If ammonia levels rise in wastewater it can trigger a series of issues. Not only is the buildup in wastewater a regulatory challenge, it’s also a serious environmental issue. If ammonia levels increase in a body of water, aquatic life will suffer. There will also be a spike in algae blooms as the amount of nutrients increases, and the water’s health and purpose will be affected.
The best way to reduce and prevent ammonia? The process of aeration. Aeration helps clean the water by adding oxygen, which boosts natural processes that lower ammonia levels.
Australian Environmental Regulations on Ammonia in Wastewater
Australia has some of the strictest regulations for managing ammonia levels in water.
State Environmental Protection Authorities (EPAs) impose ammonia discharge limits across various industries, guided by the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG).
The purpose of these regulations is to:
- Protect aquatic life from harmful, toxic ammonia.
- Prevent eutrophication, which occurs when a body of water is filled with extra nutrients. This will increase the amount of algae in the water, and kill aquatic life as it blocks oxygen and the sunlight from filtering through.
- Keep water quality safe for whatever purpose it has. This might be agricultural, recreational, or public.
Treatment facilities need fast and effective ways to remove ammonia to keep the water conditions intact and to stay compliant to the Australian regulations. A key part of the solution? The process of aeration.
Why is Ammonia a Problem in Wastewater?
The Australian government has regulations against excessive ammonia levels in place for a reason. But what makes ammonia such a problem? In wastewater, ammonia tends to come from organic waste, farming runoff, or industrial processes. If it’s left untreated, it can:
- Lower dissolved oxygen levels, causing aquatic life to suffer or die
- Bring about odours while decreasing overall water quality
- Fail to comply to environmental guidelines
- Disrupt recreational or irrigation use of affected water bodies
How Aeration Supports Ammonia Reduction
In order to overcome the issues caused by ammonia, plenty of people running the water facilities look into the process of aeration. To do this, they need powerful aerators.
Aeration is the process of adding oxygen to water by keeping it in motion at all times by means of a water pump. While doing so, the oxygen-rich top-waters sink to the bottom. And deoxygenated bottom-waters move towards the surface. Aeration occurs at the surface by gas exchange between the air and the water, and oxygen enters the water as “bad” gasses, such as ammonia leave.
Nitrosomonas and Nitrobacter are two types of beneficial bacteria found in water. You might know them as “nitrifying bacteria”. Through the process of “nitrification”, they help break down ammonia.
Here’s how:
- Nitrosomonas bacteria turn ammonia into nitrite
- Nitrobacter bacteria further oxidise nitrite into nitrate, an even less harmful form that can be removed later through denitrification
Without aeration adding oxygen into the water, these two types of bacteria wouldn’t work properly. They convert ammonia into harmless compounds and help facilities meet discharge limits.
Types of Aeration Systems for Wastewater Treatment
To help with the removal of ammonia in wastewater, different kinds of aerators are used.
These include:
Surface Aerators
Surface aerators are less commonly used in wastewater treatment as, being at the surface of the water, they can release contaminated water droplets into the air. Of course, this is a risk that operators want to avoid. However most surface aerators are designed with this in mind and have features that prevent this from happening.
They work by spinning a motor at the surface quickly, throwing water into the air to create splashes and ripples. This water, when in the air, absorbs oxygen from the atmosphere. Then, the aerator mixes the oxygen-rich water at the top with the deep water at the bottom, circulating oxygen in the water. This is known as agitation.
Key benefits of surface aerators:
- They float on the water’s surface and agitate it to boost oxygen levels
- Best suited for larger water bodies like ponds, lagoons, or wastewater basins
- Designed for safe, efficient use in wastewater environments
Air-O-Lator’s Commercial Aerator is an excellent surface aerator, as it comes with a specially engineered diffuser mounted on top to prevent any contaminated water reaching the air. It boosts aeration by redirecting the water flow without slowing it down, so water isn’t sprayed aimlessly into the air.
Sub-Surface Aeration
Sub-surface aeration is generally best for deeper lagoons, tanks, or ponds. Diffusers are generally installed at the bottom of the body of water and produce very fine bubbles that migrate to the surface. On their journey, oxygen inside them is dissolved in water and dispersed throughout the entire water body.
When this happens, the nitrifying bacteria we mentioned before has enough oxygen to get to work on any ammonia and convert it into nitrate.
Key Benefits:
- Releases fine bubbles at the bottom, promoting even oxygen distribution
- Encourages the growth of beneficial bacteria for more efficient water treatment
- Ideal for deep wastewater treatment systems that require consistent aeration
The Vertex Aerator is a great sub-surface aerator that works efficiently to promote oxygen from the bottom of a water body. It uses less power than surface aerators and can aerate water bodies of all sizes. This aerator is designed to maximise oxygen transfer and microbial activity, making it effective for treating deep wastewater systems.
Nanobubble Aerators
Nanobubble technology is still in its early days but already has a great deal of potential in wastewater treatment. By generating ultra-fine bubbles that remain suspended in water for longer, this innovative approach maximises oxygen transfer and improves the breakdown of harmful substances like ammonia. While sitting in the water, the bubbles slowly dissolve and release oxygen deep in the water where it’s needed most.
Key Benefits:
- Increases oxygen transfer efficiency by generating ultra-fine bubbles that remain suspended for longer
- Stimulates microbial activity and improves oxidation processes, enhancing ammonia breakdown
- Suitable for both industrial and municipal wastewater applications.
Our Nanobubble Aerator adds 95% of pure O2 into the water and can stay suspended for weeks at a time. As the nanobubbles stay suspended, they oxygenate deep waters where problems like algae and sludge occur.
Choosing the Right Aeration System
So what system is right for your wastewater and its particular needs? When choosing the right aeration system for wastewater treatment, keep these factors in mind:
Water Volume and Depth
For effective oxygen distribution in deeper bodies of water, sub-surface or nanobubble aeration is usually necessary, making water depth an important factor to consider. In shallow ponds, sub-surface aerators might be less necessary and effective, making surface aerators a better option.
Ammonia Levels:
The amount of ammonia in your wastewater will determine the type of aeration system required for effective removal. For example, if you have high levels of ammonia, a nanobubble aerator will target the problem area at the bottom where oxygen levels are low.
Environmental Regulations:
You need to make sure you meet the regulations when it comes to ammonia levels. It’s important that the aeration system you choose complies with local ammonia level and water quality regulations.
Energy Efficiency and Maintenance Costs:
Go for an aeration system that balances good performance, energy savings, and easy maintenance. This way, you can keep costs in check
Accelerating Ammonia Removal with Nitrifying Bacteria
Although aeration is vital for reducing ammonia in wastewater, it takes time for the bacteria needed to support the nitrification process to establish. For this reason, a lot of wastewater treatment facilities use nitrifying bacteria supplements to speed up the ammonia breakdown process. These additives contain concentrated Nitrosomonas and Nitrobacter strains, which speed up the natural process for quicker results.
Nitrifying bacteria are especially useful when:
- When rapid ammonia reduction is required to meet strict regulatory limits
- When a new aeration system is installed, and the bacterial colonies are still developing
- When ammonia spikes occur due to seasonal changes or temporary system disturbances
If you want faster results while aeration kicks in, AquaFix VitaStim Nitrifiers or WaterTreats Nitrifying Bacteria will work quickly to speed up the process. It uses strong nitrifying bacteria to speed up how quickly ammonia is broken down, helping meet environmental regulations and improving water quality quickly.
The Importance of Aeration for Controlling Ammonia
Aeration is important because it increases the amount of oxygen, which is needed for nitrifying bacteria to break down the ammonia. Aquatic life will be adequately supplied with oxygen, overall water quality will be better, and you will be in line with environmental regulations.
Investing in a high-quality aeration system is a smart choice for cleaner, healthier water. Check out our range of sub-surface aerators and air stations today for effective ammonia control, or contact us at Water Quality Solutions for more details.