Question

how are aerobic and anaerobic decomposition, BOD, dissolved oxygen concentration, and eutropication are related to each other and what does each term means

Answer 1

Aerobic decomposition: Breakdown of organic materials in presence of oxygen by microorganism or bacteria

Anaerobic decomposition: Breakdown of organic materials in absence of oxygen by microorganism or bacteria

Biological oxygen demand(BOD): this is the amount of oxygen required by  microorganism in an aerobic process to breakdown organic material present in a given sample at given temperature and time.

Dissolved oxygen concentration (DO): Amount of oxygen dissolved in water. Generally expressed as mg/L

Eutrophication: It is a process by which enrichment of an ecosystem with chemical nutrients takes place. The typically nutrients are phosphates and nitrates. These chemical nutrients promote excessive growth of algae and there by organic materials in water.

All the above terms are related to water pollution and its purification.

Lot of alge is generated by eutrophication process when large amounts of phosphates and nitrates are added to water through industrial waste. When algae decomposes it produces high levels of organic matter and the decomposing organisms deplete the dissolved oxygen concentration, posing danger to aqua life. If dissolved oxygen levels in water drop below 5.0 mg/l, aquatic life will be put under stress. The amount of organic pollutants present in a water can be determined by measuring Biological oxygen demand(BOD). The organic materials can be removed from polluted water either Aerobic decomposition /anaerobic decomposition methods.