| 摘要 |
<p>A method of keeping active the activated sludge in a waste water purification unit during a period in which the process of the purification is inactive. According to the present invention, the activated sludge is aerated and a nutrient solution is fed into it, which comprises a nitrogen source, a phosphor source and a source of organic matter, the concentration of which organic matter at least essentially corresponds to the biological oxygen demand of the waste water to be purified in a batch purification unit. With the nutrient solution it is possible to keep active the activated sludge, even though the purification plant stands unused for long periods.</p> |
