We have discussed the lengths we have to go through to purify water, it’s only right that we discuss how our wastewater is treated. It is important to note that a lot of the wastewater in Uganda is disposed of in Lake Victoria and yet much of the water from Lake Victoria is then pumped back into our water system. This then makes the majority of the population susceptible to poor sanitation. Insufficient or no sewage and wastewater treatment are a very serious health hazard and a peril to the environment today. In East Africa alone, just over 2% of the sewage and wastewater generated is treated. The numbers don’t lie, with this statistic, we are well on our way to an unhealthy society.

A sewage treatment plant, also called a wastewater treatment plant, is a facility where a person’s wastewater from their toilets, sinks, and tubs is cleaned. They are an integral part of the sanitation process to ensure the health and safety of everyone in a community. In Uganda, the Bugolobi Wastewater treatment plant is known to be the largest wastewater treatment plant of all the countries that are a part of the East African Community and is capable of processing 45,000,000 litres of wastewater daily. According to Wikipedia, the plant collects wastewater and sewerage from various parts of the city of Kampala. The services the plant offers are aimed at increasing and improving sanitation services in the city and reducing the pollution of the Nakivubo Channel, which is a surface-water effluent into Lake Victoria. This increases Lake Victoria’s environmental sustainability.

Importance of a Functional Sewage Treatment Plant.

While we hate to think about it, all our human waste needs to go somewhere. The cycle of disposing of wastewater most of the time, calls for us to dispose of our water waste by placing it back into our waterbodies. The reality is that if we don’t treat the waste, then we introduce contaminated water back into our water sources, which can harm wildlife, the ecosystem, and even ourselves.

These treatment plants take on the responsibility of handling all the wastewater in a particular area and ensuring that only clean water treated is reintroduced to the water bodies. This is done by removing any solid particles and contaminants.

Stages of water treatment.

The treatment of sewage water involves several stages, which aim to remove contaminants and pollutants from the wastewater before it is safely discharged or reused. The following are the common stages in sewage water treatment:

1. The preliminary Treatment stage involves the removal of large objects and debris from the wastewater. It typically includes processes like screening to remove items like sticks, plastics, and rags.
2. Primary Treatment is the stage where the wastewater undergoes physical treatment to separate solid particles and reduce organic matter. The wastewater flows into large settling tanks, known as primary clarifiers or sedimentation tanks. The heavy solids settle to the bottom as sludge, while lighter materials float to the surface as scum. These materials are then removed for further treatment.
3. Secondary Treatment, also known as biological treatment, focuses on the removal of dissolved and colloidal organic matter, as well as nutrients such as nitrogen and phosphorus. The wastewater is transferred to aeration tanks where it is mixed with air and microorganisms (either naturally present or added). The microorganisms consume the organic matter, converting it into carbon dioxide, water, and more microorganisms. This process, known as the activated sludge process, produces a biological sludge that is later treated separately.
4. After the biological treatment, the wastewater is directed to secondary clarifiers or settling tanks. Here, the remaining suspended solids and microorganisms settle to the bottom as sludge. The clarified water at the top is then separated and ready for further treatment.
5. Sludge Treatment requires that the sludge generated during primary and secondary treatment undergoes further treatment. This typically involves processes like thickening (to reduce water content), digestion (where microorganisms break down organic matter), and dewatering (to further reduce water content). The treated sludge can be used for beneficial purposes like fertilizer or sent to a landfill.
6. The final treated wastewater, known as effluent, undergoes disinfection to kill any remaining pathogens. Common disinfection methods include chlorination, ultraviolet (UV) irradiation, or chemical disinfectants. Once disinfected, the effluent is usually discharged into a receiving water body (such as a river or ocean), or it can be reused for non-potable purposes like irrigation or industrial processes.

These specific processes and technologies used at each stage may vary depending on the treatment plant’s design, capacity, and the quality of the influent wastewater.

Clean water is inestimably precious to waste!