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Tang S, Gong J, Song B, Cao W, Li J. Remediation of biochar-supported effective microorganisms and microplastics on multiple forms of heavy metals in eutrophic lake. JOURNAL OF HAZARDOUS MATERIALS 2024; 465:133098. [PMID: 38064949 DOI: 10.1016/j.jhazmat.2023.133098] [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: 09/01/2023] [Revised: 11/21/2023] [Accepted: 11/23/2023] [Indexed: 02/08/2024]
Abstract
In mineral-rich areas, eutrophic lakes are at risk of HMs pollution. However, few papers focused on the repair of HMs in eutrophic environment. Our study analyzed multiple forms of HMs, pore structure and microbial responses in the water-sediment system of eutrophic lake treated with biochar, Effective Microorganisms (EMs) or/and microplastics (MPs). As biochar provided an ideal carrier for EMs, the remediation of biochar-supported EMs (BE) achieved the greatest repairment that improved the bacterial indexes and greatly decreased the most HMs in various forms across the water-sediment system, and it also reduced metal mobility, bioavailability and ecological risk. The addition of aged MPs (MP) stimulated the microbial activity and significantly reduced the HMs levels in different forms due to the adsorption of biofilms/EPS adhered on MPs, but it increased metals mobility and ecological risks. The strong adsorption and high mobility of aged MPs would increase enrichment of HMs and cause serious ecological hazards. The incorporation of BE and MP (MBE) also greatly reduced the HMs in full forms, which was primarily ascribed to the adsorption of superfluous biofilms/EPS, but it distinctly depressed the microbial activity. The single addition of biochar and EMs resulted in the inability of HMs to be adsorbed due to the preferentially adsorption of dissolved nutrients and the absence of effective carrier, respectively. In the remediation cases, the remarkable removal of HMs was principally accomplished by the adsorption of HMs with molecular weight below 100 kDa, especially 3 kDa ∼100 kDa, which had higher specific surfaces and abundant active matters, resulting in higher adsorption onto biofilms/EPS.
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Affiliation(s)
- Siqun Tang
- College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China; Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, Guangdong, PR China; Shenzhen Institute, Hunan University, Shenzhen 518000, PR China
| | - Jilai Gong
- College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China; Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, Guangdong, PR China; Shenzhen Institute, Hunan University, Shenzhen 518000, PR China.
| | - Biao Song
- College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China; Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, Guangdong, PR China; Shenzhen Institute, Hunan University, Shenzhen 518000, PR China
| | - Weicheng Cao
- College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China; Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, Guangdong, PR China; Shenzhen Institute, Hunan University, Shenzhen 518000, PR China
| | - Juan Li
- College of Environmental Science and Engineering, Key Laboratory of Environmental Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082, PR China; Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, Guangdong, PR China; Shenzhen Institute, Hunan University, Shenzhen 518000, PR China
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Núñez P, Misic C, Cutroneo L, Capello M, Medina R, Besio G. Biofilm-induced effect on the buoyancy of plastic debris: An experimental study. MARINE POLLUTION BULLETIN 2023; 193:115239. [PMID: 37459835 DOI: 10.1016/j.marpolbul.2023.115239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/26/2023] [Accepted: 06/29/2023] [Indexed: 07/26/2023]
Abstract
Plastic floating on the ocean surface represents about 1 % of all plastic in the ocean, despite the buoyancy of most plastics. Biofouling can help to sink debris, which could explain this discrepancy. A set of laboratory experiments was conducted to investigate biofilm-induced effects on the buoyancy of different plastic debris. Ten materials of different densities (buoyant/non-buoyant), sizes (micro/meso/macro), and shapes (irregular/spherical/cylindrical/flat), including facemasks and cotton swabs, were evaluated. Biofilm was incubated in these materials from a few weeks to three months to investigate the effect of different growth levels on their buoyancy. Biofilm levels and rising/settling velocities were measured and compared at seven time-points. The results show a hindered buoyancy for solid materials, while hollow and open materials showed the opposite trend in early biofilm colonization stages. A relationship was established between biofilm-growth and equivalent sphere diameter that can be used to improve predictive modeling of plastic-debris transport.
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Affiliation(s)
- Paula Núñez
- IHCantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria, Santander, Spain.
| | - Cristina Misic
- Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, 16132, Genoa, Italy
| | - Laura Cutroneo
- Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, 16132, Genoa, Italy
| | - Marco Capello
- Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, 16132, Genoa, Italy
| | - Raúl Medina
- IHCantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria, Santander, Spain
| | - Giovanni Besio
- Dipartimento di Ingegneria Civile, Chimica e Ambientale, Università degli studi di Genova, Via Montallegro 1, 16145 Genoa, Italy
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