3 Apr 2025

Advancing a Framework for Rapid Assessment and Economic Valuation of Wild Pig Damage to Wetland Terrain: Year Two of Research at US Army Corps of Engineers Somerville Lake, Texas

Abstract: Wild pigs significantly impact wetlands, yet a standardized method for quantifying and valuing this damage is lacking. This research aims to develop a user-friendly ecological-economic framework for rapid assessment of wild pig damage on wetlands, building on a pilot study conducted at Lake Somerville, Texas, in FY21. The FY22 project advanced methods to value the lost benefits provided by wetlands due to wild pigs and identified methods to adapt and refine the framework for broader application. Additionally, a 65% reduction in wild pig population was achieved by Texas Wildlife Services personnel through helicopter gunning at two treatment sites, which is estimated to have prevented further damage to wetlands.

2 Apr 2025

VTIME Using ERDC as a Testbed with PLANNER

Abstract: This technical note documents the outcome of a September 2023 workshop titled “VTIME using ERDC as a Testbed with PLANNER.” PLANNER exists as a prototype installation master planning tool, operating as an application using the Virtual Toolbox for Installation Mission Effectiveness (VTIME) as a platform. The objectives of the US Army Engineer Research and Development Center (ERDC) FLEX-4 project for VTIME using “ERDC as a Testbed” with PLANNER included modeling and analyzing ERDC facilities using the PLANNER prototype and assessing the feasibility of ERDC as a pilot site for inclusion PLANNER implementation. The workshop aimed to demonstrate PLANNER for ERDC personnel and showcase a new installation planning capability that intends to transform the way the Army performs installation master planning by digitalizing and operationalizing master planning.

2 Apr 2025

Bacterial Remediation of Microsystin-HAB Toxins Utilizing Microcystinase (MlrA)

Abstract: Microcystins are a class of hepatotoxins produced by some harmful algal bloom–associated cyanobacteria and are the most reported tox-ins in freshwaters. Their cyclic structure makes them resistant to conventional methods used in water treatment operations (boiling, chlorination, and UV treatment). Some bacteria can naturally degrade microcystins via the mlrABCD cluster, a pathway initiated by the primary enzyme microcystinase (MlrA). MlrA linearizes the cyclic microcystin, greatly reducing its toxicity. Protein fusion was employed to produce a recombinant MlrA enzyme fused to maltose-binding protein ([MBP] MBP-MlrA) and to evaluate long-term enzymatic stabilization and reconstitution for future applications. MBP-MlrA degraded cyclic microcystin in vitro and demonstrated stability across a range of biological pHs. At a concentration of 0.61 ng/µl in buffer, MBP-MlrA achieved and maintained an average degradation rate of approximately 101.95 µM/h/ng of protein across fifteen freeze/thaw cycles. Stability assays demonstrated that enzyme activity was preserved over 5 months at −20°C. Results also demonstrated the effectiveness of MBP-MlrA to linearize microcystin upwards of 55.59 µM/h/ng of protein at the bench scale in both buffer and various freshwater matrices. The presence of the linear metabolite is of concern regarding intermediate toxicity, and future studies to incorporate the MlrB peptidase are discussed.

21 Mar 2025

Engineering With Nature: Integrating Plant Communities into Engineering Practices. A Guidance Manual

Abstract: Applying native plant communities in environmental engineering practices can profoundly enhance the establishment and sustainment of natural ecosystems, which is imperative for the success of healthy habitats and the wildlife communities they support. The objective of this manual is to stimulate interest in applying native plants in a wide variety of settings, including inland, upland, coastal, riparian, and grassland. The information presented in this manual illustrates natural plant communities and sustainable strategies using native vegetation. This manual discusses the application of vegetation in US Army Corps of Engineers (USACE) projects. Additional case studies incorporate Engineering With Nature® (EWN®) principles into the design and development of existing infrastructural facilities within a military installation. Specifically, the manual identifies desirable plant species suitable for propagation in various states based on historic plant communities and ecological composition and lists invasive species to avoid with suggested native alternatives. Further, it discusses the use of native vegetation in biotechnical applications. Intended users are USACE districts, local, state, and federal agencies, contractors (specialists), and other users (generalists) engaged in EWN projects. Finally, the publication helps practitioners think creatively about using native plant species before, during, and after project design phases.

19 Mar 2025

Peptide Display for Rare Earth Element Binding

Abstract: Rare earth elements (REEs) are metals that are indispensable to the function of many advanced systems and materials. The supply chain of REEs is heavily dependent on foreign sources and supply shortages are a major concern to the US government. Biological recovery approaches could be an economically feasible approach to recover REEs from unconventional or secondary sources. The objective of this project was to express a lanthanide-binding tag, with an affinity for adsorption of REEs, on the surface of the biomining bacterium, Acidithiobacillus ferrooxidans. This was to be accomplished using synthetic biology tools. The initial cloning steps were performed in Escherichia coli, since techniques are well established in this strain. Using a peptide display approach, several DNA constructs with the binding tag were designed that were regulated by constitutive or inducible promoters and cloned into plasmids that replicate in E. coli and A. ferrooxidans. All plasmids were observed to be unstable or lethal in E. coli, exhibiting sequence rearrangements or deletion of the designed construct. Conjugation between E. coli and A. ferrooxidans and subsequent REE binding assays were thus not possible due to the absence of a structurally and functionally intact plasmid.

12 Mar 2025

Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions: A Workshop

The workshop “Collaborative Development of Natural and Nature-Based Solutions for Coastal Resiliency in the Arctic and Adjacent Regions” was held in Reston, Virginia, October 24–25, 2023. The objective was to assemble diverse international partners in a hybrid in-person and virtual setting to focus on the viability of applying Nature-Based Solutions (NBS) to solve engineering challenges in the Arctic and similar cold region locations. The goals of the two-day workshop were to share recent efforts implementing NBS to mitigate coastal hazards such as flooding and erosion in northern high latitude settings and identify requirements and develop a robust program of activities to advance this work at national, regional, and local levels. This workshop report documents the presentations and discussion and summarizes key needs and recommendations for future engagement identified by speakers and workshop participants.

7 Mar 2025

Coupling Electrokinetics and Phytoremediation to Remove Uranium from Contaminated Soil: A Laboratory Pilot-Scale Study

Abstract: Uranium is a naturally occurring trace element and radionuclide. Uranium is introduced to the environment anthropogenically because of industrial, military, and nuclear energy activities. The approach of coupled electrokinetic phytoremediation has been used to remove other heavy metals from contaminated soil. The objectives here are to investigate the distribution and solubility of uranium in soils with UO2, UO, and uranyl, and examine the processes of coupled electrokinetic phytoremediation in removing U from soils with perennial ryegrass at a laboratory pilot scale. A low-intensity direct electric current field was applied to the contaminated soil for 7 d at 8 h·d−1 after ryegrass was grown for 2 weeks, then, polarity reversal was employed for another 7 d at 8 h·d−1. The uranium redistribution took place among various solid-phase components due to changes in the pH and chemistry of the electrolyte solution. The electrokinetic field increased the U bioavailability in soils as water-soluble U and exchangeable U in contaminated soils with all U species. Thus, the EKF significantly increased the U uptake and bioaccumulation by ryegrass. The current laboratory pilot-scale test confirmed our previous observation from the pot greenhouse study–the coupled electrokinetic phytoremediation may have potential for application in remediating U-contaminated sites.

26 Feb 2025

Demonstration of Photocatalytic Degradation of Per- and Polyfluoroalkyl Substances (PFAS) in Landfill Leachate Using 3D Printed TiO2 Composite Tiles

Abstract: Per- and polyfluoroalkyl substances (PFAS) are recalcitrant substances present globally in many landfill wastewater leachates and have potential ecological and human health risks. Conventional treatment technologies have shown limited efficacy for many PFAS due to the stable C–F bonds. Therefore, there is growing interest in applying advanced oxidation processes to decrease the aqueous concentrations in contaminated wastewater and mitigate risks. The goal of this study was to evaluate the photocatalytic performance of treating PFAS in landfill leachate using a novel photocatalyst composite. Treatment structures were fabricated using polylactic acid and compounded with TiO2, and 3D printed into tiles. A pilot-scale treatment system was designed to promote photocatalysis using 3D composite structures and UV irradiance intensity of 1.0 mW cm−2 following 24- and 36-h hydraulic retention times. Photocatalytic degradation was achieved for seven of the 11 PFAS evaluated in this study. Greater than 80% removal of PFOS, PFNA, PFDA, and PFOSAm was observed after 24 h of photocatalysis. These results indicate photocatalysis using TiO2 polymer composites can achieve beneficial levels of PFAS degradation. This study provides a proof-of-principle approach to inform the application of additive manufacturing of photocatalytic composites for use in the treatment of PFAS-contaminated wastewater.

19 Feb 2025

Autonomous Cyberdefense Introduces Risk; Can We Manage the Risk?

Abstract: We discuss the human role in the design and control of cyberdefenses. We focus on machine learning training and algorithmic feedback and constraints, with the aim of motivating a discussion on achieving trust in autonomous cyberdefenses.

19 Feb 2025

Lower James River Sediment Transport Modeling: Jordan Point

Abstract: US Army Corps of Engineers–Norfolk District (NAO) requested assistance from the US Army Engineer Research and Development Center (ERDC) to examine currently used placement sites within the James River, Virginia, initiative area, determine potential risk to critical environmental receptors during placement, and predict the life cycle of the placement sites. The focus of the analysis within this work is the Jordan Point placement site. The far-field, fate-transport modeling at Jordan Point shows relatively low maximum values of suspended sediment concentration (less than 40 mg/L) and deposition values (less than 0.2 cm). Material that is placed at Jordan Point appears to quickly disperse through the system, depositing in thin layers at specific areas. The life-cycle analysis performed for the Jordon Point placement site yielded an estimated useable project life of the Jordan Point placement sites of 26 years with an uncertainty of ±4 years. Analysis showed that 97% of the net sediment deposition in the navigation channel in proximity to this site is from the upper James River, 2% is from downstream sources, and 1% is from the two Jordan Point placement sites.