| 摘要 |
<p>[Problem] To provide a method for controlling the denitrification strength of a liquid mixture containing activated sludge in a process of treating the activated sludge or biological denitrification. [Solution] A precipitation test method using cylinders, which comprises, when the ratio of the liquid face level of a liquid mixture containing activated sludge in a cylinder to the liquid face level of a sludge layer after allowing the same to stand is referred to as SV, comparing SV2 with SV1 [wherein SV1 represents an SV value measured after a shorter standing time; and SV2 represents an SV value measured after a longer standing time] to thereby evaluate the denitrification level of the liquid mixture containing activated sludge. A method which comprises preliminarily adding a BOD solution to a liquid mixture containing activated sludge in a cylinder, which is to be allowed to stand over a longer time, and mixing therewith followed by standing, then measuring SV2s and comparing the SV2s with SV1 to thereby evaluate the denitrification strength according to the amount of nitrate nitrogen in the liquid mixture containing activated sludge.</p> |
