Optimum parameters for humic acid removal and power production by Al–air fuel cell electrocoagulation in synthetic wastewater

Abstract Although humic acid (HA) is a complex natural organic matter, it can potentially harm the environment and human health. In this study, aluminum–air fuel cell electrocoagulation (AAFCEC) was used to remove HAs from water while generating electricity. This device can generate electricity from the anodic oxidation of aluminum without an external power source as well produce an aluminum coagulant. Operating parameters, namely initial pH, electrolyte concentration, and HA concentration, were analyzed to determine the optimal power generation and removal efficiency. Al–Ferron complexation timed spectrophotometry was used to determine the Al speciation distribution in the solution. The power density of the cell reached 313.47 mW/cm2 for the following conditions: 1 g/L NaCl concentration, 3 cm electrode distance, 20 Ω external resistor, and pH 9. And after about an hour electrolysis, the optimum removal rate of HA was above 99%. The results demonstrate that the AAFCEC is an efficient and eco-friendly water treatment process, and it could be further developed and disseminated in the rural areas and households.