Grantee Research Project Results
Novel Mineral-Hydrogel Composites for Effective Nutrient Removal to Manage Harmful Algal Blooms
EPA Grant Number: R840084Title: Novel Mineral-Hydrogel Composites for Effective Nutrient Removal to Manage Harmful Algal Blooms
Investigators: Jun, Young-Shin , Tang, Yinjie
Institution: Washington University in St. Louis
EPA Project Officer: Ludwig-Monty, Sarah
Project Period: September 1, 2020 through August 31, 2023 (Extended to August 31, 2024)
Project Amount: $800,486
RFA: Approaches to Reduce Nutrient Loadings for Harmful Algal Blooms Management (2020) RFA Text | Recipients Lists
Research Category: Harmful Algal Blooms , Water
Description:
Harmful algal blooms (HABs) not only threaten industries like fisheries and tourism, but also affect public health by producing cyanobacterial toxins. To address the growing concerns caused by HABs, we propose to develop novel calcium alginate hydrogel composites seeded with calcium phosphate (Ca-Alg/CaP) that effectively remove and recover phosphorus (P) and nitrogen (N). The proposed work has three objectives with accompanying research approaches.
Objective:
Objective 1: Develop a nutrient removal and recovery method, based on calcium alginate (Ca-Alg) and calcium phosphate (CaP) mineral seeds, that robustly captures P and N in a wide variety of nutrient-enriched waters (in particular, municipal wastewaters or waters polluted by surface runoff). We will further develop the technology by (i) optimizing the mineral seed morphology and crystallinity, (ii) constructing composites containing both calcium silicate hydrate (CSH) and CaP, and (iii) adding the ability to adsorb N in the form of ammonium (NH4+) through the addition of polyacrylic acid grafted onto carboxymethylcullulose (PAA-g-CMC). We hypothesize that the addition of CSH will strengthen the Ca-Alg/CaP composite platforms, and that the microstructure and chemistry of the composites will control their efficacy.
Objective 2: Construct predictive kinetic and equilibrium models to quantify the composite's performance in real nutrient-enriched water so that it can be successfully scaled-up beyond the bench. In particular, we will study nutrient adsorption isotherms and removal kinetics, as well as the composite's reusability, reswellability, and nutrient recovery. We will also consider the incorporation of potentially harmful aqueous species and salinity effects.
Objective 3: Examine the effect of nutrient treatments on harmful algal growth in both bench-top experiments and pilot-scale tests to validate the effectiveness of the mineral-hydrogel composites in managing HAB. Tests will be performed in semi-outdoor conditions subjected to fluctuating light intensities, water temperatures, and bacterial contaminations. Using techno-economic and sustainability analyses, we will evaluate the potential for upscaling the developed technology.
Expected Results:
As outcomes of our proposed tasks, we will develop a robust, environmentally-sustainable, and widely applicable nutrient removal/recovery technology based on a mineral-hydrogel composite. The composite will be optimized to achieve our target nutrient removal performance, currently 0.1 mg-P/L within 8 hours of application. Its performance and effects on model algal ecosystems will then be validated.
Publications and Presentations:
Publications have been submitted on this project: View all 19 publications for this projectJournal Articles:
Journal Articles have been submitted on this project: View all 8 journal articles for this projectSupplemental Keywords:
Algal Blooms, Hydrogels, Calcium Phosphate, Phosphate, Nitrogen, CompositesProgress and Final Reports:
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.