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Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution
Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2024.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2024
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| _version_ | 1867613678469120000 |
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| access_status_str | Open Access |
| author2 | Nicol, Willem |
| author_browse | Nicol, Willem |
| author_facet | Nicol, Willem |
| collection | Thesis |
| dc_rights_str_mv | © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2024. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/95535 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:39:58.102Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2024 |
| publishDateRange | 2024 |
| publishDateSort | 2024 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/95535 Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution Nicol, Willem u17306290@tuks.co.za Brink, Gideon Hendrik Bosman, Roger Clive Nitrate, Ammonium, pH, control, Hydroponics Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2024. A control algorithm was developed and tested on a hydroponic ebb-and-flow system to assess the efficacy of the proposed control scheme. Three experimental runs were conducted with the purpose of testing the proposed control system on Brassica oleracea var. acephala. The first was an ideal case under sterile conditions, the second was under non-sterile conditions where bacteria were allowed to colonise the plant roots, and the last was a baseline run where nitrate was applied as the only nitrogen source. The system was able to control pH to within 0.5 of the set point (in this case 6.1) while EC control was sufficient to ensure that a steady stream of nutrients were available to the plants at all times. Relative growth rates were fast at maximum average values of between 0.20 per day and 0.21 per day for all of the runs and the yield of organic leaf matter was essentially the same across all the runs at 83 % to 86 % of total plant mass. Finally, the plants grown under the proposed control system were observed to exhibit some improvement in protein and chlorophyll content while the other nutritional characteristics considered were essentially unchanged between treatments. This was all accomplished without having to add any additional toxic ions like Cl- and Na+ as is the case in conventionally controlled systems. National Research Foundation Chemical Engineering MEng (Chemical Engineering) Unrestricted Faculty of Engineering, Built Environment and Information Technology SDG-02:Zero Hunger 2024-04-15T14:49:13Z 2024-04-15T14:49:13Z 2024-05 2024-03 Dissertation * (A2024) http://hdl.handle.net/2263/95535 DOI: https://doi.org/10.25403/UPresearchdata.25565295.v1 10.25403/UPresearchdata.25565295 en © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Nitrate, Ammonium, pH, control, Hydroponics Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution |
| title | Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution |
| title_full | Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution |
| title_fullStr | Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution |
| title_full_unstemmed | Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution |
| title_short | Simultaneous pH and EC control in hydroponics through real-time manipulation of the ammonium-to-nitrate ratio in the nutrient solution |
| title_sort | simultaneous ph and ec control in hydroponics through real time manipulation of the ammonium to nitrate ratio in the nutrient solution |
| topic | Nitrate, Ammonium, pH, control, Hydroponics |
| url | http://hdl.handle.net/2263/95535 |