Grantee Research Project Results

2024 Progress Report: Technology for Recovery and Reuse of Plant Nutrients as a Prevention Strategy for Hazardous Algal Blooms

EPA Grant Number: R840085
Title: Technology for Recovery and Reuse of Plant Nutrients as a Prevention Strategy for Hazardous Algal Blooms
Investigators: Apblett, Allen W. , Materer, Nicholas F.
Institution: Oklahoma State University
EPA Project Officer: Ludwig-Monty, Sarah
Project Period: September 1, 2020 through April 25, 2025
Project Period Covered by this Report: September 1, 2023 through August 31,2024
Project Amount: $687,660
RFA: Approaches to Reduce Nutrient Loadings for Harmful Algal Blooms Management (2020) RFA Text | Recipients Lists
Research Category: Harmful Algal Blooms , Water

Objective:

The main objective of the research is to develop a novel technology for sustainably and economically preventing harmful algal blooms in watering ponds. The approach is based on the hypothesis that sorption of nutrients from ponds or fertilizer run-off using a sorbent/fertilizer that allows for the absorbed nutrients to be used as a time-release fertilizer will provide a sustainable solution for the prevention of hazardous algal blooms while also reducing the environmental and financial costs associated with the decontamination of ponds and the production of fertilizers.

Progress Summary:

The research design involves: (1) The synthesis of eight candidate magnesium-aluminum oxide and magnesium-iron oxide sorbent media with varying magnesium to metal molar ratios. (2) Determination of the sorbent medias' kinetics and uptake capacities for urea, ammonium, phosphate, and nitrate ions (3) Demonstration of the sorbent medias' ability to treat algae-prone pond water (5) Field testing of the developed sorbent media in farm ponds and (6) Plant growth studies using nutrient-loaded sorbent media as a fertilizer.

The major output of this research project is a novel treatment technology for the capture of nitrogen and phosphorus from water in a fashion that the plant-nutrient containing sorbent can be applied as a fertilizer. This technology will provide improved control of nitrogen and phosphorus runoff into waterways that can reduce the occurrence of harmful algal blooms and hypoxia in U.S. waterways and coastal areas. The ability to accomplish this will have a definite positive impact on the protection of both human and ecosystem health. It will absolutely provide the means for extensive risk management of harmful algal blooms. The technology can readily be adapted to point sources and nonpoint sources of plant nutrients such as septic tanks, animal feedlots, brewery waste, municipal wastewater, and urban storm water runoff. Further, the technology could be adapted to sites that are unsuitable for traditional septic systems. The proposed solution to nutrient removal from wastewater will provide significant economic, environmental, and food supply benefits. The ability to recover some of the costs of water treatment through fertilizer sales, sorbent reuse will make it possible for municipalities, farmers, landowners and industry to economically prevent nutrient pollution of rivers, lakes, and aquifers.

Inexpensive sorbents have been synthesized from earth-abundant elements and have been optimizes to have excellent capacities for the plant nutrients, phosphate and nitrate. In particular, exceptionally high-capacity sorbents for nitrate were produced that bode well for a novel treatment technology that can capture nitrogen and phosphorus in a form that can be applied as a fertilizer. It was determined that the high uptake values are due to a unique uptake mechanism. Rather than physical adsorption on a surface, the plant nutrients undergo ion-exchange with surface hydroxides.

The new technology will provide improved control of nitrogen and phosphorus runoff into waterways that can be used to actively inhibit the occurrence of harmful algal blooms and hypoxia in U.S. waterways and coastal areas. The ability to accomplish this will have a definite positive impact on the protection of human and ecosystem health. The technology can readily be adapted to point sources and nonpoint sources of plant nutrients such as septic tanks, animal feedlots, brewery waste, municipal wastewater, and urban storm water runoff. Further, the technology could be adapted to sites that are unsuitable for traditional septic systems. It has been shown that the novel sorbents can function well in column form or in passive treatment beds to treat plant nutrient impacted and algae-prone water.

The proposed solution to nutrient removal from wastewater will provide significant economic, environmental, and food supply benefits. The ability to recover some of the costs of water treatment through fertilizer sales or its use will make it possible for municipalities, farmers, landowners and industry to economically prevent nutrient pollution of rivers, lakes, and aquifers Preventing eutrophication of lakes and ponds is critical to EPA's mission to protect environmental health while capturing and recycling nutrients is relevant to EPA's research mission to promote energy efficiency and environmental stewardship.

Future Activities:

We plan to complete the following tasks:

Objective 2 - Determination of the Sorbent Medias' Kinetics and Uptake Capacities for Plant Nutrients: Finalize for publication.
Objective 3 - Demonstration of the Medias' Ability to Treat Water from Algae-Prone Pond: Complete column treatments of waters collected from target ponds.
Objective 4 - Field Testing of Developed Media at Sites of Viable End Users.

Travel is planned to the various field sites.

Journal Articles:

No journal articles submitted with this report: View all 2 publications for this project

Supplemental Keywords:

Srinking water, watersheds, adsorption, aquatic, environmental chemistry, Midwest, recovery and reuse

Progress and Final Reports:

Original Abstract

The 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.