Impact of an external electron acceptor on phosphorus mobility between water and sediments

The present work assessed the impact of an external electron acceptor on phosphorus fluxes between water and sediment interface. Microcosm experiments simulating a sediment microbial fuel cell (SMFC) were carried out and phosphorus was extracted by an optimized combination of three methods. Despite the low voltage recorded, ∼96 mV (SMFC with carbon paper anode) and ∼146 mV (SMFC with stainless steel scourer anode), corresponding to a power density of 1.15 and 0.13 mW/m2, it was enough to produce an increase in the amounts of metal bound phosphorus (14% vs 11%), Ca-bound phosphorus (26% vs 23%), and refractory phosphorus (33% vs 28%). These results indicate an important role of electroactive bacteria in the phosphorus cycling and open a new perspective for preventing metal bound phosphorus dissolution from sediments.