| 摘要 |
<p>PCT No. PCT/NL93/00125 Sec. 371 Date Dec. 12, 1994 Sec. 102(e) Date Dec. 12, 1994 PCT Filed Jun. 10, 1993 PCT Pub. No. WO93/25485 PCT Pub. Date Dec. 23, 1993.A system for purifying nitrogenous waste water by biological nitrification and denitrification, comprises at least two essentially separated reactor chambers, a liquid supply (4) and a liquid discharge (5). The first, aerated reactor chamber (1) is 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 air supply (11, 18) and an air discharge (12) located above the supply. The first 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-depleted and the aerated reactor chambers, whereafter it is separated from the sludge and the sludge is returned to the reactor.</p> |
