Grantee Research Project Results
Final Report: High-Efficiency Nutrient Removal and Recovery for Achieving Low Regulatory Limits
EPA Contract Number: EPD18008Title: High-Efficiency Nutrient Removal and Recovery for Achieving Low Regulatory Limits
Investigators: Shirazi, Fatemeh
Small Business: Microvi Biotech, Inc.
EPA Contact: Richards, April
Phase: II
Project Period: February 1, 2018 through May 31, 2020
Project Amount: $300,000
RFA: Small Business Innovation Research (SBIR) - Phase II (2017) Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Water
Description:
The discharge of nutrients (e.g. phosphorus and ammonia) to surface waters can cause environmental imbalance and favor the formation of toxic algal blooms which threaten human health and the environment. An estimated $4.3 billion is lost each year in decreased property value, lost recreation opportunities, disturbances to wildlife, and deteriorating drinking water quality due to the eutrophication of freshwater in the United States. Current ammonia and phosphorus removal technologies such as chemical precipitation and conventional biological systems can be costly and ineffective to reliably achieve stringent effluent regulatory limits, which can be less than 0.1 mg/L for phosphorus in some regions.
The purpose of this project was to develop a novel, cost-effective solution for consolidating the treatment of phosphorus and ammonia in wastewater to achieve low limits while simultaneously facilitating the recovery of concentrated phosphorus that can be converted to a valuable resource for the agricultural industry and other markets. The core innovation behind the technology was the use of novel biocatalysts comprising of specialized microorganisms capable of rapidly and reversibly accumulating phosphorus from complex wastewaters while simultaneously degrading ammonia. Unlike conventional biological systems, the proposed technology does not rely on the growth and wasting of biomass, thereby enabling a less expensive and more energy-efficient process without the need for handling or disposing excess sludge.
Summary/Accomplishments (Outputs/Outcomes):
The Phase II project utilized a novel biocatalyst technology for enhanced biological phosphorus removal (EBPR), which allows rapid and effective removal of phosphorus from wastewater. The project's key objectives included designing, building and operating a sequencing batch reactor (SBR) pilot demonstration; determining optimal conditions for maximum phosphorus uptake; operating the reactor continuously; and determining conditions for phosphorus recovery, a key metric for proving the commercial viability of the novel technology.
Using an SBR configuration, the biocatalyst technology was installed at a local municipal wastewater treatment plant (WWTP) and tested under a variety of conditions to determine the optimal conditions for maximum phosphorus uptake. Under optimized conditions, the technology exhibited consistent removal of phosphorus down to <0.1 mg P/L from initial feed concentrations of 6-8 mg P/L within primary effluent from the WWTP. The technology was operated continuously for several months with no decrease in performance attributed to length of operation. Phosphorus removal based on the EBPR luxury uptake mechanism showed complete ammonia removal while achieving effluent P concentrations <0.1 mg/L. The activity of phosphorus uptake and release was attributed to EBPR microorganisms within novel biocatalysts and representative samples of the pilot process were profiled using 16S metagenomic sequencing. Results indicated a microbiological profile within the technology similar to conventional EBPR; the key difference is that the organisms in the biocatalyst are retained indefinitely and thus provide steady performance under changing conditions unlike conventional EBPR systems. Along with the removal of nutrients from wastewater, the recovery of phosphorus was also investigated. The technology exhibited phosphorus recovery up to 70% of that accumulated. The recovered phosphorus (up to 100 mg P/L in a recovery stream) could be concentrated and readily reused as a component of agricultural fertilizer or other industrial chemical manufacturing uses. Technoeconomic analysis was conducted for using the proposed technology compared with a conventional chemical phosphorus removal technology. Up to 52% cost savings could be realized depending on the size of the WWTP and other factors such as the resale value of recovered phosphorus.
Conclusions:
The Phase II projected supported the technical and commercial feasibility of the novel biological phosphate removal technology by identifying the optimal conditions for nutrient removal and recovery through a pilot demonstration. The achievement of phosphorus levels down to <0.1 mg P/L holds promise as an alternative to chemical precipitation to meet stringent phosphorus effluent limits imposed in many regions and jurisdictions around the world. Further, the biocatalyst technology represents a complete nutrient removal system. The research conducted in Phase II focused on an innovative technology to treat phosphorus by retaining a stable population of EBPR microorganisms and optimizing process conditions. As an added benefit, phosphorus recovery of up to 70% could be achieved, helping to offset operational costs and advance the recovery of this important resource.
Microvi's technologies have garnered significant interest from the wastewater industry in the U.S. and around the world. In addition to municipal wastewater treatment, the technology developed in Phase II has applications in the diverse industrial wastewater market as well as uses for agricultural runoff and stormwater treatment. The technology is protected by trade secrets and global patents granted and pending focusing on process design, engineering and process implementation. The novel technology is an attractive option for new and existing plants, both small and large, including those seeking higher efficiency nutrient removal options than currently implemented processes. The value proposition for the technology includes: (1) consistent phosphorus removal to below 0.1 mg/L; (2) reliable and robust operation; (3) no loss of performance due to shifts in the microbial community or water chemistry; (4) ease of implementation and operation; (5) rapid startup (days instead of weeks or months); (6) the rapid removal and subsequent release of phosphorus, leading to short retention times and decreased reactor footprints; (7) recovery of concentrated phosphorus as a high value product or as mineralization into struvite for reprocessing and reuse in agriculture; and (8) significantly lower overall costs than chemical precipitation when strict phosphorus limits are in place. Together, these advantages position the novel technology to meet significantly unmet needs in the $28 billion per annum global advanced wastewater treatment market and catalyze the transformation of wastewater treatment plants as resource recovery facilities.
SBIR Phase I:
High-Efficiency Nutrient Removal and Recovery for Achieving Low Regulatory Limits | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.