What is the difference between sewage and sludge ? Explain how it should be treated

Sewage are liquid wastes which contains dissolve and suspended impurities in it. Solid wastes like faeces,vegetable waste which removes during clarification are called sludges.

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SEWAGE

Sewage is the term used for wastewater that often contains faeces, urine and laundry waste.
There are billions of people on Earth, so treating sewage is a big priority.
Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water.
Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhoea.
Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.
Sewage is treated in water treatment plants and the waste is often disposed into the sea.
Sewage is mainly biodegradable and most of it is broken down in the environment.
In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet. When people are ill, sewage often carries harmful viruses and bacteria into the environment causing health problems

SLUDGE

1.Sludge is a semi-solid slurry and can be produced as sewage sludge from wastewater treatment processes or as a settled suspension obtained from conventional drinking water treatment and numerous other industrial processes.

2.Sludge originates from the process of treatment of waste water.

3.Due to the physical-chemical processes involved in the treatment, the sludge tends to concentrate heavy metals and poorly biodegradable trace organic compounds as well as potentially pathogenic organisms (viruses, bacteria etc) present in waste waters.

4.Sludge is, however, rich in nutrients such as nitrogen and phosphorous and contains valuable organic matter that is useful when soils are depleted or subject to erosion.

5.The organic matter and nutrients are the two main elements that make the spreading of this kind of waste on land as a fertiliser or an organic soil improver suitable.