Upon hearing the term ‘wastewater’, the first thing that comes to mind is just plain dirty water. However, it’s not just that. Wastewater, sometimes called as sewage water, is a combination of dirty water, human waste, food scraps, soaps, chemicals and many more. Basically, it refers to all used water at home or in commercial establishments. It even includes storm water from the streets and the community drainage system. Storm water washed down from the streets might look clean but it harbours harmful chemicals and other waste materials that are invisible to our eyes. While nature can adapt to little amounts of waste it gets, it can be overwhelmed when people dump billions of gallons of wastewater every day.
How it works
Sewage water is treated through a series of steps. From homes or commercial buildings, wastewater flows down into a reservoir called a wet well. It stays there for a while, waiting to be pumped out to the main sewer. When the wastewater reaches a certain level, the sewage pump turns on and moves it to the main sewer. A concrete pump station works great especially if it is a shared pumping station because of its durability and safety. From the main sewer, it goes to a treatment facility wherein the water is treated physically and chemically to lessen the contaminants before being released to the environment. The semi-solid part of the waste, called sludge is separated from the liquid portion. The sludge is treated further so it will be safe to apply on land. Industrial and hospital wastes are treated differently since they may contain hazardous chemicals.
Anaerobic and aerobic systems
There are two different types of sewage pumping systems – the anaerobic and aerobic type. The main difference between them is the presence and absence of oxygen during the process. Anaerobic sewage systems are sealed systems so no air gets in. The sewage is processed by anaerobic bacteria and reduces it to methane, carbon dioxide, and other gases. On the other hand, an aerobic sewage system is constantly exposed to air so that aerobic bacteria may thrive and break down the wastes. These types of bacteria are said to be faster in treating sewage than anaerobic ones.
Sewage treatment levels
Sewage water undergoes 3 treatment levels before it is safe for release to the environment.
- Primary Treatment – In this level, the sewage enters into huge tanks and is left to sit for a while. Through time, the sludge settles at the bottom of the tank while the grease floats on the surface. When the semi-solid part settles, it is pushed into a receptacle to be processed further.
- Secondary Treatment – After passing the first treatment, the wastewater is further cleared of biological wastes such as food scraps, human waste and soap. Bacteria and other microorganisms are used to clear up the pollutants so the resulting effluent is safe for the environment.
- Tertiary Treatment – To make sure that the effluent won’t damage the environment, it is further treated in this level.
Water is essential in our daily lives so it’s important to treat and reuse it so we won’t run out of it.