Water and Wastewater FAQs
How do I estimate the quantity of oxygen I need and what is the best way to control the dissolved oxygen levels?
Depending on the species of fish and the farm characteristics, Air Products water specialists can determine the requirements and the best way to inject and control the dissolved oxygen levels. Each species of fish and farm configuration are different and need a specific study to deliver the optimum solution. Based on many years’ experience in the sector, Air Products can specify the most suitable solution, from pure oxygen aerators to dissolved oxygen probes and transmitters. In addition, Air Products can design the oxygen injection panel to optimally manage the entire system based on the number of aerators.
What kind of gases are usually used in drinking water processes?
Ozone and carbon dioxide are the two main gases supplied by Air Products and commonly used in drinking water processes. Ozone is used for taste and odor removal, microcontaminant removal or disinfection. Carbon dioxide is mainly used for pH neutralization.
Is pure oxygen expensive compared to air to produce ozone?
Air-based ozone generators are huge consumers of energy. It is also necessary to treat the air flow before it enters the ozone generator to avoid humidity and organic pollutants entering the system. This pre-treatment requirement, allied to the high energy needs, make an air-based system expensive to operate and maintain. By using pure oxygen, the energy costs can be reduced threefold, while also eliminating the need for the expensive pre-treatments required with air. This makes the pure oxygen solution much lower in cost to the air system, while offering numerous technical advantages during operation.
Can pure oxygen replace air aerations systems?
Air Products technology allows you to boost the plant with pure oxygen without stopping the current air aeration. The concept we adopt is to cover the lack of oxygen that occurs during peak periods or to make up any shortfall from air aeration, all the while keeping the air aeration as active as possible. In some cases, pure oxygen will fully replace the air systems when the advantages, such as cost savings and productivity increase, are clearly identified or if the interactions between pure oxygen aerators and air-based aerators cannot be avoided. For every installation, Air Products’ technology and system expertise is focused on providing the most cost effective and efficient solution.
Is oxygenation a solution for nitrogen removal?
Nitrogen cycle in water plants consists of nitrification periods followed by denitrification ones. This process is managed by supplying enough oxygen during the nitrification phase (oxygenation period) to convert ammonia into nitrates that will be removed into gaseous nitrogen during the denitrification phase (period without oxygen). The balance between nitrification and denitrification phases has to be managed precisely. An effective way to cover the entire cycle of nitrification and denitrification within a limited period of time is to boost the periods of nitrification by accelerating the kinetics of reaction using pure oxygen, which allow more time for the denitrification period to reach the expected nitrogen level. Pure oxygen nitrification boosting is a reliable solution that requires no investment.
Is pure oxygen for water treatment expensive compared to air?
Air based aerators are obviously the main source of oxygen in a conventional treatment system. Although air is free, it limits the transfer efficiencies because of the huge quantity of energy required to handle the gas dissolution to make the dissolved oxygen. In the pure oxygen configuration, the gas concentration and the available pressure make the mass transfer more efficient, which results in pure oxygen devices reducing energy use fivefold compared to air-based systems. This energy savings closes the cost between the two technologies, with the pure oxygen solution similar to the air-based costs allowing you to benefit from the technical advantages offered to improve operational efficiency.
What benefits can oxygen, ozone and carbon dioxide bring to a water treatment plant?
Oxygen: this component brings process efficiency in every biological and aerobic based water treatment process. It is supplied in accordance with the process requirements to guarantee the stability and reliability of the entire treatment.
Ozone: this component is used where conventional biological treatments have reached their limits because of hard COD or low biodegradability. As a chemical precursor, ozone is one of the strongest oxidants and is easy to produce and apply.
Carbon dioxide: this product is well adapted for pH neutralization when the process requires a soft acid or when using strong acids is a safety issue.