Wastewater Treatment Plant

Our team had the opportunity of receiving a tour of the Wastewater Treatment Plant in Lethbridge. This plant was built in the early 1900s and it is a biological nutrient facility, which makes it belong to the top five percent of all the treatment plants in the world. The plant removes phosphorus,nitrogen, ammonia, total suspended solids, biochemical oxygen demand (pollution), as well as works to reduces fecal and total coliform. The wastewater treatment plant is licensed under the Alberta Government which ensures that certain rules and obligations must be met. As previously mentioned, we had the opportunity to have a tour of the plant led by Duane Guzzi, the Process Coordinator of the wastewater treatment plant. During the tour we learned valuable information that would help us for the success of our project. As our project deals with the extraction of metals from tailings ponds, going to a wastewater treatment plant was beneficial as we learned the procedures and methods they take to remove chemicals from water and make it safe for rivers.

The wastewater treatment plant treats water that come from schools, homes and businesses. This water then passes through screens to remove large materials such as plastic bags and toys, before travelling to the grit tanks where sand and dirt is removed. The rest of the wastewater known as primary influent, travels to the primary clarifiers where the water flow is slowed down and the heavier materials that are contained in the water settle to the bottom. The rest of the liquid and sludge is then pumped into the five bioreactors where it travels through a number of zones. The bacteria contained in the zones break down the organic contaminants that are found in the wastewater by using it as a food source. The first zone the liquid, sludge mixture travels through is the anaerobic zone; then it travels to two anoxic zones, and lastly an aeration zone. As this mixture passes through the different zones the fine particulate matter as well as nutrients that dissolve contaminants in wastewater are removed. For instance, phosphorus is removed from the wastewater when bacteria is placed in the anaerobic zone where it will release phosphorus due to its kreb cycle. As the wastewater passes to the anaerobic zone in the next bioreactor the bacteria does the opposite and instead takes in the phosphorus. This process is repeated until it takes up the maximum amount of phosphorus it can, when at last the bacteria is removed from the wastewater taking the phosphorus with it. After passing through the bioreactors the rest of the wastewater passes on to the secondary clarifiers where the water flow is slowed down once again so the bacteria and sludge contained in the solution settle down at the bottom of the tank. The plant processes the bacteria so it forms into flocks and forms a netting so it will sink to the bottom of the tank that it is in, so it can be removed easily. Our project is very similar to this process, as the phages that are used flocculate so they can be removed from the tailings ponds and the metals that they contain. Mr. Guzzi also gave our team advice on where our project could be integrated in the wastewater treatment plant. He stated that our project could be integrated into the secondary clarifiers, to remove the metals that are contained. If our project was integrated into the secondary clarifiers, the metals that are contained in wastewater could be removed before moving on to ultraviolet disinfection, where the microorganisms that are left in the water are disrupted and unable to reproduce and cause harm. The final product produced meets the policies of the Alberta Environmental Protection and therefore it is discharged into the river. As well as this, because our project deals with biocontainment we learned how the wastewater treatment plant deals with this issue. Mr.Guzzi helped identify the problem of our project, which was the introduction and retention of the phage in the system that will be created. Additionally, another problem he identified was how we would be able to introduce enough phage for the amount of bacteria we will contain, as well as how to keep the phage contained long enough to allow our process to occur. The wastewater treatment plant uses 15-100 000 kg of bacteria, and therefore for our project to be feasible in current plants we will need to introduce enough phage for the amount of bacteria contained. This gave us insight into the potential problems our project could have in real-world situations.

The bacteria that is not needed and the sludge that is left over is transported to the digestion system that contains anaerobic bacteria that will break down the solids to a point that is manageable for the plant. Additionally, the methane that is produced as a result of the break down will be transported to the cogeneration motors where it will then provide heat and electricity for the plant. This is ensuring that the wastewater treatment plant’s electricity costs are low. The inorganic substrate that is left over will be transported to the lagoons where it will be dewatered. The water that was taken out will be brought back to plant for treatment, and the rest of the material will be used as fertilizer for land. This inspired our project to pay more attention to the environmental impact our project could create. Therefore, by extracting metals from tailings ponds we are helping the environment by removing materials that pollute systems.

During the tour we learned valuable information that would help us for the success of our project. As our project deals with extracting metals from tailings ponds, going to a wastewater treatment plant was beneficial as we learned the procedures they take to make the water safe for rivers and it gave us insight into how our project would function.For instance, we learned where our project could be integrated into the wastewater treatment plant and what steps would need to be taken to ensure that our project can be applied to real world applications. Duane Guzzi, the Process Coordinator of the wastewater treatment plant, showed us that our project could be integrated into the primary clarifiers or when the wastewater first enters the plant, to remove the heavy metals that are contained inside. We conducted a tour as well as an interview with Duane Guzzi, the Process Coordinator of the wastewater treatment plant, and he helped in showing where our project would benefit the wastewater treatment plant the most. As well as this, because our project deals with biocontainment we learned how the wastewater treatment plant deals with this issue. Mr.Guzzi helped identify the problem of our project, which was the introduction and retention of the phage in the system that will be created. Additionally, another problem he identifies was how we would be able to introduce enough phage for the amount of bacteria we will contain, as well as how to keep the phage contained long enough to allow our process to occur. The plant processes the bacteria so it forms into flocks and forms a netting so it will sink to the bottom of the tank that it is in.