Real-time Monitoring of Nitrate Concentrations in Groundwater Using Wireless Sensor Network

Abstract

In recent times, there has been an increase in awareness of groundwater pollution caused by excess nitrate ions. This is a necessary concern as groundwater is a significant source of drinking water for many people, and intake of water polluted with nitrate, primarily by infants, causes low levels of oxygen in the blood, a fatal condition known in biological terms as methemoglobinemia or the blue baby syndrome. As more nitrate ions are introduced into groundwater by applying nitrate fertilizers each year, seepage from septic systems, more lives are threatened. In view of this, the Environmental Protection Agency (EPA) has set a drinking water standard of 10 milligrams per liter (ml/L) nitrate concentration. An effective monitoring system must regularly measure nitrate ions’ concentration in underground water to adhere to this standard. To address the issue of effectively monitoring nitrate concentrations in groundwater while considering energy efficiency and mobility of the user, a real-time monitoring system for nitrate ions in groundwater was developed using a wireless sensor network consisting of nitrate sensors which were situated in the field (groundwater) to collect nitrate concentration data and send the data wirelessly via Bluetooth and the internet to be displayed in an android application. The readings of nitrate concentration were displayed in an android application both numerically and graphically, and a notification was sent to the application user when the nitrate concentration exceeded 8mg/L. The developed monitoring system detected and measured the concentration of nitrate ions in groundwater and transmitted the data obtained to the android application via Bluetooth and the internet through an online database in a delay time of 90 seconds of operation. The system operated and displayed the concentration of nitrate ions in real-time, enhancing early detection of groundwater pollution due to excess nitrate ions.