Water Math Detention time is the length of time that water or suspended material is retained in a tank or channel, or, the length of time from when water enters a settling basin until it flows out the other end. It can also be thought of as the amount of time it takes to fill an empty tank or vessel.
Full Answer
What is detention time in math?
Water Math Detention time is the length of time that water or suspended material is retained in a tank or channel, or, the length of time from when water enters a settling basin until it flows out the other end. It can also be thought of as the amount of time it takes to fill an empty tank or vessel.
How do you calculate detention time for a basin?
Thus, some water particles are likely to move quickly through the basin and you get less credit when calculating CT. Detention time is calculated by dividing the volume of a tank or basin by the flow rate through it. The most difficult part of detention time problems is making sure that you keep your units consistent through the problem.
What is detention time in a coagulated tank?
Stated another way, the detention time is the length of time theoretically required for the coagulated water to flow through the tank / basin.
How do you calculate detention time on a septic tank?
Detention time is calculated by dividing the volume of a tank or basin by the flow rate through it. The most difficult part of detention time problems is making sure that you keep your units consistent through the problem. Many problems will give you dimensions in feet and flow rate in gallons per day or gallons per hour.
What is meant by detention time?
The actual or theoretical (calculated) time required for water to fill a tank at a given flow; pass through a tank at a given flow; or remain in a settling basin, flocculating basin, rapid-mix chamber, or storage tank.
How do you calculate detention time?
The simplest way to calculate detention time is to divide the volume of the container by the flow rate into the container. The theoretical detention time of a container is the same as the amount of time it would take to fill the container if it were empty.
What is the difference between retention time and detention time?
Detention and retention both refer to storing rain water on-site during a storm event, when the risk of flooding is highest. The difference is that when water is detained, it is slowly released into a stream or river and leaves the site. When water is retained, it is not intended to leave the site.
How do you calculate detention time for grit chamber?
The Detention Time when Volume of Each Grit Chamber is Given calculates the length of time water is retained in a grit chsmber is calculated using Detention time = (Volume*7.48*24*60)/Peak flow rate.
Why is detention time important?
Detention time is an important concept to understand because it is used in many different water treatment processes. It is used during the processes of mixing, coagulation/flocculation, and sedimentation.
What do you mean by detention time in a treatment basin?
Detention Time is the amount of time it takes for a molecule of water to travel a certain distance. In a sedimentation basin it is the time it takes for a particle to travel across the basin. Water treatment operators calculate detention times for settling basins, flocculation basins, or rapid mixing chambers.
What is difference between detention and retention?
A good rule of thumb for distinguishing these types of systems is to remember that detention is temporary but retention is intended to be permanent.
How is mean cell residence time calculated?
The mean cell residence time of an activated sludge process can be calculated by dividing the pounds of suspended solids or MLSS in the activated sludge system by the pounds per day of suspended solids leaving the activated sludge system (Equation II.
Why are retention times not a good indicator of the sample identity?
However, retention time is not a reliable factor to determine the identity of a compound. If two samples do not have equal retention times, those samples are not the same substance. However, identical retention times for two samples only indicate a possibility that the samples are the same substance.
Which of the following has minimum detention period?
Which of the following has minimum detention period? Explanation: Grit chamber has a minimum detention period with a value of 40-60 seconds.
How is grit chamber calculated?
1:282:58Problem Solved: Grit Removal Rate Problem - Wastewater MathYouTubeStart of suggested clipEnd of suggested clipLet's set this up using a formula to solve it the grit removal rate is equal to the cubic feet ofMoreLet's set this up using a formula to solve it the grit removal rate is equal to the cubic feet of grit removed divided by the volume of flow in millions of gallons.
What are the 3 types of grit chamber?
There are three general types of grit chamber: horizontal-flow – rectangular configuration. horizontal-flow – square configuration.
What is detention time for truck drivers?
Driver Detention occurs when the shipper impedes the truck driver from loading or unloading through no fault of the carrier. The acceptable industry standard is two hours, although rules tariffs (carrier rules that govern their operation and their charges) allow up to four hours.
What is detention time of septic tank?
24 to 48 hoursAs per IS code specifications the detention period of a septic tank is 24 to 48 hours. A septic tank may be defined as a primary sedimentation tank with a longer detention period i.e. 12 to 36 hours and with extra provision for digestion of the settled sludge.
How do you calculate water retention time?
The average amount of time that liquid and soluble compounds stay in a reactor or tank. It is calculated by dividing the volume of a reactor (e.g. m3) by the influent flow rate (e.t. m3/day).
How do you calculate column residence time?
Residence Time Calculation is made from the following formula: Volumetric flow rate (L/h) = (flow velocity (cm/h) x (column crossectional area (cm2) / 1000).
What Are Detention Fees and Rates?
A company’s detention rate or fee is not random – it’s based on how long it takes a shipper to load the truck before a driver can take it off to its next stop and what the value of that lost time is.
What to do if all else fails in detention?
If all else fails, put systems in place to ensure you get the detention fee you’re entitled to.
Why is truck detention important?
For freight shippers, understanding truck detention is a critical component to protecting your bottom line and keeping up with shipping and delivery schedules. If you want to keep your truckers happy, customers satisfied, and business afloat, getting a firm grasp on the inner workings of truck detention can help you take more control over your logistics.
How does detention affect drivers?
The first audience that detention financially impacts is the drivers. Sitting and waiting for their truck can wear on the spirit and lead to low employee morale. Wasting time is not on their to-do list, but detention makes that an impossibility. They’re not making money while sitting there, and they’re also losing additional opportunities to maximize their profits. These losses add up significantly. The Department of Transportation led a study just a few years ago that found that drivers lose around $1.2 billion each year from detention.
How long is a driver stuck waiting for a shipment?
If a driver is stuck waiting for three, four, or five hours instead of the initially agreed-upon two hours, that’s considered detention time. Detention time takes up any of the extra time required to finish loading a shipment or unloading one.
Is truck detention unavoidable?
Truck detention is frustrating but often unavoidable. If you understand why it happens and how it happens, you can integrate strategies to minimize detention whenever possible. However, when nothing else helps, knowing your hourly operational cost and tracking your losses will help ensure you get the detention fee you deserve.
Can shippers charge detention fees?
As a shipper or receiver, there are a few ways you can try to minimize detention so you don’t have to charge detention fees and recoup losses in the first place. You can also integrate a few strategies to ensure that, if and when charging a detention fee is necessary, you will guarantee payment.
When are sediment traps decommissioned?
Sediment traps are often temporary and usually decommissioned after the disturbed area is stabilized (i.e., with vegetation or other cover). Temporary sediment basins can be converted to permanent stormwater management basins after construction is complete.
How many acres are sediment traps?
Sediment traps and basins are very similar in their siting, sizing, and design, with sediment traps serving areas of five acres or less and basins handling larger areas. They represent one of the most effective and reliable measures for treating sediment-laden runoff from construction sites.
What is section 14.10?
Section 14.10 The general construction permit allows other effective sediment controls (e. g., a series of smaller sediment basins and/or sediment traps, silt fences, vegetative buffer strips, etc.) if sediment basin requirements are infeasible to meet on a particular site. This determination must be documented in the SWPPP ( Stormwater Pollution Prevention Plan ).
How are sediment traps used?
Sediment traps and basins are settling ponds formed by excavation and/or an embankment that intercept and retain sediment-laden runoff from a construction site for a sufficient period of time to allow the majority of sediment to settle out prior to being released from the site. They may be constructed as smaller sediment traps – serving disturbed areas of less than five acres – or as larger sediment basins, handling mass grading runoff from subdivisions, commercial/institutional sites, or roadway projects. Proper use of these structures can greatly reduce sediment transport off-site; if properly designed, installed, and maintained, sediment removal efficiency of 80 percent or greater can be achieved, depending on soil particle size. Sediment traps are often temporary and usually decommissioned after the disturbed area is stabilized (i.e., with vegetation or other cover). Temporary sediment basins can be converted to permanent stormwater management basins after construction is complete. Sediment traps and basins are very useful on construction sites with moderate to steep slopes. The selection of traps versus basins primarily depends on the size of the contributing drainage area and plans for post-construction stormwater management, as discussed below.
How many acres of soil is required for a temporary sediment basin?
Section 14.2: Temporary sediment basins are required where ten (10) or more acres of disturbed soil drain to a common location. If the acreage of disturbed soil is reduced to less than ten (10) acres due to establishment of permanent cover, the temporary basin is no longer required.
What section of the pond is required to prevent short circuiting and discharge of floating debris?
Sections 14.5, 14.6, and 14.7: Outlet structures must prevent short-circuiting and discharge of floating debris, withdraw water from the surface of the sediment pond, and have sufficient energy dissipation for the outlet within 24 hours after connecting to a surface water.
What is the purpose of Section 14.5?
Section 14.5 states: “Permittees must design basin outlets to prevent short-circuiting and the discharge of floating debris.”
