Waste Water Treatment Flashcards
What are the forms of Sewage Pollutants?
- Solid matter such as human waste, rags, paper and vegetable matter.
- Dissolved purities in solution from domestic and industrial waste.
- Colloidal matter that consists of very small solids, almost molecular in size, that is too small to settle out with sludge.
What is the strength is sewage?
The strength of Sewage is the concentration of perishable solids present in the water and the chemical character is judged by the amount of carbonaceous and nitrogenous matter present.
What is COD?
COD is the Chemical Oxygen Demand - the amount of oxygen that a sample of sewage will absorb from potassium dichromate I’m concentrated boiling sulphuric acid.
What is BOD?
BOD is the biochemical Oxygen Demand, the amount of dissolved oxygen that a sample of sewage will take up by biological purification when the sample is diluted with water and kept in a full closed bottle at 20°C for five days.
What is OA and PV?
Oxygen absorbed or permanganate value which is the amount of oxygen a sample of sewage will absorb from an acid, potassium permanganate solution on four hours at 27°C.
What will happen if sewage is not treated before discharged in a river?
Oxygen in the water will be absorbed by bacteria which will deplete the oxygen in the river that is necessary for fish and plant life.
Once the river is free of oxygen, anaerobic bacteria sets up offensive conditions and become a nuisance as well as dangerous to public health.
