Secondary Clarifier Design Tank
Secondary clarifier design tank is used in ETP. We use water for many activities, most of which contaminate the water in some Way, i.e. By using detergents, chemicals, dyes t in fabric and yarn in industrial process. This contaminated water is called waste water. Water after usage is called waste water or effluent.
Main use of Secondary Clarifier
- To Recirculation the Bacteria to the FBBR system
- To reduce the suspended solids in the effluent
- To avoided the Bacteria escape to other system
- To remove the odor in the effluent in secondary clarifier design tank
- To increase the efficiency of Electrocoagulation system
- To reduce the current and electrode consumption in EC system
- To increase the efficiency of FBBR system
Wastewater contains approximately 99.0% water and 1% solids maximum.
Expressed in another way, every 1000L of wastewater contains about 10kg of
Solids. The solids are organic and inorganic compounds and are suspended in the
Waste water. Volatile solids are about 70% of the wastewater solids and give the
Water its unpleasant characteristics.
The majority of the solids – carbohydrates, fats and proteins – are broken down
During treatment into more stable inorganic compounds by bacteria and other
Wastewater also contains some compounds that are resistant to normal treatment
Fats, oils, grease & organic chemicals
Chlorides, heavy metals, nitrogen, phosphorus and sulphur.
Hydrogen (H2), sulphide (SO2), methane (CH4) and carbon-di-oxide (CO2).
Effluent treatment plant (etp) capacity
The Effluent treatment plant is designed to treat 2000m3 of Textile dyeing combined
Effluent generated from the process house. The plant will be capable of operating at the flow rate of 100m3/hr. The operating cycle of the plant shall be 20 hours.
Raw effluent characteristics
The effluent treatment plant is designed based on the analysis of effluent analysis report of combined effluent available with us. The relevant parameters are furnished below for your reference.
Ph: 9 -11
Bod: 600 mg/l
Suspended solids: 250mg/l
Total hardness: 50 mg/l
Color: 1000 pt.c0 units
Dissolved oxygen: nil
Tds: 2000 mg/l
After electro coagulation and filteration
Bod: less than 50ppm
Cod: less than 150ppm.
Suspended solids: less then 5 ppm
Total hardness: 50 ppm
Turbidity: 5 ntu
Effluent treatment plant based on electro-coagulation and fluidized bed bio-reactor technologies.
- Primary treatment
- Secondary treatment
- Sludge management
- Bar screening
- Collection and equalization
- Fluidized bed bioreactor
- Secondary clarifier.
- Activated sludge recirculation system
- Electro-coagulation system
- Flash mixer
- High rate solid content clarifier
- Pressure sand filter
- Ec cleaning system
- Sludge thickener
- Filter press
- Sludge storage
Operating cost of etp
Etp tank size and water reserve capacity-
Equalization tank= height-20feet, capacity=2000m3
Fbbr tank= height-17 feet, capacity=1200m3
Secondary clarifier=height-10feet, capacity=0.8m3
Ec feed tank= height-10feet, capacity=60m3
Hrscc tank=height-12feet, capacity=0.8m3
Filter feed tank= height-10feet, capacity-140m3
Sludge tank= height-10feet, capacity-80m3
Total electricity consumption and cost in etp per day-
88 kw per day. Unit price- 89.75 taka/kw
Ec plate consumption per day-
Destroyed metal plate per day=254.66 kg.
unit price- 82 taka/kg
total cost= 20882 taka
join coupler used per day= 768 taka
Used chemical and cost per day-
Hcl-125 liter per day. Unit price is -6.60 taka/liter
Total cost= 825 taka
Poly electrolyte-400 gm per day. Unit price is- 1250 taka/kg
Total cost=500 taka
Dap= 5 kg. Unit price is- 33 taka/kg
Total cost=165 taka
Urea=5 kg. Unit price-12 taka/kg
Total cost= 60 taka
Molasses= 10 kg. Unit price is- 36.60 taka/kg
Total cost=366 taka
Total chemical cost per day= 1916 taka.
Man power cost-
Cost per day- 600 taka
Total cost- 2, 50, 00, 000 taka
Life time of etp- 10 years
Depreciation cost per day = 6500 taka
Discharge water per day-
32, 40,000 liter per day or 3240 m3
Total cost per day-
38564 taka per day
Cost per liter-
11.90 taka per m3 for secondary clarifier design process