Comparing heterotrophic and hydrogen-based autotrophic denitrification reactors for effluent water quality and post-treatment

This work compares a pilot-scale H₂-based membrane biofilm reactor (MBfR) and a pilot-scale packed-bed heterotrophic reactor (PBHR) for denitrification of nitrate-contaminated groundwater. The comparison includes the effluent water quality of the denitrification reactors (NO₃⁻, NO₂⁻, dissolved oxygen, SO₄²⁻, (biodegradable) dissolved organic carbon, heterotrophic plate counts (HPC), turbidity, NH₄⁺, and pH), and the impact of post-treatment on water quality. At the same nitrate carrier-surface loading, effluent water quality was generally better directly from the MBfR than from the PBHR. However, post treatment including an ozone-contact tank and a post-filter brought the finished-water quality for both systems to roughly the same level, which met all drinking water standards except for HPC.