Automatic control of external carbon source addition for nitrogen removal in sewage with low C/N ratios

摘要: For cost-effective nitrogen removal from sewage with low C/N ratios, an automatic control system for the addition of external carbon based on oxidation-reduction potential (ORP) data in anoxic reactor has been developed. In this study, it was carried out a pilot-scale modified Bardenpho process. This consisted anoxic1, aerobic1, anoxic2 and aerobic2 stages recycle ratio 150% (Q/Qinf), media packing 2.4%-2.9% (v/v) aerobic reactor. As result applying minimization source dosage, dosage decreased by about 20%. estimate ORP compared stable 75mg/L C/NOx-N influent. It necessary that set-value be regulated -120 mV to Ð80 because influent NH4+-N concentration varied 12 15 mg/L due rainfall. Correspondingly, demanded dosages were decreased. Drift real-time value more after changing -80 mV.