Sewage treatment plant or you can say waste water treatment is the process of removing pollutant that has undesired effects, or adversely affects the usefulness of a resource. Physical, chemical and biological processes are used to remove contaminants and produce treated wastewater that is safe enough for release in the environment. Sewage sludge is a by product of sewage treatment that has to undergo further treatment before being suitable for disposal or application to land. It may also be referred as wastewater treatment. For more cities, the sewer system will also carry a proportion of industrial effluent to the sewage treatment plant which has usually recieved pre-treatment at the factories to overcome the load of pollutant. Sewage water can travel towards treatment plants via piping and in a flow aided by gravity and pumps. The first part of filtration of sewage typically includes a bar screen that is used to filter larger components which are later collected in dumpsters and disposed of in landfills. Fat and greese from the water is also removed before the primary treatment of sewage. The term Sewage treatment plant is being replaced with “wastewater treatment plant”. Sewage can be treated close to where the sewage is crerated, which may be called a “decentralized system”. Sewage can be collected and transported by a network of pipes and pump stations that is called centralized system.
How does STP Work?
Treating wastewater has the aim to produce an effluent that will do less harm as possible when discharged to the surrounding environment, thereby pretending pollution compared to releasing untreated wastewater into the environment. sewage treatment generally involves three stages that includes primary, secondary and tertiary treatment. In the primary treatment, it temporarily hold the sewage in a basin where heavy solids settled down while oil, greese and lighter solids float to the surface. The settled and the floating materails are removed and the remaining liquid discharged to secondary treatment. In secondary treatment dissolved and suspended biological matter removed. It may require a separation process to remove the micro-organisms from treated water prior to discharge or tertiary treatment. The third and the final process that is known as tertiary treatment is more than primary and secondary one’s. It allows the ejection into a highly sensitive and fragile ecosystem. Treated water is sometimes disinfected chemically or physically for e.g by lagoons and microfiltration.
Uses of STP Plant
With suitable technology, it is possible to reuse sewage effluent for drinking water, although this process is done in places with limited water supplies. Treated water is being used in agriculture. Sewage treatment plants can have multiple effects on nutrient levels in the water that the treated sewage flows into. Many processes in the watewater treatment plant are designed to minimize the natural treatment processes that occur in the environment, whether the environment is a natual water body or the ground.