FROM STOCK TO FLOC: AN INVESTIGATION INTO THE PHYSICAL/CHEMICAL PROCESSES CONTROLLING ALUMINUM SULFATE AND POLYALUMINUM CHLORIDE BEHAVIOR IN A GRAVITY POWERED DRINKING WATER TREATMENT PLANT

Coagulation and flocculation processes have been utilized in municipal scale drink-ing water treatment plants for many decades. Coagulation mechanisms have been defined and flocculation parameters have been tested in many studies. However, this knowledge has not been successfully aggregated into an overarching theory of coagulation and flocculation that can be applied to the design, construction, and operation of drinking water treatment plants. To this end, a prototype chem-ical dose controller was designed and tested to be used in conjunction with a linear flow meter for the accurate and consistent dosing for coagulant chemicals into the influent water in a plant. Scalable, physically based algorithms for the automated design of the flow meter and dose controller are available online at aguaclara.cornell.edu. A bench-scale water treatment plant apparatus with a hydraulic flocculator was created and validated to quantify flocculation performance for a wide array of conditions. Extensive data processing was also carried out to characterize the sedimentation of the flocculated suspensions. This powerful combination of bench