An experimental procedure to investigate the effects of supplementing a low-density magnetic field on the performance of removal efficiency within the Orbal reactor.

The use of Orbal reactors for wastewater treatment by activated sludge is deemed efficient by various literature sources. Furthermore, it is interesting to determine the potential methodologies to improve removal efficiencies. This study aims to investigate the performance of removal efficiency when a magnetic field is incorporated within the reactor. In this experiment, two magnetic fields of different intensities (1.3 and 2 mT) were used. To generate these magnetic fields, several neodymium magnets were applied to the reactor. The experiment and sampling lasted approximately over a 156-d period to observe the performance of the reactor, with and without the application of a magnetic field. Upon the reactor achieving a steady-state, results were taken. It should be highlighted that, before application, four different inflows were discharged into the reactor to attain the optimum retention time. To confirm the validity, results from relatable studies were compared with this study's findings. Upon application of the magnetic fields, removal efficiencies of total nitrogen, chemical oxygen demand, and biochemical oxygen demand for five days increased by 11%, 6%, and 7%, respectively. Nitrate concentration in effluent had decreased by 21%. Furthermore, the food to microorganism ratio had decreased within a 13%-15% range. Results indicated, also, that the application of different strength magnetic fields had minor effects on removal efficiency. [ABSTRACT FROM AUTHOR]