To study the effect of aeration on the batch digestion of the sheep manure, three columns were done from a PVC tube of diameter of 25 cm and each column is of height of 50 cm and its capacity is 24 liter. Three levels of aeration were investigated. These levels are: 1.8, 3.6 and 5.4 W. Firstly, the columns were loaded intermittently with equal quantities of the effluent of an anaerobic digester operating on diluted and smashed sheep manure. Then the columns were emptied and filled with a mixture of its emptied media and diluted smash sheep manure for a batch aerobic digestion which lasted for 28 days. TS of the new media was 5.5% and its pH was 8.2. TS and pH were measured intermittently and ambient temperature was recorded.
The experiment concluded to that:
1- The mean recorded ambient temperature was 29.5oC.
2- Diluted sheep manure needs a high rate of aeration to degrade which may make the process of digesting sheep manure uneconomic. Reduction in TS was: 15.4, 5.6 and 2% for the aeration levels: 5.4, 3.6 and 1.8 W respectively.
3- Aerobic degradation of TS of sheep manure can be represented by a linear function with a high correlation coefficient.
4- Under the three treatments, the pH decreased through the first four days of the digestion while it increased – generally – from the sixteenth day till the end of the experiment.
The study ended to that sheep manure needs a high rate of aeration to be degrade and may, economically, the aerobic digestion of sheep manure be not efficient.