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Wu S, Peng X, Sun X, Min F, Zhu W. Dewatering and strength characteristics of dredged slurry under curing-flocculation-vacuum filtration. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:15885-15899. [PMID: 38308778 DOI: 10.1007/s11356-024-32254-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 01/25/2024] [Indexed: 02/05/2024]
Abstract
Addressing the substantial yearly production of waste dredged slurry with high water content, it is imperative to adopt effective technical treatments for sustainable development. This paper establishes that the curing-flocculation-vacuum filtration (C-F-VF) method efficiently converts high-water content dredged slurry into back-fill soil, achieving rapid dewatering. The study delves into the mechanism facilitating swift dewatering and the heightened mechanical properties of the dewatered soil. The synergy of curing, flocculation, and vacuum filtration expedites the dewatering process. The pre-addition of a curing agent reduces the zeta potential of the slurry, enhancing its efficiency in subsequent flocculation and vacuum filtration. Although the curing agent experiences some loss during vacuum filtration, over 91.22% remains in the dewatered soil, fortifying its strength. Soil strength correlates with the water content post-vacuum filtration and the amount of cement added pre-filtration, with a proposed relevant strength prediction formula.
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Affiliation(s)
- Silin Wu
- School of Architecture and Civil Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212100, China
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China
- Shenzhen Key Laboratory of Green, Efficient and Intelligent Construction of Underground Metro Station, Shenzhen University, Shenzhen, 518060, China
| | - Xiao Peng
- School of Architecture and Civil Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212100, China
| | - Xiaohui Sun
- Shenzhen Key Laboratory of Green, Efficient and Intelligent Construction of Underground Metro Station, Shenzhen University, Shenzhen, 518060, China.
- College of Civil and Transportation Engineering, the Underground Polis Academy, Shenzhen University, Shenzhen, 518060, China.
| | - Fanlu Min
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China
- College of Civil and Transportation Engineering, Hohai University, Nanjing, 210024, China
| | - Wei Zhu
- Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing, 210024, China
- College of Civil and Transportation Engineering, Hohai University, Nanjing, 210024, China
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Yang N, Xiao H, Pi K, Fang J, Liu S, Chen Y, Shi Y, Zhang H, Gerson AR, Liu D. Synchronization of dehydration and phosphorous immobilization for river sediment by calcified polyferric sulfate pretreatment. CHEMOSPHERE 2021; 269:129403. [PMID: 33385664 DOI: 10.1016/j.chemosphere.2020.129403] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/29/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
Disposal of dredged river sediment requires decreases in both water content for reduction in disposal area, and the amount of eutrophication pollutants at risking of leaching. The effects of CaCl2, polyferric sulfate (PFS) and calcified polyferric sulfate (CaPFS) on dewatering and phosphorus immobilization were examined. Upon CaPFS dosage of 1.88 mg Ca + Fe kg-1 raw sediment (RS) the moisture content of the sediment was 41.1 wt% after pressure filtration, with filtrate dissolved inorganic phosphorus (DIP) of 6.1 mg L-1; better outcomes than for equivalent dosages of CaCl2 or PFS. On CaPFS dosage of 4.98 mg Ca + Fe kg-1 RS, DIP in the filtrate was <0.5 mg L-1. Dosages of CaCl2 and PFS required to achieve <0.5 mg L-1 DIP were 6.79 mg Ca kg-1 RS and 5.64 mg Fe kg-1 RS. CaPFS aids particle surface charge neutralization and sweep flocculation by polymeric iron, improving dehydration efficiency. Synergistic effects of aqueous Ca and Fe promote P stability reducing DIP mobility. For treatment of 10000 m3 of this dredged sediment, CaPFS has the potential to reduce the discharge of eutrophicated water by 74 ± 6% compared with PAC + PAM conditioning, demonstrating the promising application of CaPFS conditioning.
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Affiliation(s)
- Nan Yang
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Hang Xiao
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Kewu Pi
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Jing Fang
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Shuze Liu
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Yuhan Chen
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Yafei Shi
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Huiqin Zhang
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
| | - Andrea R Gerson
- Blue Minerals Consultancy, Wattle Grove, Tasmania, 7109, Australia.
| | - Defu Liu
- School of Resource and Environmental Engineering, Hubei University of Technology, Wuhan, Hubei, 430068, China.
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