Removing contaminants from household or industrial wastewater is known as sewage treatment or wastewater treatment. Sewage treatment plants employ various chemical, physical, and biological procedures to remove contaminants and pump out environmentally safe water. Additionally, sewage treatment processes also produce a sludge that is processed before it is fit for land usage.

Sewage, when recycled, can be utilized for various reasons such as gardening, toilet flushing, car washing, cooling towers, etc. Today, the government has mandated large and upcoming real estate projects to have their own treatment facilities. There are two types of sewage treatment methods that can be used for various projects. Here is a brief overview of both processes:

Anaerobic Sewage Treatment

In the anaerobic sewage treatment, the sewage is partially decomposed by anaerobic bacterias. This process forces the organic matter to convert into methane, carbon dioxide, hydrogen sulfide, etc. This treatment is utilized for treating organic waste and sludge since it provides huge capacity and reduces the input material to a large extent.

Aerobic Sewage Treatment

Unlike the previous treatment process, in the aerobic sewage treatment the contaminants are digested by aerobic bacterias while they are constantly provided with air. Today, aerobic sewage treatment plants utilize the natural air currents to help facilitate the process. This treatment process removes pollutants and odours due to oxidation. The treated water can be discharged for further use.

Most sewage treatment plants employ two to three steps before they start with any of the above steps. Let’s take a look at them:

Primary treatment

This is the first step and the process allows for the sewage to flow-through tanks. These tanks are designed so that the sludge settles at the bottom while oil and grease float to the top which is then removed. Moreover, the sludge collected at the bottom is continuously pushed out with the help of scapers. This sludge is them sent for the sludge treatment.

Secondary treatment

During this process, all biological waste such as human waste, soap, food, and detergent are removed with the help of the aerobic process. Once the treatment is done, the effluent is filled with dissolved biological matter. To remove this, municipal corporations then use the aerobic micro-organisms that can absorb these pollutants. Once this process if over, the water can safely be discharged into environmental water bodies.

Tertiary treatment

This is the last stage of the filtration process and the effluent is treated further to discharge the highest quality water into the environment This process is generally used when the water from the first two steps isn’t clean enough. This process also reduces phosphorous, ammoniacal nitrogen, and other pollutants that may be harmful for the environment.

Even though the Earth consists of 70% water, we only have 1% of usable water in the world. Therefore, it’s vital that we recycle water and use it for tasks that do not require the use of freshwater.