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Liu Q, Sheng Y, Wang Z, Liu X. New insights into the sustainable use of co-pyrolyzed dredged sediment for the in situ remediation of Cd polluted sediments in coastal rivers. JOURNAL OF HAZARDOUS MATERIALS 2024; 466:133664. [PMID: 38309161 DOI: 10.1016/j.jhazmat.2024.133664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/02/2024] [Accepted: 01/28/2024] [Indexed: 02/05/2024]
Abstract
The remediation of Cd-polluted sediment in coastal rivers is essential because of its potential hazards to river and marine ecosystems. Herein, a co-pyrolysis product of contaminated dredged sediment (S@BC) was innovatively applied to cap and immobilize Cd-contaminated sediment in coastal rivers in situ, and their remediation efficiencies, mechanisms, and microbial responses were explored based on a 360 d incubation experiment. The results showed that although S@BC immobilization and capping restrained sediment Cd release to the overlying water, S@BC capping presented a high inhibitory efficiency (66.0% vs. 95.3% at 360 d). Fraction analysis indicated that labile Cd was partially transformed to stable fraction after remediation, with decreases of 0.5%- 32.7% in the acid-soluble fraction and increases of 5.0%- 182.8% in the residual fraction. S@BC immobilization and capping had minor influences on the sediment bacterial community structure compared to the control. S@BC could directly adsorb sediment mobile Cd (precipitation and complexation) to inhibit Cd release and change sediment properties (e.g., pH and cation exchange capacity) to indirectly reduce Cd release. Particularly, S@BC capping also promoted Cd stabilization by enhancing the sediment sulfate reduction process. Comparatively, S@BC capping was a priority approach for Cd-polluted sediment remediation. This study provides new insights into the remediation of Cd-contaminated sediments in coastal rivers.
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Affiliation(s)
- Qunqun Liu
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China
| | - Yanqing Sheng
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China.
| | - Zheng Wang
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xiaozhu Liu
- Key Laboratory of Coastal Zone Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, China; University of Chinese Academy of Sciences, Beijing, China
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Chen Y, Zhen Z, Li G, Li H, Wei T, Huang F, Li T, Yang C, Ren L, Liang Y, Lin Z, Zhang D. Di-2-ethylhexyl phthalate (DEHP) degradation and microbial community change in mangrove rhizosphere gradients. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 871:162022. [PMID: 36775151 DOI: 10.1016/j.scitotenv.2023.162022] [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: 10/17/2022] [Revised: 01/17/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Di-2-ethylhexyl phthalate (DEHP) is a widespread persistent organic pollutant in the environment. As an ultimate barrier preventing pollutant entry into the ocean, mangrove plays an important role in coastal ecosystem. However, little information is known about DEHP degradation in mangrove rhizosphere. In this study, a rhizobox was used to separate four consecutive rhizosphere compartments with distance of 0-2, 2-4, 4-6, and > 6 mm to the rhizoplane of Kandelia obovata and investigate DEHP gradient degradation behavior in rhizosphere. Sediments closer to the rhizoplane exhibited higher DEHP degradation efficiencies (74.4 % in 0-2 mm layer). More precisely, mangrove rhizosphere promoted the benzoic acid pathway and non-selectively accelerated the production of mono(2-ethylhexyl) phthalate, phthalic acid and benzoic acid. Higher sediment organic matter content, lower pH and less humus in rhizosphere benefited DEHP hydrolysis. In addition, rhizosphere significantly increased microbial biomass and activities comparing to bulk sediments. Some bacterial lineages with potential DEHP degradation capability exhibited a distance-dependent pattern that decreased with the distance to the rhizoplane, including Bacillales, Acidothermaceae, Gammaproteobacteria, and Sphingobacteriales. Our findings suggested that mangrove rhizosphere could accelerate DEHP degradation by altering sediment physicochemical properties and microbial composition, showing positive effects on coastal ecosystem services for eliminating phthalate acid ester contamination.
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Affiliation(s)
- Yijie Chen
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Zhen Zhen
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Gaoyang Li
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Huijun Li
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Ting Wei
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Fengcheng Huang
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Tao Li
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Changhong Yang
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Lei Ren
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Yanqiu Liang
- Faculty of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang 524088, PR China
| | - Zhong Lin
- College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang 524088, PR China; Shenzhen Research Institute of Guangdong Ocean University, Shenzhen 518108, PR China.
| | - Dayi Zhang
- College of New Energy and Environment, Jilin University, Changchun 130021, PR China; Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130012, PR China.
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