4.4.5 What is to be done if there is no available space for post-treatment?

For this scenario, the digestate must undergo treatment at a semi-centralised treatment plant. Additionally, a holding tank with sufficient capacity must be constructed to align with the desludging schedule.

Let’s say that the deluding intervals occur every 35 days. What volume would be needed? Due to the low TS concentration of 1.3% and the digester’s TS removal rate of 50%, the total volume reduction is approximately 0.8%, which can be disregarded when calculating the holding tanks’ capacity. Therefore, the input volume will equal the output volume, which was previously determined to be 3.72m3/d. Multiplying this by 35 days, a holding tank capacity of 130m3 will be necessary.