The challenge with sewage disposal is getting the bacteria and organic matter out of the water and destroying them so they don’t irritate the senses or provide a health risk. An ineffective disposal strategy that has been carefully examined sewage in a tank while treating it with chemicals like copperas or other substances is one method that has been tested. Alum will cause the solids to coagulate, causing them to either float to the surface or sink to the bottom. After that, the clarified liquid can be extracted. This system is costly, insecure, and impracticable, and a health official won’t often need to take it into account.
The dispersal of sewage across agricultural land’s surface is another system. This has also been widely tried, but it has almost always failed. The sewage has very little fertilising effect, its disposal requires a sizable area, labour costs make the system expensive, and the crops are unsafe for human consumption due to the presence of disease germs. If a health official criticises a surface disposal system due to cost and health risks, he is doing the correct thing.
Discharging sewage into a lake, river, bay, or another body of water is a third method of sewage disposal. This is a risky way to dispose of waste, particularly if the body of water is utilised as a water supply source. The oxidising bacteria is mostly responsible for the water’s natural cleansing actions of the water’s naturally dissolved oxygen. If the sewage percentage to the amount of water it discharges is between 1 and 200, the amount of oxygen in the water will be diminished to the point where some fish species can no longer survive in the water.
The amount of oxygen will be reduced to the point that putrefaction may occur if the sewage to water ratio is 1 to 50. However, even if the water does not become unpleasant to the senses, illness germs may still be present. Preventing sewage from polluting bodies of water is one of the major issues that health departments must deal with. Almost all sewage disposal systems that a health officer must deal with rely on bacterial decomposition for their action, followed by an additional purification step such as oxidation or soil filtering.
The organic materials in the sewage will either be eliminated or completely oxidised into carbon dioxide, water, and other minerals that are naturally present in ground water. Additionally, the water that flows away will be free of bacteria. This indicates that the purification process has been successful. Sewage can be cleaned up to the point where it can be used as drinking water.
The following tools are frequently used for sewage purification: a collecting tank, subsurface irrigation pipelines, a contact bed, sprinkler filters, sand filters, and chlorinating equipment. These tools are frequently combined in different ways, such as a collecting tank, a sprinkler filter, and a chlorinating system.
