Mixing, Flocculation, and Solids Contact Processes

Chemical Mixing, Flocculation and Solids Contact Processes 

These processes depend on fluid shear for coagulant dispersal and for promoting particle contacts. Shear is most commonly introduced by mechanical mixing equipment. In certain solids contact processes shear results from fluid passage upward 

In mineral addition to biological wastewater treatment systems, coagulants may be added directly to mixed biological reactOTs such as aeration tanks or rotating biological 

The proper measure of flocculation effectiveness is the performance of subsequent solids separation units in terms of both effluent quality and operating requirements, such as filter backwash frequency. Effluent quality depends greatly on the reduction of residual primary size particles during flocculation, while operating requirements relate more to the floe volume applied to separation imits. 

In a lications other than coagulatim with alum or ircm salts, flocculation parameters may be quite differoit. Lime precipitates are granular and benetit little from prolonged 

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