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‫معالجة مياه الصرف الصناعى وإعادة‬
‫استخدامها بمصانع شركة الدلتا للسكر‬
Chemist
Ahmed M. S. Hamad
B.Sc. Microbiology , Faculty of Science, Tanta
University(1997)
and
Diploma of Science and Technology of sugar
industry (Chemistry section), Sugar Technology
Research Institute Assiut University(2007)
and
Master in Science and Technology of sugar
industry
Sugar Technology Research Institute,
Assiut University (2012)
PREFACE
Over a period of 30 years, the Egyptian citizen's
share of Nile water will drop from 2000 cubic
meters to only 600 cubic meters per capita.
 While the international water poverty line is set
at 1000 cubic meters per year .
Now with Egypt's water quota is remaining as it
is and the population is growing year after year,
the water share of every citizen will continue to
drop further.
 So we look for non-conventional water sources
like reusing of treated waste water.
North Delta especially Delta Sugar
Company suffers from water shortage
at the campaign (during the season of
rice cultivation).
 High lights the importance of research
in complete recycling and reuse of 400
m3/h treated waste water, by adding a
new tertiary treatment under very
economic conditions.
Introduction
Beet factories produce more waste products than
cane factories or raw sugar refineries.
Beet factory generate two types of waste waters,
flume wastes and factory wastes.
The flume waste water system is used for
transporting and cleaning of beets. The sugar
that is leached into this water contributes a high
organic load in the flume system (few hundred
mg/L to more than 20,000 mg/L BOD).
 Due to the high strength of beet factory wastes
(flume wastes and factory wastes), anaerobic
digesters are almost universal.
 While sugar (the main contaminant of sugar factory effluent)
is not toxic, it readily the ideal substrate for microorganisms
growth .
 The exponential growth of microorganisms causes the
depletion of oxygen in natural streams.
 Aquatic organisms that require oxygen will suffer and may
die as a result.
 Waste water treatment systems utilize the very same process,
but under controlled conditions.
 The quest for zero effluent is a desirable journey and has
economic and environmental benefits.
• Egypt is an arid country.
• The United Nations reports pointed that per
capita is declining continuously after the share
was 3000 cubic meters in 1960, and decreased to
1200 cubic meters in 2000.
• Also pointed out that at 2025 bringing per capita
to 337 cubic meters per year.
Water resources in Egypt are restricted to
Status
of Water
Supply
the following
resources:
· Nile River
· Rainfall and flash floods,
· Groundwater in the deserts and Sinai
· Possible desalination of sea water
Each resource has its limitation on use;
the following is a description of each of
these resources.
1.
• Main
Nile River Water
and almost exclusive resource of fresh
water is the Nile River.
• The
Convention on the Nile Basin countries,
concluded in 1929, gives Egypt the right to use
55.5 billion cubic meters of Nile water.
• There are great difficulties faced Egypt in the
modified convention of the Nile Basin countries
to reduce their share of water.
Egyptian government officials have been
meeting with their counterparts from the
Nile River basin countries to re-examine
and re-evaluated the 1929 Nile River
water sharing with Egypt. No agreement
has been reached.
Without the Nile River flowing through,
there will be no more Egypt as we know.
2 . Rainfall
Rainfall happened only in the
winter season in the form of
scattered showers. Therefore, it
cannot be considered a dependable
source of water.
3. Flash Floods
Flash floods due to short-period heavy
storms are considered a source of
environmental damage especially in the
Red Sea area and southern Sinai.
This water could be directly used to meet
part of the water requirements or it could
be used to recharge the shallow ground
water .
4. Groundwater in the Western
Desert and Sinai
Groundwater found in the western desert ,the
New Valley governorate and the region east of
Owaynat. It has been estimated that about
2000,000 BCM of fresh water are stored in this
aquifer.
However, groundwater found at great depths
and the aquifer is generally non-renewable.
Therefore, the utilization of such water depends
on pumping costs and its depletion rate versus
the potential economic return on the long run.
5. Desalination of Sea Water
Desalination of seawater in Egypt has
been given low priority as a source of
water.
That is because the cost of treating
seawater is high compared with other
sources, even the unconventional sources.
Non-conventional Water Resources
There are other sources of water can be used
to meet part of the water requirements.
These sources are called non-conventional
sources, which include :-
· The reuse of agricultural drainage water
· The reuse of treated sewage water
Reuse of Treated Waste Water
Waste water treatment could become an
important source of water and should be
considered in any new water resource
development policy.
Proper attention must be paid to the
associated issues with such reuse.
The major issues include public health and
environmental hazards as well as technical,
institutional, and socio-cultural.
Objectives of this study
Physical, chemical and biological analysis of
the influent and effluent water after factory
treatments
Different treatments of the effluent water after
factory treatments by using:
1- CaO for fluming water
2- H2SO4 for juice extraction
3- Temperature for juice extraction
4- Formalin for juice extraction
5- SO 2 for juice extraction
6- Chlorination for condensate water
RESULTS
After this conventional waste water
treatment process the treated waste
water from Delta Sugar waste water
plant is 400 cubic meters per hour.
I. Physical analysis
II. Chemical analysis
III. Biological analysis
Table (1) : Physical properties of the treated waste water
Parameters
Influent
Effluent
Law 48/1982
Temp° C
35-40
35
35
TDS ppm
2880
1675
2000
pH
6-8
7-8
6-9
B.O.D ppm
1596
35
60
C.O.D ppm
2968
50
100
S.S ppm
214
9
60
EC µs /cm
1728
921
-
Toxicity test
Toxic
Nontoxic
-
Table (2) Chemical properties of the treated waste water
Parameters
Influent
effluent
Law
48/1982
NO3 ppm
14.7
5.4
40
PO4 ppm
9.95
3.l
10
Cu ppm
0.370
0. 230
1
Fe ppm
0.05
0.00
1
Pb ppm
0.29
0.15
0.5
Cd ppm
0.340
0.01
0.05
SO4 ppm
0.89
0.64
1
NH3 ppm
1.9
0.5
3
From Tables (1,2) the
physical
and
chemical
characteristics are suitable
and safe to be used in beet
sugar processes
Biological assay of treated waste water
• The samples were inoculated in bacterial and
fungal media and incubated for 24 hr. and 7 days,
respectively. The results were:
1. 37.5×102/100cm3 coliform sp. (on lauryl tryptose
broth media as blank and brilliant green lactose
bile broth, BGB).
2. 9 ×104 (cfu/ml) Bacterial specices. (on nutrient
agar media)
3. 160×102(cfu/ml) Fungi organisms and 7×102 Yeast
sp. on Czapeks҆’ Culture and Emmons media,
respectively.
o The industrial problem is that this water
is containing microorganisms specialized
in breaking hydrogen bond, leading to
hydrolyzing of sucrose in the factory.
o So, searching for suitable disinfectant to
kill microorganisms and safety reuse in
sugar beet processing in the form of new
treatment process (tertiary treatment) is
the main goal of this research.
Identification of bacterial samples
With screening the treated waste water sample
on nutrient agar culture medium the dominant
bacterial growth was restricted in five colonies.
 These five colonies were isolated, purified and
identified at sequencer unit and biotechnology
research institute,
in City for
scientific
research and technology applications, Borg ElArab, Egypt.
• The isolate no. 1 is related to be Acinetobacter
sp., Acinetobacter junii with 80 % similarity ,
and Acinetobacter calcoaceticus with 79%. It
may be new isolates or mutated bacteria.
Acinetobacter species
• The isolate no. 2 is related to Bacillus subtilis,
Bacillus amyloliquefaciens and Bacillus
methylotrophicus. with 90% similarity
A
B
A: Bacillus subtilis and B: Bacillus amyloliquefaciens.
• The isolate no. 3 is related to be Providencia sp.
and close to Providencia stuartii with 99%
similarity
Providencia species
• The isolate no. 4 is related to be Bacillus sp.
With 95% similarity to Bacillus licheniformis
and Bacillus subtilis
Bacillus licheniformis
• The isolate no. 5 is related to Aeromonas sp and
give 93% similarity with Aeromonas punctata
and Aeromonas hydrophila .
A
B
A: Aeromonas hydrophila sp, and B: Wound infections
caused by Aeromonas hydrophila, in a fish
Tertiary Treatment
The residual carbonated mud was the first think
for disinfecting the treated waste water for using
as flume water due to:
No economical cost
High concentration of CaCO3
Unfortunately, this residual mud elevated the
pH 8.7 only. Moreover the COD was increased
due to the organic component adsorbed on the
mud. Also the springily soluble of the
carbonated mud another disadvantage. calcium
oxide was the second choice.
1. Use calcium oxide as disinfection
for flume water
Raw water which used in washing beet, is
250 cubic meters per hour.
The following experiment was designed to
determine the sufficient amount of CaO to
be added for killing all micro-organisms in
the treated waste water to be used as flume
water.
Table (3) Effect of different concentration of CaO on the total bacterial
and fungal counts in effluent treated waste water.
CaO dose
g/L
pH
Total bacterial
count(cfu/ml)
Total fungal
count(cfu/ml)
0.0
8.3
6×104
3.3×103
0.4
10.4
1.3×102
1.7×102
0.6
10.7
59
22
0.8
11.1
8
3
1.0
11.4
0
2.0
11.9
0
0
3.0
12.0
0
0
0.4
12.1
0
0
5.0
12.2
0
0
0
As shown in Table (3), both total bacterial
and fungal counts reached to zero in the
effluent treated waste water when used 1.0
gm CaO / l.
This dose of CaO increase the pH value into
11.4. So, this is the ideal dose of CaO.
So, the quantity of CaO which will be add to
250 m3/h is 250 Kg CaO / h (i.e 6 ton Cao /
day )
 In beet sugar factory calcium oxide already be
used in beet washing to disinfect the bacterial
growth in flume water, prevent the destruction
of sucrose in the beet washing process and
improve settling mud from water to be
recycled
So there is no economic cost when using the
treated waste water instead of the raw water in
beet washing and transporting.
How Lime Treatment Works
Calcium oxide is an alkaline compound that can
create pH levels as high as 12, the cell membranes
of microorganisms are destroyed.
When quicklime (CaO) is used, an exothermic
reaction with water occurs. This heat release can
increase the temperature of the biological waste to
70ºC, which provides effective pasteurization.
The solubility of calcium hydroxide also provides
free calcium ions, which react and form complexes
with odorous sulfur species.
2. Uses the treated waste water in
juice extraction
• The biggest challenge is how to use the
treated waste water in juice extraction(100
m3/h) in diffuser because the pH in diffuser
is (5.8 to 6.2) needed for best juice
extraction from beet slice.
• It is not suitable for using CaO at pH 11.4.
A. Use sulfuric acid as a biocide for treated waste
water
H2SO4
pH of Effluent
Total bacterial
count(cfu/ml)
ml/l
0.0
8.2
6×104
0.4
6.5
4×104
0.9
5.1
32×103
1.2
4.6
15×103
5.0
4.0
1.1×103
15.0
3.3
800
20.0
2.8
440
25.0
2.4
150
There is no complete disinfection to the bacterial growth. Thus,
sulfuric acid cannot be used as a biocide for the treated waste water.
B. Effect of increasing temperature for disinfection the
treated waste water.
Temp. °C
Total bacterial
count(cfu/ml)
30
6×104
45
3.4×105
60
4.1×103
65
3.2×103
70
3.7×102
75
1.2×102
80
90
85
40
90
16
Raising temp up to 90°C caused a decrease in the number of bacterial
count to certain extend. Thus no complete disinfection was observed
until 90°C.
C. Effect formalin 37% as biocide for the effluent
Dose of HCHO ppm
Total bacterial count(cfu/ml)
5
2.2×104
10
5×103
15
2.9×103
20
1.4×103
25
6×102
30
140
35
80
40
25
45
7
50
0
55
0
The effective dose of 37% HCHO is 50 ppm
Formalin is traditionally being used as
biocide in beet sugar diffuser with maximum
dose 90 ppm.
The application of formalin has been
discontinued in some countries and is
expected to be discontinued in the remaining
countries soon.
D. Use sulfur dioxide as biocide for effluent
Several attempts are being made by sugar technologists
to find a suitable substitute for formaldehyde, including
sulfur dioxide (SO2). Today, sulfitation is used in many
factories because sulfur dioxide is a good biocide, which
improves sugar beet processing in the following ways:
Disinfects the diffusion juice
Lowers the pH of the diffuser
Improves the pressing qualities of the pulp
Reduces the color of the juice and also prevents colorformation in the next processing stations, where the
temperature is too high (during evaporation)
• Sodium metabisulfite, containing more than 66.0%
SO2 w/w releases sulfur dioxide gas when mixed
with water.
• The following experiment was to determine the
optimum dose to kill all microorganisms in treated
waste water by using Na2S2O5.
• The suitable concentration of Na2S2O5 is 100 ppm
at which there is no living microorganism is found.
• The proposal daily amount of sodium metabisulfite
for disinfecting 2400 m3 treated waste water is 240
Kg costs 792 £ per day.
Effect of different concentrations of sodium metabisulfite on the
total bacterial and fungal counts in effluent treated waste water.
Dose of Na2S2O5 ppm
Total bacterial count(cfu/ml)
5
5.2×104
3.1×103
10
4.6×104
2.9×103
15
2.9×104
1.4×103
20
1.2×104
9×102
25
8×103
7×102
30
3.9×103
6×102
35
3.1×103
4×102
40
2.9×103
2.5×102
45
2.4×103
2.2×102
50
1.8×103
1.6×102
55
1.5×103
1.2×102
60
1.1×103
90
65
8×102
60
70
3.3×102
27
75
1.2×102
9
80
70
3
85
32
1
90
13
0
95
4
0
Total fungal count(cfu/ml)
This calculation for disinfection of the treated waste
water which will be used for 100 m3/h as fresh water in
diffuser but if we want to use Na2S2O5 as a biocide for
juice in diffuser.
Where the rate of using SO2as biocide in sugar beet
processing is 0.3 Kg/t the calculation will be as the
following.
Na2S2O5
2 SO2
190
128
0.445
0.30
the rate of beet processing in our factory 16000 ton
of beet in day.
16000 ton/d × 0.445 = 7120 Kg/d = 23496 £
how sulfur dioxide acts as biocide
Sulfur dioxide is most effective as an antimicrobial
agent in acidic media.
This effect may result from conditions that permit
dissociated compounds to penetrate the cell
wall.
The reduction of essential disulfide linkages in
enzymes, and the formation of bisulfide addition
compounds that interfere with respiratory
reactions.
3. Disinfection of the condensate water
o 50 m3/h of a “dirty” stream of evaporation
condensate and evaporated water from a
crystallization stage is used in diffuser.
o This water connection is not active because of
its high microorganism's content.
o Chlorination with sodium hypochlorite,
containing 15 % to 16 % of active chlorine, is
an economical and effective procedure for this
water disinfecting.
Effect of different doses of NaOCl on the total
bacterial and fungal counts in condensate water
NaOCl dose
gm/l
Total bacterial
count(cfu/ml)
0.0
4×102
1.1×102
0.01
60
40
0.015
7
3
0.02
0
0
0.03
0
0
Total fungal
count(cfu/ml)
 Amount of chlorine that would destroy
microorganisms approximately 0.02 gm/L of
technical NaOCl.
 The water pH value must be maintained at 7.0
to increase the efficiency of sodium
hypochlorite by using technical, HCl 33 %.
 The required volume fraction of technical
HCl that would decrease the pH value of water
from an average value 8.7 to7.0 was
determined experimentally to 0.1 mL/L.
Recommendations
To achieve zero effluent of the treated waste
water from the Delta sugar company by
reusing the whole amount it in three circuits:
 250 m3/h used for beet unload, transport and
washing (treated with 1 gm CaO / L)
 100 m3/h used for juice extraction in diffuser
( treated with 100 ppm of Na2S2O5 )
 50 m3/h after secondary treatment used without
any additions to industrial process which there are
no contact between juice or beet and the treated
waste water ( cleaning, transporting, cooling,…).
On the basis of results, and after
recycling 400 m3/h which discharged
from Delta Sugar Waste water Plant and
achieved zero effluent, we suggest taking
into consideration the following simple,
but effective rules:
good housekeeping and regular
maintenance (diminished costs on one
side and prevention of unnecessary
water losses on the other).
50 m3/h with condensate, warm water,
cooling water and evaporated water from
the crystallization stage (0.02 gm/L of
technical NaOCl + 0.1 mL/L HCl 33 % ).
division of waste water streams with
different quality in order to enable more
possibilities for water reuse, regeneration
reuse or recycling reuse.