sludge
<span>Sewage treatment is also known as wastewater treatment. It is
a process whereby contaminant is removed from wastewater. Thus, chemical,
biological and physical process are commonly used to remove contaminants from
wastewater and the by-products of wastewater treatment is usually inform of
solid waste known as sewage sludge.</span>
One of the reasons for the success of the smallpox eradication campaign was that small pox only occurred in humans. Smallpox is an extremely contagious and deadly virus for which there is no known cure. it is caused by two variants, Variola major and Variola minor. it is a disease of the past that was eliminated by worldwide vaccination.
1. Variations
2. Extinction
3. Behavioral
4. Functional
5. Structural
Because the lung has two bronchi, it can still function if one bronchus is blocked by a foreign object. No gas exchange will happen to the affected side, and the other lung will compensate for the loss of air. The blocked portion though can become inflamed and can lead to infection and damage.