A system for automatic cultivation of microogranisms in the biology laboratory

Currently, the biology laboratory at the University of Stavanger has a manually controlled microorganism cultivation setup used for studying different types of biological wastewater treatment. The setup uses a sequencing batch reactor (SBR) where the sampling of wastew- ater and data logging must be done manually. With this in mind, this thesis aims to create an automated version of the SBR setup to make it easier for the lab users to perform exper- iments and to make it possible to get more reliable automatically measured and sampled, data for analysis. Our automated setup consists of a computer and a developed control program, that communi- cate with connected devices such as sensors, pumps, valves, and magnetic mixers. All device communication is achieved by digital communication, where the devices support different data transmission schemes and communication protocols. Through this communication and with the use of the developed control program, the operation of the reactor and its internal environment is controlled. With the use of the control program’s graphical user interface, the user can easily control and monitor the active reactor process. The user of the control program can choose the control parameters of the process to meet the desired reactor environment. The user is also provided with three different control methods for the reaction stage; Oxygen uptake rate (OUR)-, reactor-, and sequential mode. These modes provide different options in the reactor’s air supply control and for automatic esti- mation of bacterial growth. Throughout the process, all data and actions are logged into an excel spreadsheet for later analysis. In addition, a control cabinet is made to support the interface hardware for the SBR setup. Every device connects to the computer through this control cabinet. If needed, the device’s physical communication interface is converted/adapted to USB. The control cabinet also handles power distribution for both AC and DC components. The verification tests show a working automated SBR setup, and the three control methods work as intended. Unfortunately, due to covid-19, some delays on the equipment prevent testing more than one reactor setup. Both the control program and the control cabinet is made to control up to four reactors simultaneously