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http://dx.doi.org/10.12791/KSBEC.2020.29.2.141

Real-time Nutrient Monitoring of Hydroponic Solutions Using an Ion-selective Electrode-based Embedded System  

Han, Hee-Jo (Department of Biosystems Engineering and Biomaterials Science, College of Agriculture and Life Sciences, Seoul National University)
Kim, Hak-Jin (Department of Biosystems Engineering and Biomaterials Science, College of Agriculture and Life Sciences, Seoul National University)
Jung, Dae-Hyun (Department of Biosystems Engineering and Biomaterials Science, College of Agriculture and Life Sciences, Seoul National University)
Cho, Woo-Jae (Department of Biosystems Engineering and Biomaterials Science, College of Agriculture and Life Sciences, Seoul National University)
Cho, Yeong-Yeol (Major of Horticultural Science, Jeju National University)
Lee, Gong-In (Department of Agricultural Engineering, National Institute of Agricultural Sciences)
Publication Information
Journal of Bio-Environment Control / v.29, no.2, 2020 , pp. 141-152 More about this Journal
Abstract
The rapid on-site measurement of hydroponic nutrients allows for the more efficient use of crop fertilizers. This paper reports on the development of an embedded on-site system consisting of multiple ion-selective electrodes (ISEs) for the real-time measurement of the concentrations of macronutrients in hydroponic solutions. The system included a combination of PVC ISEs for the detection of NO3, K, and Ca ions, a cobalt-electrode for the detection of H2PO4, a double-junction reference electrode, a solution container, and a sampling system consisting of pumps and valves. An Arduino Due board was used to collect data and to control the volume of the sample. Prior to the measurement of each sample, a two-point normalization method was employed to adjust the sensitivity followed by an offset to minimize potential drift that might occur during continuous measurement. The predictive capabilities of the NO3 and K ISEs based on PVC membranes were satisfactory, producing results that were in close agreement with the results of standard analyzers (R2 = 0.99). Though the Ca ISE fabricated with Ca ionophore II underestimated the Ca concentration by an average of 55%, the strong linear relationship (R2 > 0.84) makes it possible for the embedded system to be used in hydroponic NO3, K, and Ca sensing. The cobalt-rod-based phosphate electrodes exhibited a relatively high error of 24.7±9.26% in the phosphate concentration range of 45 to 155 mg/L compared to standard methods due to inconsistent signal readings between replicates, illustrating the need for further research on the signal conditioning of cobalt electrodes to improve their predictive ability in hydroponic P sensing.
Keywords
Cobalt electrode; Hydroponics; Ion-selective electrode; Macronutrients; PVC membrane;
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1 Asadnia, M., M. Myers, G.A. Umana-Membreno, T.M. Sanders, U.K. Mishra, B.D. Nener et al. 2017. $Ca^{2+}$ detection utilising AlGaN/GaN transistors with ion-selective polymer membranes. Anal. Chim. Acta. 987:105-110.   DOI
2 Bamsey, M., T. Graham, C. Thompson, A. Berinstain, A. Scott, and M. Dixon. 2012. Ion-specific nutrient management in closed systems: The necessity for ion-selective sensors in terrestrial and space-based agriculture and water management systems. Sensors (Switzerland). 12:13349-13392.   DOI
3 Cho, W., H. Kim, D. Jung, C.I. Kang, G.L. Choi, and J.E. Son. 2017. An embedded system for automated hydroponic nutrient solution management. T. ASABE. 60:1083-1096.   DOI
4 Choi, J.M. and J.W. Park. 2007. Growth, deficiency symptom and tissue contents of leaf perilla (Perilla frutesens Britt) influenced by phosphorus concentrations in fertigation solution. Korean J. Environ. Biol. 16:358-364.
5 Dorneanu, S.A., V. Coman, I.C. Popescu, and P. Fabry. 2005. Computer-controlled system for ISEs automatic calibration. Sensor Actuat B-Chem. 105:521-531.   DOI
6 Jung, D.H., H.J. Kim, S.H. Kim, J. Choi, D. J. Kim, and H.S. Park. 2019. Fusion of spectroscopy and cobalt electrochemistry data for estimating phosphate concentration in hydroponic solution. Sensors, 19:2596.   DOI
7 Jung, D.H., T.I. Ahn, , and Sudduth, K. A. 2015. Automated lettuce nutrient solution management using an array of ion-selective electrodes. T. ASABE. 1309-1319.
8 Kim, D.W., D.H. Jung, W. J. Cho, K. C. Sim, and H. J. Kim. 2017. On-site water nitrate monitoring system based on automatic sampling and direct measurement with ionselective electrodes. J. Biosyst. Eng. 42:350-357.   DOI
9 Kim, H.J., J.W. Hummel, K.A. Sudduth, and S.J. Birrell. 2007. Evaluation of phosphate ion selective membranes and cobalt based membranes and cobalt based electrodes for soil nutrient sensing. T. ASABE. 50:415-426.   DOI
10 Kim, H.J., D.W. Kim, W.K. Kim, W.J. Cho, and C.I. Kang. 2017. PVC membrane-based portable ion analyzer for hydroponic and water monitoring. Comput. Electron. Agric. 140:374-385.   DOI
11 Kim, H.J., W.K. Kim, M.Y. Roh, C.I. Kang, J.M. Park, and K.A. Sudduth. 2013. Automated sensing of hydroponic macronutrients using a computer-controlled system with an array of ion-selective electrodes. Comput. Electron. Agric. 93:46-54.   DOI
12 Kim, H.J., K.A. Sudduth, J.W. Hummel, and S.T. Drummond. 2013. Validation testing of a soil macronutrient sensing system. T. ASABE. 56:23-31.   DOI
13 Rius-Ruiz, F.X., F.J. Andrade, J. Riu, and F.X. Rius. 2014. Computer-operated analytical platform for the determination of nutrients in hydroponic systems. Food Chem. 147:92-97.   DOI
14 Savvas, D. 2002. Automated replenishment of recycled greenhouse effluents with individual nutrients in hydroponics by means of two alternative models. Biosyst. Eng. 83: 225-236.   DOI
15 Savvas, D., and G. Manos. 1999. Automated composition control of nutrient solution in closed soilless culture systems. J. Agric. Eng. Res. 73:29-33.   DOI
16 Schefer, U., D. Ammann, E. Pretsch, U. Oesch, and W. Simon. 1986. Neutral carrier based $Ca^{2+}$-selective electrode with detection limit in the sub-nanomolar range. Anal. Chem. 58:2282-2285.   DOI
17 Yamazaki, K. (1982). Soilless Culture (in Japanese). Tokyo, Japan: Hakuyu Press.
18 Xiao, D., H.Y. Yuan, J. Li, and R.Q. Yu. 1995. Surfacemodified cobalt-based sensor as a phosphate-sensitive electrode. Anal. Chem. 67:288-291.   DOI