WASTE WATER TREATMENT FACTS

Source: http://www.biopro.ie/

There are different levels of wastewater treatment. We consider the definition “at least primary treatment”, which removes a lot of suspended solids and reduces biochemical oxygen demand. Extra steps may be taken to treat the water further. The downstream effects of untreated wastewater are bad for public health and the health of aquatic ecosystems. When pollutants enter the water cycle, aquatic species and human can be directly harmed through infection or the disruption of their biological development, and they can be harmed indirectly through nutrient loading that causes eutrophication.

Here are some wastewater facts:

1. Upto 90% of wastewater in developing countries is sent into rivers and open water bodies.

2. 80% of the world’s marine pollution comes from sources onland, and wastewater contributes to much of it.

Here’s the process of wastewater treatment plant :

1. Used/polluted water goes to wastewater treatment plant.
2. Large objects screened out and hauled to landfill.
3. Sand and gravels fall to the bottom of setting tank and are sent to landfill; floating grease and oil are skimmed off.
4. Aerated water supports “good” bacteria which consume pollutants and harmful bacteria.
5. Spent bacteria from a sludge or made into fertilizer.
6. Water is disinfected and clarified with chlorine or ultraviolet light.
7. Finally, clean water returned to river to be used again.

Treated wastewater can be used to grow food. In many countries, raw sewage is used for food production, which can cause the spread of disease. Wastewater creates gas that can be turned into energy using digesters.