1
|
Coughlan NE, Maguire D, Oommen AA, Redmond C, O'Mahoney R, Walsh É, Kühnhold H, Byrne EP, Kavousi F, Morrison AP, Jansen MAK. On the rise: Development of a multi-tiered, indoor duckweed cultivation system. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2023; 95:e10964. [PMID: 38124406 DOI: 10.1002/wer.10964] [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: 06/06/2023] [Revised: 10/31/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023]
Abstract
Duckweed species (Lemnaceae) are suitable for remediation and valorization of agri-feed industry wastewaters and therefore can contribute to a more sustainable, circular economy where waste is a resource. Industrial applications will, however, require space efficient cultivation methods that are not affected by prevailing weather conditions. Here, the development and operation of a multi-tiered duckweed bioreactor is described. The developed prototype bioreactor depicted in this paper is composed of four cultivation layers (1 m2 each) with integrated LED lighting (generating up to 150 μmol m-2 s-1 ), a system of pumps and valves to manage the recirculatory flow (2.5 L min-1 ) of wastewater, and an automatic harvesting system. Using a nutrient poor medium, good growth of the duckweed species Lemna minor was achieved in the bioreactor, and this was matched by strong nutrient depletion from the medium, especially for phosphorus (45-mg total phosphorus [TP] removed per m-2 day-1 ). A fully automatic harvesting arm reliably captured similar amounts of duckweed biomass across multiple harvesting cycles, revealing a future scenario whereby labor and interventions by human operators are minimized. Further developments to advance the system towards fully automated operation will include, for example, the use of specific nutrient sensors to monitor and control medium composition. It is envisaged that multi-tiered, indoor bioreactors can be employed in the agri-feed industry where wastewaters are, in many cases, continuously generated throughout the year and need remediating immediately to avoid costly storage. Given the extensive use of automation technology in conventional wastewater treatment plants, multi-tiered duckweed bioreactors can be realistically integrated within the operating environment of such treatment plants. PRACTITIONER POINTS: Duckweed is suitable for remediation and valorization of agri-feed wastewater. Industrial duckweed applications require space efficient cultivation methods. Development and operation of a multi-tiered duckweed bioreactor is detailed. Flow dynamics and automatic harvesting in the bioreactor are optimized. It is concluded that a multi-tiered bioreactor can be used in industry.
Collapse
Affiliation(s)
- Neil E Coughlan
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
| | - Daniel Maguire
- Process and Chemical Engineering, School of Engineering and Architecture, University College Cork, Cork, Ireland
| | - Abin Abraham Oommen
- Electrical and Electronic Engineering, School of Engineering and Architecture, University College Cork, Cork, Ireland
| | - Cian Redmond
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
| | - Rachel O'Mahoney
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
| | - Éamonn Walsh
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
| | - Holger Kühnhold
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
| | - Edmond P Byrne
- Environmental Research Institute, University College Cork, Cork, Ireland
- Process and Chemical Engineering, School of Engineering and Architecture, University College Cork, Cork, Ireland
| | - Fatemeh Kavousi
- Process and Chemical Engineering, School of Engineering and Architecture, University College Cork, Cork, Ireland
| | - Alan P Morrison
- Environmental Research Institute, University College Cork, Cork, Ireland
- Electrical and Electronic Engineering, School of Engineering and Architecture, University College Cork, Cork, Ireland
| | - Marcel A K Jansen
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland
- Environmental Research Institute, University College Cork, Cork, Ireland
| |
Collapse
|
2
|
Wang F, Wang S, Xu S, Shen J, Cao L, Sha Z, Chu Q. A non-chemical weed control strategy, introducing duckweed into the paddy field. PEST MANAGEMENT SCIENCE 2022; 78:3654-3663. [PMID: 35613133 DOI: 10.1002/ps.7008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 05/21/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Herbicide resistance in weeds and environmental pollution resulting from excessive application of chemical herbicides keeps increasing. Development of environment-friendly and effective weed management strategies are required for sustainable agricultural production. In this study we investigated the effects of duckweeds (Landoltia punctata (G. Meyer) Les & D. J. Crawford and Spirodela polyrhiza (Linnaeus) Schle iden) introduction on the weed community and rice growth in paddy fields. RESULTS The study was conducted in the two rice-growing seasons (2018 and 2019) with three treatments: rice grown without duckweed introduction (CK), with L. punctata introduction (LP), and with S. polyrhiza introduction (SP). On average, LP and SP significantly reduced total weed density by more than 90% and 97%, respectively. Early in the rice-growing season, both duckweed species completely prevented weed growth. Further, both species significantly promoted rice plant growth in the advanced stages. SP significantly improved grain yield of rice by 23%. Light transmittance, temperature of the floodwater and soil, floodwater pH, and dissolved oxygen content significantly decreased following introduction of the duckweeds, indicating that the duckweeds introduction might inhibit weeds growth by altering environmental factors. CONCLUSION This study provides a possible environment-friendly way to inhibit weed biomass in the paddy field by introducing duckweeds and interpreted the possible reasons of the impacts of duckweed on environmental variables. Weed control is beneficial for rice growth. Duckweed coverage might be limited in open fields and the associated practice requires additional investigation. © 2022 Society of Chemical Industry.
Collapse
Affiliation(s)
- Feng Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Shuang Wang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Shuhan Xu
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Jianying Shen
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Linkui Cao
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Zhimin Sha
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
- Key Laboratory of Technology and Model for Cyclic Utilization from Agricultural Resources, Ministry of Agriculture and Rural, China
| | - Qingnan Chu
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| |
Collapse
|