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Zhang Q, Tang T, Cui G, Wang Z, Liu Y. Pressurized electro-osmotic dewatering treatment of sludge: focusing on the influences on nutrients for agricultural application. ENVIRONMENTAL TECHNOLOGY 2024; 45:4805-4819. [PMID: 37970842 DOI: 10.1080/09593330.2023.2283090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/09/2023] [Indexed: 11/19/2023]
Abstract
Sewage sludge requires effective dewatering and high nutrients retention before disposal for agricultural application. Pressurized electro-osmotic dewatering (PEOD) process with low energy consumption can effectively remove water from sludge, but the influences of PEOD process on nutrients for agricultural application still lacks in-depth research. In this study, the influences of PEOD process on nutrients for agricultural application were investigated, including organic matter, nitrogen, phosphorus, potassium and silicon contents. Layered experiments were conducted to investigate the layered variation of nutrients in sludge and to understand the potential change mechanisms. The experimental results showed that PEOD process caused small losses (<10%) of organic matter and total phosphorus (TP) in sludge, but caused 11.2-18.4% loss of total nitrogen (TN). PEOD process also caused 18.6-27.0% loss of total potassium (TK) and over 80% loss of available potassium in sludge, and could weaken the potential salt damage during the agricultural application of sludge. Furthermore, the available phosphorus content of sludge in the anode area increased significantly after the PEOD process, indicating that PEOD process could enhance the phosphorus bioavailability of sludge in the anode area. Besides, PEOD process caused a slight loss of silicon components in sludge, but improved the long-term silicon dissolution and release ability of sludge. This work could expand the knowledge about the influences of PEOD process on sludge nutrients and provide scientific guidance for the agricultural application of PEOD sludge.
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Affiliation(s)
- Qiming Zhang
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Tian Tang
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Guodong Cui
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Zheng Wang
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
| | - Yangsheng Liu
- College of Environmental Sciences and Engineering, Peking University, Beijing Key Laboratory for Solid Waste Utilization and Management, Beijing, People's Republic of China
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Bai S, Han X, Feng D. Shoot-root signal circuit: Phytoremediation of heavy metal contaminated soil. FRONTIERS IN PLANT SCIENCE 2023; 14:1139744. [PMID: 36890896 PMCID: PMC9987563 DOI: 10.3389/fpls.2023.1139744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
High concentrations of heavy metals in the environment will cause serious harm to ecosystems and human health. It is urgent to develop effective methods to control soil heavy metal pollution. Phytoremediation has advantages and potential for soil heavy metal pollution control. However, the current hyperaccumulators have the disadvantages of poor environmental adaptability, single enrichment species and small biomass. Based on the concept of modularity, synthetic biology makes it possible to design a wide range of organisms. In this paper, a comprehensive strategy of "microbial biosensor detection - phytoremediation - heavy metal recovery" for soil heavy metal pollution control was proposed, and the required steps were modified by using synthetic biology methods. This paper summarizes the new experimental methods that promote the discovery of synthetic biological elements and the construction of circuits, and combs the methods of producing transgenic plants to facilitate the transformation of constructed synthetic biological vectors. Finally, the problems that should be paid more attention to in the remediation of soil heavy metal pollution based on synthetic biology were discussed.
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Affiliation(s)
- Shiyan Bai
- College of Biological Science and Engineering, Fuzhou University, Fujian, China
| | - Xiao Han
- College of Biological Science and Engineering, Fuzhou University, Fujian, China
| | - Dan Feng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
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Cao R, Liu S, Yang X, Wang C, Wang Y, Wang W, Pi Y. Enhanced remediation of Cr(VI)-contaminated groundwater by coupling electrokinetics with ZVI/Fe 3O 4/AC-based permeable reactive barrier. J Environ Sci (China) 2022; 112:280-290. [PMID: 34955212 DOI: 10.1016/j.jes.2021.05.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 04/18/2021] [Accepted: 05/06/2021] [Indexed: 05/22/2023]
Abstract
Although widely used in permeation reaction barrier (PRB) for strengthening the removal of various heavy metals, zero-valent iron (ZVI) is limited by various inherent drawbacks, such as easy passivation and poor electron transfer. As a solution, a synergistic system with PRB and electrokinetics (PRB-EK) was established and applied for the efficient removal of Cr(VI)-contaminated groundwater. As the filling material of PRB, ZVI/Fe3O4/activated carbon (ZVI/Fe3O4/AC) composites were synthesized by ball milling and thermal treatment. A series of continuous flow column experiments and batch tests was conducted to evaluate the removal efficiency of Cr(VI). Results showed that the removal efficiency of Cr(VI) remained above 93% even when the bed volume (BV) reached 2000 under the operational parameters (iron/AC mass ratio, 2:1; current, 5 mA). The mechanism of Cr(VI) removal by the PRB-EK system was revealed through field emission scanning electron microscopy images, X-ray diffraction, X-ray photoelectron spectroscopy, Fe2+ concentration, and redox potential (Eh) values. The key in Cr(VI) reduction was the Fe2+/Fe3+ cycle driven by the surface microelectrolysis of the composites. The application of an externally supplied weak direct current maintained the redox process by enhancing the electron transfer capability of the system, thereby prolonging the column lifetime. Cr(VI) chemical speciation was determined through sequential extraction, verifying the stability and safety of the system. These findings provide a scientific basis for PRB design and the in-situ remediation of Cr(VI)-contaminated groundwater.
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Affiliation(s)
- Ruolin Cao
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control (Ministry of Education), School of Environment, Henan Normal University, Xinxiang 453007, China
| | - Shiqing Liu
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control (Ministry of Education), School of Environment, Henan Normal University, Xinxiang 453007, China
| | - Xinyu Yang
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control (Ministry of Education), School of Environment, Henan Normal University, Xinxiang 453007, China
| | - Chunfeng Wang
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control (Ministry of Education), School of Environment, Henan Normal University, Xinxiang 453007, China.
| | - Yanbin Wang
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control (Ministry of Education), School of Environment, Henan Normal University, Xinxiang 453007, China
| | - Wanfeng Wang
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control (Ministry of Education), School of Environment, Henan Normal University, Xinxiang 453007, China
| | - Yunqing Pi
- Henan Key Laboratory for Environmental Pollution Control and Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control (Ministry of Education), School of Environment, Henan Normal University, Xinxiang 453007, China.
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Shao X, Hao W, Konhauser KO, Gao Y, Tang L, Su M, Li Z. The dissolution of fluorapatite by phosphate-solubilizing fungi: a balance between enhanced phosphorous supply and fluorine toxicity. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:69393-69400. [PMID: 34302245 DOI: 10.1007/s11356-021-15551-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/17/2021] [Indexed: 06/13/2023]
Abstract
Fluorapatite (FAp) is the largest phosphorous (P) reservoir on Earth. However, due to its low solubility, dissolved P is severely deficient in the pedosphere. Fungi play a significant role in P dissolution via excretion of organic acids, and in this regard, it is important to understand their impact on P cycling. The object of this study was to elucidate the balance between P release and F toxicity during FAp dissolution. The bioweathering of FAp was assisted by a typical phosphate-solubilizing fungus, Aspergillus niger. The release of elements and microbial activities were monitored during 5-day incubation. We found that the release of fluorine (F) was activated after day 1 (~90 mg/L), which significantly lowered the phosphate-solubilizing process by day 2. Despite P release from FAp being enhanced over the following 3 days, decreases in both the amount of biomass (52% decline) and the respiration rate (81% decline) suggest the strong inhibitory effect of F on the fungus. We thus concluded that F toxicity outweighs P supply, which in turn inhibits fungi growth and prevents further dissolution of FAp. This mechanism might reflect an underappreciated cause for P deficiency in soils.
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Affiliation(s)
- Xiaoqing Shao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Weiduo Hao
- Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Kurt O Konhauser
- Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada
| | - Yanan Gao
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Lingyi Tang
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Mu Su
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Zhen Li
- College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
- Jiangsu Key Laboratory for Organic Waste Utilization, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
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