It has been shown that it is possible to electrochemically immobilize iron (Fe) and manganese (Mn) in sediments due to the formation of a redox- and pH-barrier. This paper describes the influences of important operational and technical parameters on the procedure's effectiveness. Voltage, degree of electrode covering of the sediment, distance between anode and cathode, electrode material and positioning of the electrode system significantly affect the process and were optimized. Optimum operation was achieved using high-grade steel electrodes driven with a voltage of U = 3-4 V, or carbon fleece electrodes with a voltage of U = 4-5 V (current density per electrode area I/A_E = 0.02-0.05 mA/cm²). Fast and complete immobilization of Fe and Mn occurred at an electrode covering 12% of the sediment surface. No significant improvement was achieved at higher electrode-sediment area ratios. An optimum distance of about 10 cm between anode and cathode was determined. Temporary initial mobilization of Fe and Mn was found at greater electrode distances. The positioning of the electrode system relative to the sediment surface significantly affected the remobilization of Fe and Mn after the current was switched off. If the anode was placed in the sediment, a steep pH-gradient was formed between the aqueous phase and the anode region (ΔpH > 5), which considerably improved the immobilization of Fe and Mn. Low periodic turbulence at the sediment-water interface did not significantly influence the fixation of Fe and Mn.