, Weifang 262700, China; Shandong Engineering Research Center of Green and High-value Marine Fine Chemical, Weifang 262700, China; Weifang Key Laboratory of Chemical Wastewater Pollution Control and Resource Reuse, Weifang 262700, China
| | - Yongwei Li
- School of Chemical Engineering and Environment, Weifang University of Science and Technology, Weifang 262700, China; Shandong Engineering Research Center of Green and High-value Marine Fine Chemical, Weifang 262700, China
| | - Shaohong You
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin 541004, China; Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology of Guilin University of Technology, Guilin 541004, China.
| | - Guofu Huang
- School of Chemical Engineering and Environment, Weifang University of Science and Technology, Weifang 262700, China; Shandong Engineering Research Center of Green and High-value Marine Fine Chemical, Weifang 262700, China; Weifang Key Laboratory of Chemical Wastewater Pollution Control and Resource Reuse, Weifang 262700, China.
| |
Collapse
|
2
|
Li Y, Zhou W, Huang X, Wang Y, Liang J, Liu Y, Tong M. Is crystalline chromium phosphate environmentally stable? A study on the formation, dissolution and oxidation risk of CrPO 4·6H 2O. J Hazard Mater 2024; 465:133112. [PMID: 38043420 DOI: 10.1016/j.jhazmat.2023.133112] [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: 07/30/2023] [Revised: 11/22/2023] [Accepted: 11/26/2023] [Indexed: 12/05/2023]
Abstract
Hexavalent chromium (Cr(VI)) contamination in soil and groundwater is usually remediated via reduction techniques. The formation of crystalline chromium phosphate (CrPO4·6 H2O) occurs as a byproduct during Cr(VI) remediation processes in the presence of phosphate, yet its stability in the environment has received limited attention. In this study, the formation conditions, structure, properties, and risks associated with the dissolution and oxidation of CrPO4·6 H2O were comprehensively assessed. Results showed that crystalline CrPO4·6 H2O was formed under pH 5 - 7 at room temperature. CrPO4·6 H2O exhibits higher dissolution risk compared to Cr(OH)3·3 H2O due to a long Cr-P bond (4.2 Å). H+ and OH- increased the risk of dissolution at pH 5 and 11, respectively, owing to the formation of CrH2PO42+ and Cr(OH)4-. In addition, under faintly acidic conditions, the high solubility of CrPO4·6 H2O increases the risk of oxidation; under neutral and weakly alkaline conditions, the presence of positively charged Cr(H2O)63+ structures on the surface elevates its susceptibility to contact and oxidation by δ-MnO2 compared to Cr(OH)3·3 H2O. Specifically, at pH 11, the conversion of CrPO4·6 H2O to Cr(OH)3·3 H2O results in similar oxidation risks for both Cr(III) precipitates.
Collapse
Affiliation(s)
- Yunyi Li
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China.
| | - Wenshuai Zhou
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Xinmiao Huang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Yutong Wang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Jialiang Liang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, PR China
| | - Yangsheng Liu
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| | - Meiping Tong
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China
| |
Collapse
|
3
|
Witt K, Kaczorowska MA, Bożejewicz D. Efficient, fast, simple, and eco-friendly methods for separation of toxic chromium(VI) ions based on ion exchangers and polymer materials impregnated with Cyphos IL 101, Cyphos IL 104, or D2EHPA. Environ Sci Pollut Res Int 2024; 31:7977-7993. [PMID: 38177645 PMCID: PMC10821846 DOI: 10.1007/s11356-023-31648-5] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 12/17/2023] [Indexed: 01/06/2024]
Abstract
In this study, we present the results of the first comparison of the elimination of toxic Cr(VI) ions, which are hazardous contamination of the environment, from aqueous solutions using ion exchangers (IEs) and polymer materials (PMs) impregnated with D2EHPA or ionic liquids (Cyphos IL 101 and Cyphos IL 104). Sorption of Cr(VI) ions and desorption from the formulated sorption materials were carried out. In comparison, classical solvent extraction was accomplished. Fourier transform infrared-attenuated total reflectance spectroscopy (FTIR-ATR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), and atomic force microscopy (AFM) have been used for characterization of the structure of developed IEs and PMs. The highest efficiency of adsorption of Cr(VI) ions was obtained using PMs with ionic liquids (>82%). Desorption from these materials were also very efficient (>75%). On the contrary, the application of IEs allowed for obtaining the best results of both, sorption and desorption processes when using D2EHPA (75% and 72%, respectively). The application of PMs and IEs is part of the green chemistry, and the conducted elimination of chromium(VI) ions using developed materials allows for the conclusion that they can potentially be used on a larger scale, e.g., for the treatment of industrial wastewater rich in Cr(VI) ions.
Collapse
Affiliation(s)
- Katarzyna Witt
- Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, 3 Seminaryjna Street, 85326, Bydgoszcz, PL, Poland.
| | - Małgorzata A Kaczorowska
- Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, 3 Seminaryjna Street, 85326, Bydgoszcz, PL, Poland
| | - Daria Bożejewicz
- Faculty of Chemical Technology and Engineering, Bydgoszcz University of Science and Technology, 3 Seminaryjna Street, 85326, Bydgoszcz, PL, Poland
| |
Collapse
|
4
|
Zhang W, Jin D, Guo X, Qin X, Liu X. Geoenvironmental properties of a Cr(VI)-contaminated soil treated by alkali-activated GGBS under freeze-thaw cycles: Insights into Cr species transformation and microscopic mechanism. Sci Total Environ 2023; 903:166450. [PMID: 37634723 DOI: 10.1016/j.scitotenv.2023.166450] [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: 06/12/2023] [Revised: 08/18/2023] [Accepted: 08/18/2023] [Indexed: 08/29/2023]
Abstract
Stabilization/solidification is the most frequently used method for treating soils contaminated by heavy metals; however, degradation of the treatment will occur under freeze-thaw (F-T) cycles. In this paper, a low-carbon emission by-product, ground granulated blast furnace slag (GGBS), was adopted as a binder to treat Cr(VI)-contaminated soil after alkali excitation. Built on the usage scenarios of subgrade materials, the impact of F-T cycles and initial water content on the geoenvironmental properties of the treated soils, including leaching toxicity, unconfined compressive strength (UCS), pH, Eh, and permeability, were discussed. To investigate the mechanisms of the changing properties, this study analyzed the chemical morphology of Cr, the micromorphology of the reaction products, and the pore characteristics. The results demonstrated that negative impact of F-T cycles on treatment effectiveness was low at the optimal water content. After 28 F-T cycles, the Cr(VI) component increased by 6.4 %, and the leached Cr concentration showed a significant increase, especially for specimens with low water content. A new solid phase with mixed valence Mn(III/IV), mainly composed of birnessite and manganite, was observed via microscopic analysis. During the first 3 F-T cycles, the content of hydration gel increased by 0.18 %, and the cumulative pore volume decreased such that the UCS increased by an average of 1.2 MPa. This study demonstrated that a few F-T cycles would result in a secondary alkali-activated GGBS reaction, enhancing the treatment effect. However, additional F-T cycles would create an oxidizing environment under which the initially precipitated Cr(III) would react with manganese oxide, resulting in more Cr(VI) released. The degree of reoxidation was closely related to the initial water content of the solidified soil.
Collapse
Affiliation(s)
- Wenjie Zhang
- College of Civil and Architectural Engineering, Taizhou University, 318000 Taizhou, PR China.
| | - Dian Jin
- School of Mechanics and Engineering Science, Shanghai University, 200444 Shanghai, PR China.
| | - Xingzhang Guo
- Geotechnical and Structural Engineering Research Center, Shandong University, Jinan, Shandong, PR China
| | - Xiang'ao Qin
- School of Mechanics and Engineering Science, Shanghai University, 200444 Shanghai, PR China
| | - Xiangning Liu
- School of Mechanics and Engineering Science, Shanghai University, 200444 Shanghai, PR China
| |
Collapse
|