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Liang F, Shi Z, Wei S, Yan S. Biogas slurry purification-lettuce growth nexus: Nutrients absorption and pollutants removal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 890:164383. [PMID: 37216991 DOI: 10.1016/j.scitotenv.2023.164383] [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: 03/20/2023] [Revised: 05/12/2023] [Accepted: 05/19/2023] [Indexed: 05/24/2023]
Abstract
As a main by-product of anaerobic digestion in biogas plants, biogas slurry contains a high concentration of mineral elements (such as ammonia‑nitrogen and potassium) and chemical oxygen demand (COD). So determining how to dispose the biogas slurry in a harmless and value-added ways is crucial from the perspective of ecological and environmental protections. This study explored a novel nexus between biogas slurry and lettuce, in which the biogas slurry was concentrated and saturated with carbon dioxide (CO2) to serve as a hydroponic solution for lettuce growth. Meanwhile, the lettuce was used to purify the biogas slurry through removing pollutants. Results showed that when concentrating the biogas slurry, the total nitrogen and ammonia nitrogen contents in the biogas slurry decreased with the increase of concentration factor. The CO2-rich 5-time-concentrated biogas slurry (CR-5CBS) was screened as the most suitable hydroponic solution for lettuce growth after comprehensively considering the nutrient element balance, energy consumption of concentrating the biogas slurry and CO2 absorption performance. The quality of lettuce cultivated in CR-5CBS was comparable to that of the Hoagland-Arnon nutrient solution in terms of physiological toxicity, nutritional quality, and mineral uptake. Obviously, the hydroponic lettuce could effectively utilize the nutrients in CR-5CBS to purify CR-5CBS, meeting the standard of reclaimed water quality for agricultural reuse. Interestingly, when the same yield of lettuce is targeted, using CR-5CBS as the hydroponic solution to cultivate lettuce can save about US $151/m3-CR-5CBS for lettuce production compared to the Hoagland-Arnon nutrient solution. This study might provide a feasible method for high-value utilization and harmless disposal of biogas slurry.
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Affiliation(s)
- Feihong Liang
- Technology & Equipment Center for Carbon Neutrality in Agriculture, College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China; College of Life Science, Yulin University, Yilin 719000, PR China
| | - Zhan Shi
- Department of Land, Environment, Agriculture and Forestry, University of Padova, Legnaro, PD 350207, Italy
| | - Shihui Wei
- Technology & Equipment Center for Carbon Neutrality in Agriculture, College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Shuiping Yan
- Technology & Equipment Center for Carbon Neutrality in Agriculture, College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China.
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Liang F, Xu L, Ji L, He Q, Wu L, Yan S. A new approach for biogas slurry disposal by adopting CO 2-rich biogas slurry as the flower fertilizer of Spathiphyllum: Feasibility, cost and environmental pollution potential. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 770:145333. [PMID: 33517019 DOI: 10.1016/j.scitotenv.2021.145333] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/13/2021] [Accepted: 01/17/2021] [Indexed: 06/12/2023]
Abstract
A new approach for biogas slurry disposal was put forward in this study through converting biogas slurry to the organic fertilizer of Spathiphyllum. The biogas slurry was firstly concentrated by vacuum distillation to reduce its volume by 80% who is called 5CBS, and then CO2 saturated to reduce its pH to about 6.50 ± 0.20. With or without adding the exogenetic Ca, Mg and P nutrients, CO2-rich 5CBS (i.e., CR-5CBS) was adopted as the root or foliar fertilizer to cultivate Spathiphyllum. Additionally, the commercial Spathiphyllum fertilizer was also experimented as a control. Results showed that the cases adopting CR-5CBS as the root or foliar fertilizer can obtain the agronomic traits and ornamental values of Spathiphyllum better those irrigated by the commercial fertilizer. Exogenetic nutrients added into CR-5CBS can lead to a decreased dead leaf number of Spathiphyllum, an enhanced N assimilation performance, however only a slightly improved assimilation performance of Ca, Mg and P. In terms of the fertilizer economy, CR-5CBS without exogenetic nutrient addition may be a promising for replacing the commercial Spathiphyllum fertilizer in the future. Economic and environmental pollution potential (EPP) analyses indicated that treating biogas slurry as the organic flower fertilizer can achieve a high net profit with about $ 28.89/m3-biogas slurry and a negative EPP value (-3.9), showing its profitability and environmental friendliness.
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Affiliation(s)
- Feihong Liang
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, PR China
| | - Lang Xu
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, PR China
| | - Long Ji
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, PR China
| | - Qingyao He
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, PR China
| | - Lanlan Wu
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, PR China
| | - Shuiping Yan
- College of Engineering, Huazhong Agricultural University, Wuhan 430070, PR China; Key Laboratory of Agricultural Equipment in Mid-lower Yangtze River, Ministry of Agriculture and Rural Affairs, Wuhan 430070, PR China.
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