8) he Onceler\'s Thneed factory is polluting a stream with Gloppity Glop at a di

Question

8) he Onceler's Thneed factory is polluting a stream with Gloppity Glop at a discharge rate of 50 gpm and concentration of 100 mg/L. Upstream of the factory, the stream has a flow rate of 1000 gpm and is completely free of "glop." The Lorax has determined that the factory must reduce its effluent glop concentration to 20 mg/L for the humming fish population to recover. The Onceler decides the cheapest way to achieve this limit is to divert water from the stream into the plant and dilute the effluent down to the required concentration. a) What is the present glop concentration in the stream downstream from the factory discharge? How much water would be needed to dilute the factory waste discharge from its current glop concentration down to the required effluent glop concentration? b) c) What will be the glop concentration in the stream downstream of the factory if the Onceler puts his scheme into operation? Will the humming fish hum again under this plan?

Explanation / Answer

a)Let subscript S is for stream

Subscript gg for Gloppity Glop

let Qs be Discharge in stream & Qgg be Discharge of Glopitty Glop.

Let Ss be concentration of stream & Sgg be concentration of Glopitty Glop.

Qpresent=((Qs*Ss)+(Qgg*Sgg))/(Qs+Qgg)

=((0*1000)+(50*100))/(1000+50)=4.76 mg/l

b)We have to dilute the Glopitty Glop by 5 times.

Hence we have to mix 1 unit of Glopitty Glop into 4 unit of water.

For 50 gpm of Glopitty Glop Discharge we need 50*4=200 gpm of water.

c)Qafter=((Qs*Ss)+(Qgg*Sgg))/(Qs+Qgg)

=((0*1000)+(50*20))/(1000+50)=0.952 mg/l.

Hence, Fish will be able to hum again.

Related Questions

Navigate

• Browse (All)
• Browse 8
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.