MicroSludge destroys (lysis) the cell membranes of waste activated sludge (WAS) microbes. This “liquefies” the microbial cells, which significantly enhances anaerobic or aerobic digestion.
The step-by-step process shown in the accompanying figure works as follows:
- A fine screen removes non-microbial debris from WAS. Since such debris will not breakdown to produce biogas there is no benefit in feeding this material to digesters.
- If required, excess water is removed from the sludge to increase its solid content. Increasing the thickness of WAS increases the effective capacity of digesters, which are expensive.
- A very small dose of caustic solution is added to WAS to chemically pre-weaken the cell membranes.
- This conditioned WAS is fed to a cell disrupter which lyses the cells, which makes digesters work more effectively and much faster.
MicroSludge processed WAS is fed to anaerobic digesters or aerobic systems. (There are many configurations of these systems.)
MicroSludge Cell Disrupter
The heart of the MicroSludge process is a cell disrupter, consisting of a high pressure positive displacement pump and a special cell disruption valve. WAS is subjected to enormous shear by passing through the cell disruption valve at high pressure, the combination high shear and high velocity of impact ruptures the cells of the thickened waste activated sludge (TWAS), releasing the cells’ cytoplasm.