Oxidation

Question 1

Aerobic oxidation

Answer 1

Aerobic oxidation produces new cells and relatively stable end products quickly. It is the most important process in self-purification.

Question 2

Anaerobic oxidation

Answer 2

Anaerobic oxidation produces new cells and relatively unstable end products slowly. Takes place where there is rich organic matter and ‘sludge digestors’. It is biochemically inefficient and produces some foul smelling by-products.

Question 3

BOD value

Answer 3

Valuable indicator which gives information on biodiversity and biological uptake. A BOD test is a laboratory test to determine BOD of a water sample.

Question 4

Basic BOD Model

Answer 4

BOD is traditionally modelled using a continuous 1st order reaction process, where the rate at which organic matter is oxidised is proportional to the amount of oxidisable material left.

Question 5

Reaeration

Answer 5

The most significant re-oxygenating process across the air/water interface. The most important factor which influences the rate of aeration is the oxygen saturation deficiency.

Question 6

Reaeration equation

Answer 6

Oxygen dissolves into water at a rate proportional to the dissolved oxygen deficit.

Question 7

The Sag Curve

Answer 7

The solution to the Streeter-Phelps equation. It describes how the oxygen level in a river changes downstream of an oxygen demanding input.