Question

Brackish water is desalinated by evaporation for irrigation purposes. If the feed water has 800.96 ppm of salt, and if the product has to contain 0.0034 % salts as illustrated in Fig 1, what fraction of the feed water should bypass the evaporator?

Answer 1

feed water = 800.96 ppm

product water = 0.0034% = 34 ppm

$800.96 ×( 1-x)= 34 × x\\ 800.96- 800.96x = 34x\\ 800.96 = 834.96x\\ x = 800.96/834.96 = 0.959$

part needed to bypass = $1-0.959$ =

$0.041$