Primary Treatment – STP
The sewage passes into large sedimentation tanks to provide a quiescent settlement period. Most of the solids settle to the bottom of the tanks and form a watery sludge, known as ‘primary sludge’.
The tanks are used to settle sludge while grease and oils rise to the surface and are skimmed off.
Primary settling tanks are usually equipped with mechanically driven scrapers that continually drive the collected sludge towards a hopper in the base of the tank where it is pumped to sludge treatment facilities
Secondary Treatment
Secondary treatment may require a separation process to remove the micro-organisms from the treated water prior to discharge or tertiary treatment.
Secondary treatment removes dissolved and suspended biological matter with help of microorganisms.
In Secondary treatment System we use various treatment process some are highlighted below
FAB Media used reduces aeration tank size Moving Bed Biofilm Reactor (MBBR) processes improve reliability, simplify operation, and require less space than traditional wastewater treatment systems. MBBR technology employs thousands of polyethylene biofilm carriers operating in mixed motion within an aerated wastewater treatment basin.
The MBBR process utilizes floating High Capacity Micro Organism Bio Chips media within the aeration and anoxic tanks. The microorganisms consume organic material. The media provides increased surface area for the biological microorganisms to attach and grow.
More than one reactor provides effective treatment to the sewage Sequencing batch reactors (SBR) or sequential batch reactors are a type of activated sludge process for the treatment of wastewater. SBR reactors treat wastewater such as sewage or output from anaerobic digesters or mechanical biological treatment facilities in batches.
Using Ultra Filtration membranes to get treated sewage water, drastically reduces STP area required A Membrane Bioreactor (MBR) is a process which combines a microfiltration or ultrafiltration membrane unit with a suspended growth bioreactor, and is now widely used in both municipal and industrial Wastewater Treatment Plants. Here waste water in filtered through as ultrafiltration membrane giving Very clear product. This works at High MLSS loads also.
