Sand-Ballasted high rate settling technology,
Process for the treatment of surface water prior to use by industries for industrial supply water, particularly
as an effective pretreatment system prior to membrane systems used to produce high purity water. Sandballasted
settling is a high-rate coagulation/flocculation/sedimentation process that utilizes microsand as a
seed for floc formation. The microsand provides a surface area that enhances flocculation and acts as a
ballast or weight. The resulting floc settles very fast, allowing for compact clarifier designs with high overflow
rates and short detention times. These designs results in system footprints between 5 and 30 times smaller
than conventional clarification systems of similar capacity. The use of microsand also permits the unit to
perform well, even when the inlet flow rate and influent water quality dramatically change either separately
or in tandem, while still producing high quality treated effluent. The paper will discuss a number of case
studies which highlight the performance of the ACTIFLO® process for the treatment of surface waters.