MITIGATING UPTAKE OF PER- AND POLYFLUOROALKYL SUBSTANCES BY CROPS USING SOIL AMENDMENTS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: ACTIVE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1027882
• Grant No.: 2022-67019-36487
• Cumulative Award Amt.: $750,000.00
• Proposal No.: 2021-09098
• Project Start Date: Jan 1, 2022
• Project End Date: Dec 31, 2026
• Grant Year: 2022
• Program Code: [A1411]- Foundational Program: Agricultural Water Science

Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824

Performing Department
PLANT SOIL MICROBIAL

Non Technical Summary
Background. Per- and polyfluoroalkyl substances (PFASs) have been frequently found in agricultural irrigation water and soils. Irrigation with PFASs-contaminated water could cause the accumulation of PFASs in field crops during plant growth. The subsequent dietary consumption of PFASs-tainted agricultural product could impact human and animal health. Human consumption of crops/vegetables should be considered an important exposure pathway to PFASs, which is comparable (if not more important than) to the drinking water exposure pathway. Therefore, in order to improve food safety and human health while maintaining the profitability of agricultural production, effective and low-cost soil management strategies are critically needed to mitigate the transfer of PFASs from agricultural irrigation water to fresh produce.Goal and Hypothesis. The overarching goal of this project is to develop pragmatic management practices that can immobilize PFASs in soils, reduce their bioavailability to plant root uptake, and mitigate their accumulation in agricultural produce. Irrigation with PFASs-contaminated water introduces PFASs into soils, transport with water to plant root zone, and accumulate in agricultural crops grown in the soils. In this project, we propose to elucidate the fate and transport of PFASs in soil-water-plant systems, and investigate the feasibility to interfere with the transport of PFASs to food crops using sorbent amendments. The central hypothesis is that soil pore water is the major carrier by which PFASs are moved from soil to plant root zones. Sorbent amendments could effectively immobilize PFASs in soils and reduce their bioavailable fractions to plant root uptake.Specific Objectives. (1) Evaluate PFASs sorption, transport and immobilization in soils amended with layered double hydroxide (LDH) and Al-, Fe-modified biochars. (2) Determine the bioavailability of PFASs to plant uptake from soils amended with LDH and modified biochars. (3) Validate the to-be-developed management to mitigate the accumulation of PFASs in field crops.Approaches. We will integrate laboratory experiments of PFASs sorption and transport in soils, greenhouse pot experiments and field plot trials of plant uptake of PFASs, and advanced LC-MS/MS analysis that can quantify PFASs at environmentally relevant concentrations to understand the mechanistic determinants of PFASs movement from soil to plant. PFASs sorption by soils, plant physiological activities and soil pore water movement are the critical processes that will be studied for their impacts to uptake and accumulation of PFASs in crops. We will examine whether PFASs concentration in soil pore water could be significantly reduced in the presence soil amendments LDH and Al- Fe-modified biochars, and whether this approach could effectively lead to the mitigation of PFASs uptake and accumulation in field crops.Expected Outcome and Potential Impacts. This project will advance the mechanistic knowledge on PFASs interaction with soils, LDH and biochars, transport from soils to plant, and plant accumulation related to PFASs properties and plant physiological activities. These individual processes will be integrated to evaluate and model the fate and transport of PFASs in soil-water-plant systems. The results will provide the foundation on using LDH and modified biochars as sorbent amendment to immobilize PFASs in soils while mitigating the accumulation of PFASs in agricultural crops. The results will provide guideline for generating science-informed management practices with respect to sorbent amendment, and irrigation with PFASs-contaminated water. These outcomes will lead to actionable solutions that ensure the sustainable agricultural environment and safe food production.

Animal Health Component

40%

Research Effort Categories

Basic

50%

Applied

40%

Developmental

10%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0110	2000	15%
102	0110	2010	15%
133	0110	2000	15%
133	0110	2010	10%
102	0210	2000	10%
133	0210	2000	15%
133	1499	2000	10%
133	1510	2000	10%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 133 - Pollution Prevention and Mitigation;

Subject Of Investigation
1499 - Vegetables, general/other; 1510 - Corn; 0110 - Soil; 0210 - Water resources;

Field Of Science
2010 - Physics; 2000 - Chemistry;

Keywords

food safety

irrigation

pfass

plant uptake

soil amendment

water quality

Goals / Objectives
Our overarching goal is to develop pragmatic management practices that can immobilize per- and polyfluoroalkyl substances (PFASs) in soils and decrease their bioavailability to plant uptake in order to mitigate their accumulation in agricultural produce. Irrigation with PFASs-contaminated water introduces PFASs into soils, transport with water to plant root zone, and accumulate in agricultural crops grown in the soils. We propose to elucidate the fate and transport of PFASs in soil-water-plant systems, and investigate the feasibility to interfere with the transport of PFASs to food crops using sorbent amendments. Although previous studies have investigated sorption and transport of PFASs in soils and plant uptake, little has been done to develop mitigation strategy to use sorbent amendments to mitigatePFASs bioavailability for plant uptake from soils. Our central hypothesis is that soil pore water is the major carrier by which PFASs are moved from soil to plant root zones. Sorbent amendments could effectively immobilize PFASs in soils and reduce their bioavailable fractions to plant uptake. To test the hypotheses and achieve our overall research goal, we propose the following three integrated specific objectives:(1) evaluate PFASs sorption, transport and immobilization in soils amended with layered double hydroxides (LDH) and Al-, Fe-modified biochars.(2) determine the bioavailability of PFASs to plant uptake from soils amended with LDH and modified biochars.(3) validate the to-be-developed management to mitigate the accumulation of PFASs in field crops.The knowledge to be gained could guide the development of science-based best management practices to abate the accumulation of PFASs in agricultural produce at the initial farming production stage via immobilizing PFASs in soils.

Project Methods
We will integrate laboratory experiments of PFASs sorption and transport in soils, greenhouse pot experiments and field plot trials of plant uptake of PFASs, and advanced LC-MS/MS analysis that can quantify PFASs at environmentally relevant concentrations to understand the mechanistic determinants of PFASs movement from soil to plant. PFASs sorption by soils, plant physiological activities and soil pore water movement are the critical processes that will be studied for their impacts to uptake and accumulation of PFASs in crops.Under the research objective 1, we will evaluate PFASs sorption, transport and immobilization in soils amended with LDH and Al-, Fe-modified biochars. Specifically, we will prepare different types of LDHand Al-, Fe-modified biochars, and measure their sorption for PFASs and the leachability of sorbent-sorbed PFASs. In addition, we will determine the transport of PFASs in soils amended with the selected LDHand Al-, Fe-modified biochars using column experiments under saturated and unsaturated conditions. A clear understanding of sorption and transport behaviors of PFASs in soils will facilitate the selection of the optimal LDH or biochar amendments to immobilize PFASs in soils.Under the research objective 2, we will determine the bioavailability of PFASs to plant root uptake from soils amended with LDH and modified biochars. PFASs present in irrigation water could be sorbed by soils after application, which can be continuously desorbed to pore water, and become bioavailable to plant root uptake. Soil pore water flow could carry a portion of these compounds to plant root zones for uptake. Therefore, PFASs concentration in soil pore water, and water flow in soil and within plants (transpiration) directly influence their uptake and distribution in plants. The immobilization of PFASs within LDH and modified biochar amendments could mitigate the amount of PFASs present in soil pore water which is the major bioavailable fraction to plant root uptake. We will select a series of PFASs and conduct pot experiments in greenhouse to examine their uptake and accumulation in field crops corn, wheat, and carrot. We will also determine PFASs concentrations in soil pore water and calculate the corresponding bioconcentration factor (BCF) based on PFASs concentration in soil pore water. We expect that PFASs concentration in soil pore water could be significantly reduced because of the immobilization of PFASs within soil amendments LDH and Al- Fe-modified biochars. The reduced PFASs concentration in soil pore water could effectively mitigate the uptake and accumulation of PFASs by field crops.Under the research objective 3, we will validate if the to-be-developed management could effectively mitigate the accumulation of PFASs in crops using field plot trials. Thestrategy to diminish the bioavailability of PFASs in soils is key to controlling PFASs uptake through crop roots, and sorbent amendment is a feasible operation in agricultural fresh production at field scale. The strong affinity of PFASs to LDH or modified biochar amendments could substantially reduce the amount of PFASs present in soil pore water hence mitigating the accumulation in crops. To test this hypothesis, we will construct raised-bed small plots to evaluate the effectiveness using LDH and Fe-/Al-modified biochars as sorbent amendment to immobilize PFASs in soils. The sorbent amendment application rate will be determined based on the result analysis of from Objectives 1 and 2. The plants will be irrigated with tap water containing PFASs and maintain 50% of maximum water holding capacity. We will collect soil samples, hand harvestcarrot, wheat and corn. Thesoils, plant tissues and edible parts will be collected for PFASs analyses. We will compare PFAS accumulation in the edible parts of field crops, and expect a priori that sorbent amendments could effectively immobilize PFASs in soils alleviating their accumulation in crops.

Progress 01/01/24 to 12/31/24

Outputs
Target Audience:The target audience of this project involves environmental water and soil science professionals, environmental stewardship stakeholders, food scientists, agricultural food crop producers, water treatment utility professionals, policy makers, as well as individuals and the general public who are concerned on environmental quality and food safety relevant to PFAS present in agricultural ecosystems and products. We delivered the presentations of our research findings at professional conferences, published research papers in peer-reviewed journals, and communicated with state policy makers, local stakeholders, and farmers. In addition, the research findings are incorporated in PIs' courses and disseminate the knowledge to graduate and undergraduate students in classroom. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided many opportunities to train postdoctoral research associates, graduate students, and undergraduate students who have benefited from this research project by improving their laboratory skills, critical thinking, data analysis, manuscript and proposal writing, and problem solving. The training will help them to advance their professional development and careers. Three PhD students were working on the project. One postdoctoral research associates and an undergraduate student were also working on projects during 2024. The training included analysis of PFAS in soil, water, and plant issues, measurement of sorption isotherm and understanding of sorption mechanism by soils and sorbent amendments, greenhouse experiments on plant uptake of PFAS from soils, and communications with stakeholders. How have the results been disseminated to communities of interest?The results from this project are disseminated primarily through publications in peer-reviewed journals in environmental science and food sciences, and presentations in regional, national and international professional conferences to scientists, stakeholders and policy makers. The results are also reported to the general public who are interested in the relevant issues. During this year, three oral conference presentations were delivered at Soil Science Society of America, and the stakeholder on biosolids communities. Three peer-reviewed papers on PFAS in soils have been published in scientific journals. What do you plan to do during the next reporting period to accomplish the goals?From January 2025, we will usethe EPA 1633A method to analyze PFAS concentration in 620 soil pore water, soil and plant samples collected from greenhouse pot experiments (continue the work described above). The EPA analytical method takes a very long time in sample preparation. We expect the analysis to be finished by August 2025, and the data will be analyzed to elucidate the processes of PFAS at the nexus of soil-water-plant systems. From July 2025, we plan to conduct greenhouse pot experiments using soil amendment to investigate the mitigation of PFAS uptake by plants and followed by data analysis. During this period, we expect to finish the work described in project Objective 2.

Impacts
What was accomplished under these goals? During the third year of this project, we were working on (1) testing sorbents for sorption of a series of PFAS in soilamendments, (2) determining PFAS sorption by soil amended with a Rembind adsorbent, and (3) evaluating uptake of PFAS by several crops from the irrigation water. Activated carbon, Fluorosorb 200, and two Rembind sorbents all demonstrated strong sorption for the seventeen selected PFAS chemicals including perfluoro-3-methoxypropanoic acid (PFMPA), perfluoro(2-ethoxyethane) sulfonic acid (PFEESA), hexafluoropropylene oxide dimer acid (HFPO-DA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFOA), perfluorooctanoic acid (PFHpA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorobutanesulfonic acid (PFBS), perfluorohexanesulfonic acid (PFHxA), perfluoropentanesulfonic acid (PFPeS), perfluorooctanesulfonic acid (PFOS), 1H,1H,2H,2H-perfluorohexanesulphonic acid (4:2 FTS), 6:2 perfluorotelomer sulfonic acid (6:2 FTS), 1H,1H,2H,2H-perfluorodecanesulfonic acid (8:2 FTS), and perfluorooctanesulfonamide (PFOSA). The selected PFAS chemicals include a wide range of structural properties such as short-chain and long-chain compounds, and PFAS precursors. Since short-chain PFAS chemicals have a high mobility in the environment and potentially elevated uptake by plants, we focused mainly on sorption and retention of short-chain PFAS by the amendments. The measured sorption isotherm of short-chain PFAS was fitted well with the Freundlich sorption model. Sorption of short-chain PFAS followed the order of PFPeS > 4:2FTS > PFBS > HFPO-Da > PFPeA > PFMPA, depending highly on the chain length and functional groups of PFAS. With the same number of carbon fluorine chains, PFAS containing sulfonic acid group (i.e. PFBS) manifested a higher sorption than that with carboxylic acid (i.e. PFPeA). The substitution of fluorine with hydrogen atoms or the addition of ether group could lead to the reduced sorption by these sorbents. Among the short-chain PFAS, PFMPA demonstrated the least sorption by the four sorbents tested. Based on the sorption results, one Rembind was identified for further study simply based on the higher sorption for PFMPA. Next, the selected Rembind was mixed with a clay loam soil (with organic carbon content of 4.0% and cation exchange capacity of 17.2 cmol(+)/kg) at the percentage of 1.0%, 2.0%, 5.0% and 10% of the adsorbent in the soil. The results indicate that the Rembind in the soil can still function effectively to sorb PFAS from water, with a significant portion of sorbed PFAS attributed to the amendment. At a lower sorbent amendment rate (0.5% and 1%), the measured sorption was ~50-70% less than the estimated values by assuming that soil and Rembind contribute to PFAS sorption individually. This could be because the released components from the soil might block the sorption sites in rembind. As the Rembind amendment rate increased to 5%, this adverse impact of soil on the sorption by Rembind became negligible. For the group of intermediate chain-length PFAS including PFHxA, PFHpA, PFOA, PFHxS, PFOS, 6:2FTS and PFEESA, the measured sorption is close to the estimated values at the Rembind amendment rate of 1.0%. At a lower amendment rate of 0.5%, the measured value was approximately 10% to 60% of the estimated values suggesting the adverse impact of soil matrices on the sorption effectiveness of Rembind at a lower rate. It is interesting to note that when the mass percentage of Rembind sorbent increased to 2% and 5%, the estimated sorption of this group of PFAS was higher than the calculation of individual contribution of soil and Rembind. We also conducted greenhouse experiments to examine plant uptake of PFAS from the irrigation water. The plants tested were corn, wheat, soybean and cucumber. We grew these plants from seeds to fully mature stage during which water with low concentration of PFAS was frequently used to irrigate the plants. The targeted PFAS were those 17 chemicals described above. The primary results indicated that these PFAS can enter the plants but at varying degrees. Short-chain PFAS can easily enter the plant roots, stems, then leaves and even to grains. Long-chain PFAS demonstrated a less transport and bioaccumulation compared to the short-chain PFAS.

Publications

• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2025 Citation: Heather E. Preisendanz, Hui Li, Michael Mashtare, Odette Mina, 2025, PFAS in Agroecosystems: Sources, Impacts, and Opportunities for Mitigating Risks to Human and Ecosystem Health, Journal of Environmental Quality, 54: 1-5.
• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Fang Wang, Leilei Xiang, Kelvin Sze-Yin Leung, Martin Elsner, Ying Zhang, Yuming Guo, Bo Pan, Hongwen Sun, Taicheng An, Guangguo Ying, Bryan W Brooks, Deyi Hou, Damian E Helbling, Jianqiang Sun, Hao Qiu, Timothy M Vogel, Wei Zhang, Yanzheng Gao, Myrna J Simpson, Yi Luo, Scott X Chang, Guanyong Su, Bryan M Wong, Tzung-May Fu, Dong Zhu, Karl J Jobst, Chengjun Ge, Frederic Coulon, Jean Damascene Harindintwali, Xiankui Zeng, Haijun Wang, Yuhao Fu, Zhong Wei, Rainer Lohmann, Changer Chen, Yang Song, Concepcion Sanchez-Cid, Yu Wang, Ali El-Naggar, Yiming Yao, Yanran Huang, Japhet Cheuk-Fung Law, Chenggang Gu, Huizhong Shen, Yanpeng Gao, Chao Qin, Hao Li, Tong Zhang, Nat�lia Corcoll, Min Liu, Daniel S Alessi, Hui Li, Kristian K Brandt, Yolanda Pico, Cheng Gu, Jianhua Guo, Jianqiang Su, Philippe Corvini, Mao Ye, Teresa Rocha-Santos, Huan He, Yi Yang, Meiping Tong, Weina Zhang, Fid�le Suanon, Ferdi Brahushi, Zhenyu Wang, Syed A Hashsham, Marko Virta, Qingbin Yuan, Gaofei Jiang, Louis A Tremblay, Qingwei Bu, Jichun Wu, Willie Peijnenburg, Edward Topp, Xinde Cao, Xin Jiang, Minghui Zheng, Taolin Zhang, Yongming Luo, Lizhong Zhu, Xiangdong Li, Dami� Barcel�, Jianmin Chen, Baoshan Xing, Wulf Amelung, Zongwei Cai, Ravi Naidu, Qirong Shen, Janusz Pawliszyn, Yong-guan Zhu, Andreas Schaeffer, Matthias C Rillig, Fengchang Wu, Gang Yu, James M Tiedje, 2024, Emerging Contaminants: a One Health Perspective, The Innovation, 5(4):100612.
• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2023 Citation: Ganga M. Hettiarachchi, Linda S. Lee, Hui Li, Dominic Brose, Nicholas Basta, 2023, Translating Soil Science to Improve Human Health, Frontiers in Environmental Science doi: 10.3389/fenvs.2023.1215416.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Qianqian Dong, Zhiliang Xu, Wei Zhang and Hui Li, 2024, Immobilization of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in soil amended with geosorbents. International Annual Meeting of International Annual Meeting of ASA/CSSA/SSSA, San Antonio, Texas, November 10-13.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Andrew C. Huang, Wei Zhang, Brian J. Teppen, and Hui Li, 2024, Evaluation of Cation-Bridging Sorption of Per- and Polyfluoroalkyl Acids by Soils. International Annual Meeting of International Annual Meeting of ASA/CSSA/SSSA, San Antonio, Texas, November 10-13.
• Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Hui Li, 2024, Fate and Transport of Per- and Polyfluoroalkyl Substances in Agricultural Environment, 2024 Michigan Water Environment Association Conference, Bath township, Michigan, August 22.

Progress 01/01/23 to 12/31/23

Outputs
Target Audience:The target audience of this project involves environmental water and soil science professionals, environmental stewardship stakeholders, food scientists, agricultural food crop producers, water treatment utility professionals, policy makers, as well as individuals and the general public who are concerned on environmental quality and food safety relevant to PFAS present in agricultural ecosystems and products. We delivered the presentations of our research findings at professional conferences, published research papers in peer-reviewed journals, and communicated with state policy makers, local stakeholders, and farmers. In addition, the research findings are incorporated in PIs' courses and disseminate the knowledge to graduate and undergraduate students in classroom. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided many opportunities to train postdoctoral research associates, graduate students, and undergraduate students who have been benefited from this research project by improving their laboratory skills, critical thinking, data analysis, manuscript and proposal writing, and problem solving. The training will help them to advance their professional development and careers. A PhD student and a visiting PhD student were working on the project. Two postdoctoral research associates and an undergraduate student were also working on projects during 2023. The training included analysis of PFAS in soil, water, and plant issues, understanding sorption mechanism by soils and sorbent amendments, plant uptake of PFAS from soils, and communications with stakeholders. How have the results been disseminated to communities of interest?The results from this project are disseminated primarily through publications in peer-reviewed journals in environmental science and food sciences, and presentations in regional, national and international professional conferences to scientists, stakeholders and policy makers. The results are also reported to the general public who are interested in the relevant issues. During this year, two oral conference presentations and one poster presentation were delivered at American Chemical Society Annual Meeting, International Annual Meeting of American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, and the Annual Symposium of Michigan State University PFAS Research Center. A review paper on PFAS in soils and remediation has been published. An education seminar was presented to Michigan 4-H educators on PFAS in soils and remediation. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we will summarize the data collected and submit manuscripts to peer-reviewed journals for publication. At the same time, we will further evaluate soil amendments on PFAS sorption and transport in soils. In addition, we will continue to compare the bioavailability of PFAS in soils to plant uptake in the presence and absence of amendments.

Impacts
What was accomplished under these goals? During the second year of this project, we were working on screening sorbents for sorption of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) from water by biochar, Fe-modified biochar, layered double hydroxide (LDH) and other commercially available amendments such as Fluorosorband Rembind. Fluorosorb 200 is an organo-clay, and Rembind sorbent is a composite of activated carbon and aluminum/iron oxides. More studies were conducted to measure sorption of sixteen PFAS chemicals by the selected sorbents. Biochar is a class of cost-effective carbonaceous materials produced via pyrolysis of organic feedstocks. We measured PFOS and PFOA sorption by biochar from water. The results showed a relatively strong sorption for PFOS with sorption coefficient of 104 L/kg levels. Sorption of PFOA by biochar was much less than sorption of PFOS. To enhance the sorption, biochar was modified with Fe-minerals. The specific surface area of biochar modified with hematite (α-Fe2O3) and goethite (α-FeO(OH)) increased by 53% and 110% relative to that of the unmodified biochar. Hematite and goethite appeared to heterogeneously deposit as aggregates on biochar surfaces, rather than in biochar meso-/micropores. PFOA sorption coefficient reached the range of 102 to 103 L/kg; no apparent increase was observed for PFOS sorption between biochar and Fe-modified biochars. We also measured sorption of PFOA and PFOS by a commercially available granular LDH. The sorption was much lower than the LDHs we synthesized in the laboratory. Fluorosorb 200 and Rembind sorbents demonstrated strong sorption for seventeen selected PFAS chemicals including six perfluoroalkyl acids (PFCA), four perfluorosulfonic acids (PFSA), three fluorotelomer sulfonate, perfluorooctanesulfonamide (PFOSA), perfluoro(2-methyl-3-oxahexanoic) acid (HFPO-Da), perfluoro-3-methoxypropanoic acid (PFMPA), and perfluoro(2-ethoxyethane) sulfonic acid (PFEESA). The selection includes a wide range of PFAS such as short-chain and long-chain compounds, and PFAS precursors. Sorption coefficient of a short-chain chemical perfluoropentanoic acid (PFPeA) by Rembind sorbent is four orders of magnitude greater than that by soil. Sorption coefficient of a PFAS precursor HFPO-Da by Fluorosorb 200 reaches five orders of magnitude greater higher than sorption by soil. These sorbents could be more effective to sorb long-chain PFAS chemicals. These results suggest that these sorbents could be promising effective amendment for reducing the bioavailability of PFAS in soils for plant uptake. A detailed sorption/desorption study with these commercial sorbents is being conducted to develop an appropriate guideline to estimate the amendment application rate in soils and meet the requirements for a wide range of PFAS at relatively low concentrations.

Publications

• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2023 Citation: Hui Li, and Pulane Koosaletse-Mswela, 2023, Occurrence, Fate and Remediation of Per- and Polyfluoroalkyl Substances in Soils: A Review. Current Opinion in Environmental Science & Health, 34: 100487.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Hui Li, 2023, Plant Uptake and Accumulation of Per- and Polyfluoroalkyl Substances in Agricultural Environments. Center for PFAS Research Annual Symposium, PFAS: Current Knowledge and Applications for Agricultural Production, East Lansing, MI, October 22-24.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Harley Curtiss, Geoffrey Rhodes, Raymond Hammerschmidt, Wei Zhang, and Hui Li, 2023, Casparian Strip Retards PFAS Translocation from Arabidopsis Roots to Shoots. International Annual Meeting of American Society of Agronomy (ASA), Crop Science Society of America (CSSA), and Soil Science Society of America (SSSA), St. Louis, MO, October 29 - November 1.
• Type: Conference Papers and Presentations Status: Published Year Published: 2023 Citation: Jingyi Feng, Narasimhan Loganathan, Geoff Rhodes, Wei Zhang, Daniel Sheng, Angela K. Wilson, and Hui Li, 2023, Interaction between Perfluorosulfonic Acids and Layered Double Hydroxides: Sorption Experiments and Molecular Dynamic Simulations. American Chemical Society National Meeting & Exposition, San Francisco, CA, August 13-17.

Progress 01/01/22 to 12/31/22

Outputs
Target Audience:The target audience of this project involves environmental water and soil science professionals, environmental stewardship stakeholders, food scientists, agricultural food crop producers, policy makers, as well as individuals and the general public who are concerned on environmental quality and food safety relevant to PFASpresent in agricultural ecosystems and products. We will deliver the presentations of our research findings at professional conferences, publish research papers in premier peer-reviewed journals, and communicated with state policy makers and farmers. In addition, the research findings will be incorporated in PIs' courses and disseminate the knowledge to graduate and undergraduate students in classroom. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided many opportunities to train postdoctoral research associateand graduate students who have been benefited from this research by improving their laboratory skills, critical thinking, data analysis, manuscript writing, and problem solving. These trainings willhelpthem to advance their professional development and careers. A PhD student Harley Cutiss and a postdoctoral research associated Qianqian Dong started working on the project in2022. A visiting PhD student Jingyi Feng also worked on the project. How have the results been disseminated to communities of interest?The results from this project are disseminated primarily through publications in peer-reviewed journals in environmental science and food sciences, and presentations innational and international professional conferences to scientists and policy makers. The results are also reported to the general public who are interested in the relevant issues. During the first year, two oral conference presentations were delievered inAmerican Chemical Society Annual Meeting and the Annual Symposium of Michigan State University PFAS Research Center. A review paper on PFAS in soils and remediation has been submitted to a peer-reviewed journal for possible publication, and the manuscript is currently under review. PI Li also provided an audio to the general public for the education purpose. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we will submit the manuscript on PFAS sorption by LDH to apeer-reviewed journal for publication. At the same time, we will further evaluate soil amendments on PFAS sorption and transport in soils. In addition, we will start Objective 2, determine the bioavailability of PFAS to plant uptake from soils in the presence of amendments.

Impacts
What was accomplished under these goals? During the first year of this project, we are focusing on Objective 1 on sorption of PFAS by layered double hydroxides (LDH). LDHsare a class of environmental-friendly inorganic sorbents for sorption of PFAS,particularly anionic PFAS species from water, owing to therelatively large surface area and high abundance of structural positive charges within the LDH minerals. Several perfluorosulfonic acids (PFSA) were selected to measure their sorption isotherms by LDH from water in the presence of varying ion type and strength. Three LDHs with Mg to Al molar ratio of 2, 3 and 4 were synthesized as sorbents for sorption of perfluorooctanesulfonic acid (PFOS), perfluorohexanesulphonic acid (PFHxS) and perfluorobutanesulfonic acid (PFBS) from water. LDH demonstrated strong sorption for PFOS, PFHxS and moderate sorption for PFBS. Molecular dynamics simulations were utilized to elucidate the interaction mechanism of PFSA with LDH surfaces. The results revealed no apparent relation between PFSA sorption and LDH Mg/Al ratio. Long-chain PFAS demonstrated greater sorption than short-chain analogues. Sorption of PFOS and PFHxS by LDH manifested virtually linear isotherm at a low aqueous concentration, and became convex with increasing PFASconcentration in solution, whereas the sorption isotherm of PFBS remainedlinear within the wide range of PFAS aqueous concentration. The hydrodynamic radius of LDH particles increased with sorbed concentration of PFHxS and PFOS by LDH. In contrast, the mineral particle size remained nearly constant for the LDH with sorbed PFBS. The presence of inorganic anions in solution could effectively reduce sorption of PFASby LDH, and this trend became more apparent for the anions of either higher concentration in solution or more negative charges. These observations are currentlyelucidated with the analysis of molecular dynamics simulations.

Publications

• Type: Journal Articles Status: Under Review Year Published: 2023 Citation: Hui Li, and Pulane Koosaletse-Mswela, 2023, Occurrence, Fate and Remediation of Per- and Polyfluoroalkyl Substances in Soils: A Review. Current Opinion in Environmental Science & Health, (in review).
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Jingyi Feng, Geoff Rhodes, Wei Zhang, Daniel Sheng, Brian J. Teppen and Hui Li, 2022, Defluorination of Perfluorooctane sulfonic Acid Sorbed in Layered Double Hydroxides, American Chemical Society Annual Meeting, San Diego, California, March 20-24.
• Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Hui Li, 2022, Defluorination of Perfluorooctane sulfonic Acid (PFOS) in Nano-Sized Reactor: Confined Layered Double Hydroxide Surfaces, 2022 Center for PFAS Research Inaugural Annual Symposium: Emerging Technologies in PFAS Remediation and Toxicity. East Lansing, MI, October 25.