Start-up and operation of PNDPR-A treatment of actual sewage

Abstract:

The partial nitrification, denitrifying phosphorus removal and anammox (PNDPR-A) was proposed, which is a new type of efficient energy-saving coupling process. To further reduce the energy consumption of sewage treatment, the PNDPR-A process was adopted for the treatment of actual domestic sewage. The proportion of domestic sewage was gradually increased in three stages (25%, 50%, and 100%) to adapt to actual domestic sewage. Affected by the complex water quality of the sewage in the early stage, the NH+₄-N oxidation rate of PNDPR unit decreased and the NO-₂-N accumulation was reduced, which directly affected the subsequent denitrification effect of Anammox unit. To tackle this problem, the aeration intensity in aerobic 1 period was increased by 10% for PNDPR unit, so as to achieve NH+₄-N oxidation rate and NO-₂-N accumulation effect comparable to those of simulated sewage. In phase Ⅲ, 10-20 mg/L of NO-₂-N were added to Anammox unit, aiming at alleviating the problem of non-ideal influent nitrogen content of Anammox unit due to the low NH+₄-N oxidation rate of PNDPR unit in the early stage. After 40 d of cultivation and domestication, the PNPDR-A process was realized for actual domestic sewage treatment. The average effluent COD, NH+₄-N, NO-₂-N, and NO-₃-N concentrations of the subsequent system were 6,3.4,5.2, and 1.1 mg/L, respectively, indicating the high-efficient treatment of actual domestic sewage.