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## How do you calculate biological oxygen demand?

Measuring biochemical oxygen demand requires taking two measurements. One is measured immediately for dissolved oxygen (initial), and the second is incubated in the lab for 5 days and then tested for the amount of dissolved oxygen remaining (final).

What is the mathematical equation of BOD?

Change Equation

BOD = biochemical oxygen demand
L = ultimate biological demand
k = deoxygenation rate constant
t = time
D1 = initial diluted seeded wastewater dissolved oxygen

How do you calculate BOD in wastewater?

For example: 1.0 mL of a full strength wastewater sample added to 9.0 mL of DI water results in a 0.1 dilution of the wastewater. The DO concentration (mg/L) reduction must then be multiplied by 10 to determine the final BOD concentration.

### What does biological oxygen demand indicate?

Biological Oxygen Demand (BOD) refers to the amount of dissolved oxygen that aerobic organisms need in order to break down organic material in water over time. Its high value indicates the intense level of microbial pollution.

What is COD and BOD in wastewater?

The biochemical oxygen demand (BOD) represents the amount of dissolved oxygen (DO) consumed by biological organisms when they decompose organic matter in water. The chemical oxygen demand (COD) is the amount of oxygen consumed when the water sample is chemically oxidised.

What is the importance of biological oxygen demand?

The BOD is an important parameter for assessing water quality. It deals with the amount of oxygen consumption (mg O2 L− 1) by aerobic biological organisms to oxidize organic compounds. Sewage with high BOD can cause a decrease in oxygen of receiving waters, which in turn can cause the death of some organism.

## What is the difference between dissolved oxygen and biological oxygen demand?

(The amount of oxygen consumed by these organisms in breaking down the waste is known as the biochemical oxygen demand or BOD. Oxygen is measured in its dissolved form as dissolved oxygen (DO).

Why is BOD done for 5 days?

The standard oxidation (or incubation) test period for BOD is 5 days at 20 degrees Celsius (°C) (BOD5). The BOD5 value has been used and reported for many applications, most commonly to indicate the effects of sewage and other organic wastes on dissolved oxygen in surface waters (see TECHNICAL NOTE).

What happen if BOD is high?

The greater the BOD, the more rapidly oxygen is depleted in the stream. This means less oxygen is available to higher forms of aquatic life. The consequences of high BOD are the same as those for low dissolved oxygen: aquatic organisms become stressed, suffocate, and die.

### What do you mean by biochemical oxygen demand?

WHAT IS BOD? Biochemical Oxygen Demand (BOD) is the amount of oxygen, expressed in mg/L or parts per million (ppm), that bacteria take from water when they oxidize organic matter.

How is the amount of oxygen used by bacteria determined?

To determine BOD, the amount of oxygen the bacteria use is calculated by comparing the amount left at the end of five days with the amount known to be present at the beginning. At room temperature, the amount of oxygen dissolved in water is 8 mg/L.

How to calculate activated sludge tank in Excel?

Activated Sludge Aeration Tank Design Calculations with Excel Spreadsheets 1 V = [ (8.34* So * Qo )/ VL ] (1000) 2 VMG = V *7.48/1,000,000 3 HRT = 24* VMG / Qo 4 F:M = (8.34* So * Qo )/ (8.34* %Vol * X * VMG) = ( So * Qo )/ ( %Vol * X * VMG)

## How is oxygen saturated in a BOD test?

PROCEDURE FOR THE DILUTION METHOD BOD TEST 1. Select the required BOD Nutrient Buffer Pillow, shake, cut open, and add the contents to a jug containing the required amount of distilled water at 20 °C. 2. Cap the jug and shake vigorously for 1 minute to dissolve the slurry and to saturate the water with oxygen.