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بسم الله الرحمن الرحيم. " وجعلنا من الماء كل شئ حي". صدق الله العظيم. Industrial Waste Water Treatment And Reuse In Delta Sugar Company . معالجة مياه الصرف الصناعى وإعادة استخدامها بمصانع شركة الدلتا للسكر.
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بسم الله الرحمن الرحيم " وجعلنا من الماء كل شئ حي" صدق الله العظيم
Industrial Waste Water Treatment And Reuse In Delta Sugar Company معالجة مياه الصرف الصناعى وإعادة استخدامها بمصانع شركة الدلتا للسكر
ChemistAhmed M. S. HamadB.Sc. Microbiology , Faculty of Science, Tanta University(1997)andDiploma of Science and Technologyof sugar industry (Chemistry section), Sugar Technology Research Institute Assiut University(2007)andMaster in Science and Technology of sugar industrySugar 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 . • Nowwith 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.
Status of Water Supply Water resources in Egypt are restricted to 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.
Nile River Water • Main 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 happenedonly 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 ResourcesThere 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.
Objectivesof 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- CaOfor fluming water 2- H2SO4 for juice extraction 3- Temperature for juice extraction 4- Formalin for juice extraction 5- SO2 for juice extraction 6- Chlorination for condensate water
Afterthis conventional waste water treatment process the treated waste water from Delta Sugar waste water plant is 400 cubic meters per hour. • Physical analysis • Chemical analysis • Biological analysis
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: • 37.5×102/100cm3 coliform sp. (on lauryl tryptose broth media as blank and brilliant green lactose bile broth, BGB). • 9 ×104(cfu/ml) Bacterial specices. (on nutrient agar media) • 160×102(cfu/ml) Fungi organisms and 7×102 Yeast sp. on Czapeks҆’ Culture and Emmons media, respectively.
The industrial problem is that this water is containing microorganisms specialized in breaking hydrogen bond, leading to hydrolyzing of sucrose in the factory. • 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.
Identificationof 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 El-Arab, Egypt.
The isolate no. 1 is related to be Acinetobacter sp., Acinetobacterjuniiwith 80 % similarity , and Acinetobactercalcoaceticuswith 79%. It may be new isolates or mutated bacteria. Acinetobacterspecies
The isolate no. 2 is related to Bacillus subtilis,Bacillus amyloliquefaciensand 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 Providenciastuartiiwith 99% similarity Providenciaspecies
The isolate no. 4 is related to be Bacillus sp. With 95% similarity to Bacillus licheniformisand Bacillus subtilis Bacillus licheniformis
The isolate no. 5 is related to Aeromonassp and give 93% similarity with Aeromonaspunctataand Aeromonashydrophila . A B A: Aeromonashydrophilasp, and B: Wound infections caused by Aeromonashydrophila, 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.
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.
As shown in Table (3), both total bacterial and fungal counts reached to zero in the effluent treated waste water when used 1.0 gmCaO / l.This dose of CaO increase the pH value into 11.4.So, this is the ideal dose of CaO. So,the quantity of CaOwhich 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.
Use sulfuric acid as a biocide for treated waste water 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. 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.
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 color-formation 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.
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 190128 0.445 0.30the 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 • 50 m3/h of a “dirty” stream of evaporation condensate and evaporated water from a crystallization stage is used in diffuser. • This water connection is not active because of its high microorganism's content. • Chlorination with sodium hypochlorite, containing 15 % to 16 % of active chlorine, is an economical and effective procedure for this water disinfecting.