Environmental Engineering Reference
In-Depth Information
9.7
Describe the ultraviolet irradiation process for disinfection.
9.8
Describe the ozonation disinfection process.
9.9
What are the safety hazards associated with the ultraviolet irra-
diation and ozonation processes?
9.10 What is the major advantage of bromine chloride when compared
with chlorine for disinfection?
9.11 You are currently adding 450 lb of chlorine per day to a wastewa-
ter flow of 6.55 MGD. What is the chlorine dose in mg/L?
9.12 The chlorine dose is 8.22 mg/L. If the residual is 1.10 mg/L, the
chlorine demand is
.
9.13 Why is dechlorination required to be installed (in many facilities)
following chlorination for disinfection?
9.14 The plant adds 350 lb per day of dry hypochlorite powder to the
plant effluent. The hypochlorite powder is 40% available chlorine.
What is the chlorine feed rate in pounds per day?
9.15 The plant uses liquid hypochlorite, which is 69% available chlo-
rine and has a specific gravity of 1.28. The required feed rate to
comply with the plant's discharge permit total residual chorine
limit is 280 lb/day. What is the required flow rate for the hypochlo-
rite solution in gallons per day?
9.16 The plant currently uses 45.8 lb of chlorine per day. Assuming
the chlorine usage will increase by 10% during the next year, how
many 2000-lb cylinders of chlorine will be needed for the year
(365 days)?
9.17 Why are chlorine additions to critical waters, such as natural
trout steams, prohibited?
