Design of pH Control in a Wastewater Treatment System Using an ESP8266 Microcontroller Based on IoT Thingspeak

Industrial activities in producing goods or services make various positive impacts in Indonesian economic activities. However, every production activity conducted by particular industries certainly also brings negative impacts, namely waste as a by-product of these industrial activities. The effects of the waste produced can certainly disrupt environmental balance. One of the wastes produced by an industry can be liquid waste. Liquid waste is the remainder of a business and/or activity in liquid form. Every industry must process their liquid waste or pollutants properly in order to prevent the industry from violating the quality standard limits set by the government. One of the liquid waste parameters that must be maintained to prevent pollution does not occur is pH. Therefore, wastewater control is needed to keep the pH value. This study designs a pH monitoring and control system in a wastewater neutralizer tub at a wastewater treatment plant (WWTP). This study uses a system that provides data on the pH value of wastewater in wastewater neutralizer tanks at wastewater treatment plants (WWTP) where the pH sensor 4502C and NodeMcu ESP8266 function as microcontrollers. The data are then sent to the ThingSpeak IoT platform, where the measurement results are sent to an application called Kodular, which is accessible on an Android smartphone. The results show that based on testing the pH 4502C sensor, this study has obtained good readings with an error rate of 0.34% - 0.37% and a good error rate of 6%. In addition, the monitoring process is running well. The indicator can be seen from the value displayed on ThingSpeak and the Android application according to the results displayed via the Arduino IDE serial monitor. In terms of monitoring data transmission on the ThingSpeak platform, there are still many delays because ThingSpeak can only send data every 15 seconds. 0.1s in the opposite direction until it returns to its original location.