A membrane reactor with an integrated flow-through photometric sensor was developed for real-time monitoring of sodium ferrate concentration. The materials for the reactor housing, sensor, and consumable anodes were selected, along with optimal electrolysis parameters that ensure increased ferrate yield and concentration, reduced energy consumption, and stable operation for up to 8 hours. The developed equipment and the produced reagent were tested on wastewater from oil extraction treatment facilities at the South Priobskoye field under Arctic conditions. At one site, ferrate was added directly to the wastewater with subsequent filtration; at another, it was used as part of an integrated treatment system including aeration and multi-stage filtration. Field trials demonstrated the high efficiency of sodium ferrate as an oxidant, coagulant, and flocculant: achieving degradation of organic and toxic compounds, removal of petroleum products, and water disinfection. Treated wastewater met regulatory standards and allowed safe discharge into the environment. The obtained results confirm the possibility of introduction of automated adaptive equipment for sodium ferrate synthesis into water treatment systems at oil production facilities. Utilizing sodium ferrate enhances treatment efficiency, lowers operating costs, and improves the environmental sustainability of production.