Simultaneous algae-containing water treatment and power generation using floating iron-air electrocoagulation fuel cell

The outbreak of cyanobacteria bloom in surface water has been a long-term global issue, as the adverse impact on aquatic ecosystem and drinking water safety. Electrocoagulation is an efficient method for cyanobacteria removal, but consumption of energy hampers the application. In this study, an efficient and energy generating electrocoagulation process for cyanobacteria removal by a floating iron-air fuel cell (FIAFC) was successfully applied. At different solution conductivities (2.33 ± 0.25 mS/cm and 4.94 ± 0.55 mS/cm), 100 % removals of algal cells were achieved within 50 min and 30 min, respectively. The maximum power densities of FIAFC were 1.34 W/m² and 2.48 W/m² at the corresponding current densities of 4.58 A/m² and 12.43 A/m². In the FIAFC, algal cells were removed mainly through charge neutralization and sweep flocculation processes with zeta potential, scanning electron microscope (SEM) and atomic force microscopy (AFM) analysis. These results suggested that FIAFC was effective for algae removal and electricity generation, which is a promising method for algae - laden water treatment.