The process of primary sedimentation is highly employed in the sewage treatment plants. It happens after the water has gone through the screening procedure, which removes any non-organic solids such as non-dissolved pollutants and debris.
Stages of primary treatment in sewage treatment
· Screening: The process of removing coarse, floatable materials from untreated sewage. The most popular screening tools are bar screens.
· Removal of grit: Heavy, tiny materials with a higher organic mass are separated by gravity.
· Sedimentation tanks: Large basins known as “sedimentation tanks” allow materials to settle to the bottom, and be transferred to the subsequent treatments due to low agitation.
Let’s understand the role of primary sedimentation tanks for the removal of sludge in STPs.
What does primary sedimentation remove?
Primary sedimentation removes floating organic matter and suspended sediments, from sewage treatment plants.
Sewage passes via primary sedimentation tanks. Pathogens in the liquid waste stream will not be significantly impacted by the primary treatment. It simply provides a basic level of filtration for water or wastewater.
The first treatment is typically followed by secondary treatments. These techniques employ a trickling filter, activated sludge, or a treatment that has been chemically improved. They are utilized when there is a significant concentration of germs.
How is sludge removed through primary sedimentation tanks?
The installation and configuration of the primary sedimentation tanks will allow for parallel operation. For purposes of maintenance or repair, either tank may be isolated.
1: The sludge is sent to a thickening zone and a sump by a mechanical scraper, which rotates around each tank’s sloped bottom. Positive displacement plunger pumps in the head works remove sludge from the tanks, and transfer it to the anaerobic digestion tanks.
2: Each tank has a single scum sump that is situated on the south side of the sedimentation tank, where floating matter is mechanically skimmed into collecting hoppers, before being piped to.
3: A positive displacement plunger pump in the headworks pumps the scum from the sump, to anaerobic digestion. To aid in the separation of sewage sludge, plant effluent is recycled from the effluent pump station to the primary sedimentation tanks.
Conclusion
Essentially, the fundamental sedimentation process is a physical one that makes use of gravitational forces. Together with any grit carryover from the headworks, settleable and suspended solids, which make up the majority of sludge and are heavier than water, settle out of the sewage.
Skimming is used to remove scum, which floats to the surface because it is lighter than water. As part of primary sedimentation, gravitational forces will eliminate roughly 60 to 65 percent of the suspended materials.
The primary sedimentation tanks’ wastewater overflows into circular double-sided launders, before entering the effluent junction boxes. The sewage water is then routed to the aeration basins for further treatment.
The leading manufacturer and supplier of high-quality sewage treatment plants in India
Netsol Water is the best manufacturer of water and wastewater treatment plants. We provide primary sedimentation tanks in STPs along with benefits, such as:
1. It is an easy and affordable method of pre-treating water.
2. It can manage a range of flows and has low operating expenses.
3. Coagulants reduce the amount of time needed for suspended solids to settle out.
4. It is easy to clean of sludge and has a high efficiency of clarifying.
5. It works best with plants that have reliable flow rates and quality.
6. It’s occasionally possible to get natural coagulants at a modest cost.
For expert advice, contact Netsol Water Solutions at +86 13717116442 or info@pumpvv.com