Sewage Treatment Plant Overview
Aug 14, 2015
Sewage Treatment PlantOverview
Wastewater Treatment Objectives
1. Wastewater treatment system accepts grey liquid waste from kitchen, bathroom & other general washing waste and purifies it enough to safely return to environment.
2. But why to throw this clean water if it is safe to use again ?
3. This water is cleaned up to such an extent that it is safe to again use it for flushing toilets, washing, gardening & irrigation.
4. Wastewater treatment system uses the same process of purification that occurs in a natural aquatic system only it does it faster and in a controlled situation.
5. Lot of water will be saved with the help of this Water Treatment Plant.
Environmental Effects
1. Grey water contains Pathogens which are disease causing agents.
2. Grey water contains a lot of organic waste, manure & detergents, which reduce the oxygen content from water & increases the Oxygen Demand.
3. If water does not have the required amount of oxygen, it is bound to kill the environment, as it cannot survive this type of water.
4. Even if we want to leave the water in the environment, it should have a certain specified quality so that the environment remains unharmed.
1. The oxygen demand in water made by the environment is technically termed as BOD, i.e. Biological Oxygen Demand.
2. It is the amount of oxygen in water naturally required by the environment.
3. BOD is very high in grey water, which makes it unacceptable in nature.
4. High levels of BOD kill fish life, aquatic plant life, other organisms & reduce the soil quality making it unfit for irrigation.
5. In water treatment, this BOD is drastically reduced when the polluting organic waste matter is killed with the help of added bacteria.
What is Oxygen Demand
Plant over view
Water Treatment Steps
1. Screening
2. pH correction
3. Aeration
4. Sedimentation
5. Bio Reactor
6. Coagulation Flocculation
7. Sludge Settling
8. Filtrate Chlorination
9. Disinfection
10. Sand Filtration
11. Carbon Adsorption
12. De Chlorination
13. pH correction
Depending on the type of treatment and water quality, the treatment proceeds in the following sequence
1. Primary Treatment (Physical Separation)
1. Filtering of large objects using bar screens at entrance of the collection tank.
2. Providing aeration for minimizing odour.
3. Physical settling of primary suspended solids before pumping. (Primary Sludge)
4. Flocculating chemicals may be added to enhance sedimentation if required.
Basic Treatment Scheme
RAWSEWAGE
SCREEEN
COLLECTION TANK
TO MBBR
DIAGRAM:
Ph CORRECTION
Basic Treatment Scheme
2. Secondary Treatment (MBBR)
1. The term MBBR is used for Moving Bed Bio Reactor.
2. In this reactor the main pollutants BOD & COD will be treated and reduced up to 90%.
3. This will be achieved by the help of bacteria added and aerationprovided to stimulate aerobic degradation by this bacteria.
4. The bacteria degrades organic load in to CO2.
Basic Treatment Scheme
Basic Treatment Scheme
DIAGRAM:
FROMCOLLECTION
AIR SUPPLY
TO SETTLING
MBBR TANK
BACTERIA
3. Settling Tank
1. Clear water received from MBBR enters the settling tank.
2. Meanwhile coagulants & flocculants are added and they settle in this settling tank with the help of settling media.
3. The settlement is collected as sludge at the conical bottom and removed by pumps.
4. Still more clear water leaves the settling tank.
Basic Treatment Scheme
Basic Treatment Scheme
DIAGRAM:
FROM MBBRTO CHLORINATION
SETTLING TANK
SLUDGE OUTSLUDGE RETURN
FLOCCULANT
CLEAR LIQUID
SLUDGE
4. Tertiary treatment (Chlorination)
1. Water received from the settling tank is now free from organic pollutants. Water is visibly clear.
2. But some chemical pollutants still persist, dissolved in water which are not practically visible.
3. Tertiary treatment is designed to remove these chemicals with the addition of chlorine.
4. Chlorine kills majority of the virus pending in the water.
Basic Treatment Scheme
Basic Treatment Scheme
DIAGRAM:
FROM SETTLER PSF & ACF
CHLORINE TANK
CHLORINE
5. PSF & ACF
1. Chlorine kills Majority of the virus pending in water. But some free chlorine remains in the water which is harmful.
2. Chlorine removal is achieved by acute filtration & adsorption units comprising of Pressure Sand Filter (PSF) & Active Carbon Filter (ACF).
3. This is the final filtration step which gives out the desired quality of water.
4. This water can be now readily used for gardening, flushing and washing. It can be also used for irrigation.
Basic Treatment Scheme
Basic Treatment Scheme
DIAGRAM:
FROM Cl2 TANK
SAND CARBON
ACTIVATED CARBONFILTER
PRESSURE SANDFILTER
TREATED WATER
Advanced Treatments
In addition to these basic treatments new techniques are also used in water treatment.
1. UV disinfection.2. Ozonation3. Ultra filtration
These systems can be used as per the water conditions but are not mandatory.But these systems do improve the final water quality.
COLLECTION
TANK
1
MBBR
TANK
2
SETTLING
TANK
3
CHLORINE
CONTACT
4
PSFACFTREATED
WATER
SLUDGE
TANK
DRAIN WATER
WATER FOR USE
Process Flow Scheme
5SLUDGE
MANAGEMENT
Lot of developers now opt for this water solution for their up coming projects and provide their customers with better solution for water usage.
You can join this mission by utilization of these plants for your projects, and contribute your favour to the environment.
We at Pinnacle Engineers, will guide and help you design these plants with accuracy & complete engineering standards.
We are ready to serve youThank You
B 205, Bharat Bhavan, B Build, 2nd floor, 1360 Shukrawar Peth, Pune 411002. Mob. 9604648696, Ph. 020 24474695, email: [email protected], [email protected]