1979 Volume 45 Issue 9 Pages 1147-1150
In a intermittently aerated lagoon, in which a high rate of removal of nitrogen had been observed, a seasonal variation of mud on the bottom was investigated using a new mud sounder which consisted of ultraviolet lamps and a blueprint marker. The volume of mud ranged between 35 and 132m3. The mud increased in winter and decreased in spring. The total amount of nitrogen found in the mud and mixed liquor was large in winter and spring and small in summer and autumn.
To control the increase of mud in winter, a treatment test was done for shallow lagoon water conditions. The results were that the volume of mud was maintained almost constant, the total amount of nitrogen found did not increase, and the rate of nitrogen removal remained high.