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Industrial wastewater treatment

The quantity and quality of industrial wastewater in different factories and industries are different on the base of the type and nature of production and, their treatment method is different, similarly. In the treatment of industrial wastewater, physical removal, Chemical and biological methods are used to catch the environmental approval.

The most important point in the treatment of industrial wastewater is the recognition of its nature and the quality of elements and items such as toxic compounds, decomposable, TSS, BOD, COD and color.
By Considering each of these factors, it is possible to design appropriate treatment methods of industrial sewage and wastewater.

 Industrial wastewater treatment by aerobic and anaerobic process

 industrial wastewater analysis

Recognition of the quantity and quality of industrial wastewater is the first step in the design of wastewater treatment. Today, in various manufacturing industries, wastewater or sewage is caused from chemical, physical, and mechanical activities that are carried out on different materials and products. Because water plays a significant role as a strong chemical solvent in many manufacturing processes, the wastewater or sewage are in most industries.

 In a total division, industries can be treated in terms of production of wastewater such as below divided into:

1. industries without water consumption, and hence without producing industrial wastewater, such as appliances, household and complementary metalwork and assembly industries.

 2. The manufacturing industries, which are part of its processes dependent on water, and the amount of industrial wastewater produced is modest, such as textile and dyeing industries.

3. industries that use water in all processes and high industrial waste water and sewage, such as dairy, starch and leather industries.

From quantitative terms, the amount of industrial wastewater production of per production is calculated based on the number and type of process, but it is possible to estimate the amount of generated wastewater as follows from some sources and valid books:
Equivalent table of wastewater production for various industries;

Produced wastewater Industry and production
4 to 10 cubic meter 1 tone of milking 
10 to 20 cubic meter  1 tone of sugar beet for sugar cube and sugar
4 to 6 cubic meter  1 tone of canned fruit
20 cubic meter 1 tone of vegetable oil
5 to 20 cubic meter  1 cubic meter of soft drinks
6 to 26 cubic meter 1 tone of confectionery
300 to 900 liter  Slaughterhouse for per cow
300 to 900 liter Slaughterhouse for two lambs
75 liter Livestock for per cow
20 liter  Livestock for per sheep
40 to 60 cubic meter 1 tone of skin tanner
5 liter 1 tone of shoes
20 to 50 cubic meter Dyeing the 1 tone of fabric
50 cubic meter  1 tone of  drug manufacturing
25 cubic meter  1 tone of soap making
100 cubic meter 1 tone of Rubber manufacturing

The quality of industrial generated wastewater for treatment

In addition to the quantitative issue, industrial waste water quality is also importance. After accurately recognizing the quantitative and qualitative wastewater from the industrial wastewater treatment plant, it is possible to design the appropriate design for its treatment. The most important compounds which are present in industrial wastewater and should be treated in different ways are organic sources.

Organic sources of industrial wastewater include carbohydrates, fat, protein, colorants. Identifying the nature of industrial wastewater and familiarity with its production process has a prominent role in designing wastewater treatment plants.

Some of the parameters that should be measured quantitatively on industrial waste water in order to design the industrial wastewater treatment plant include:

1. Measurement of fats and oils which are present in the wastewater and indicate the suspended and non-stagnation fat.

2. Measurement of qualitative parameters which are commonly used.: COD, BOD, TSS, TKN, pH, EC,

 2. Measuring the toxic ions such as phenolic compounds and metals foe example zinc, nickel, cadmium and elements such as arsenic and bromine, and colored compounds.

 4. Measurement of wastewater biodegradability.

 5.Determination of the amount of solid suspended particles and their depositability

The process of treatment of wastewater and industrial wastewater;

 There are two general sections in industrial wastewater treatment, which include chemical and physical and biological treatment that takes place due to the quantitative and qualitative recognition of the choice of industrial wastewater treatment methods. The main methods for the preliminary treatment of industrial wastewater include the following:

 1. Removal of fat and insoluble oils as well as solid particles that can be deposited in the initial sedimentation tank or septic tanks.

2.  Deletion of fat and soluble oil in the advanced lubricant by air of DAF solution.

3. Sludge and removal of colloidal suspended solids by chemical addition in chemical coagulation.

4.  Removing colored, toxic and solid suspended particles by electrical coagulation.

5.  Using advanced oxidation to eliminate insoluble matter.

 The major methods of biological treatment of industrial wastewater also have the following:

 1. Application of anaerobic methods for the growth and proliferation of anaerobic organisms such as UASB UAFBR, UABR

 2. Use of aerobic and air injection into industrial wastewater for biological purification such as extensive aeration techniques such as MBBR and EAAS adhesive growth aeration

 3. Use of disinfection units, final settling and digestion and disinfection of treated sludge.


 Different types of structures in the industrial wastewater treatment

We can use industrial sewage and wastewater from buried polyethylene structures, metal structures with epoxy paint or concrete structures. The key issue is that industrial waste can damage metal and concrete structures due to corrosive compounds and acidic pH. So, in addition to recognizing the quality of the wastewater, a high-quality epoxy paint coating should be used in metal structures.

 Also, the use of cement of type 5 in concrete structures is needed to enhance the corrosion resistance and erosion of concrete.

The use of metal constructions in wastewater and sewage treatment plants is economical in small dimensions, but usually conventional concrete structures are large. The polyethylene drainage structure for industrial wastewater treatment is common in cases where there is a severe shortage of land.
 dairy wastewater treatment

Applications of industrial wastewater treatment

 Wastewater treatment applications are very wide-spread and have been used in almost industries. Clearly, these applications include:

1. Treatment and restoring the water and wastewater; Carwash and carpet weavers which include floors and detergents.

2. Wastewater treatment of dairy factories which are generated by the CIP process and washing the tanks and pipes of dairy such as milk, yogurt, butter and cheese and includes the fatty substances.

3. Wastewater treatment of starch, glucose and gluten plants, which have large amounts of carbohydrates, and there are various processes of fermentation and condensation.

 4. Wastewater treatment of dyeing and textile industries with organic matter, suspended solids and solid particles and hard disintegrating compounds.

5. Wastewater treatment of carton and paper mills and recycling of used water at the beginning of the production line by removing organic compounds which are present in the sewage.

6. Treatment of industrial food waste such as sausage and wiener, which have a high protein and fat content.

7. Treatment of wastewater of detergent factories that have indissoluble and toxic substances.

8. Treatment of tannery and leather dressings and removing sulfide, solid particles, cream compounds.

The results of using an industrial wastewater treatment system

The results of using an industrial wastewater treatment system is like a sanitary wastewater treatment system. This means that the treated wastewater can be used after irrigation, agricultural or disposal into surface water or absorbent wells.

In addition to the above, if an industrial and production unit is installed in the industrial complex, it can treat its sewage to the following parameters and connect to the industrial waste water collection and treatment network:
Regulation of Iran Industrial Enterprises about the quality of industrial imported wastewater of the town:

Discharge to industrial wastewater collection network  wastewater composition
BOD 5  1000 mg/L
COD 2000 mg/L
TSS 500 mg/L
pH  6.5~8.5