Wastewater plant begins nutrient recovery process

Canada's first commercial nutrient recovery facility has been opened at Saskatoon's Wastewater Treatment Plant (WWTP). The facility is the first of its kind in the country to recover nitrogen and phosphorus from wastewater at the WWTP in order to be used as a form of fertiliser.

The recovered components will be used to create a slow-release fertiliser, called crystal Green, which provides enhanced-energy to crops. The WWTP is a Level 4 plant, which is the highest available level of certification available for a wastewater treatment facility. This means that the facility is monitored 24 hours a day, seven days a week to ensure that all processes are performing correctly.  Quality is assured through the hundreds of thousands of analyses performed each year and by the electronic controls in place.

The new recovery equipment will enable the facility to remain below the nutrient discharge limits that are in place, which can help to reduce any potentially harmful substances from affecting the local environment. The removal of the nutrients will also help the machinery have a longer life, as the levels of struvite scale build-up will be reduced.

Struvite scale can reduce the machinery's ability to correctly function and increases the cost of maintenance and overall running at the WWTP. It is a deposit of minerals that has a similar consistency to concrete, meaning it is incredibly difficult to get rid of. Not only will the new recovery equipment reduce this build up and allow the machines to function correctly, it will also help to lower annual costs.

Some ten per cent of the nitrogen contained within the wastewater will be recovered, along with around 75 per cent of the phosphorous. This alternative also means that chemicals are not needed to reduce the build-up of struvite.

Jeff Jorgenson, utility services general manager, said: "Our priority is to protect the people, property and environment of the community we serve. This system makes our world-class facility even stronger, helping to fulfil our mandate as frontline stewards of our region’s watershed by removing otherwise polluting elements and transforming them into renewable and valuable resources."