Design a Primary Sedimentation Basin. The average flowrate at a small municipal wastewater$-$treatment plant is $27,000$ m$3/$d$.$ The highest observed peak daily flowrate is $77,000$ m$3/$d$.$ Design rectangular primary clarifiers with a channel width of $7$ m$.$ Use a minimum of two clarifiers. Calculate the scour velocity, to determine if settled material will become re$-$suspended. Estimate the BOD and TSS removal at average and peak flow. Use an overflow rate of $37$ m$3/$m$2.$d at average flow and a side water depth of $3\mathrm{.}7$ m$.$

Use the following values:

Cohesion constant k $=0\mathrm{.}05$

Specific gravity S $=1\mathrm{.}25$

Acceleration due to gravity g $=9\mathrm{.}81$ m$/$s$2$

Diameter of particles d $=110$ x $10-6$ m

Darcy$-$Weisbach friction factor f$=0\mathrm{.}027$