Biological Nutrient Removal Systems & Process
Wastewater Treatment: Nitrification & Denitrification
Wastewater usually refers to water that is adversely affected in quality by influences that are anthropogenic. Sewage is the division of wastewater that is contaminated with excreta, domestic, municipal, or industrial liquid waste products that is disposed of via a pipe or sewer. Wastewater leads to water pollution and can be severely hazardous to health if left without proper treatment. But the good news is that there are various wastewater treatment solutions available in the market that treats wastewater and allows safe reuse. One such process is nutrient removal from wastewater.
if you are looking for nutrient removal in wastewater treatment solutions, then you have come to the right place as we at IDS Water have it all and much more. We are committed towards connecting our clients to numerous vendors and vendors who are pioneers in manufacturing and distribution of various wastewater treatment and technology related components, testing and consultancy.
What are Water Nutrients?
Nutrients are chemical compounds that are found in wastewater. These contain nitrogen phosphorous and potassium. These water nutrients are essential for life. However, the levels of these nutrients are usually high in wastewater. excessive release to the environment can lead to a buildup of nutrients, called eutrophication in receiving waters.
How does Water Nutrients result in Water Contamination?
High levels of water nutrients lead to overgrowth of weeds, algae, and cyanobacteria. It also causes an algae bloom. Algae eventually dies as the algae numbers are unsustainable. The decomposition of algae by bacteria uses up so much oxygen in the water that most or all plants and animals die. In addition to causing deoxygenation, some algal species produce toxins that result in water contamination of various water resources.
Due to this different wastewater treatment processes are required to for nutrient removal. IDS Water will connect you to suppliers and water vendors that will provide you nutrient removal systems for municipal and industry wastewater. The suppliers associated with us ensure that nutrient removal systems are of the highest quality for regulatory compliance so that continued health of receiving water resources is maintained.
Biological Nutrient Removal
The process used for removing nitrogen and phosphorus from wastewater before it is discharged into various water resources or groundwater is called biological nutrient removal. High levels of harmful nutrient compounds in wastewater cause summer algae bloom. This presents problems for ecosystem and people by leading to low dissolved oxygen, fish kills, muddy water, and depletion of flora and fauna in water resources.
Due to this, wastewater treatment plants these days are increasingly implementing biological nutrient removal process to reduce effluent water nutrients concentration to safe levels. Biological nutrient removal primarily involves the following:
In biological nitrogen microorganisms to molecular nitrogen in a two-step process convert removal the ammonium in the industrial or municipal wastewater. First step is nitrification where the ammonium is oxidized to nitrate by nitrifying bacteria. Whereas in the following denitrification step, nitrate is reduced to molecular nitrogen by denitrifying bacteria.
A modification of an activated sludge process to include nitrogen removal usually requires larger tank volumes. Moreover higher sludge age is required for slow growth rate of nitrifying bacteria that are responsible for the nitrification. Unfortunately, high sludge age can lead to process upset as bulking sludge contains filamentous bacteria such as microthrix parvicella. , the design and operation of nitrogen removal process enables the wastewater treatment system to optimize nitrification and denitrification processes.
Wastewater comprises of soluble and particulate phosphorous. Particulate phosphorous can be removed from wastewater through solids removal. The fraction of soluble phosphorous should also be targeted in order to achieve low effluent concentration. Biological phosphorous removal mainly relies on phosphorous uptake by aerobic heterotrophs, which are capable of storing orthophosphate in excess of their biological growth requirements. The wastewater treatment process can be engineered to promote the growth of these organisms, known as phosphate accumulating organisms in mixed liquor.
Chemical precipitation also helps in removing phosphorous from wastewater. Aluminum and iron coagulants are primarily used in chemical precipitation to form chemical flocs with phosphorous. These flocs are then settled out to remove phosphorous from the wastewater. However, chemical processes have higher cost of operation, produce more sludge, and result in added chemicals in sludge as compared to biological removal of phosphorous. But a combination of biological and chemical processes may turn out to be less expensive than either process by itself when total phosphorous levels close to 0.1 mg/L are required.
Biological Nutrient Removal Process
These are numerous biological nutrient removal process configurations available. Some biological nutrient removal systems are designed to remove only total nitrogen or total phosphorous or both. The configuration for any particular water nutrients removal process depends on the target effluent quality, influent quality, operator experience and existing wastewater treatment processes, if retrofitting an existing facility. Biological nutrient removal configuration varies based on the sequencing of environmental conditions like aerobic, anaerobic and anoxic, and timing. Common system configurations include:
- Modified Ludzack-Ettinger (MLE) Process: This is a continuous flow suspended growth process with an initial anoxic stage followed by an aerobic stage. It is used to remove total nitrogen.
- A /O Process: MLE process preceded by an initial anaerobic stage. This is used to remove both total nitrogen and total phosphorous.
- Step Feed Process: This process alternates between anoxic and aerobic stages. However, influent flow is split to numerous feed locations and the recycle sludge stream is sent to the beginning of the process. It is used to remove total nitrogen.
- Bardenpho Process (Four-Stage): This is also a continuous flow suspended growth process. It alternates between anoxic and aerobic stages. It is used to remove total nitrogen.
- Modified Bardenpho Process: Bardenpho process with addition of an initial anaerobic zone is used to remove both total nitrogen and total phosphorous.
- Sequencing Batch Reactor (SBR) Process: This is a suspended growth batch process, which is sequenced to simulate a four-stage process. It is used to remove total nitrogen.
- Modified University of Cape Town (UCT) Process: A /O Process with a second anoxic stage where the internal nitrate recycle is returned. It is primarily used to remove both total nitrogen and total phosphorous.
- Rotating Biological Contactor (RBC) Process: This is a continuous flow process, which uses RBCs along with sequential anoxic and aerobic stages. It is used to remove total nitrogen.
- Oxidation Ditch: This is a continuous flow process that uses looped channels to create time sequenced anoxic, aerobic, and anaerobic stages. It is mainly used to remove both total nitrogen and total phosphorous.
Even though the exact configurations of each system differ, biological nutrient removal systems designed for removing total nitrogen must have an aerobic zone for nitrification and an anoxic zone for denitrification. Whereas systems designed to remove total phosphorous must have an anaerobic zone free of dissolved oxygen and nitrate. Many a times, sand or other media filtration is used to remove particulate matter when low total nitrogen and total phosphorous effluent concentrations are required. Sand filtration can also be merged with attached growth denitrification filters to further reduce soluble nitrates and effluent total nitrogen levels.
Based on the above we can conclude that with the right configuration of water nutrients removal systems, high levels of nitrogen and phosphorus can be removed from wastewater. we at IDS Water have all the mentioned biological nutrient removal systems and much more. So what are you waiting for just browse through our directory as it will provide you with the details of numerous prospective vendors, vendors and suppliers to meet all your wastewater treatment requisites.
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