| 摘要 |
<p>A biological treatment system of effluents with a surplus of nitrogen, esp. municipal sewage, applies aerobic and anaerobic methods in alternating successive basins. The distribution of the inflow to the individual basins is controlled as a function of type and content of the biologically digestible components, the inflow rate, and the trends of the pollutants and of the inflow rate. This ensures that before the start of a peak load with nitrogenous cpd., enough nitrite and/or nitrate is present to reduce at once the matter, which is harmful to a nitrification, by means of biosludge and of the fixed oxygen in nitrite and nitrate. In a municipal sewage plant contg. a preclarification, a first aeration basin, a first denitrification basin, a second aeration basin, a second denitrification basin and a reclarification basin, the recycled sludge from the reclarification basin goes to the first aeration stage. At night, most of the small amt. of sewage is directed into the second denitrification basin; the first aeration stage receives little, except the clear water from the sludge digestion plant. This produces much nitrite and nitrate which passes to the second denitrification basin for reaction. During the daytime the proportion of sewage going to the first stage is gradually increased. In the case of heavy rainfall, the principle of oxidation and elimination of nitrogen in the first stages is maintained.</p> |
