Lecture notes of Industrial Waste Treatment (Elective -III) as per syllabus of Solapur university for BE Civil Prepared by Prof S S Jahagirdar, Associate Professor, N K ORchid College of Engg and Tech, Solapur

1. LL--2424
Distillery IndustryDistillery Industry
Industrial Waste Treatment

2. Introduction
There are two types of industries
1.Beverages
2. Molasses distilleries2. Molasses distilleries
Which produce alcohol.

3. WHAT IS MOLASSES
On industrial scale, ethanol can be
prepared by the fermentation of
molasses. Molasses is the mother
liquor left after the crystallization of
sugarcane juice.
It is a dark coloured viscous liquid.
Molasses contains about 60%
fermentable sugar.

4. METHOD OF PREPARATION
1. DILUTION OF MOLASSES:- Molasses is first
diluted with water in 1:10 (molasses : water)
ratio by volume.
2. ADDITION OF AMMONIUM SULPHATE:- If
nitrogen content of molasses is small, it is now
fortified with ammonium sulphate to providefortified with ammonium sulphate to provide
adequate supply of nitrogen to yeast.
3. ADDITION OF SULPHURIC ACID:- Fortified
solution of molasses is then acidifies with
small quantity of sulphuric acid. Addition of
acid favours the growth of yeast but unfavours
the growth of useless bacteria.

5. 4. FERMENTATION:- The resulting solution
is received in a large tank and yeast is
added to it at 30O C and kept for 2 to 3
days.
During this period, enzymes sucrase and
zymase which are present in yeast,zymase which are present in yeast,
convert sugar into ethyl alcohol.
C12H22O11 + H2O C6H12O6 + C6H12O6
C6H12O6 C2H5OH + 2CO2

6. 5. FRACTIONAL DISTILLATION :- Alcohol
obtained by the fermentation is called
WASH, which is about 7% to 10% pure.
By using fractional distillation technique, it
is converted into 95% pure alcohol which
is known as rectified spirit or commercial
alcohol.alcohol.

7. Ethanol manufacturing

10. Fermentation
tank

11. Fermentation
tank

12. General characteristics of spent wash
Parameter Value
Flow 15 to 18 lit/lit of alcohol
pH 4 to 4.5
COD 80,000 to 1,00,000
BOD 40,000 to 60,000BOD 40,000 to 60,000
TS 60,000 to 1,50,000
SS @1000
Potash 900 to 1200
Phophorus 500 to 800
Alaklinity 380 to 510

14. Characteristics of Distillery waste
Paramete
r
Yeast
sludge
Combine
d waste
Spent
wash
Spent
wash
pH 4.8 3.9-4.3 3.5-3.65 4-4.5
Temp 0C --- --- --- 90-95
COD mg/l 368000 27900- 118000 70000-COD mg/l 368000 27900-
73000
118000 70000-
151200
BOD mg/l 165000 12230-
40000
41380 28000-
80000
TS mg/l --- 16640-
26000
99000 59100-
114500
SS mg/l 73000 4500-
12000
350 1000

15. Parameter Yeast
sludge
Combined
waste
Spent
wash
Spent
wash
Total
nitrogen
mg/l
--- --- 1135 14800-
19000
Alkalinity
mg/l
--- 380-510 --- ---
Colour Dark
brown
Dark
brown
Rate of
waste
flow
0.9-1.0
MLD
0.82 MLD
DO -- -- NIL --

16. Treatment alternatives
1. Disposal for irrigation after dilution: -
Waste + Dilution water For irrigation
2. Two stage biological treatment:-
Lime BiogasLime Biogas
Waste
Effluent
Neutralization
Anaerobic
treatment
Aerobic
treatment

17. Anaerobic treatment includes
i. Digester or
ii. Lagoons
• Aerobic treatment includes
i. ASP
ii. Trickling filter and SSTii. Trickling filter and SST
3. Composting:- Nutrients
Spentwash
Manure
Press mud or
Solid waste
Composting

18. 4. Potash recovery

19. Objective questions
1. Molasses is waste generated from
__________ industry, whereas spent wash is
generated from ___________ industry.
2. pH of distillery spentwash is ______.
3. BOD value of spentwash is3. BOD value of spentwash is
________________.
4.Because of high nutrient content of spentwash,
_________ recovery is possible.
5. Spentwash, _____________ and ________
can be used for biocomposting.

20. Theory Questions
Q1. Draw a neat flow sheet for molasses based
distillery industry and discuss processes in
brief.
Q2. give general characteristics of distillery spentQ2. give general characteristics of distillery spent
wash and suggest suitable treatment
alternatives