Study of a combined sulfur autotrophic with proton-exchange membrane electrodialytic denitrification technology: Sulfate control and pH balance

► A novel combined denitrification system was developed and tested. ► The system consisted of sulfur and bio-electrodialysis part. ► The combined process could achieve pH balance thus avoiding nitrite accumulation. ► The sulfate generation could be controlled by HRT of sulfur part. ► The removal rate of bio-electrodialysis part was controlled by applied current.