Micro-sized air bubbles required for DAF Plant

Veolia Northern Territory was looking for a low-maintenance, low-operator requirement, simple, cost-effective solution to provide a large amount of micro-sized air bubbles for the DAF system at its wastewater treatment facility at Berrimah, according to the company's Technical Services Engineer, Dion Meta.

The options

“An article by Sustainability Matters was published which outlined the benefits of the EDUR DAF pump. This then prompted me to look into the product as we needed something simple and reliable,” Meta said. In that article, Australian distributor for EDUR Pumps, Hydro Innovations, described how the single EDUR pump could replace not only the existing recycle pump, but also the air saturation vessel and the compressor.

How does the EDUR ‘multiphase’ pump work?

The EDUR multiphase pump has the unique ability to handle a gas/liquid mixture. This enables the pump to draw in atmospheric air when pumping recycled water from the DAF tank where it mixes the air with the water being simultaneously drawn from the DAF tank.

A discharge throttle valve puts the discharge air/water mix under pressure [approximately 6 bar], which ‘forces’ the air into solution with the water. When the solution reaches the DAF tank, the reduced pressure in the tank causes the air to come out of solution to form microscopic bubbles [30-70 microns] which then attach to fats, oils and grease, and floats them to the surface.

The results

“The results have been very good. We are producing a significant amount of dissolved air and our treatment results have improved (eg, reduction in sulphide, reduction in hydrocarbons),” Meta said.

Besides the simplicity of the system, asset owners can expect a reduction in running costs, according to Hydro Innovations. Although Veolia did not have a compressor previously, other DAF plant asset owners can cut the costs associated with running a compressor, cut the yearly certification costs of the air saturation vessel, and won’t need the more complicated control systems.

When asked what he expected from his new EDUR pump asset, Meta said “Long-term benefits are that our results continue to improve. I am also hopeful that the DAF pump will last a long period of time with little maintenance requirements.”

Image credit: ©stock.adobe.com/au/schankz