| 摘要 |
<p>The invention relates to a system and a process for purifying nitroge- nous waste water by biological nitrification and denitrification. The system comprises at least two essentially separated reactor chambers, a liquid sup- ply (4) and a liquid discharge (5). The first, aerated reactor chamber (1) i s provided at the top with an overflow to the second, oxygen-depleted reactor chamber (2). The oxygen-depleted reactor chamber (2) is divided at the top into a degassing chamber (7) and a settling chamber (8) having an overflow (9) to the liquid discharge. The first reactor chamber is provided with an a ir supply (11, 18) and an air discharge (12) located above the supply. The firs t reactor chamber may be partly divided into a riser (14) and a downcomer (15) which allow, as a result of the air supply, mass circulation to take place in the aerated reactor chamber. According to the process, waste water with bacterial sludge on a carrier circulates alternately through the oxygen-de- pleted and the aerated reactor chambers, whereafter it is separated from the sludge and the sludge is returned to the reactor.</p> |
