Electrolysis-enhanced ecological floating bed and its factors influencing nitrogen and phosphorus removal in simulated hyper-eutrophic water.

To enhance ammonia nitrogen (NH-N) and phosphate (PO-P) removal in hyper-eutrophic water, electrolysis-enhanced ecological floating bed (EEEFB) was designed with a Mg-Al alloy anode, a Ir-Ta-Ti metal oxide-coated titanium anode, and an Fe anode with the same graphite cathode. The results showed that the Mg-Al alloy anode with graphite cathode had a better ability to enhance NH-N and PO-P removal. When the current density was 0.37 mA·cm, the electrolysis time was 24 h/d, and the net removal rates of NH-N and PO-P were 62% and 99.4%, respectively. In winter, the purification efficiencies of NH-N and PO-P were as high as 7388.4 mg·m and 4297.5 mg·m, respectively, by EEEFBs which were significantly higher than the traditional ecological floating bed (p < 0.05). Scanning electron microscopy (SEM) and X-ray spectrometry confirmed that the PO-P was deposited in the sediment of EEEFBs with Mg-Al alloy anode and Fe anode.