Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

QUESTION 4 The Chaudhari et al paper discussed in this course is concerned with

ID: 534812 • Letter: Q

Question

QUESTION 4 The Chaudhari et al paper discussed in this course is concerned with the treatment of spent wash water coming from a molasses-based alcohol distillery. This spent wash is dark brown in colour and has very high levels of CoD (up to 200 kg/m and BoD (up to 75 kg/m 0. Around 15 m of spent wash are formed per m3 ethanol produced. This stream is sent first to an anaerobic reactor which greatly reduces its organic load (quoted values for the biodigester effluent are COD 38,800 mg/L, BOD 7,200 mg/L).

Explanation / Answer

Step I

For per m3 of ethanol produced in the distillery, 15 m3 of spent wash are formed. So for the given problem, 1000 m3 of ethanol is produced per day which says that 15000 m3 of spent wash are formed from the given distillery.

Step II

Now concentration of Iron = 65 x 10-3 M

Volume = 15 x 106 L

Moles = Concentration x Volume = 65 x 15 x 103

Moles = 975000

Step III

Mass of FeCl3.6H2O needed = 975000 * molecular weight

m = 975000 x 270.29

m = 263.53 tonne per day