Grantee Research Project Results

2022 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, 2021 through August 31,2022
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:

In year 2 the project objectives were:

Objective 1: Synthesis of Magnesium-Aluminum and Magnesium-Iron Layered Double Hydroxide Materials.
- Complete the optimization of the synthesis parameters for the 2Mg:Al and 2Mg:Fe sorbent medias
Objective 2: Determination of the Sorbent Medias’ Kinetics and Uptake Capacities for Plant Nutrients
- Perform kinetic measurements for rates of uptake be analyzing sorbent/ aqueous plant nutrient mixtures by colorimetry with time
Objective 3: Demonstration of the Medias’ Ability to Treat Water from Algae-Prone Ponds
- Collect water from the selected ponds, analyze for phosphorus and nitrogen species and treat with media using fixed bed columns and the Bed Depth Service Time (BDST) model
Objective 4: Field Studies
- Beginning in spring 2022, collect and analyze water bimonthly from the target ponds. The freshly drawn samples will be subjected to water quality measurements including redox potential, dissolved oxygen concentration, total hardness, and the total alkalinity using appropriate meters and test strips. In the laboratory, the concentrations of urea, nitrate, ammonium, total nitrogen, and phosphate will be determined.

Progress Summary:

Inexpensive sorbents have been synthesized from earth-abundant elements and have been shown to have high capacity 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.

This 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. Thetechnology 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 was determined 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 3: Demonstration of the Medias’ Ability to Treat Water from Algae-Prone Ponds.
- Complete batch and column treatment of waters collected from target ponds
Objective 4: Field Testing of Developed Media at Sites of Viable End Users
- Includes lab testing and in-field remediation activities. In addition to the activities in the proposal, there is a site in the feed water to the Lawton pond where we will test a passive treatment with a porous bag of media after a rain event leads to flow through the drainage ditch.
Objective 5: Plant Growth Studies Using Nutrient-Loaded Sorbent as a Fertilizer.

Journal Articles:

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

Supplemental Keywords:

drinking 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.