UASB Design Calculations Spreadsheet

Posted on May 17, 2017 by Harlan Bengtson

Where to Find a UASB Design Calculations Spreadsheet

To obtain a UASB Design Calculations Spreadsheet, click here to visit our spreadsheet store. This Excel spreadsheet is intended for making design calculations for the upflow anaerobic sludge blanket wastewater treatment process. You can buy a convenient spreadsheet for making USAB design calculations for a very reasonable price. It is available in either U.S. units or S.I. units. Read on for background information about upflow anaerobic sludge blanket wastewater treatment design calculations.

Background for a UASB Design Calculations Spreadsheet

The upflow anaerobic sludge blanket wastewater treatment process is typically used for treatment or pretreatment of wastewaters with a high BOD concentration. The process has a sludge blanket in the reactor zone, through which the influent wastewater flows. Also, the top part of the reactor includes a means for collecting the methane biogas generated by the anaerobic process. A schematic flow diagram of the process is shown here:

Example UASB Design Calculations Spreadsheet

An example UASB design calculations spreadsheet is partially shown in the image below. This Excel spreadsheet can be used to calculate the required UASB reactor volume and dimensions, sludge production rate, methane production rate, and required alkalinity addition based on user input information on wastewater flow and characteristics, biokinetic parameters, methane stoichiometry parameters, and reactor configuration and design parameters. This Excel spreadsheet, as well as others for wastewater treatment process design calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

References:

1. Metcalf & Eddy, Inc, (Revised by Tchobanoglous, G, Burton, F.L, Stensel, H.D.), Wastewater Engineering, Treatment and Reuse, 4th Ed., New York, NY, 2003.

2. Metcalf & Eddy, Inc, (Revised by Tchobanoglous, G, Burton, F.L, Stensel, H.D.), Wastewater Engineering, Treatment and Resource Recovery, 5th Ed., New York, NY, 2014.

3. Bengtson, Harlan, “Upflow Anaerobic Sludge Blanket Wastewater Treatment,” an online blog article

Dissolved Oxygen Saturation in Water Calculator Speadsheet

Posted on November 13, 2015 by Harlan Bengtson

Where to Find a Dissolved Oxygen Saturation in Water Calculator Spreadsheet

To obtain a Dissolved Oxygen Saturation in Water Calculator Excel spreadsheet, click here to visit our spreadsheet store. Look in the Dissolved Oxygen category on the Download page. This Excel spreadsheet is intended to calculate the dissolved oxygen solubility at a specified water temperature and atmospheric pressure for water temperature of 35 to 80 degrees F and atmospheric pressure of 600 to 760 mm Hg. You can buy a convenient dissolved oxygen saturation in water calculator Excel spreadsheet for a very reasonable price. This spreadsheet calculates dissolved oxygen saturation based on user specified water temperature and atmospheric pressure. Calculations may be made in either U.S. or S.I. units. Read on for information about using a dissolved oxygen saturation in water calculator spreadsheet.

Background for Dissolved Oxygen Saturation in Water Calculator Spreadsheet

There are many tables available with values for the dissolved oxygen solubility in water over a range of water temperatures and atmospheric pressures. With an Excel spreadsheet, formulas can be derived using Excels graph plotting capability, for saturation dissolved oxygen concentration as a function of water temperature for a range of different values for atmospheric pressure. The spreadsheet can then conveniently calculate the dissolved oxygen solubility (saturation concentration) at user specified values for water temperature and atmospheric pressure. That is done in the spreadsheet being discussed here. The

Example Dissolved Oxygen Saturation in Water Calculator Excel Spreadsheet

An example dissolved oxygen saturation in water calculator Excel spreadsheet is partially shown in the image below. This Excel spreadsheet can be used to calculate the dissolved oxygen solubility in water at a specified water temperature and atmospheric pressure. This Excel spreadsheet, as well as others for wastewater treatment calculations, is available for both U.S. or S.I. units for a very reasonable price in our spreadsheet store.

References

United States Geological Survey, DOTABLES (Dissolved oxygen solubility tables), www.water.usgs.gov/software/DOTABLES/.
Bengtson, Harlan, Dissolved Oxygen Solubility in Water Calculator, an informational blog article.

Nitrification Denitrification Activated Sludge Process Spreadsheet

Posted on August 25, 2015 by Harlan Bengtson

Where to Find a Nitrification Denitrification Activated Sludge Process Excel Spreadsheet

To obtain a nitrification denitrification activated sludge process Excel spreadsheet, click here to visit our spreadsheet store. Look in the wastewater treatment category on the Download page. This Excel spreadsheet is intended for completely mixed activated sludge nitrification/denitrification calculations. You can buy a convenient nitrification denitrification activated sludge process Excel spreadsheet for a very reasonable price. This spreadsheet calculates the completely mixed aeration tank volume for BOD removal and nitrification as well as the volume for a pre-anoxic tank to achieve denitrification.. It is available in either U.S. or S.I. units. Read on for information about using a nitrification denitrification activated sludge process Excel spreadsheet.

Background for Nitrification Denitrification Activated Sludge Process Excel Spreadsheet

The activated sludge wastewater treatment process can be designed for removal of BOD (organic matter that exerts an oxygen demand in the water), or for BOD removal and nitrification, or for BOD removal, nitrification and denitrification. Nitrification is oxidation of ammonia nitrogen in the wastewater to nitrate and denitrification is removal of nitrate from the wastewater.

A flow diagram for a nitrification denitrification activated sludge process is shown below. It includes a completely mixed activated sludge aeration tank for BOD removal and nitrification as well as an anoxic basin for denitrification.

Example Nitrification Denitrification Activated Sludge Process Excel Spreadsheet

An example nitrification denitrification activated sludge process Excel spreadsheet is partially shown in the image below. This Excel spreadsheet can be used to make design calculations for a nitrification denitrification activated sludge process. This Excel spreadsheet, as well as others for wastewater treatment calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

References

1. Metcalf and Eddy, Inc, (Revised by Tchobanoglous, G, Burton, F.L., Stensel, H.D.), Wastewater Engineering, Treatment and Reuse, 4th Ed., McGraw Hill, New York, NM, 2003.

2. Bengtson, Harlan, Nitrification Denitrification Wastewater Treatment Process Spreadsheets, an informational online blog article.

A Spreadsheet for Choked Air Flow Calculation

Posted on July 3, 2014 by Harlan Bengtson

Where to Find a Spreadsheet for Choked Air Flow Calculation

To obtain a spreadsheet for choked air flow calculations , click here to visit our spreadsheet store. Intended for use in making fanno flow calculations with adiabatic compressible flow of air, you can buy a convenient spreadsheet for choked air flow calculations for a very reasonable price. This spreadsheet will also calculate the frictional pressure drop, and is available in either U.S. or S.I. units. Read on for information about a choked air flow calculation spreadsheet for compressible pipe flow.

Conditions for Choked Air Flow Calculation with a Fanno Flow Excel Spreadsheet

For flow of air in a pipe with the frictional pressure drop less than 20% of the inlet air pressure, satisfactory results can be obtained using incompressible flow calculations with the Darcy-Weisbach equation. For background information on that type of calculation, see the article, “Pipe Flow-Friction Factor Calculations with Excel Spreadsheets.” If the frictional pressure drop is more than 20% of the incoming air pressure, then Fanno Flow equations should be used, as discussed here using a Fanno Flow Excel spreadsheet.

With adiabatic compressible flow conditions, the maximum air flow rate that can pass through a pipe is that which occurs when the exit Mach number is 1.0. This is referred to as “choked flow.”

Equations for Choked Air Flow Calculations with a Fanno Flow Excel Spreadsheet

Shown below are the primary equations used in the fanno flow excel spreadsheet being discussed here for compressible flow of air in a pipe. These equations are for compressible pipe flow with negligible heat transfer with the surroundings, but including effects of friction in the flow.

The parameters in these fanno flow equations are as follows:

f = Moody friction factor
L = pipe length
D = pipe diameter
k = adiabatic constant for the flowing air
M = mach number
T = air temperature
P = air pressure
ρ = air density

Parameters with an asterisk refer to conditions at the “choke point” in the pipe, where the Mach number is 1.

Screenshot for a Choked Air Flow Calculation Spreadsheet Using Fanno Flow Equations

The screenshot below shows part of a fanno flow excel spreadsheet for making compressible air flow calculations. These calculations are for air flow in a pipe, in S.I. units. This Excel spreadsheet and others for compressible pipe flow calculations in a fanno flow excel spreadsheet are available in either U.S. or S.I. units at a very reasonable cost in our spreadsheet store.

Reference:

Bengtson, Harlan H., “Compressible Flow Pressure Drop Calculator Spreadsheet,” an online blog article

Trickling Filter Design Calculations Spreadsheet

Posted on April 13, 2014 by Harlan Bengtson

Where to Find a Trickling Filter Design Calculations Spreadsheet using the NRC Formula

To obtain a trickling filter design calculations spreadsheet using the NRC formula, click here to visit our spreadsheet store. For use in making trickling filter design calculations with the NRC equation, you can buy a convenient trickling filter design calculations spreadsheet for a very reasonable price. This spreadsheet will use the NRC equations to calculate the trickling filter diameter needed for either a single stage or a two stage system and will calculate the estimated treatment efficiency for a specified trickling filter system, in either U.S. or S.I. units. Read on for information about a trickling filter design calculation spreadsheet that uses the NRC formula.

Trickling Filter Design Calculations Background

The trickling filter process is widely used for biological wastewater treatment all over the world. It is an attached growth biological wastewater treatment process. The aerobic microorganisms grow on a solid medium and the wastewater to be treated flows through the bed. A flow diagram for a typical single stage trickling filter wastewater treatment plant is shown in the diagram below. The diagram shows the typical flow pattern through the primary clarifier, trickling filter and secondary clarifier.

Example Trickling Filter Design Calculations Spreadsheet

A trickling filter design calculations spreadsheet is partially shown in the image below. It can be used to calculate the trickling filter diameter needed for either a single stage or a two stage trickling filter system using the NRC formula. The spreadsheet will also calculate an estimated treatment efficiency for a specified single stage or two stage trickling filter system. This Excel spreadsheet, as well as others for wastewater treatment calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

References for Further Information:

1. Metcalf & Eddy, Inc, (revised by Tchobanoglous, G, Burton, F.L., Stensel, H.D., Wastewater Engineering Treatment and Reuse, 4th Edition, New York, NY, 2003.

2. Vesilind, P.A. and Morgan, S.M., Introduction to Environmental Engineering, 2nd Edition, Belmont, CA, Brooks/Cole, 2004.

3. Bengtson, H. H., “Trickling Filter NRC Equation Spreadsheet“, a blog article at www.EngineeringExcelTemplates.com

A Spreadsheet to Calculate Oxygen Requirement Activated Sludge Process

Posted on March 27, 2013 by Harlan Bengtson

Where to Find a Spreadsheet to Calculate Oxygen Requirement Activated Sludge Process

To obtain a spreadsheet to calculate oxygen requirement activated sludge process, click here to visit our spreadsheet store. For use in calculating oxygen requirements and blower specifications, you can buy a convenient spreadsheet to calculate oxygen requirement activated sludge for a very reasonable price. This spreadsheet will calculate the oxygen requirement and blower specifications for BOD removal or for BOD removal and nitrification for specified wastewater flow and characteristics and diffuser characteristics, in either U.S. or S.I. units. Read on for information about Excel spreadsheets that can be used to calculate oxygen requirement activated sludge process parameters.

Oxygen Requirement Activated Sludge Background

The theoretical oxygen requirement for BOD removal can be approximated as ranging from 0.90 lb O2/lb BOD removed at an SRT of 5 days to 1.3 lb O2/lb BOD removed at an SRT of 20 days. This leads to the equation:

O₂ requirement in lb/day = 0.90 + [(SRT – 5)/(20 – 5)](1.3 – 0.9)(lb/day BOD removed)

A design increase factor (safety factor) is typically multiplied times the calculated oxygen requirement to get the design oxygen transfer rate. The design oxygen transfer efficiency and the air density at design conditions can then be used to calculate the design air flow rate. The blower horsepower can then be calculated from the following equation:

Blower hp = (Q_air)(ΔP)/(229*η)

Where:

Q_air is the air flow rate in cfm to be delivered by the blower
ΔP is the pressure rise across the blower in psi = outlet pressure – inlet pressure
η is the blower efficiency

If oxygen is to be provided for nitrification as well as BOD removal, then additional calculations are needed to estimate the oxygen requirement for nitrification.

Example Spreadsheet to Calculate Oxygen Requirement Activated Sludge Process

A spreadsheet to Calculate oxygen requirement activated sludge process is partially shown in the image below. It can be used to calculate the oxygen requirement and blower specifications for an activated sludge wastewater treatment system. This Excel spreadsheet, as well as others for wastewater treatment calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

References:

Bengtson, Harlan H., “Activated Sludge Oxygen Requirement,” an online blog article.
Bengtson, Harlan H., “Activated Sludge Calculations Spreadsheet: Aeration Tank Calculations,” an Amazon Kindle e-book.
Bengtson, Harlan H., “Biological Wastewater Treatment Process Design Calculations,” available as a paperback book or Amazon Kindle e-book

Sequencing Batch Reactor Design Calculation Spreadsheet

Posted on March 20, 2013 by Harlan Bengtson

Where to Find a Sequencing Batch Reactor Design Calculation Spreadsheet

To obtain a Sequencing Batch Reactor Design Calculation excel spreadsheet, click here to visit our spreadsheet store. For use in wastewater treatment design calculations, you can buy a convenient sequencing batch reactor design calculation excel spreadsheet for a very reasonable price? This spreadsheet will make calculations for BOD removal, nitrification, denitrification, and biological phosphorus removal for given information about wastewater flow rate and characteristics, in either U.S. or S.I. units. Read on for information about Excel spreadsheets that can be used for SBR design calculations.

Sequencing Batch Reactor Design Calculation Background

A typical activated sludge wastewater treatment process operates as a continuous flow process, with incoming wastewater flow coming into a primary clarifier and treated effluent continuously coming off from the secondary clarifier. A sequencing batch reactor wastewater treatment system, on the other hand, operates as a batch system. Two or more tanks are required. While one tank is receiving influent wastewater (the “fill” part of the cycle), another tank is undergoing aeration (the “react” part of the cycle), settling (the “settle” part of the cycle) and decanting of treated effluent (the “decant” part of the cycle). This is illustrated in the diagram below.

Sequencing Batch Reactor Design Calculation Applications

A sequencing batch reactor wastewater treatment system has a great deal of flexibility. It can be used for traditional BOD removal and nitrification using the four cycle components shown above. In that case there may be aeration for at least part of the fill cycle. If denitrification is to be accomplished also, then there should be no aeration during the fill cycle. If the SBR wastewater treatment system is to be designed for biological phosphorus removal as well, then an anaerobic react period is needed after the fill portion of the cycle, and an anoxic react is needed after the aerobic react part of the cycle, as shown in the diagram below.

Example Sequencing Batch Reactor Design Calculation Excel Spreadsheet

The Sequencing Batch Reactor Design Calculation excel spreadsheet partially shown in the image below can be used to make a variety of design calculations for an SBR wastewater treatment system. Based on input information about the wastewater flow rate and characteristics, as well as the treatment objectives, the spreadsheet leads the user through calculations for deciding on times for each part of the SBR cycle, tank number and size, and checks on the adequacy of the design. This Excel spreadsheet, as well as others for wastewater treatment calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

Reference:

Bengtson, Harlan H., “SBR Wastewater Treatment Plant Design Spreadsheet,” an online blog article.

Design Storm Hyetograph Generation Spreadsheet

Posted on February 6, 2013 by Harlan Bengtson

Where to Find a Design Storm Hyetograph Generation Spreadsheet

To obtain a Design Storm Hyetograph Generation excel spreadsheet, click here to visit our spreadsheet store. For use in stormwater management calculation, you can buy a convenient Design Storm Hyetograph generation excel spreadsheet for a very reasonable price? This spreadsheet will generate a design storm hyetograph using the Chicago storm model, a triangular storm model or the “alternating blocks” procedure in either U.S. or S.I. units. Read on for information about Excel spreadsheets that can be used for design storm hyetograph generation.

Models for Design Storm Hyetograph Generation

Several different hyetograph models can be used for design storm hyetograph generation, including the Chicago storm, triangular, or rectangular (constant intensity design storm) models or the “alternating blocks” procedure for constructing a design storm hyetograph. An initial step typically needed is the generation of an equation for storm intensity as a function of storm duration at the design location, for the design recurrence interval.

The Chicago Storm Hyetograph

For example, the Chicago storm hyetograph model uses the equation at the left for the portion of the hyetograph before the peak storm intensity. A slightly different equation is used for the portion of the design storm hyetograph that is after the peak storm intensity. The resulting hyetograph has the general shape shown in the diagram at the right. A user specified parameter is r, which is the fraction of the hyetograph that is before the point of peak storm intensity. The triangular hyetograph model is similar in shape, but the lines before and after the peak storm intensity are straight instead of curved.

Example Design Storm Hyetograph Generation Excel Spreadsheet

The Design Storm hyetograph generation excel spreadsheet partially shown in the image below can be used to generate a triangular or Chicago storm hyetograph as discussed above. The portion shown is for generating an equation for storm intensity as a function of storm duration. This Excel spreadsheet, as well as others for stormwater management calculations, is available in either U.S. or S.I. units for a very reasonable price in our spreadsheet store.

References

1. American Iron and Steel Institute, Modern Sewer Design, 4th Edition, 1999.

2. Bengtson, Harlan H., “Chicago Storm Hyetograph Generation Spreadsheet,” an online informational blog article.

Air Viscosity Temperature Calculator Spreadsheet

Posted on February 3, 2013 by Harlan Bengtson

Where to Find an Air Viscosity Temperature Calculator Spreadsheet

To obtain an Air Viscosity Temperature Calculator excel spreadsheet, click here to visit our spreadsheet store. Why use online calculators or tables to find the viscosity of air at a specified pressure and temperature when you can buy a convenient air viscosity temperature calculator excel spreadsheet for only $4.95? This spreadsheet will calculate the viscosity of air at specified pressure and temperature in either U.S. or S.I. units. Read on for information about Excel spreadsheets that can be used as an Air viscosity temperature calculator for specified pressure and temperature.

Air Viscosity Temperature Calculator Spreadsheet Applications

An Air Viscosity Temperature calculator excel spreadsheet can be used for any situation where a value of air viscosity is needed at a specified pressure and temperature. This could include calculations for air flow in a pipe, drag force or drag coefficient calculations for flow of an object through air, and any other calculation requiring the Reynolds number for air flow or flow through air. For example, see the related article, Fanno Flow Excel Spreadsheet for Air Flow in a Pipe.

Equations for an Air Viscosity Temperature Calculator Spreadsheet

Equations are available for an air viscosity temperature calculator to calculate the viscosity of air at specified temperature and pressure. The spreadsheet shown in the diagram below calculates air density using an equation for air viscosity as a function of temperature ratio, T_r , and density ratio, ρ_r , where in U.S. units: T_r= T/238.5 with T in degrees R and ρ_r= ρ/0.6096 with ρ in slugs/ft³. Since the air density is needed for this calculation, the spreadsheet also calculates the density of air at the specified air temperature and pressure. The complete equations are included in the spreadsheet discussed above and shown in the screenshot below.

Example Air Viscosity Temperature Calculator Excel Spreadsheet

The Air Viscosity Temperature calculator excel spreadsheet shown in the image below can be used to calculate the viscosity of air at given temperature and pressure as discussed above. This Excel spreadsheet and others for fluid properties calculations, in either U.S. or S.I. units are available for very reasonable prices in our spreadsheet store.

References

1. Bengtson, Harlan H, “Air Viscosity Calculator Pressure Temperature Spreadsheet,” An online informational blog article.

Manning Equation Open Channel Flow Calculator Excel Spreadsheets

Posted on December 27, 2012 by Harlan Bengtson

Where to Find a Manning Equation Open Channel Flow Calculator Spreadsheet

To obtain a Manning equation open channel flow calculator excel spreadsheet, click here to visit our spreadsheet store. Why use online calculators or make open channel flow/Manning Equation calculations by hand when you can buy a variety of Manning equation open channel flow calculator excel spreadsheets or spreadsheet packages for prices ranging from $6.95 to $27.95? Read on for information about Excel spreadsheets that can be used as a Manning equation open channel flow calculator.

An excel spreadsheet can conveniently be used as a Manning equation open channel flow calculator. The Manning equation can be used for water flow rate calculations in either natural or man made open channels. Uniform open channel flow calculations with the Manning equation use the channel slope, hydraulic radius, flow depth, flow rate, and Manning roughness coefficient. Image Credit: geograph.org.uk

Uniform Flow for a Manning Equation Open Channel Flow Excel Spreadsheet

Open channel flow may be either uniform flow or nonuniform flow, as illustrated in the diagram at the left. For uniform flow in an open channel, there is always a constant volumetric flow of liquid through a reach of channel with a constant bottom slope, surface roughness, and hydraulic radius (that is constant channel size and shape). For the constant channel conditions described, the water will flow at a constant depth (usually called the normal depth) for the particular volumetric flow rate and channel conditions. The diagram above shows a stretch of uniform open channel flow, followed by a change in bottom slope that causes non-uniform flow, followed by another reach of uniform open channel flow. The Manning Equation, which will be discussed in the next section, can be used only for uniform open channel flow.

Equation and Parameters for a Manning Equation Open Channel Flow Calculator Excel Spreadsheet

The Manning Equation is:

Q = (1.49/n)A(R^2/3)(S^1/2) for the U.S. units shown below, and it is:

Q = (1.0/n)A(R^2/3)(S^1/2) for the S.I. units shown below.

Q is the volumetric water flow rate in the reach of channel (ft³/sec for U.S.) (m³/s for S.I.)
A is the cross-sectional area of flow (ft²for U.S.) (m²for S.I.)
P is the wetted perimeter of the flow (ft for U.S.) (m for S.I.)
R is the hydraulic radius, which equalsA/P(ft for U.S.) (m for S.I.)
S is the bottom slope of the channel, (dimensionless or ft/ft -U.S. & m/m – S.I.)
n is the empirical Manning roughness coefficient, which is dimensionless

The equation V = Q/A, a definition for average flow velocity, can be used to express the Manning Equation in terms of average flow velocity,V, instead of flow rate,Q, as follows:

V = (1.49/n)(R^2/3)(S^1/2) for U.S. units with V expressed in ft/sec.

Or V = (1.0/n)(R^2/3)(S^1/2) for S.I. units with V expressed in m/s.

It should be noted that the Manning Equation is an empirical equation. The U.S. units must be just as shown above for use in the equation with the constant 1.49 and the S.I. units must be just as shown above for use in the equation with the constant 1.0.

The Manning Roughness Coefficient for a Manning Equation Open Channel Flow Calculator Excel Spreadsheet

All calculations with the Manning equation (except for experimental determination of n) require a value for the Manning roughness coefficient, n, for the channel surface. This coefficient, n, is an experimentally determined constant that depends upon the nature of the channel and its surface. Smoother surfaces have generally lower Manning roughness coefficient values and rougher surfaces have higher values. Many handbooks, textbooks and online sources have tables that give values of n for different natural and man made channel types and surfaces. The table at the right gives values of the Manning roughness coefficient for several common open channel flow surfaces for use in a Manning equation open channel flow calculator excel spreadsheet.

Example Manning Equation Open Channel Flow Excel Spreadsheet

The Manning equation open channel flow calculator excel spreadsheet shown in the image below can be used to calculate flow rate and average velocity in a rectangular open channel with specified channel width, bottom slope, & Manning roughness, along with the flow rate through the channel. This Excel spreadsheet and others for Manning equation open channel flow calculations for rectangular, trapezoidal or triangular channels, in either U.S. or S.I. units are available for very reasonable prices in our spreadsheet store.

References

1. Bengtson, Harlan H., Open Channel Flow I – The Manning Equation and Uniform Flow, an online, continuing education course for PDH credit.

2. U.S. Dept. of the Interior, Bureau of Reclamation, 2001 revised, 1997 third edition, Water Measurement Manual.

3. Chow, V. T., Open Channel Hydraulics, New York: McGraw-Hill, 1959.

4. Bengtson, Harlan H., “Manning Equation Open Channel Flow Excel Spreadsheets,” an online blog article, 2012.

5. Bengtson, Harlan H., “The Manning Equation for Open Channel Flow Calculations“, available as an Amazon Kindle e-book and as a paperback.