In a municipal sewer plant, sewage needs to be dried before further processing a

Question

In a municipal sewer plant, sewage needs to be dried before further processing and either usage or disposal. If sewage containing 55% solids by mass and the balance water is passed through a processing system, water is evaporated, and sewage containing 85% solids by mass leaves the drying plant, how much water is evaporated per metric ton of sewage input (assume that the output evaporation stream is pure liquid water)? Draw a Process Flow Diagram, labeling all streams, write the correct balance(s), and perform calculations to solve the problem.

Explanation / Answer

Basis : entering Stream : 1 ton =1000 kgs it contains 55% solids, solids in the sewage= 550 kgs and water is 450 kgs

The amount of solids before and after drying remains the same at 550 kg

let the outlet stream =y

y*0.85=550 y= 550/0.85 kgs=647 kgs

The difference between input and output is the water evaporated= 1000-647= 353 kgs

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

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