Sewage treatment or domestic wastewater treatment is the process of removing contaminants from wastewater and household sewage, both runoff (effluents) and domestic. It includes physical, chemical, and biological processes to remove physical, chemical and biological contaminants. Its objective is, to produce an environmentally-safe fluid waste stream (or treated effluent) and a solid waste (or treated sludge) suitable for disposal or reuse (usually as farm fertilizer).

A3S Enviro using advanced technology it is now possible to re-use sewage effluent for drinking water, nevertheless, Singapore is the only country to implement such technology on an invention scale in its production of new water.
Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment.
Primary treatment
It consists of temporarily holding the sewage in a quiescent basin where heavy solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled and floating materials are removed and the remaining liquid may be discharged or subjected to secondary treatment.
Secondary treatment
This removes dissolved and suspended biological matter. Secondary treatment is typically performed by indigenous, waterborne micro-organisms in a managed habitat. Secondary treatment may require a separation process to remove the micro-organisms from the treated water prior to discharge or tertiary treatment.
Tertiary treatment
This is sometimes defined as anything more than primary and secondary treatment in order to allow rejection into a highly sensitive or fragile ecosystem (estuary, low-flow river, coral reef). Treated water is sometimes disinfected chemically or physically (for example, by lagoons and microfiltration) prior to discharge into a stream, river, bay, lagoon or wetland or it can be used for irrigation of a golf course, green way or park. If it is sufficiently clean, it can also be used for groundwater recharge or agricultural purposes.

A3S Enviro & Consultants are offering wide Range of STP Plant in Below Technology :

MBBR/FBBR/FAB- Moving Bed Bio Reactor

SBR/ASBR – Sequential batch reactor(conventional/Advance)

MBR  – Membrane Bio Reactor

CWT – constructed wetland Technology 

SAFF (Submerged Aerobic Fixed Films )

UASB- up flow aerobic sludge blanket

ASP/Extended Aeration 


Anaerobic digesters 

Plants Type :

Compact/ Packaged 


Civil Based- underground /above ground 

Portable/ containerized 

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