The three main stages of treatment for wastewater (and sewage), are Primary Treatment, Secondary Treatment, and then the Tertiary Treatment. So, what is removed from water during the tertiary wastewater treatment nutrient removal? Tertiary treatment is used to purify and improve the quality of water after the primary and second-stage treatments.
The then treated water can be safely released into the environment (and into bodies of water such as rivers and lakes) after what is removed from water during the tertiary wastewater treatment nutrient removal. It can then be used for industrial, agricultural, and in some cases, domestic purposes.
Tertiary Wastewater Treatment
When it comes to answering what is removed from water during the tertiary wastewater treatment nutrient removal - the truth is, even after the wastewater has reached the tertiary stage of treatment, it still contains suspended matter and fine particles. It also contains a high amount of nutrients like nitrogen and phosphorus, as well as microbes and an odor.
Different methods can be used to remove any contaminants or properties from the wastewater during the tertiary process. Filtration is the first stage in tertiary wastewater treatment. It helps to remove suspended matter from wastewater. This is usually done using sand filtration.
Sometimes residual toxins can be found in wastewater. Activated carbon is used to absorb these toxins and then are removed from the wastewater. Some fine particulate matter can still be found in wastewater after filtration. This is why there are three steps in the filtration process that includes what is removed from water during the tertiary wastewater treatment nutrient removal.
After the primary treatment and secondary treatment processes, the wastewater is then treated further by being transferred to lagoons equipped with filter feeders. Further removal of fine particulate matter is possible in the lagoon's biologically rich environment. However, the wastewater could still contain high levels of nutrients. High concentrations of phosphorus and nitrogen are common in wastewater.
If the wastewater is left untreated, this can lead to an excessive growth of death causing bacteria (among other things). The amount of oxygen in the wastewater from bacterial activity is reduced by the death of algae, which makes it less suitable for aquatic life. It is important to reduce the nitrogen and phosphorus levels before wastewater is released into water bodies. Both nitrogen and phosphorous can be removed by biological processes that involve different bacteria.
Ammonia, which is nitrogen, is first oxidized into nitrates. Then nitrates are converted to nitrogen gas. However, what is removed from water during the tertiary wastewater treatment nutrient removal includes things like phosphorus - which can also be removed biologically by chemical precipitation using salts of iron or aluminum.
A high amount of phosphorus can be accumulated by bacteria, and the biomass can also be used as fertilizer. The phosphate-rich sludge, which is formed during chemical treatment to remove phosphorus, has good value as a fertilizer. Before releasing the wastewater into the environment, the final steps of tertiary wastewater treatment are to remove any unwanted microbes and also eliminate odors.
This tertiary wastewater treatment nutrient removal stage is crucial for the effectiveness and efficiency of the disinfection process. It is important that wastewater is clear and not cloudy. There are many disinfection agents that can be used, depending on the wastewater condition (pH and clarity). The most popular disinfection agents are chlorine, ozone and ultraviolet (UV) light.
Each has its advantages and disadvantages. The effectiveness of chlorine as a disinfection agent has been proven time and again. But, prolonged use and an unregulated dosage may lead to the formation of chlorinated-organic chemicals from the chlorination residual organic matter in water. These compounds can be carcinogenic.
Still not sure what is removed from water during the tertiary wastewater treatment nutrient removal? Well, if the water is going to be used for drinking, it is necessary to de-chlorinate. The ultraviolet light treatment for disinfection doesn't leave behind any compounds or residues in the water, but it is important that the wastewater be clean for it to work. For long-term UV light usage, it is important to maintain the equipment and lamp properly.
The main cause of wastewater odor is the release of gases such as hydrogen sulfurize from wastewater treatment plants. Carbon reactors can be used to regulate the levels of hydrogen peroxide and calcium nitrate. It can be used to reduce the odors in wastewater and manage hydrogen sulfide.
After the tertiary treatment, the wastewater can be allowed to flow into the environment for further reuse. We hope this helps shed some perspective on what is removed from water during the tertiary wastewater treatment nutrient removal.