The International Water Association (IWA) is hosting its 2015 Nutrient Removal and Recovery Conference in Gdansk, Poland, from May 18-21. CH2M’s Samuel Jeyanayagam presents disruptive technologies and innovative practices for sustainable nutrient management.
Samuel presented his paper, “Accelerating the Implementation of Extractive Nutrient Recovery as an Integral Component of Sustainable Nutrient Management,” co-authored by R. Latimer, W. Khunjar, A. Pramanik, C. Mehta, and D. Batstone, on Monday, May 18, during the 2015 International Water Association’s Nutrient Removal and Recovery Conference. He will also moderate the session, “Source Separation for Nutrient Recovery,” on Tuesday, May 19, at 10:30.
Growing populations and rapid urbanization have strained our world’s resources. A recent study conducted by the Water Environment Research Foundation (WERF) identified innovative opportunities and technologies to enable water resource recovery facilities (WRRF) to make the paradigm shift to adopt extractive nutrient recovery to support the water-energy-nutrient nexus—a pivotal component of the Basins of the Future initiative.
Extractive nutrient recovery, defined as the production of chemical nutrient products devoid of significant organic matter, is seen as a disruptive technology in the wastewater industry.
Nitrogen (N) and phosphorus (P) are life essential macronutrients that are extensively used in agricultural applications. Production of synthetic fertilizers containing N and P is an energy intensive process that uses non-renewable resources. To minimize the accumulation of these nutrients in the environment, the current approach is to remove N and P prior to discharge to a water body. In this scenario, energy and other non-renewable resources are supplied to replenish nutrient supply for agricultural uses and again to remove these nutrients from wastewater before discharge to the environment. This linear approach, which assumes unlimited and cheap supply of energy and resources, is unsustainable, and therefore, disruptive approaches like extractive nutrient recovery are needed to reverse the status quo.
By implementing nutrient recovery, WRRFs can:
- Manage recycle loads and enhance P removal process
- Achieve chemical and energy savings
- Reduce solids production
- Achieve lower biosolids P content
- Minimize struvite nuisance scaling and lower maintenance requirements/cost
- Generate an environmentally-friendly product
- Create potential revenue stream from a highly desirable fertilizer product
- Enhance sludge dewaterability
- Achieve overall sustainability benefits
While nutrient recovery is being practiced via land application of biosolids and effluent reuse, extraction of a chemical nutrient product with low organic matter content has not been widely applied within the wastewater treatment industry. The nutrient concentration in municipal wastewater typically ranges from 10 to 50 mg N/L and from 1 to 10 mg P/L. Since the efficiency of extractive nutrient recovery is lower at these concentrations, a three-step framework is needed which includes accumulation of nutrients to high concentrations, release of nutrients to a small liquid flow with low COD and extraction of a chemical nutrient product that is marketable and could potentially off-set operating costs and synthetic fertilizer use.
Taking this approach, WRRFs can be part of the solution to optimizing the water-energy-nutrient nexus, in addition to accelerating the shift in industry perception of wastewater from ‘waste’ that must be treated to valuable ‘resource’ that can be recovered and reused.
Included in the WERF study, is an Excel™ based tool which allows users to perform a site-specific triple bottom line evaluation and explore payback scenarios of the treatment options by considering 13 factors, such as net present value, environmental benefits, technology maturity and treatment plant impacts, among others. Utilities, such as the Hampton Roads Sanitation District’s Nansemond Treatment Plant in Virginia, USA, have used this tool and adopted sustainable nutrient management practices.
Samuel Jeyanayagam is a technologist at CH2M. With more than 35 years of consulting and academic experience, Samuel is an expert in nutrient removal/recovery, biosolids management and disinfection. He has authored and presented more than 160 papers and co-authored more than 25 Water Environment Federation (WEF) publications. He serves as Task Force Chair for WEF’s Nutrient Roadmap. He is located in the firm’s Chantilly, Virginia office.