pharmaceutical wastewater needs a minimum BOD/N/P of 100/3.0/0.7 for biological treatment. The wastewater characteristics are BOD = 740 mg/l, suspended solids = 250 mg/l, soluble nitrogen = 10 mg/l, and soluble phosphorous = 5 mg/l. What ammonium nitrate and phosphoric acid additions would you recommend to ensure adequate nutrients for a daily flow of 28 m3/d

An existing rural 4-lane highway is to be replaced by a 6-lane divided expressway (3 lanes in each direction). Traffic volume data on the highway indicate that the AADT (both directions) during the first year of operation is 24,000 with the following vehicle mix and axle loads. Passengercars=50percent 2-axle single-unit trucks (12,000lb/axle)=40percent 3-axle single-unit trucks (16,000lb/axle)=10percent The vehicle mix is expected to remain the same throughout the design life of 20 years, although traffic is expected to grow at a rate of 3.5 percent annually. Using the AASHTO design procedure, determine the minimum depth of concrete pavement required for the design period of 20 years. Pi=4.5J=3.2Pt=2.5Cd=1.0Sc=650lb/in.2So=0.3Ec=5106lb/in.2R=95k=130lb/in.3

A hydrometer test has the following result: Gs = 2.65, temperature of water = 26 C, and L = 10.4 cm at 45 minutes after the start of sedimentation (see Figure 2.25). What is the diameter D of the smallest-size particles that have settled beyond the zone of measurement at that time (that is, t = 45 min)? Figure 2.25 ASTM 152H type of hydrometer placed inside the sedimentation cylinder (Courtesy of Khaled Sobhan, Florida Atlantic University, Boca Raton, Florida)