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At least 793 records · Page 44

Characterization and Stimulation of Selenium Reducing Microbial Consortia from Real Flue Gas Desulfurization Wastewater Biological Treatment System

Selenium is released into the environment via anthropogenic activities such as coal combustion. The U.S. Environmental Protection Agency’s Effluent Limitation Guideline (ELG) Rule limits the release of selenium species into U.S. waterways. To meet the ELG limit for selenium, coal-fired power plants must treat the wastewater produced by the flue gas desulfurization (FGD) systems. Selenium removal is of interest because small changes of the concentrations of selenium in the environment can cause detrimental ecological consequences. Biological treatment is used to remediate this wastewater, but little is known about the individual species in the microbial consortium that reduce toxic water-soluble selenium oxyanions to insoluble elemental selenium. To optimize current biological treatment capabilities of this water, the selenium-reducing capabilities must be leveraged. In order to do so, the selenium-reducing bacteria (SeRB) in biological treatment systems must be characterized. This study will be the first to characterize the microbial consortia from a real FGD WW biological treatment system and provide insights on how to better achieve selenium removal via biological treatment. This work will provide insights into the microorganisms predominantly responsible for the reduction of selenium oxyanions in FGD wastewater biological treatment systems, which can be used to better optimize more efficient biological treatment strategies of this industrial waste.

geomicrobiology↗

SPRUCE Soil Volumetric Water Content in Experimental Plots, Marcell Experimental Forest, Minnesota, 2017-2025

This dataset contains soil volumetric water content (VWC) measurements from the Spruce and Peatland Responses Under Changing Environments (SPRUCE) Experiment. Measurements were made inside SPRUCE experimental plots in the S1 Bog at the US Forest Service Marcell Experimental Forest in northern Minnesota, USA from 2018-2025 (2018-06-14 to 2025-12-31). Observations were made with METER 10HS soil moisture sensors. To reduce bulk density related variability, 10HS sensors were placed inside mesh tubes filled with peat at a standard bulk density. The observations under standard bulk density represent relative differences in water content between hummock and hollow positions, and in response to experimental treatments. Productivity of peatlands, and their keystone species sphagnum, are highly dependent on water availability, which is affected by lateral inputs, precipitation, ground water depth and evapotranspiration. Knowledge of near surface and sphagnum water content is useful to understand peatland function. This dataset contains 8 data files in comma-separate values (.csv) format. Additional metadata are provided: one data dictionary and a file-level metadata file in comma-separate values (*.csv) format and a user guide in PDF (*.pdf) format.

Warren, Jeffrey [ORNL] (ORCID:0000000206804697)↗

Impacts of anthropogenic gadolinium on the activity of the ammonia oxidizing bacterium Nitrosomonas europaea

Widespread use of gadolinium-based contrast agents in medical imaging has resulted in increased Gd inputs to municipal wastewater treatment plants. Others have reported that typical wastewater treatment does not attenuate Gd, resulting in discharges to natural waters. However, whether elevated Gd impacts the performance of biological treatment has not been investigated. We examined whether gadolinium chloride or Gd chelated with diethylenetriaminepentaacetic acid (DTPA) affected the activity of the model nitrifying bacterium Nitrosomonas europaea. At nominal GdCl 3 additions ranging from 1 to 500 µM, no impact was observed compared to the control. Most (>98%) of the added Gd precipitated, and extracellular GdPO 4 nanoparticles were observed. When chelated with DTPA, Gd remained soluble, but no statistically significant impact on ammonia oxidation was observed until the highest concentrations tested. At 300 and 500 µM Gd-DTPA, a temporary reduction of nitrite production relative to the control (effect size 1.3 mg l -1 and 1.5 mg l -1 , respectively, at 24 h) was seen. By itself, DTPA was highly inhibitory. Modeling suggested that DTPA likely chelated other metals, but adjusting the concentrations of the most abundant metals in the medium, calcium and magnesium, indicated that lowering their free ion activities was probably not the cause of inhibition. Complexation of other essential metals was more likely. Furthermore, our studies indicate that while the low bioavailability of Gd may limit its ecosystem impacts, the role of synthetic ligands used with Gd and other rare earth elements should e considered as the production, use and disposal of these elements increases.

54 ENVIRONMENTAL SCIENCES↗

Application of electrodialysis pretreatment to enhance boron removal and reduce fouling during desalination by nanofiltration/reverse osmosis

we report membranes have emerged as promising technologies for treatment of non-traditional waters, but fouling and poor rejection of small, neutral solutes (e.g., boric acid) impede their further implementation for water purification. Boron rejection is increased by raising the pH to convert boric acid to borate ion, but this change often leads to calcite supersaturation. This study investigated the use of a hybrid electrodialysis-nanofiltration/reverse osmosis (ED-NF/RO) system to reduce fouling from calcite precipitation and calcium-polysaccharide sorption to NF/RO membranes. Also, the study examined the potential of the hybrid process to increase permeate flux and boron rejection during NF/RO of synthetic saline water. ED pretreatment reduced calcite oversaturation and reduced flux decline during NF/RO. Low alginate concentrations (25 mg/L) limited NF/RO fouling, but high concentrations (100 mg/L) appeared to promote calcite scaling. ED pretreatment reduced the osmotic pressure of the NF/RO feed water, enabling lower operating pressures or greater permeate water fluxes. Boron rejection during NF/RO increased with ED pretreatment, probably due to stronger electrostatic repulsion and an increase in the fraction of total boron present as B(OH)4- following ED. This hybrid ED-NF/RO system shows promise as a novel approach to enhancing the performance of current membrane systems for treating complex feed waters.

alginate↗

Carrot rhamnogalacturonan I structure and composition changed during 2017 in California

Detailed composition, fine structure, and function were determined for carrot pomace fiber remaining after commercial juice extraction from carrots harvested at four different times during 2017, in different California, USA locations. This pomace was treated with commercial enzymes and the changes in carbohydrate composition were analyzed. The enzyme-treated carrot pomace contained pectic oligosaccharides that were branched, unsaturated, partially acetylated and methylated rhamnogalacturonan I (RG-I) with arabinogalacto-oligosaccharide side chains as well as free galacto-oligosaccharides and galacturono-oligosaccharides detected by MALDI-TOF MS and NMR analysis. The molecular weight and degree of galacto-oligosaccharide polymerization decreased while water solubility increased following enzymatic treatment. While carrot soluble dietary fiber remained relatively constant, insoluble dietary fiber and total dietary fiber increased during the year. The carrot pomace fiber structure changed between the June and September harvests so that it was more susceptible to enzymatic degradation, and its shape became more linear. The diversity of carrot RG-I oligosaccharide structures was the greatest in the enzyme-treated pomace harvested in September and the RG-I became almost completely debranched by the enzyme treatment for the pomace harvested in December. The structural properties of these carrot pomace fiber fractions suggest that they can function as a low viscosity beverage food ingredient, and the rhamnogalacturonan I structure indicated the potential for anti-viral, immuno-modulatory and prebiotic properties. Furthermore, the rhamnogalacturonan structural composition changes during the growing season highlights the need for bioactivity monitoring of carrot pomace obtained from different sources, and harvested at different times during the year.

59 BASIC BIOLOGICAL SCIENCES↗

Disentangling plant- and environment-mediated drivers of active rhizosphere bacterial community dynamics during short-term drought

Abstract Mitigating the effects of climate stress on crops is important for global food security. The microbiome associated with plant roots, the rhizobiome, can harbor beneficial microbes that alleviate stress, but the factors influencing their recruitment are unclear. We conducted a greenhouse experiment using field soil with a legacy of growing switchgrass and common bean to investigate the impact of short-term drought severity on the recruitment of active bacterial rhizobiome members. We applied 16S rRNA and 16S rRNA gene sequencing for both crops and metabolite profiling for switchgrass. We included planted and unplanted conditions to distinguish environment- versus plant-mediated rhizobiome drivers. Differences in community structure were observed between crops and between drought and watered and planted and unplanted treatments within crops. Despite crop-specific communities, drought rhizobiome dynamics were similar across the two crops. The presence of a plant more strongly explained the rhizobiome variation in bean (17%) than in switchgrass (3%), with a small effect of plant mediation during drought observed only for the bean rhizobiome. The switchgrass rhizobiome was stable despite changes in rhizosphere metabolite profiles between planted and unplanted treatments. We conclude that rhizobiome responses to short-term drought are crop-specific, with possible decoupling of plant exudation from rhizobiome responses.

59 BASIC BIOLOGICAL SCIENCES↗

Differential timing of gene expression and recruitment in independent origins of CAM in the Agavoideae (Asparagaceae)

Crassulacean acid metabolism (CAM) photosynthesis has evolved repeatedly across the plant tree of life, however our understanding of the genetic convergence across independent origins remains hampered by the lack of comparative studies. Here, we explore gene expression profiles in eight species from the Agavoideae (Asparagaceae) encompassing three independent origins of CAM. Using comparative physiology and transcriptomics, we examined the variable modes of CAM in this subfamily and the changes in gene expression across time of day and between well watered and drought-stressed treatments. We further assessed gene expression and the molecular evolution of genes encoding phosphoenolpyruvate carboxylase (PPC), an enzyme required for primary carbon fixation in CAM. Most time-of-day expression profiles are largely conserved across all eight species and suggest that large perturbations to the central clock are not required for CAM evolution. By contrast, transcriptional response to drought is highly lineage specific. Yucca and Beschorneria have CAM-like expression of PPC2 , a copy of PPC that has never been shown to be recruited for CAM in angiosperms. Together the physiological and transcriptomic comparison of closely related C 3 and CAM species reveals similar gene expression profiles, with the notable exception of differential recruitment of carboxylase enzymes for CAM function.

54 ENVIRONMENTAL SCIENCES↗

Evaluate Synergies of Using Hydrothermal Liquefaction and Anerobic Digestion Treatment Technologies for Wastewater Resource Recovery Facilities (CRADA 516 Final Report)

The research focuses on utilizing a new anaerobic digestion (AD) configuration to treat the aqueous by-product generated by hydrothermal liquefaction (HTL) of sewage sludge. This report found that for Anaerobic Digestion for HTL By-product, Anaerobic biofilms can degrade some HTL wastewater contaminants, but co-digestion is essential to address nutrient deficiencies and optimize performance. Without AD, toxicity of HTL aqueous streams may limit broader adoption in wastewater treatment plants (WWTPs). Great Lakes Water Authority (GLWA) used an innovative reactor design, involving a dynamic membrane anaerobic bioreactor to promote biofilm growth, improving contaminant degradation. The tree-like structure inside the reactor supports biofilm development with recirculation enhancing microbial activity. Overall, a 70% chemical oxygen demand (COD) removal was achieved, although nutrient supplementation is required for stability. The reactor achieved a diverse microbial community, including methanogens and bacteria capable of degrading phenols and aromatics.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Distribution and significance of carbon compounds on the moon.

Exploration of available information concerning carbon on the moon, following review of what is known about carbon on the earth, and consideration of the results of studies of meteorites, which have provided the first direct clues about extraterrestrial carbon. Carbon and carbon isotope composition data taken from Apollo 11 samples are tabulated. Carbon compounds produced by pyrolysis, extracted with benzene-methanol, extracted with water, and freed by acid treatment are discussed. Carbon and carbon compounds in lunar rocks and soils appear to be distributed heterogeneously.

Chang, S.↗

The action of ultrasounds on Bezostaia 1 winter wheat grown in sand pots treated with Knop solution

The results of 3 years of research are presented concerning the increase in length and weight of the aerial biomass as compared with the underground biomass, as well as the productivity indexes of Bezostaia 1 winter wheat. The experiment involved two varieties, each of them with nine repetitions. Sterile sifted sand treated several times with a Knop solution during the vegetative period was used as a seed bed. The seeds were kept in water for 2 hours before treatment. Biometric and statistical measurements showed significant responses in the treated varieties.

Albu, N.↗

In situ detection of microbial respiration in soils and salt flats

Increase in CO2 partial pressures over a desert soil treated with casamino-acids glucose solution correlated with bacterial growth. Few or no increases in numbers of bacteria or CO2 concentrations were noted in similar plots treated with water only or receiving no treatment. Growth in the soil appeared to be severely nutrient limited during the 10 day experiment. Especially rapid growth took place between the third and fifth day, when temperatures ranged from 0 deg. (night) to a maximum of 17.4 deg. (day). Under the conditions of the experiment, intermittent CO2 assay was an insensitive indicator of growth, possibly because of restiction of gas escape by the desert pavement or solution, exchange, or precipitation of carbonate, but more likely because of inefficient sealing of hoods to and below the soil surface. CO2 assay was unable to detect microbial successions. The unpredictable course of these successions, plus unpredictable relative retentions mitigates against assay of organic gases as reliable in situ detection of microbial activity, except perhaps in very alkaline environments such as Owens Lake salts.

Tew, R. W.↗

Semi-Lagrangian integration of a grid-point shallow water model on the sphere

This paper describes a semi-Lagrangian technique for integrating the equations of motion on the global domain. The technique uses an auxiliary spherical coordinate system at each near-polar gridpoint of the latitude-longitude grid; the auxiliary system is obtained by a rotation such that the new equator passes through the gridpoint in question and the new coordinate directions coincide with those of the original system at that point. The technique was applied to the shallow water equations, incorporating a semiimplicit treatment of the adjustment terms on a C-grid, with two-time levels. A five day integration was successfully carried out for a situation involving strong cross-polar flow. No filtering or diffusion was required to maintain stability over a five day period.

Mcdonald, A.↗

Bioisolation on the Space Station

Animal research on the Space Station presents the need for bioisolation, which is here defined as instrumental and operational provisions, which will prevent the exchange of particles greater than 0.3-micron size and microorganisms between crew and animals. Current design principles for the Biological Research Project thus call for: (1) use of specific pathogen-free animals; (2) keeping animals at all times in enclosed habitats, provided with microbial filters and a waste collection system; (3) placing habitats in a holding rack, centrifuge, and workbench, all equipped with particulate and odor filters, (4) washing dirty cage units in an equipment cleaner, with treatment and recycling of the water; (5) designing components and facilities so as to ensure maximal accessibility for cleaning; and (6) defining suitable operational procedures. Limited ground tests of prototype components indicate that proper bioisolation can thus be achieved.

Bonting, Sjoerd L.↗

Packaged Waste Treatment

This Jacksonville, Florida, apartment complex has a wastewater treatment system which clears the water, removes harmful microorganisms and reduces solid residue to ash. It is a spinoff from spacecraft waste management and environmental control technology.

Source record↗

Characterization of Volume F Trash from Four Recent STS Missions: Microbial Occurrence, Numbers, and Identifications

The fate of space-generated solid wastes, including trash, for future missions is under consideration by NASA. Several potential treatment options are under active technology development. Potential fates for space-generated solid wastes: Storage without treatment; storage after treatment(s) including volume reduction, water recovery, sterilization, and recovery plus recycling of waste materials. For this study, a microbial characterization was made on trash returned from four recent STS missions. The material analyzed were 'Volume F' trash and other bags of accompanying trash. This is the second of two submitted papers on these wastes. This first one covered trash content, weight and water content. Upon receipt, usually within 2 days of landing, trash contents were catalogued and placed into categories: drink containers, food waste, personal hygiene items, and packaging materials, i.e., plastic film and duct tape. Microbial counts were obtained with cultivatable counts on agar media and direct counts using Acridine Orange fluorescent stain (AODC). Trash bag surfaces, 25 square cm , were also sampled. Direct counts were approximately 1 x 10(exp 6) microbes/square cm and cultivatable counts ranged from 1 x 10 to 1 X 10(exp 4) microbes/ square cm-2. Aerobic microbes, aerobic sporeformers, and yeasts plus molds were common for all four missions. Waste items from each category were placed into sterile ziplock bags and 1.5 L sterile DI water added. These were then dispersed by hand shaking for 2 min. prior to inoculation of count media or determining AODC. In general, cultivatable microbes were found in drinks, food wastes, and personal hygiene items. Direct counts were usually higher than cultivatable counts. Some pathogens were found: Staphylococcus auerus, Escherichia coli (fecal wastes). Count ranges: drink pouches - AODC 2 x 10(exp 6) to 1 X 10(exp 8) g(sub fw) (exp -1); cultivatable counts variable between missions; food wastes: Direct counts were close to aerobic plate counts. Counts ranged from 10(exp 6) to 10(exp 9) per g(sub fw). Identities of isolates from cultivation media were obtained using a Biolog Microbial ID System or microSEQ molecular ID methodology using an ABI3130 gene analyzer.

Strayer, Richard F.↗

Removal, distribution and retention of metals in a constructed wetland over 20 years

The A-01 wetland treatment system (WTS) was designed to remove metals (primarily copper) from the effluent at the A-01 National Pollution Discharge Elimination System (NPDES) outfall at the Savannah River Site, Aiken, SC. This research investigated metal removal, distribution and retention in the A-01 WTS over a period of 20 years. The findings are important for ensuring continued metal sequestration in the A-01 WTSs over time, providing management guidance for constructed wetlands, and investigating changes in metal remediation effectiveness as a wetland ages. During 20 years of operation, systematic water and sediment sampling validated the wetlands' performance. After passage through the treatment cells, Cu concentrations were well below permit limits during all years of operation, often falling below 10 μg L -1 . Cu removal has been consistent over time, averaging about 80% despite large changes in influent Cu concentrations. Most divalent metals were rapidly removed from the water and held in the sediments shortly after the water entered the treatment wetland. Average removal of Pb from water by the wetland system was 67 and 74% in 2004 and 2020, respectively. Comparable values for Zn were 52 and 65%, respectively. Generally, the highest concentrations of Cu, Pb, and Zn were found in the sediment from the first cell in each pair of cells suggesting that most of the Cu, Pb, and Zn in the A-01 effluent was bound to the sediment quickly. Diffusive gradients in thin films (DGT) measurements of Cu and Zn in the sediments were much lower than bulk sediment concentrations. These results suggest that most of the Cu and Zn in the A-01 WTS sediments was not bioavailable, hence not toxic to aquatic organisms, as a likely consequence of adsorption to sediment particles and complexation with organic and inorganic substances.

54 ENVIRONMENTAL SCIENCES↗