Sanitaire is a name has the been synonymous with fine bubble and coarse aeration for years in the municipal water and wastewater markets. If you have installed any of their systems in your plant, then you have the O&M Manual explaining the what’s, how’s and when’s of routine maintenance; but how many plants are really keeping up with it? What difference does it make to the operation of your system from a process standpoint? What about from an efficiency standpoint? The following will explain why you should keep your ceramic diffusers clean and how we propose that you do it.

Biological secondary treatment is the single largest energy cost for a municipal activated sludge wastewater treatment plant, accounting for up to 60% of the total energy consumption of a plant. As a result, there is a great opportunity to save energy and money by ensuring that the system is running as efficiently as possible. The gradual fouling of diffusers happens over time and increases with each shutdown/ start-up that the aeration blowers experience. A fouled diffuser not only causes backpressure on the air header, but also results in inefficient transfer of oxygen. The photo below shows the impact that the fouling has on the bubble size and uniformity.

As you can see from the photograph, there is a notable difference in the quantity and size of the bubbles which greatly affects the oxygen transfer efficiency of your system as well as its energy usage. Regular cleaning and maintenance of your system will ensure that your system is working optimally with consistent performance and doing so with a substantial reduction in energy costs. There are five general warning signs that it’s time for you to clean your diffusers:

1. More air is required to maintain process performance
2. Residual DO levels are decreasing or are too low
3. The back pressure at the blowers in increasing
4. There is an increase in energy consumption of the blowers
5. It has been over a year since your last cleaning

The in-place gas cleaning that Pro Aqua offers has some very unique benefits that can greatly improve the performance of your aeration system and also minimize any impact to the process of the plant. The key benefits of the patented In-Place Gas Cleaning are as follows:

1. The cleaning can be done while the plant is in service without interruption or reduction in capacity. It is an in situ process that uses the air from normal blower operation to push the anhydrous HCl gas through the ceramic diffusers. There is no need to dewater the aeration tanks and remove them from service to return them to like-new.
2. It eliminates the need for any labour-intensive manual cleaning in confined spaces and the need to remove tanks from service.
3. The cleaning of the porous ceramic discs removes biologically-fouling and scaling.
4. The result of the In-Place Gas Cleaning will reduce the diffuser Dynamic Wet Pressure (DWP) to like-new condition and restores the Oxygen Transfer Efficiency (OTE) to the same.
5. It reduces blower back pressure, discharge volume, and electrical energy costs.
6. Diffuser cleaning not only has direct impacts on the process and performance of the diffusers, but also extends the life of blowers. Not only will there be a reduction in header pressure, but the amount of air required to maintain BOD goes down. As you can see in the photo above, the bubbles become much finer increasing contact surface area and maximizing the efficiency of the oxygen transfer.
7. This system is proven. There have been hundreds of installations to date that have returned the operation of the aeration systems to like-new condition.

The bottom -line benefits are significant power savings, improvement of process performance, elimination of plant downtime and reduced maintenance costs and it should be done routinely at least once per year depending on your plant’s loading.

To inquire further about our In-Place Ceramic Diffuser HCL Cleaning Service and see what the potential cost savings are for your plant, please contact Scott Lenhardt at 905-330-9244 or scott@proaquasales.com.