Grantee Research Project Results

Novel Process and Supply Network Design for the Recovery of Key Fertilizer Macronutrients for Safe and Reliable Drinking Water

EPA Grant Number: SU841124
Title: Novel Process and Supply Network Design for the Recovery of Key Fertilizer Macronutrients for Safe and Reliable Drinking Water
Investigators: Tian, Yuhe
Institution: West Virginia University
EPA Project Officer: Brooks, Donald
Phase: I
Project Period: March 1, 2025 through February 28, 2027
Project Amount: $75,000
RFA: 21st Annual P3 Awards: A National Student Design Competition Focusing on People, Prosperity, and the Planet Phase I (2024) RFA Text
Research Category: P3 Awards , Drinking Water , Clean Water , Groundwater, Organic Contaminants, Treatment, Modeling , Groundwater, Contaminant Fate and Transport , Groundwater, chlorinated organics, biodegradation, TCE, sorption , Groundwater, Metals, Treatment, Biotransformation , Groundwater, Contaminants, Treatment , Aquatic Ecosystems , Biology/Life Sciences , Water Quality , Human Health , Water , Land and Waste Management , P3 Challenge Area - Safe and Sustainable Water Resources , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Chemical Safety , Environment , Aquatic Toxicology

Description:

The key research phases required to achieve the project objectives include: (i) the design and optimization of a polyelectrolyte-based nanofiltration membrane to enhance the separation efficiency of nutrients and organic pollutants, aiming for the highest possible selectivity at neutral pH; (ii) the
development and optimization of a crosslinked polyelectrolyte membrane to separate NH4+ and K+ into two distinct product streams; (iii) process modeling of the chemical precipitation and membrane technologies employed in this study to facilitate scaling up; (iv) conducting techno-economic and life cycle
3 analyses to evaluate the feasibility of integrating this technology; and (v) analyzing the supply and demand of recovered nutrients on a statewide basis.
The project focuses on developing a comprehensive nutrient recovery process through multiple interconnected tasks. The research team will create surface-modified polyelectrolyte multilayer membranes utilizing commercial NF membranes (NF270) as support. These membranes will be assessed for nutrient and organic pollutant rejection percentages at neutral pH, employing both synthetic anaerobic digestate. Based on experimental developments, we will explore data-driven modeling and predictive design of membrane materials leveraging machine learning which represent another key novelty of the proposed work. To this purpose, synthetic data generation techniques will be employed to address limited experimental data availability, aiming to identify key features impacting membrane performance and optimize membrane design parameters for enhanced selectivity and permeability. Process design, technoeconomic analysis, and life cycle assessment for the integrated nutrient recovery plant will be studied to assess the economic viability and sustainability. To quantify the impact of the proposed technology on the supply network, we will investigate the state-wide supply chain management accounting for local resource availability, transportation infrastructure, regulatory environment, and market demand. By integrating policy incentives and resource availability considerations, the project aims to develop an efficient, economically viable, and environmentally sustainable nutrient recovery process while considering regional factors and policy frameworks. The research team and PI will involve students from West Virginia University and nearby high schools by offering opportunities for undergraduate and high school students to actively participate in this project. Additionally, the group will collaborate with local organizations such as the West Virginia Water Research Institute to identify nearby anaerobic digestate point sources with the highest nutrient loads. The technology will be tested using these waste streams to ensure that experimental testing aligns with real-world conditions. Similar efforts will be made to engage with local water and wastewater treatment plants (WWTPs) to enhance understanding of community needs, implement best practices, and assess scalability criteria.

Objective:

The discharge of phosphorus, ammonium, and potassium nutrient loads from wastewater treatment plants represents a notable point source, releasing an abundance of nutrients into the environment via waste streams. This can induce harmful algal blooms, leading to detrimental impacts on aquatic
ecosystems, fisheries, recreational pursuits, water sources, and public health, all linked to the phenomenon of eutrophication. The recovery of nutrients from these specific point sources offers a viable solution to the eutrophication issue, simultaneously providing raw materials (N, P, K) for agricultural fertilization. Nutrient recovery technology can be proven advantageous if it incorporates lower energy consumption compared to the conventional manufacturing process for N, P, K fertilizers. The anaerobic digestate from various wastewater treatment plants, including municipal, poultry, pharmaceutical, and others, can serve as significant point sources, containing substantial quantities of N, P, K nutrients. However, these sources also contain s harmful emerging organic pollutants (300-10000 mg/L depending on the source) that pose risks to human and aquatic life. This proposal aims to selectively recover nutrients from AD, with the dual purpose of mitigating nutrient pollution in freshwater sources and utilizing these nutrients as raw materials for agricultural fertilizers. The project aims to design an integrated technology combining chemical precipitation and membrane filtration for the selective recovery of nutrients. In our prior work, we employed a chemical precipitation technique to recover phosphorus from anaerobic digestate (AD) supernatant of municipal wastewater, following which membrane separation is leveraged for phosphorus and ammonia recovery from anaerobic digestate. On this basis, the major research objectives of this proposal are: (i) developing NF membrane technology to selectively separate nutrients (N and K) while removing organic pollutants, with the objective of adjusting the final fertilizer product to various N:P:K ratios; (ii) conducting process design, techno-economic analysis, and life cycle analysis for the integrated nutrient recovery plant to assess the feasibility of this technology; and (iii) implementing statewide supply chain management for nutrient recovery. The results obtained from both the experimental and modeling teams will be shared to establish a feedback loop, fostering ongoing enhancement of the system. The findings of this study will be disseminated among relevant academic and industrial entities to ensure accessibility to these practices for broader community engagement.

Expected Results:

The expected outcome of this research study includes: (i) Development of surface modified nanofiltration membranes with high organic rejection and selective permeation of nutrients (NH4+, K+) in tunable proportions. (ii) Development of a machine learning model to analyze membrane properties and
process conditions, optimizing membrane design for enhanced selectivity and permeability. This will lead to the identification of optimal membrane configurations for selective nutrient recovery. Additionally, collaborative validation with experimental groups using real wastewater samples will ensure practical applicability, with iterative refinement based on feedback to improve predictive accuracy. (iii) Design of a comprehensive model using Aspen Plus to simulate the nutrient recovery process, optimizing process efficiency and membrane design. This includes conducting a techno-economic analysis to assess the plant's economic viability and sustainability, guiding decision-making for implementation and scalability. (iv) Optimal supply chain management strategies for the state of West Virginia with energy, resource, and policy considerations. (v) A modular nutrient recovery plant demonstration to local farmers.