ABSTRACT
ABSTRACT: In this study, a synthetic river environment reactor packed with corncobs was used to purify wastewater contaminated with nitrate by biological denitrification, where corncob was used as carbon source and bio-carrier. The operation efficiency and the influence of DO on the system were tested. The experimental results showed that well nitrogen removal efficiency was found even in higher DO condition. During more than 30-days process under aerobic condition (DO > 3 mg/L), the nitrate removal efficiency was still higher than 60%. It means biological denitrification with corncob as carbon source and substrate was less affected by DO. Structural biofilm was found on corncob surface by electron microscope scanning, which could well prevent diffusion of DO into the interior region and minimized the negative effect of oxygen. By preserving stability against DO inhibition, carbon source/ substrate integration denitrification process will be a reasonable way for denitrification in low C/N ratio and high DO environment.
