front 1 What is the proper range of microsand concentration for a ballasted flocculation process unit? | back 1 2 to 6 g/L |
front 2 Very small, finely divided solids that do not settle due to their small size and similar electrical charge are called what? | back 2 Colloidal solids |
front 3 A tank or zone where the water is gently mixed, allowing small particles to bump into each other forming larger particles is called what? | back 3 Flocculation tank |
front 4 Changes to the source water that will require chemical adjustments of the coagulation process are increases or decreases in what water characteristics? | back 4 Color or alkalinity |
front 5 Which of the following is considered a coagulant aid? | back 5 Bentonite clay |
front 6 What is the cloudy appearance of a source water that is caused by the presence of suspended and colloidal matter known as? | back 6 Turbidity |
front 7 The operator observes the floc as it enters the flocculation basins from the flash mixing zone. The floc is small and well dispersed throughout the flow entering the basin. This observation indicates: | back 7 Everything is just right |
front 8 Why should the operator avoid adding microsand immediately near
the | back 8 Deflection and stress to the mixer impeller and shaft could damage mixer assembly |
front 9 How often should jar tests be run? | back 9 Jar tests should be run at least daily and more often when the quality of the raw water changes |
front 10 The operator observes the floc as it enters the flocculation basins from the flash mixing zone. The water has a milky appearance with a slight blueish tint. This observation indicates: | back 10 The alum dosage is too high |
front 11 What is a process that uses microsand added to the flocculation stage to encourage floc settling called? | back 11 Ballasted flocculation |
front 12 If an increase in turbidity or in the color of the raw water being fed to a ballasted flocculation unit occurs during normal operation, the operator should ensure that the microsand concentration is: | back 12 At the high end of the operating range |
front 13 What test is performed by the water plant operators and plant engineers to determine which coagulant will work best for their water and what dosage of that chemical will produce the lowest turbidity and clearest water? | back 13 Jar test |
front 14 With regard to a water's natural alkalinity, what condition could exist that would lead to incomplete precipitation of the aluminum sulfate (alum)? | back 14 Insufficient alkalinity leads to poor precipitation |