Journal Executive Summary - Vol. If one coagulant sludge proved easier to dewater than the other, benefits could include easier sludge handling as well as reduced costs. Water treatment sludges can be difficult to dewater.
Lime is an effective conditioner that facilitates the dewatering process.
Its dense and porous crystals are incorporated into sludges, providing a matrix that allows rapid removal of water. At the university facility, conditioning with lime sludge improved dewatering of both the ferric and the alum coagulant sludges. Ultimately, however, the ferric sludge proved easier to dewater than alum sludge. The greater dewaterability of the ferric sulfate sludge may influence plant managers' decisions about which coagulant is best suited for their operations. Although use of the lime sludge conditioner is a good way to recycle a waste product, it poses a drawback in that a substantial volume of sludge is necessary to accomplish successful dewatering.