The following are related to wastewater treatment:

a What is the main purpose of the primary, secondary and treatment facility?

b. What is the percentage BOD removal in each of the primary and secondary treatment?

c. What are tve two commonly used approaches in the secondary (biological) treatment? What is the main difference between the two approaches? advanced treatment in a wastewater

a) Objective of primary treatment of water is simply the removal of organic and inorganic solids that are settleable. WHILE

Objective of secondary water treatment is the further treatment of the effluent remaining from the primary treatment for the removal of the residual organics and suspended solids.

b) The BOD for primary treatment of water is 35%

WHILE

The BOD for secondary treatment is 85%

c) Biological aerobic approach and Biological aerobic approach

cii) The difference is one occurs in the presence of oxgen while other in absence.

Explanation:A) Objective of primary treatment of water is simply the removal of organic and inorganic solids that are settleable, using sedimentation, and the removal of material that can float by skimming. Almost about 25 to 50% of the biochemical oxygen demand which is reffered to as BOD which is 50 to 70% of the total suspended solids and also 65% of the oil and grease are removed during primary treatment.

Many organic elements such as nitrogen, organic phosphorus, and heavy metals that are solids are also removed during primary sedimentation while the colloidal and dissolved constituents are not affected.

WHILE

Objective of secondary water treatment is the further treatment of the effluent remaining from the primary treatment for the removal of the residual organics and suspended solids.

Often, the secondary treatment is usually carried out after primary treatment and involves the removal of biodegradable dissolved and colloidal organic matter using aerobic biological treatment processes.

B) The BOD for primary treatment of water is 35%

WHILE

The BOD for secondary treatment is 85%

C) Aerobic, as the can be explained as the biological treatment of water in the presence of air i. e oxygen, for the removal of particles during water ttreatment.

WHILE

Anaerobic Biological treatment approach takes place in the absence of air (oxygen). These two approach are directly related to the type of bacteria or microorganisms which are present in the degradation of organic waste in given wastewater and the operating conditions of the bioreactor