Auto-Vac® Handles Fine Alum Sludge

An Auto-Vac® Filtration and Dewatering System has been modified to handle fine alum sludge generated by the Tewksbury, MA, water treatment plant.

The system removed all particles larger than 0.5 microns (including the alum) and yielded a residue concentration of between 29 percent and 32 percent concentrate without using polymer. Filtrate water produced by the system has been approved for re-discharge into the headwork of the facility.