Secondary Treatment - Wastewater Operators - page 290

7.7 Name three main parts of the trickling filter, and give the pur-

pose or purposes of each part.

7.8 Name three categories of trickling filter based on their organic

loading rate.

7.9 Which classification of trickling filter produces the highest qual-

ity effluent?

7.10 What is the purpose of recirculation?

7.11 The recirculation ratio is 0.80. The influent flow rate is 2.3 MGD.
What is the total flow being applied to the filter in MGD?

7.12 Why is a settling tank required following the trickling filter?

7.13 List three things that should be checked as part of the normal
operations and maintenance procedures for a trickling filter.

7.14 A trickling filter 90 ft in diameter treats a primary effluent flow
rate of 0.288 MGD. If the recirculated flow to the clarifier is 0.366
MGD, what is the hydraulic loading rate on the trickling filter in
gallons per day per square foot (gpd/ft 2 )?

7.15 A treatment plant receives a flow rate of 3.0 MGD. If the trickling
filter effluent is recirculated at a rate of 4.30 MGD, what is the
recirculation ratio?

7.16 Describe the RBC.

7.17 Describe the process occurring in the RBC process.

7.18 Can an RBC be operated without primary settling?

7.19 What does a chalky white biomass indicate?

7.20 Name two types of RBC media.

7.21 What makes the RBC similar to the trickling filter?

7.22 What makes the RBC perform at approximately the same levels of
performance throughout the year?

7.23 Describe the appearance of the slime when the RBC is operating
properly. What happens if the RBC is exposed to a wastewater
containing high amounts of sulfur?

7.24 The slime in the first stages of the RBC is gray and shaggy. The
slime in the last two stages of the train is reddish brown. What
does this indicate?

7.25 An RBC unit treats a flow rate of 0.45 MGD. The two shafts used
provide a total surface area of 200,000 ft 2 . What is the hydraulic
loading on the unit in gpd/ft 2 ?

referenCe and suggesTed reading

Culp, G.L. and Heim, N.F. (1978). field manual for Performance
evaluation and Troubleshooting at municipal Wastewater Treatment
facilities. Washington, D.C.: U.S. Environmental Protection Agency.