Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant Growth
This study aimed to optimize hydroponic systems for simultaneous wastewater treatment/nutrient recovery and plant growth. Various hydroponic systems (geyser pump, full flow, ebb and flow, nutrient film techniques, aeroponics, misting) were constructed using 160 mm PVC waste pipes supported on a 200...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-07-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/14/8032 |
| _version_ | 1797590455121084416 |
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| author | Dominic Clyde-Smith Luiza C. Campos |
| author_facet | Dominic Clyde-Smith Luiza C. Campos |
| author_sort | Dominic Clyde-Smith |
| collection | DOAJ |
| description | This study aimed to optimize hydroponic systems for simultaneous wastewater treatment/nutrient recovery and plant growth. Various hydroponic systems (geyser pump, full flow, ebb and flow, nutrient film techniques, aeroponics, misting) were constructed using 160 mm PVC waste pipes supported on a 200 L reservoir. Secondary wastewater was used to cultivate rice (<i>Oryza sativa</i>), ivy (<i>Hedera helix</i>), tomatoes (<i>Solanum lycopersicum</i>), and wheatgrass (<i>Triticum aestivum</i>). Parameters such as plant height, biomass, retention time, temperature, conductivity, pH, dissolved oxygen, ammonia, nitrite, nitrate, total phosphorus, COD, BOD, TDS, TSS, and TS were monitored. Results indicated minor variations in pH, EC, and TDS over time in systems with and without plants, with no significant differences. Turbidity decreased significantly (<i>p</i> ≤ 0.001) in all systems, while TOC levels reduced significantly (<i>p</i> ≤ 0.05) only in the presence of plants. BOD and COD levels exhibited similar reductions with and without plants. Ammonium levels decreased in plant systems, while nitrite levels remained unchanged. Nitrate levels increased significantly in plant systems, and phosphate levels showed no significant difference. Additionally, significant (<i>p</i> ≤ 0.001) plant length (12.84–46.75%) and biomass (31.90–57.86%) increases were observed in all hydroponic systems, accompanied by higher levels of dissolved oxygen (36.26–53.65%), compared to the control (4.59%). The hydroponic system that created a moist atmosphere, either through misting or aeroponics, thus allowing maximum access to oxygen, showed the greatest growth. This study confirmed the importance of oxygen availability to the rhizosphere for plant growth and wastewater treatment. It also identified limitations and investigated the impact of dissolved oxygen concentration on plant–microorganism interactions. Optimal oxygen availability was achieved when plant roots were exposed to a moist atmosphere created by the hydroponic system through aeroponics or misting. The findings have practical implications for hydroponic system design in urban vertical farms, benefiting wastewater treatment, mitigating eutrophication, and reducing food miles. |
| first_indexed | 2024-03-11T01:21:41Z |
| format | Article |
| id | doaj.art-84064fee69ad496e94e28c0fe9fd3cce |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-11T01:21:41Z |
| publishDate | 2023-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-84064fee69ad496e94e28c0fe9fd3cce2023-11-18T18:07:12ZengMDPI AGApplied Sciences2076-34172023-07-011314803210.3390/app13148032Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant GrowthDominic Clyde-Smith0Luiza C. Campos1Department of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 6BT, UKDepartment of Civil, Environmental and Geomatic Engineering, University College London, London WC1E 6BT, UKThis study aimed to optimize hydroponic systems for simultaneous wastewater treatment/nutrient recovery and plant growth. Various hydroponic systems (geyser pump, full flow, ebb and flow, nutrient film techniques, aeroponics, misting) were constructed using 160 mm PVC waste pipes supported on a 200 L reservoir. Secondary wastewater was used to cultivate rice (<i>Oryza sativa</i>), ivy (<i>Hedera helix</i>), tomatoes (<i>Solanum lycopersicum</i>), and wheatgrass (<i>Triticum aestivum</i>). Parameters such as plant height, biomass, retention time, temperature, conductivity, pH, dissolved oxygen, ammonia, nitrite, nitrate, total phosphorus, COD, BOD, TDS, TSS, and TS were monitored. Results indicated minor variations in pH, EC, and TDS over time in systems with and without plants, with no significant differences. Turbidity decreased significantly (<i>p</i> ≤ 0.001) in all systems, while TOC levels reduced significantly (<i>p</i> ≤ 0.05) only in the presence of plants. BOD and COD levels exhibited similar reductions with and without plants. Ammonium levels decreased in plant systems, while nitrite levels remained unchanged. Nitrate levels increased significantly in plant systems, and phosphate levels showed no significant difference. Additionally, significant (<i>p</i> ≤ 0.001) plant length (12.84–46.75%) and biomass (31.90–57.86%) increases were observed in all hydroponic systems, accompanied by higher levels of dissolved oxygen (36.26–53.65%), compared to the control (4.59%). The hydroponic system that created a moist atmosphere, either through misting or aeroponics, thus allowing maximum access to oxygen, showed the greatest growth. This study confirmed the importance of oxygen availability to the rhizosphere for plant growth and wastewater treatment. It also identified limitations and investigated the impact of dissolved oxygen concentration on plant–microorganism interactions. Optimal oxygen availability was achieved when plant roots were exposed to a moist atmosphere created by the hydroponic system through aeroponics or misting. The findings have practical implications for hydroponic system design in urban vertical farms, benefiting wastewater treatment, mitigating eutrophication, and reducing food miles.https://www.mdpi.com/2076-3417/13/14/8032hydroponicsdesignmunicipal wastewaterrhizosphereoxygenurban farm |
| spellingShingle | Dominic Clyde-Smith Luiza C. Campos Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant Growth Applied Sciences hydroponics design municipal wastewater rhizosphere oxygen urban farm |
| title | Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant Growth |
| title_full | Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant Growth |
| title_fullStr | Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant Growth |
| title_full_unstemmed | Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant Growth |
| title_short | Engineering Hydroponic Systems for Sustainable Wastewater Treatment and Plant Growth |
| title_sort | engineering hydroponic systems for sustainable wastewater treatment and plant growth |
| topic | hydroponics design municipal wastewater rhizosphere oxygen urban farm |
| url | https://www.mdpi.com/2076-3417/13/14/8032 |
| work_keys_str_mv | AT dominicclydesmith engineeringhydroponicsystemsforsustainablewastewatertreatmentandplantgrowth AT luizaccampos engineeringhydroponicsystemsforsustainablewastewatertreatmentandplantgrowth |