What is Side water depth?
When a design engineer is developing new clarity equipment or reviewing existing units, side water depth (SWD) is crucial. The depth of the water at the basin's sidewall is known as sidewater depth or sidewall depth.
The choice of side water depth has a lot to do with how the clarifier/settling tank is used.
-The side water depth in a grit collector when the material obeys Stokes Law can be rather shallow. The side water depth in waste treatment primary units is governed by the holding solids inventory.
-In chemical clarifiers, the side water depth may be determined by the solids inventory and detention period for flocculation and separation. The same criteria are utilized for water treatment units as they are for chemical clarifiers/settling tanks. All of these variables are also site-specific.
The following is a discussion of final clarifiers for waste activated sludge. With respect to SWD, the design looks to be more of an art than just following a set of scientific standards.
Final Clarifiers/Settling Basins for Waste Activated Sludge
Overflow rate, detention period, mass loading, settling velocity, and other design parameters for final clarifiers are all important factors. Surface overflow rate and mass loading are commonly used to construct and evaluate clarifiers. Detention time was formerly employed to determine the depth of the clarifier. Currently, the side water depth is chosen independently of the detention time. However, there is little or no reliable evidence on the impact of side water depth on the performance of final clarifiers.
Enough Depth for Effective Operation
For optimum functioning, a clarifier should have enough depth to manage the transportation and solids inventory. Gross carry-over of particles into the effluent might occur if the solids-holding depth is insufficient, lowering effluent quality.
The question then becomes whether the clarifier will require more depth to manage the increased mixed liquid suspended solids (MLSS). With this in mind, it appears that the side water depth should be determined by the amount of sludge detention time necessary as well as the necessity to manage the aforementioned extra mixed liquor suspended particles.
Importance of having a good design for clarifier/settling tank
Examining the distinct settling zones (which have varied settling properties) formed by waste activated mixed liquor reveals the depth of the clarifier.
The following are the zones (beginning at the top of the basin):
1: Zone of clarified water
2: Particle zone by itself
3: Zone that is obstructed
4: Zone of Transition
5: Zone of compression
6: Zone of alternate concentration
For final clarifiers, the top and bottom zones are the most important. The mass loading and the removal device have an impact on the bottom concentration zone. The kind of input and overflow rate have an impact on the top clarified zone. These zones should be examined since the main objective of a final clarifier is to provide ultimate clarity of the treated sewage.
Feel free to contact Netsol Water with any queries you may have about custom-designing and manufacturing clarifiers. Call us on +919650608473 or contact via email at enquiry@netsolwater.com
You may also schedule a conversation with an engineer or obtain an estimate by visiting our website. We can guide you through the process of determining the best solution and determining realistic pricing for your water and wastewater treatment system requirements.