Environmental Engineering Reference
In-Depth Information
10.13 When sludge is pumped from primary settling directly to the
anaerobic digester, pumping should be controlled to produce a
sludge with
solids.
10.14 To oxidize biosolids using lime stabilization, what is required?
10.15 Can sludge be added to a floating cover anaerobic digester with-
out withdrawing an equal amount of supernatant or sludge?
10.16 What do the digestion rate and the volatile matter reductions
achieved by an anaerobic digester depend on?
10.17 What is the volatile acids-to-alkalinity ratio when the anaerobic
digester contains 387 mg/L of volatile acids and 5805 mg/L of
alkalinity?
10.18 The biosolids pump operates 30 min every 3 hr. The pump deliv-
ers 65 gpm. If the biosolids are 5.1% solids and have a volatile
matter content of 64%, how many pounds of volatile solids are
removed from the settling tank each day?
10.19 Name three general ways that biosolids can be dewatered.
10.20 What two actions take place in a biosolids drying bed?
10.21 Thickened thermally conditioned biosolids are pumped to a vac-
uum filter at a rate of 30 gpm. The vacuum area of the filter is 10
ft wide with a drum diameter of 8.4 ft. If the biosolids concentra-
tion is 11%, what is the filter yield in lb/hr/ft
2
? Assume the sludge
weight is 8.34 lb/gal.
