Design of wash-water and alum-sludge disposal facilities

The authors describe, with the aid of diagrams and tables, the investigations leading to the design of improved wash-water and alum-sludge disposal facilities to reduce pollution of the heavily-polluted Passaic river, N.J., by discharges from the Passaic Valley Water Commission. The process includes thickening of the sludge with polyelectrolytes, centrifuging, lime-conditioning, pre-coating, and sludge pressing, with the cakes discharged on to trucks for transport to a landfill.