Treatment of waste sludges from water purification plants

Accelerated interest in water pollution control has led to increased concern about a wide variety of polluting substances. One of these is the waste sludge from water treatment plants. A frequent practice is to discharge these wastes, without treatment, into the nearest available watercourse. There are two major reasons for this expediency. First, state anti-pollution agencies have, until recently, expressed little concern about these discharges, and second, little work has been done to demonstrate the available methods for treatment, dewatering, and ultimate disposal of these sludges.

The primary objective of this research was to study in detail possible methods for concentration, dewatering, and ultimate disposal of various types of water treatment plant sludges resulting from conventional processes. The use of newly-developed synthetic organic polyelectrolytic coagulant aids was investigated as a pretreatment method in combination with both open sand bed drying and vacuum filtration. The suitability of the dried product for ultimate disposal as landfill was evaluated.