The treatment of wastewater or industrial effluent happens in multiple stages or steps. Because the wastewater goes through these different steps, it’s treated by more and more advanced ways of treatment that filter and break lower the dissolved impurities. In the following paragraphs I explain what these stages in treatment are.
The entire process of treating effluent or wastewater could be manufactured under 4 groups or steps.
Step One: Preliminary Treatment – The raw wastewater contains several impurities like suspended particles and solids besides oil and grease. An unhealthy feature here is odor. Each one of these particles need to be filtered or taken off wastewater to avoid them from interfering within the downstream treatment processes. The main treatment methods implemented within this stage are – use of grates and screens to filter large solids, grinders or comminutors to pulverize coarse solids, grease traps to filter the grease and minimal aeration of wastewater to avoid odor.
Step Two: Primary Treatment – In this stage within the treatment process, the readily settleable solids are permitted to stay towards the bottom developing a sediment layer. Hence this task is also referred to as primary clarification. This stage is going to be been successful by biological treatment. The primary approach to clarification involves using sedimentation tanks or settling basins. Other auxiliary stages in treatment of wastewater may also be used in addition to this clarification process. These involve using fine screens for filtration aside from flocculation and flotation.
Step Three: Secondary Treatment – The goal at this time would be to purify the wastewater. This is done by adopting techniques that let the microorganisms within the wastewater to decompose and breakdown the organic matter within the wastewater. Such organic matter might be inside a dissolved or suspended condition in wastewater. There are lots of ways that this biological treatment method could be implemented. But each one of these methods could be categorized as anaerobic treatment method, pond or lagoon based treatment method, land treatment method, activated sludge method, or biological filtration. One way by which biological filtration is transported out involves using biological filters the same shape as rotating dvds.
Step Four: Auxiliary Treatment – This task is also referred to as Tertiary Treatment or Secondary Clarification. In this stage within the treatment process a multitude of physical and chemical processes are utilized to treat the wastewater. The auxiliary stages in treatment of wastewater could be implemented even just before or following the the secondary treatment. These physical and chemical processes are frequently carried out to achieve specific treatment targets or standards.
While designing an effluent treatment plant, several procedures for that treatment of wastewater might be considered. Which procedure is finally selected to become implemented depends largely around the efficiency from the procedure in filtering a specific group of contaminants.