This report proposed a novel technique for the regulation of phosphorus flux based on a bioelectrochemical system. In the simulated water system, a simple in situ sediment microbial fuel cell (SMFC) was constructed. SMFC voltage was increased with time until it was 0.23 V. The redox potential of the sediment was increased from -20 mV to -78 mV during the process. Phosphorus concentration in the water system was decreased from 0.1 mg/L to 0.01 mg/L, compared with 0.09 mg/L in the control. The installation of a SMFC produced an external current and internal circuit, which promoted the transfer of phosphate in overlying water to the sediment, enhanced the microbial oxidation of Fe2+, and increased the formation of stable phosphorus in sediment. In conclusion, phosphorus flux from the overlying water to sediment was enhanced by SMFC, which has the potential to be used for eutrophication control of water bodies. (C) 2016 Elsevier Ltd. All rights reserved.