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Liu X, Tan Q, Wang P, Deng P, Peng L, Xu Y, Yuan S, Dai X. Pre-drying limitedly affected the yield, fuel properties, pyrolysis and combusion behavior of sewage sludge hydrochar. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 184:63-71. [PMID: 38795541 DOI: 10.1016/j.wasman.2024.05.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/30/2024] [Accepted: 05/21/2024] [Indexed: 05/28/2024]
Abstract
While pre-drying of sewage sludge prior to hydrothermal carbonization is rarely practiced, various pre-drying methods have been performed in literature at lab-scale for convenient solid-to-liquid ratio adjustment. This has created a barrier for comparing hydrochar quality between different studies. Given pre-drying can destroy the floc structure of sewage sludge, we hypothesize that pre-drying may promote the hydrolysis step during hydrothermal carbonization process, resulting in improved hydrochar quality with low nitrogen content. In the current study, the influence of different pre-drying methods (freeze-dry, air-dry and vacuum-dry at 70 °C and 105 °C) on the subsequent hydrothermal carbonization of sewage sludge at 220 °C was assessed in terms of sewage sludge and hydrochar's chemical composition, fuel properties, pyrolysis and combustion behavior, as well as the characterization of the liquid phase. The results indicate that although pre-drying impacts sewage sludge's chemical composition, pyrolysis and combustion behavior, no significant differences exist in the yield, chemical composition, fuel properties, and pyrolysis and combustion behavior of the hydrochar. Therefore, the use of pre-drying would not affect the hydrothermal carbonization process of sewage sludge, and a comparison can be made on hydrochar quality between different studies with or without pre-drying.
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Affiliation(s)
- Xiaoguang Liu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Qingtong Tan
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Peisheng Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Peiyue Deng
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Ling Peng
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Yaman Xu
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; School of Life Sciences, Jinggangshan University, Ji'an 343009, China
| | - Shijie Yuan
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
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Wu J, Hua Y, Feng Y, Xie W. Nitrated hydrochar reduce the Cd accumulation in rice and shift the microbial community in Cd contaminated soil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 342:118135. [PMID: 37216875 DOI: 10.1016/j.jenvman.2023.118135] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/03/2023] [Accepted: 05/08/2023] [Indexed: 05/24/2023]
Abstract
Rice grown on Cd-contaminated soil may accumulate Cd in grain, which is extremely harmful to human health. Several managements are developed to reduce the Cd load in rice, while in-situ immobilization by soil amendments has been attractive for its feasibility. Waste-derived hydrochar (HC) has been shown effective at immobilizing Cd in soil. However, potential plant negative effects and huge application amount are crucial to resolving in extensive application of HC. Nitric acid ageing may be an effective method to deal with these problems. In this paper, HC and nitrated hydrochar (NHC) were added to the Cd-contaminated soil at rates of 1% and 2% in a rice-soil column experiment. Results showed that NHC markedly promoted root biomass of rice by 58.70-72.78%, whereas HC had effects of 35.86-47.57%. Notably, NHC at 1% reduced the accumulation of Cd in rice grain, root and straw by 28.04%, 15.08% and 11.07%, respectively. A consistent decrease of 36.30% in soil EXC-Cd concentration was caused by NHC-1%. Following soil microbial community was shifted greatly under HC and NHC applications. The relative abundance of Acidobacteria was decreased by 62.57% in NHC-2% and by 56.89% in HC-1%. Nevertheless, Proteobacteria and Firmicutes were promoted by NHC addition. In contrast to HC, co-occurrence network of dominated bacteria was more complex and centralized generated by NHC. Key bacteria in that metabolic network of NHC such as Anaerolineae and Archangiaceae played key roles in Cd immobilization. These observations verified that NHC was more efficient to decrease Cd accumulation in rice and could alleviate the negative roles to plant by microbial changings in community composition and network. It could provide an enrichment of paddy soil microbial responds to the interaction of NHC with Cd and lay a foundation for the remediation of Cd-contaminated soil by NHC.
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Affiliation(s)
- Jing Wu
- Department of Environmental Science & Engineering, School of Energy & Environment, Anhui University of Technology, Maanshan, 243002, China
| | - Yun Hua
- Key Laboratory for Crop & Animal Integrated Farming of Ministry of Agriculture & Rural Affairs, Institute of Agricultural Resources & Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - YanFang Feng
- Key Laboratory for Crop & Animal Integrated Farming of Ministry of Agriculture & Rural Affairs, Institute of Agricultural Resources & Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - WenPing Xie
- State Key Laboratory of Soil & Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
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