Grantee Research Project Results

Final Report: Energy and Nutrient Extraction From Onsite Wastewater

EPA Contract Number: EPD13017
Title: Energy and Nutrient Extraction From Onsite Wastewater
Investigators: Smith, Daniel P.
Small Business: Applied Environmental Technology
EPA Contact: Richards, April
Phase: I
Project Period: May 15, 2013 through November 14, 2013
Project Amount: $79,938
RFA: Small Business Innovation Research (SBIR) - Phase I (2013) RFA Text | Recipients Lists
Research Category: SBIR - Water , Small Business Innovation Research (SBIR)

Description:

Onsite systems treat over 20 percent of U.S. wastewater and result in substantial nutrient release into the environment. Elevated nutrient loadings lead to stimulation of primary production, eutrophication and harmful ecological effects in receiving waters. Nitrogen release in particular is implicated in deterioration of surface water quality, including Cape Cod and Chesapeake Bay. Applied Environmental Technology (AET) has developed a biological and ion exchange process to capture nutrients and energy from wastewater that is suitable for onsite applications. Extracting nutrients and energy reduces environmental pollution and creates options for beneficial use.

Summary/Accomplishments (Outputs/Outcomes):

The Phase I project evaluated a completely passive "single-box" biological/ion exchange process that operates without aeration, energy supply, or process control. AET demonstrated that the process was highly effective in reducing nitrogen from real wastewaters.Two systems were evaluated at different locations, one receiving whole-house wastewater and the second receiving primary effluent. Total nitrogen reduction was consistently greater than 95 percent in both systems, and ammonium ion was below detection limits in system effluent. The captured nitrogen is known to be sorbed reversibly and can be recovered from the media for beneficial use. It also was demonstrated that the production of oxidized nitrogen was eliminated completely in continuous operation over extended times. Effluent from the biological/ion exchange process was suitable for dispersal in natural soil, as evidenced by near-saturation dissolved oxygen levels after being passed through an external unsaturated granular media column. Time-course monitoring of nitrogen species and water chemistry were conducted, as well as tracer analysis, in order to elucidate key performance factors and establish a basis-of-design for full-scale systems. Life Cycle Cost Analysis confirmed the economic viability of the process and elucidated the critical factors affecting process costs.

Conclusions:

Two prototypes of a biological/ion exchange process were operated to evaluate nutrient and energy extraction from wastewater.
The process operates passively without aeration, energy supply or process control.
The process is an environmentally friendly, appropriate technology for local onsite deployment.
Total nitrogen reduction was consistently greater than 95 percent in both systems, and ammonium ion was below detection limits in system effluents.
The production of oxidized nitrogen was eliminated completely.
Tracer analysis elucidated the non-ideal characteristics of flow.
A basis-of-design was established for full-scale systems.
The economic viability of the process was confirmed.
The process opens an avenue for beneficial nitrogen and sorbent reuse.

The Phase I effort provided proof-of concept, the basis to optimize full-scale module designs and commercial feasibility. Commercialization will be realized when successful field pilot results are completed and certified. Pilot testing will be conducted in a real-world milieu at the Massachusetts Alternative Septic System Test Center on Cape Cod. Commercial applications include single-family homes, multihome cluster systems and commercial establishments. Commercialization partners will be incorporated for manufacture, marketing and installation. Additional research and development will be conducted to evaluate media regeneration schemata and beneficial use of extracted nitrogen, which will further increase economic viability.

Supplemental Keywords:

wastewater treatment, ion exchange, biological treatment, nitrogen, nutrient removal

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