Air and Water Pollution Prevention and Control Engineering
Homework # 8
1.- Investigate the separation efficiency of a proposed design of a type I sedimentation basin to separate particles
all of the same density but with a lognormal size distribution function of parameters Dg = 3 x 10-6 and sg = 3
contained in water flowing at a rate of 105 m3/day. The proposed basin width and length are B =4 and L = 2 m ,
respectively.
2.- The following data was collected using a type II sedimentation column with three sample ports at 60 cm, 120
cm and 180 cm from the top of the column. Use te data to calculate and graph the separation efficiency at each
height as a function of time. How long would it take to remove 50% of the particles at heights 60, 120 and 180 cm,
respectively?
Time
Concentration (mg/L)
(min) 60 cm 120 cm 180 cm
0
5
10
20
30
40
50
60
75
430
357
310
252
198
163
144
116
108
430
387
346
299
254
230
196
179
143
430
396
366
316
288
252
232
204
181
3.- A media filter consist of uniformly sized spherical particles of size 0.5 mm and is packed to minimum porosity
(close-packing of spheres). Estimate the number of media particles and their total surface area per cubic meter of
filter.
4.- Produce a ~ 500 word essay summarizing your progress in your water pollution project.