What is Sewage?
Sewage is a mixture of domestic and industrial wastes containing 99% water, but the remainder contains some ions, suspended solids, toxic chemicals and harmful bacteria that must be removed before releasing of water into the sea.
Sewage contains organic impurities such as BOD, COD which cause bad smell and contains harmful gases. If it is not treated properly than it will lead to many irreversible problems for human & other living things.
Why Sewage treatment is necessary?
Sewage is a resource that can be recycled for various uses like gardening, toilet flushing, car wash, cooling towers. Faced with the alarming fact that over 60% of the sewage generated in our country goes untreated, with its negative impact on human health, the government is focusing on waste management through centralized sewage treatment plants and by mandating large upcoming real estate projects to have their own treatment facility.
Sewage Treatment is essential to ensure that the receiving water into which the effluent is ultimately discharged is not significantly polluted. It works on producing environmentally safe fluid waste stream and a solid waste suitable for disposal or reuse.
Excel Filtration Pvt. Ltd (EFPL)’s approach is to see wastewater as an opportunity, not a burden.
Process Description of Sewage Treatment Plant
Sewage treatment involves:
It involves the process of removing contaminants from wastewater and household sewage, both effluents and domestic. It includes physical, chemical and biological process to remove physical, chemical and biological contaminants. The objective of sewage treatment is to produce a disposable effluent without causing harm to the surrounding environment and prevent pollution.
Sources of waste water:
· Human waste
· Washing water
· Domestic sources
· Highway drainage
· Rainfall collected on roofs, yards, hard-standings.
· Elimination of plugging.
· Design and implementation efficiencies ensure lower capital and operation costs than conventional alternatives.
· Simple media addition allows for easy plant expansion to accommodate population growth or other needs for capacity.
· The sequential batch reactor (SBR) process is a fill and draw type activated sludge process where individual reactors are filled one by one in five discrete periods i.e. Fill, React, Settle, Decant and Idle/ Waste Sludge.
Membrane Bio Reactor
MBR technology combines biological activated sludge process with physical separation treatment using membranes which are submerged in the tank (instead of secondary clarifier). This technology has become more popular, abundant, accepted in recent years for treatment of different types of waste waters. This technology improvises overall operational effectiveness and reduces space requirement.
Membrane is made of cost-effective non-woven fibrous material. It has many outstanding properties, such as controllable pore sizes and easy fabrication of the membrane module to achieve the desired surface area.
Combined treatment consists of combining several stages of treatment in package units called membrane bioreactors (MBRs).
Up flow Anaerobic Sludge Blanket Reactor(UASB)
This process includes anaerobic treatment is carried out in absence of oxygen/air which leads to conversion of organic matters into CH4 and end products like CO2 and NH3. This system uses granulated bacteria which are contacted to organic components present in the wastewater. Methane gas is also produced due to decomposition of organic components.
It is suitable for high strength waste water and also use for domestic sewage in warm climates. The process takes place into two zones.
Reduce Sludge Yield
Eliminates sludge ability issues
High removal efficiency for Nitrogen, BOD and COD
Fewer process to achieve comparable effluent quality
Small foot prints, reduce land use
Proven technology with reliable performance
Minimum maintenance requirements
Treated water reuse in irrigation and grey water applications
Enhanced storage capacity