Oxygenation wastewater treatment

Wastewater treatment is crucial in many industrial and domestic sectors. It guarantees the quality of the water discharged into the environment, prevents pollution and ensures public health. This complex, multi-stage process involves various technologies and solutions which, when properly implemented, enable sustainable water management.

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Novair designs and manufactures innovative oxygen generators, offering a self-contained, reliable and highly energy-efficient solution for optimizing the oxygen supply required for wastewater treatment.

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Understanding wastewater treatment

Wastewater treatment is essential for preserving water resources and limiting pollution. It encompasses a series of physical, chemical and biological processes designed to eliminate the pollutants present in water before it is discharged into collection networks or used again for various applications. Treatment takes place in several stages: collection, pre-treatment, primary, secondary and sometimes tertiary treatment.
To assess the efficiency of these treatments, two major indicators are used: Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD).

• COD measures the total quantity of oxygen required to chemically oxidize the organic matter present in water, including substances that are difficult to degrade.
• BOD measures the oxygen consumed by micro-organisms to biologically decompose biodegradable organic matter, over a given period (usually 5 days).

These parameters are essential for sizing plants and monitoring the efficiency of biological treatment stages.

Definition of wastewater treatment and its importance for the environment and industry

Wastewater treatment is the removal of harmful substances from water. Wastewater comes from a variety of sources: industrial, domestic, agricultural and so on. The main aim is to reduce pollution, including organic matter, sludge, solid waste and pathogens. This treatment ensures that the water returned to the networks or discharged into the environment complies with water quality standards, thus protecting public health and aquatic ecosystems.

Common stages involved in the wastewater treatment process

The wastewater treatment process generally follows several stages:

• Wastewater collection:
  domestic wastewater, initially discharged into a gravity sewer system, as well as industrial wastewater, is conveyed to treatment facilities via pumping stations and a lifting network. This stage is often faced with issues such as odors and corrosion, mainly caused by H₂S.
  
  
• Primary treatment:
  the aim is to eliminate coarse solid waste, suspended solids and reduce the organic load, mainly by decantation or filtration.
  
  
• Secondary treatment: Secondary treatment relies on biological processes using micro-organisms (bacteria and others) to break down dissolved organic matter. This stage can take place under aerobic or anaerobic conditions, but aerobic filtration is the most widespread, thanks to the maintenance of dissolved oxygen levels via aeration. However, the use of pure oxygen is gaining in popularity thanks to its superior performance.
  
  
• Tertiary treatment:
  This stage is optional and allows specific treatment of remaining pollutants, such as phosphorus, nitrates and other chemicals.
  
  
• Sludge disposal:
  The sludge generated throughout the process is treated and, in some cases, recycled.

The benefits of industrial gases in wastewater treatment

Oxygen is an essential element in wastewater treatment, particularly in the biological stages. Traditionally, oxygen is supplied by aeration, using ambient air containing only 20% oxygen. However, pure oxygen is 4.8 times more soluble in water than oxygen from air, enabling more efficient oxygenation. Its use optimizes the degradation of organic pollutants, reduces the load of organic matter and significantly improves the efficiency of wastewater treatment systems.

Explaining the use of oxygen in wastewater treatment

Oxygen is essential to promote the activity of aerobic bacteria, which break down organic pollutants in wastewater treatment plants. On-site oxygen production, via generators, ensures 95% purity, guaranteeing optimal purification.

The Advantages of Oxygen

The use of oxygen in wastewater treatment offers several benefits:

• Increased Treatment Capacity: Pure oxygen dissolves in water more efficiently than air. Injecting pure oxygen into your biological basin can boost the capacity of your wastewater treatment plant by up to 50%.
  
  
• OPEX Savings: The total electrical power required to transfer pure oxygen into water is reduced by 50% compared to transferring air. This leads to at least a 25% reduction in operational and maintenance costs.
  
  
• CAPEX Reduction: Implementing pure oxygen technology reduces the size of new wastewater treatment plants or increases the capacity of existing ones. Enhanced oxygen dissolution facilitates nitrification (ammonia oxidation) within your treatment basin.
  
  
• Foam Elimination: Foam often forms in wastewater treatment plants due to an excess of filamentous bacteria, where large quantities of injected air create flocs in the water. Using pure oxygen instead of air reduces the amount of filamentous bacteria and gas by a factor of 5.
  
  
• Odor Elimination: Insufficient dissolved oxygen for microorganism respiration leads bacteria to consume sulfur compounds from water pollutants. This produces hydrogen sulfide (H₂S), a volatile compound with an unpleasant odor. Using pure oxygen eliminates this odor by providing sufficient dissolved oxygen.
  
  
• Efficient Sludge Treatment: Ozonation of sludge maintains bacterial activity, increases settling speed (SVI index between 50–100 ml/g), and decreases excess sludge production by 60%. Our solution allows for the reuse of oxygen-rich off-gas from the ozonation process, making the entire treatment process cost-effective.

Innovation from Novair in wastewater treatment

Novair is a leading innovator in on-site oxygen production for wastewater treatment. Thanks to its advanced oxygen production technologies, Novair offers high-performance solutions tailored to the needs of wastewater treatment plants, sewage networks and industries.

Introducing Novair's innovative technologies and solutions for on-site oxygen production

Novair offers oxygen generators for on-demand production with 95% purity. These tailor-made systems meet the requirements of water treatment plants, reducing dependence on external suppliers and guaranteeing seamless continuity of service.

Use cases for oxygen generators in water treatment

Novair oxygen generators play a key role in optimizing wastewater treatment processes, whether for municipal or industrial applications. Here are their main uses:

• Preventing the formation of H₂S in lifting networks.
  In wastewater collection stages, our oxygen generators enable the direct injection of oxygen into lift networks. This prevents the formation of hydrogen sulfide (H₂S), a gas responsible for infrastructure corrosion and unpleasant odors.
  
  
• Biological treatment in wastewater treatment plants
  Our oxygen generators are used for biological stages in wastewater treatment plants, whether for domestic or industrial wastewater. Pure oxygen injected into biological basins enhances the degradation of organic matter, promotes nitrification and increases the efficiency of aerobic processes.
  
  
• Feeding ozone generators for chemical treatment
  In some cases, oxygen produced on site is used to power ozone generators. Ozonation, an advanced chemical process, eliminates micropollutants and disinfects wastewater to meet more stringent quality standards.

Benefits of Novair's on-site gas solutions

Novair's on-site gas solutions offer multiple advantages for both industry and public networks.

Improved gas purity

Oxygen produced at 95% guarantees optimum performance in water treatment plants, contributing to better treated water quality.

Reduced logistical constraints linked to gas supply

Producing gases directly on site reduces the costs and constraints associated with the delivery of compressed or liquid gases, offering a more economical and reliable solution.

Positive impact on operational safety

Novair oxygen generators are designed to operate autonomously, minimizing the risk of downtime and ensuring worker safety.

Practical applications and customer testimonials

Novair solutions are successfully used in various sectors to improve wastewater treatment. Customer testimonials from both the public and private sectors demonstrate the positive impact of Novair technologies on the performance of water treatment systems.

Case studies demonstrating the effectiveness of Novair solutions in wastewater treatment

In an urban wastewater treatment plant, the introduction of Novair generators has improved treatment efficiency, reducing treatment times and guaranteeing the quality of the water discharged into the networks.

Customer testimonial

A wastewater treatment plant in Milan, Italy, gained greater autonomy and efficiency in its operations by choosing NOVAIR's on-site oxygen production solutions. Our high-efficiency LPSA oxygen generator, model OP-80+EOP-80 Ecoline, provides the optimum oxygen required for wastewater treatment, eliminating dependence on external liquid oxygen suppliers.

This turnkey solution, housed in a convenient 40' HC shipping container, provides:

• 80 m³/h oxygen production at 93% purity and 3 bar outlet pressure
• Reduced operating costs: Specific energy efficiency of 0.9 kW/m³.
• Increased operational flexibility: LPSA master and slave generator concept ensures continuous operation.
• Environmentally friendly: Low energy consumption minimizes environmental impact
• Quiet operation: Noise level reduced to 75 dBA

Novair's commitment to the environment and safety

Novair's commitment to the environment and safety is at the heart of its approach. The solutions we offer enable us to effectively treat wastewater while complying with the most stringent environmental standards.

Sustainable practices and the company's environmental commitments

Novair is committed to minimizing its environmental impact by developing eco-responsible solutions that promote the reduction of pollution and the sustainable management of water resources.

Certifications and safety standards respected by Novair

All Novair installations comply with strict quality and safety standards, guaranteeing risk-free operations and optimum performance in water treatment.

Conclusion

Wastewater treatment is a priority to guarantee water quality, reduce pollution and protect the environment. Novair, with its innovative on-site gas production solutions, offers considerable advantages for water treatment plants, sewage networks and industries.