SETIER Project: An open source flowmeter for monitoring flow rates output of waste water treatment
Authors: Imig Arnold , Guyard Hélène , Prost-boucle Stephanie , Quatela Valerie , Moreau Sylvain , Sudre Julien , Clément Rémi 
Published: March 2024

Different types of sensors are used continuously or intermittently in urban water management systems. They are primarily useful for monitoring and controlling medium to large treatment plants, allowing the recording of physical parameters such as inflow and/or outflow rates or the temperature of the facilities (Murphy et al., 2015). Additionally, continuously measured parameters include those specifically used to monitor physico-chemical processes throughout the treatment: electrical conductivity, pH, turbidity, redox potential, or dissolved oxygen in the basins, as well as insufflated air flow rates. For smaller-scale stations (< 2,000 EH), water quality monitoring is often more limited, frequently confined to batch counting or using malfunction sensors (for instance, effluent overflow).Furthermore, taking the example of reed bed filters (RBF), which are primarily advantageous for operators due to their operational simplicity, the use of sensors could be seen as complicating this system primarily intended for rural areas (Rao et al., 2013). The costs of purchasing and maintaining measurement chains may appear excessively high depending on the parameters used, an opinion shared by municipalities and operators whose financial resources are increasingly constrained (Prost-Boucle et al., 2022). The issue of sensor costs is particularly significant for smaller stations, significantly impacting operational budgets. It is also worth noting the difficulty in repairing and maintaining these solutions, often regarded as black boxes for users, requiring complete upgrades at regular intervals. As part of the Setier project, we have developed a series of Open-hardware tools for the management and monitoring of wastewater treatment plants. The objective of our presentation will be to showcase an open-source ultrasonic flowmeter. This flowmeter allows monitoring variations in Venturi channels, encompassing heights from 0 to 1 meter. It offers a 1mm resolution, and all design elements are shared online. The uniqueness of our system lies in its requirement for no component soldering like &#8220;Lego&#8221;. The flowmeter is programmable via the Arduino IDE. As for data collection, it is done using a smartphone through a web server embedded in the Arduino MKR1010 Wifi board. Our presentation will highlight the first measurement results from a 6-month wastewater treatment plant.&#160;Murphy, K., Heery, B., Sullivan, T., Zhang, D., Paludetti, L., Lau, K.T., Diamond, D., Costa, E., O&#1523;Connor, N., Regan, F., 2015. A low-cost autonomous optical sensor for water quality monitoring. Talanta 132, 520&#8211;527. https://doi.org/10.1016/J.TALANTA.2014.09.045Prost-Boucle, S., Kamgan Nzeufo, H., Bardo, T., Moreau, S., Guyard, H., Duwig, C., Kim, B., Dubois, V., Gillot, S., Clement, R., 2022. Capteurs bon march&#233; et centrales d&#8217;acquisition DIY pour les eaux us&#233;es&#8239;: le projet Setier: Low-cost sensors and datalogger open hardware for wastewaters: Setier project. TSM 35&#8211;44. https://doi.org/10.36904/tsm/202201035Rao, A.S., Marshall, S., Gubbi, J., Palaniswami, M., Sinnott, R., Pettigrovet, V., 2013. Design of low-cost autonomous water quality monitoring system. Presented at the 2013 International Conference on Advances in Computing, Communications and Informatics (ICACCI), pp. 14&#8211;19. https://doi.org/10.1109/ICACCI.2013.6637139