13 Jul 2022

Effects of Impure Water Sources on Early-Age Properties of Calcium Sulfoaluminate Cements for Rapid Airfield Damage Recovery

Abstract: In austere environments with limited access to clean water, it is advantageous to use nonpotable water for construction (i.e., mixing water for concrete.) In rapid-response situations such as rapid airfield damage recovery (RADR), the use of calcium sulfoaluminate (CSA) cements is beneficial for expedient pavement repairs because of their rapid strength gain characteristics. However, the hydration products formed by CSA cements are substantially different from those formed by ordinary portland cement and might react differently to impurities that water sources may contain. A laboratory study component investigated the application of various salts and impure sources of mixing water with commercially available CSA cement-based products. A field component studied the application of naturally occurring impure water sources for RADR. Recommendations are made for implementation of impure mixing water for RADR using commercially available flowable fill and concrete products made with CSA cement.

12 Jul 2022

Boronic Acid Functionalized Ferrocene Derivatives Towards Fluoride Sensing

Abstract: In this technical report (TR), a robust, readily synthesized molecule with a ferrocene core appended with one or two boronic acid moieties was designed, synthesized, and used toward F- (free fluoride) detection. Through Lewis acid-base interactions, the boronic acid derivatives are capable of binding with F- in an aqueous solution via ligand exchange reaction and is specific to fluoride ion. Fluoride binding to ferrocene causes significant changes in fluorescence or electrochemical responses that can be monitored with field-portable instrumentation at concentrations below the WHO recommended limit. The F- binding interaction was further monitored via proton nuclear magnetic resonance spectroscopy (1H-NMR). In addition, fluorescent spectroscopy of the boronic acid moiety and electrochemical monitoring of the ferrocene moiety will allow detection and estimation of F- concentration precisely in a solution matrix. The current work shows lower detection limit (LOD) of ~15 µM (285 μg/L) which is below the WHO standards. Preliminary computational calculations showed the boronic acid moieties attached to the ferrocene core interacted with the fluoride ion. Also, the ionization diagrams indicate the amides and the boronic acid groups can be ionized forming strong ionic interactions with fluoride ions in addition to hydrogen bonding interactions.

30 Jun 2022

Other Social Effects and Social Vulnerability Analysis: Existing Resources

Purpose: The following technical note (TN) provides a summary of existing resources available to the US Army Corps of Engineers’ (USACE) districts that address benefits in the Other Social Effects account for evaluating the effects of water resource projects. Consideration of social factors is key to a complete, robust, water-resources analysis, and these resources provide planners and project development teams with approaches and tools for their consideration. "social effects—the constituents of life that influence personal and group definitions of satisfaction, well-being, and happiness —OSE Primer, 3" This TN is limited in scope and does not cover ecosystem goods and services or environmental-quality metrics that can also be used to assess benefits outside of economic benefits from water-resource projects. The following resources and their associated metrics are presented in a manner that is focused on assisting districts during the project-planning phase, although the metrics can be used to assess benefits or impacts during other project phases as well (for example, construction, operations, and maintenance).

28 Jun 2022

Two Years of Post-Project Monitoring of a Navigation Solution in a Dynamic Coastal Environment, Smith Island, Maryland

Abstract: In 2018, jetties and a sill were constructed by the US Army Corps of Engineers adjacent to the Sheep Pen Gut Federal Channel at Rhodes Point, Smith Island, Maryland. These navigation improvements were constructed under Section 107 of the Continuing Authorities Program. Material dredged for construction of the structures and realignment of the channel were used to restore degraded marsh. Following construction and dredging, 2 years of monitoring were performed to evaluate the performance of navigation improvements with respect to the prevention of shoaling within the channel, shoreline changes, and impacts to submerged aquatic vegetation (SAV). Technical Report ERDC/CHL TR-20-14 describes the first year of post-project monitoring and the methodologies employed. This report describes conclusions derived from 2 years of monitoring. While the navigation improvements are largely preventing the channel from infilling, shoaling within is occurring at rates higher than expected. The placement site appears stable and accreting landward; however, there continues to be erosion along the shoreline and through the gaps in the breakwaters. SAV monitoring indicates that SAV is not present in the project footprint, even though turbidity is comparable to the reference area. Physical disturbance of the bottom sediment during construction may explain SAV absence.

15 Jun 2022

Simulated Herbicide Spray Retention on Floating Aquatic Plants as Affected by Carrier Volume and Adjuvant Type

Abstract: Foliar delivery of herbicides is a common means for plant management in aquatic environments. Though this technique is decades old, little is known about vegetative spray retention relative to this application method. A more complete understanding of maximizing herbicide retention could lead to improved plant management while simultaneously decreasing pesticide load in aquatic environments. Therefore, outdoor mesocosm experiments were conducted in 2020 to evaluate the effect of adjuvant type on foliar spray retention in waterhyacinth [Eichhornia crassipes (Mart.) Solms]. Additionally, the effect of carrier volume on spray retention in waterhyacinth, waterlettuce (Pistia stratiotes L.), and giant salvinia (Salvinia molesta D.S. Mitchell) was documented. Spray deposition did not differ among the nine adjuvants tested; however, spray retention was reduced 6% to 11% when an adjuvant was excluded from the spray solution. The effect of carrier volume on spray retention in waterhyacinth, waterlettuce, and giant salvinia was also investigated. Decreases in spray retention were most sensitive to increased carrier volume in waterhyacinth, followed by giant salvinia and waterlettuce. Among species, spray retention potential, as determined by intercept estimates, was greatest in water-lettuce and giant salvinia regardless of carrier volume. Asymptotes estimates for waterhyacinth, waterlettuce, and giant salvinia were 33%, 46%, and 79% spray retention, respectively. In other words, spray retention was the lowest and remained relatively constant at these values for the high carrier volumes tested (935 and 1,870 L ha−1), which were likely due to the presence of pubescence on leaves and flatter leaf architecture represented by waterlettuce and giant salvinia compared to the glabrous vertical leaves of waterhyacinth. Future research will evaluate these concepts under field condition.

13 Jun 2022

Evaluation of Multiparameter Water Meter for Environmental Toolkit for Expeditionary Operations

Purpose: A new, commercially available, field-portable water sensor was evaluated for efficacy during operation and compatibility with current Environmental Toolkit for Expeditionary Operations (ETEO) software. The ETEO provides sensors to Soldiers to rapidly identify and quantify environmental contamination in soil, air, and water at potential new base sites during initial reconnaissance to ensure Soldier safety and minimize unnecessary remediation efforts by the Army. The primary objective of this study was to enhance ETEO performance by providing the capability to evaluate multiple water quality properties simultaneously.

13 Jun 2022

A Review of Empirical Algorithms for the Detection and Quantification of Harmful Algal Blooms Using Satellite-Borne Remote Sensing

Abstract: Harmful Algal Blooms (HABs) continue to be a global concern, especially since predicting bloom events including the intensity, extent, and geographic location, remain difficult. However, remote sensing platforms are useful tools for monitoring HABs across space and time. The main objective of this review was to explore the scientific literature to develop a near-comprehensive list of spectrally derived empirical algorithms for satellite imagers commonly utilized for the detection and quantification HABs and water quality indicators. This review identified the 29 WorldView-2 MSI algorithms, 25 Sentinel-2 MSI algorithms, 32 Landsat-8 OLI algorithms, 9 MODIS algorithms, and 64 MERIS/Sentinel-3 OLCI algorithms. This review also revealed most empirical-based algorithms fell into one of the following general formulas: two-band difference algorithm (2BDA), three-band difference algorithm (3BDA), normalized-difference chlorophyll index (NDCI), or the cyanobacterial index (CI). New empirical algorithm development appears to be constrained, at least in part, due to the limited number of HAB-associated spectral features detectable in currently operational imagers. However, these algorithms provide a foundation for future algorithm development as new sensors, technologies, and platforms emerge.

26 May 2022

Growth Assessments of Starry Stonewort (Nitellopsis obtusa) in Various Substrate Types for Large-scale Cultivation Studies

Purpose: The purpose of this study was to compare multiple substrate types to optimize cultivation conditions for the invasive macroalga Nitellopsis obtusa (Desv. in Loisel.) J. Groves, commonly known as starry stonewort. Large-scale cultivation will allow for tiered approaches to management evaluation research while minimizing the influence of confounding variables.

26 May 2022

Spatial and Temporal Variability of the Alligatorweed Pathogen, Alternaria alternantherae, in Louisiana

Abstract: Alligatorweed leaf spot is a disease of invasive Alternanthera philoxeroides(Alligatorweed) in the southern US, caused by Alternaria alternantherae. However, little is known about when or where this pathogen naturally occurs. To better understand this species’life history, we examined temporal (every 2–3 weeks) and spatial (latitudinal) patterns of A. alternantherae occurrence at sites in Louisiana for 2 y. Pathogen presence reflectedclear within-year temporal and spatial patterns. Overall, the percentage of leaves infectedwith A. alternantherae was low during spring each year (0–20% infected) but increasedthroughout summer (maximum of 50% infected), and plants in northern sites had lowerfrequency of infection relative to southern sites until later in the year (late summer/early fall) but only in 1 of the 2 years of our study. The mean proportion of leaves infected with A. alternantherae declined with latitude both years (P = 0.01) and variability increasedwith latitude (P = 0.04), a pattern suggestive of range limitation in northern areas. We estimate a northern distributional limit of 34°N for A. alternantherae in Louisiana, but Alligatorweed occurs farther north. Although we did not directly examine disease impacts to Alligatorweed during the study, they may be greatest in southern areas, where the pathogenis more common early and throughout the growing season, and thus may be less likely to provide control in northern infestations of the invasive Alligatorweed.

18 Apr 2022

Sustainable Harmful Algal Bloom Mitigation by 3D Printed Photocatalytic Oxidation Devices (3D-PODs)

Abstract: The impacts of Harmful Algal Blooms (HAB), often caused by cyanobacteria (Figure 1), on water resources are increasing. Innovative solutions for treatment of HABs and their associated toxins are needed to mitigate these impacts and decrease risks without introducing persistent legacy contaminants that cause collateral ecosystem impacts. This technical note (TN) identifies novel opportunities enabled by Additive Manufacturing (AM), or 3D printing, to produce high surface area advanced material composites to rapidly prototype sustainable environmental solutions for aquatic nuisance species control. This innovative research explores deployment of 3D-printable polymer composite structures containing nano-scale photocatalysts for targeted open water treatment of HABs that are customizable to the site-of-concern and also retrievable, reusable, and sustainable. The approach developed to control cyanobacteria HAB events has the potential to augment or replace broadcast, non-specific chemical controls that otherwise put non-target species and ecological resources at long-term risk. It can also augment existing UV-treatment HAB treatment control measures. The expected research outcome is a novel, effective, and sustainable HAB management tool for the US Army Corps of Engineers (USACE) and resource managers to deploy in their HAB rapid response programs. The research will provide a framework for scale-up into other manufacturing methods (e.g., injection molding) to produce the devices in bulk (quickly and efficiently). Research for this project title “Mitigation of Harmful Algal Bloom Toxins using 3D Printed Photocatalytic Materials (FY21-23)” was sponsored by the US Army Engineer Research Development Center’s (ERDC) Aquatic Nuisance Species Research Program (ANSRP).