Sediment microbial fuel cells (SMFCs) have attracted great attention for its high feasibility of renewable energy source and biodegradation technology. Here, we aim to experimentally evaluate the electrode distance effects in sediment by forced electron recovery based on variances in the profiles of sediment properties (pH, ORP) and the electrode potential. Large increases in ORP (or electrode potential) and decreases in pH were found near the anode electrode. The gradients of pH, ORP, and the electrode potential formed along with increases in the distance from the anode electrode. Based on the gradient profiles, the sediment located up to 8 cm from the anode electrode was affected by the forced electron recovery. This distance was 10-fold longer comparing to that of SMFCs operated with normal conditions.