Principles of Water and Wastewater Treatment (CVET-450–01)
Homework Assignment #10
Due: Friday, April 6, 2018
Re–grading Deadline: Friday, April 20, 2018
Problem 9-5:
Using the values in Table 9–3, calculate the amounts of BOD, suspended solids, nitrogen and
phosphorus (all in lb/day) contained in 50,000 gpd of milk-processing waste. If the sewer
ordinance limits BOD to 500 mg/L, suspended solids to 400 mg/L, nitrogen and phosphorus to
35 mg/L, would the discharge be in compliance? Be sure to check each parameter for
compliance and state if it is within limits.
Problem 11–23: (Use the values below; there are lots of errors in the textbook problem.)
A single–stage rock media trickling filter plant consists of two 60–ft diameter by 7–ft deep
trickling filters. The flow rate into the plant is 1.05 MGD (total for both filters) and the
recirculation flow rate is 450 gpm per filter. The incoming BOD is 205 mg/L and suspended
solids are 200 mg/L. Assume a BOD removal in the primary clarifier (before the trickling filter)
of 25%. Using Figures 11–22 and 11–24 (posted), calculate:
