The use of either quick or slaked lime for sludge stabilization is an attractive and cost effective way to reduce odours, killed pathogens and converts sludge into a usable product for land application in case of acid soil. Because lime has low solubility in water, lime molecules persist in biosolids. This helps to maintain the pH above 12 and prevent regrowth of pathogens.
The targets of this sludge treatment are :
- the stabilization of the sludge, which objective is to reduce its fermentability in order to decrease or remove the odors
- the reduction of the sludge water content, which results of a sludge volume decrease and improve its physical properties (such as enhanced storage properties : angle of repose)
- hygienization which target is to kill all the pathogens