Introduction to Wastewater Treatment (Book) Part One

What temperature is the BOD test done at?

20 C (68F)

1 Kg of BoD = ____ Kg of oxygen

1 Kg of oxygen

BOD can be further divided into 3 types, what are the other two besides BOD?

Carbonaceous biochemical demand

Nitrogenous biochemical demand

Additional oxygen may be used by special group of bacteria, the nitrifying bacteria, to convert ammonia to ___ or __

This reaction consumes ___ Kg of oxygen for every 1 Kg of ammonia converted to nitrate.

Nitrite or nitrate

4.5 Kg of oxygen

if an analyst wants to measure only the CBOD a substance that is ___ to nitrifying bacteria is added

Toxic

Because ammonia can be toxic to aquatic life, it can be converted to _____ to mitigate the toxicity

Nitrate

Nitrogen in water can cause ____ syndrome

Baby blue

For total nitrogen removal, nitrate is converted to _____ and then released to the atmosphere which is ____ % Nitrogen

Nitrogen gas

78%

Chemicals used to adjust the pH or alkalintiy

Sodium hydroxide (Caustic Soda)

Sodium carbonate/bicarbonate compounds (soda ash)

Chemical used for odor control

Ferric chloride (or others)

Chemicals for coagulation

Aluminum sulphate (alum)

PACL

Iron Salts

Chemicals used to remove chlorine

Sodium bisulfite

Sulfur dioxide

____ is used for flocculation

Polymers

3 main categories of wastewater treatment

Physical

Chemical

Biological

Describe sanitary sewers

Sanitary sewers convey wastewater from residential, commercial, institutional, and industrial sources