Almost, every city, industry, and agricultural activities generate large amounts of wastewater. This majority of wastewater ends up in natural water bodies.
Eutrophic water bodies have nitrogen concentrations greater than 1.9 mg/L, which can cause algal blooms. Therefore, it becomes essential to remove nutrients like nitrogen and phosphorous from wastewater, before disposing them in natural river bodies.
Why there is a need to remove nitrogen and phosphorus from wastewater?
The removal of nitrogen and phosphorus from wastewater is a growing global concern, because these compounds cause eutrophication in natural water. Many microalgae grow on the water's surface, blocking sunlight and releasing oxygen from aquatic bodies.
Aquatic life habitats are shrinking as oxygen levels fall. Furthermore, nitrate poses a risk to human health, particularly as a possible cause of infant methemoglobinemia.
What are the WWT applications for nitrogen and phosphorous removal?
Biological processes based on suspended biomass are effective, for removing phosphorus and nitrogen from municipal wastewater treatment plants.
Biofilm processes have proven to be reliable for organic carbon and nutrient removal, while avoiding some of the issues associated with activated sludge processes. Biofilm reactors are particularly useful when slow-growing organisms such as nitrifiers, must be maintained in a wastewater treatment process. In biofilm reactors, both nitrification and denitrification processes have been successful.
There are already numerous biofilm systems in use, including trickling filters, rotating biological contactors (RBCs), fixed media submerged biofilters, granular media biofilters, and fluidized bed reactors, each with their own set of advantages and disadvantages.
MBBR for removing nitrogen and phosphorus
The moving bed biofilm reactor process is a promising process for improving nitrification, denitrification, and phosphorus removal in conventional activated sludge systems, which can be used for upgrading biological nutrient removal, particularly when space is limited or modifications require a significant financial investment.
The moving bed biofilm reactor is a highly efficient biological treatment process, based on conventional activated sludge and biofilter processes. It is a completely mixed and continuously operated biofilm reactor, in which biomass is grown on small carrier elements that have a slightly lower density than water, and are kept in motion inside the reactor along with a water stream.
Aeration in an aerobic reactor and a mechanical stirrer in an anaerobic or anoxic reactor, can cause movement within the reactor.
Biological Nitrogen Removal through Nitrification & Denitrification
Total nitrogen removal in wastewater treatment plants is most commonly and economically accomplished, through a two-stage system, namely nitrification and denitrification.
Nitrification is the process by which ammonia is converted to a more oxidized nitrogen compound, such as nitrite or nitrate, which is then converted to nitrogen gas in the denitrification process. This final step involves the creation of nitric oxide (NO), nitrous oxide (N2O), and nitrogen gas (N2). All three products are gases that can be released into the environment.
Because, nitrification occurs under aerobic conditions while denitrification occurs in the absence of oxygen, nitrification and denitrification are typically carried out in separate reactors.
Which organisms are responsible for nitrification and denitrification?
Nitrosomonas and Nitrobacter are responsible for nitrification in wastewaters, while denitrifying organisms, such as Pseudomonas, Achromobacter, Acinetobacter, Agrobacterium, Alcaligines, Arthrobacter, and Bacillus, are thought to be responsible for denitrification, though an organic carbon source is required.
How can we assist?
If you have any questions about wastewater treatments to remove nitrogen and phosphorous from water or wastewater, or if you would like to discuss your specific needs, please contact the Netsol Water team right away. Our team is an expert in providing solutions for water and wastewater treatment, and can help you tailor a solution to your specific requirements.