[캐나다] 영양염류 재생 시술, 수질 오염 억제에 도움

Portage la Prairie의 수질 오염 통제 시설(WPCF)은 시설의 영양염류 부하 처리 및 관리를 돕는 혁신적인 기술을 평가하기 위해 파일럿 프로그램을 시행하고 있다고 밝혔다.
Ostara Nutrient Recovery Technology에서 개발한 Ostara Pearl 공정은 처리된 폐수에서 인을 회수하고 환경친화적인 완용성 비료로 전환한다. 이 공정은 새로운 인 배출 제한을 충족하고 추가적인 재원을 도시에 제공한다.

The City of Portage la Prairie's Water Pollution Control Facility (WPCF), located in the Central Plains Region of Manitoba, Canada, is implementing a pilot program to evaluate innovative technologies that help manage nutrient loads treated at the facility.

One such technology is the Ostara Pearl®process, developed by Ostara Nutrient Recovery Technologies, which recovers phosphorus from treated wastewater streams and transforms it into an eco-friendly, slow-release fertilizer. The process will not only help the plant meet new phosphorus discharge limits but would provide an additional source of revenue to the city -- all while helping to protect the local watershed.

Portage la Prairie is a part of the massive Lake Winnipeg watershed, which is the focus of a concerted provincial environmental policy effort designed to reduce nutrient runoff entering the lake. Excess phosphorus contributes to the growth of algae, which chokes off sunlight and oxygen, destroying aquatic life. As part of its comprehensive water strategy, the province has identified nutrient management initiatives as a key driver of water quality.

"While the primary goal of this pilot program is to provide strategic options to help us meet nutrient discharge obligations, it also allows us to play an active role in supporting the province's efforts to reduce the environmental impact of nutrient pollution on the Lake Winnipeg watershed," said Kelly Braden, director of operations at the facility.

Over 55 percent of the 15 million liters of influent treated every day at the WPCF is industrial wastewater, originating from local food processors, such as Simplot and McCain Foods, and containing significantly higher concentrations of phosphorus and nitrogen compared to non-industrial sources. According to Braden, the new technologies could help the facility treat these elevated nutrient loads.

Ostara's Pearl process recovers up to 85 percent of the phosphorus and 25 percent of the nitrogen from treated wastewater streams, helping plants overcome operational issues caused by the unintentional build-up of struvite scale, a concrete-like mineral deposit caused by excess nutrients that chokes process equipment, increases operating costs and undermines plant reliability. The recovered nutrients are transformed into a slow-release, eco-friendly fertilizer called Crystal Green®.

Unlike conventional water-soluble fertilizers, Crystal Green is highly insoluble in water. Instead, it is Plant-Activated™, releasing nutrients in response to root growth, resulting in greater efficiency, lower application rates and reduced risk of nutrient loss through leaching and runoff. Likewise, a nutrient recovery system at Portage la Prairie could potentially recover close to 100 tons of phosphorus each year, enough to produce 650 tons of Crystal Green.

In addition to the Ostara process, the city is also evaluating a solution to remove ammonia. Veolia's ANITATM Mox system helps treatment plants manage ammonia loads in their wastewater streams with a removal efficiency of over 80 percent. This is the first time the Pearl process will be deployed with an ammonia removal system, potentially providing greater efficiencies in nutrient recovery and management. The city expects the pilot program to be completed by July 30, 2014.

[출처 = Water World / 2014년 7월 1일]