Enhanced disinfection of wastewater by combining wetland treatment with bioelectrochemical H2O2 production

A highly-loaded constructed wetland (up to 44 +/- 21 g COD m (2) d (1)) was connected to a bioelectrochemical system (BES) to produce hydrogen peroxide for disinfection purposes. The anode delivered a current from the wetland effluent up to 3.5 A m (2) (maximum 62% anodic efficiency) but was limited in the supply of organic carbon. Hydrogen peroxide could be produced in situ in wetland effluent. Production rates were tested at various current densities with a maximum rate of 2.7 g m(electrode) (2) h (1) (4 h at 10 A m (2), 41% cathodic efficiency). Little difference was observed between production rate in wetland effluent or a 0.3% NaCl solution. The resulting hydrogen peroxide (0.1%) was used to disinfect wetland effluent successfully (<75 CFU ml (1) after 1 h contact time). The combination of wetland water treatment with peroxide production in a BES thus enables generating higher water qualities, including disinfected water, without external input of chemicals. (C) 2013 Elsevier Ltd. All rights reserved.