Biogeochemical Indicators of Nutrient Enrichments in Wetlands: The Microbial Response as a Sensitive Indicator of Wetland Eutrophication

All cities face complex challenges managing urban stormwater while also protecting urban water bodies. Green stormwater infrastructure and process-based restoration offer alternative strategies that prioritize watershed connectivity. We report on a new urban floodplain restoration technique being tested in the City of Seattle, USA: an engineered hyporheic zone. The hyporheic zone has long been an overlooked component in floodplain restoration. Yet this subsurface area offers enormous potential for stormwater amelioration and is a critical component of healthy streams. From 2014 to 2017, we measured hyporheic temperature, nutrients, and microbial and invertebrate communities at three paired stream reaches with and without hyporheic restoration. At two of the three pairs, water temperature was significantly lower at the restored reach, while dissolved organic carbon and microbial metabolism were higher. Hyporheic invertebrate density and taxa richness were significantly higher across all three restored reaches. These are some of the first quantified responses of hyporheic biological communities to restoration. Our results complement earlier reports of enhanced hydrologic and chemical functioning of the engineered hyporheic zone. Together, this research demonstrates that incorporation of hyporheic design elements in floodplain restoration can enhance temperature moderation, habitat diversity, contaminant filtration, and the biological health of urban streams.

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Internal dose assessment of 148Gd using isotope ratios of gamma-emitting 146Gd or 153Gd in accidently released spallation target particles

Scientific Reports ◽

10.1038/s41598-020-77718-3 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

C. Rääf ◽

V. Barkauskas ◽

K. Eriksson Stenström ◽

C. Bernhardsson ◽

H. B. L. Pettersson

Keyword(s):

Operation Time ◽

Isotope Ratios ◽

Dose Assessment ◽

Sensitive Indicator ◽

Whole Body ◽

Internal Dose ◽

Tungsten Target ◽

Alpha Emitter ◽

Spallation Source ◽

Effective Doses

AbstractThe pure alpha emitter 148Gd may have a significant radiological impact in terms of internal dose to exposed humans in case of accidental releases from a spallation source using a tungsten target, such as the one to be used in the European Spallation Source (ESS). In this work we aim to present an approach to indirectly estimate the whole-body burden of 148Gd and the associated committed effective dose in exposed humans, by means of high-resolution gamma spectrometry of the gamma-emitting radiogadolinium isotopes 146Gd and 153Gd that are accompanied by 148Gd generated from the operation of the tungsten target. Theoretical minimum detectable whole-body activity (MDA) and associated internal doses from 148Gd are calculated using a combination of existing biokinetic models and recent computer simulation studies on the generated isotope ratios of 146Gd/148Gd and 153Gd/148Gd in the ESS target. Of the two gamma-emitting gadolinium isotopes, 146Gd is initially the most sensitive indicator of the presence of 148Gd if whole-body counting is performed within a month after the release, using the twin photo peaks of 146Gd centered at 115.4 keV (MDA < 1 Bq for ingested 148Gd, and < 25 Bq for inhaled 148Gd). The corresponding minimum detectable committed effective doses will be less than 1 µSv for ingested 148Gd, but substantially higher for inhaled 148Gd (up to 0.3 mSv), depending on operation time of the target prior to the release. However, a few months after an atmospheric release, 153Gd becomes a much more sensitive indicator of body burdens of 148Gd, with a minimum detectable committed effective doses ranging from 18 to 77 µSv for chronic ingestion and between 0.65 to 2.7 mSv for acute inhalation in connection to the release. The main issue with this indirect method for 148Gd internal dose estimation, is whether the primary photon peaks from 146 and 153Gd can be detected undisturbed. Preliminary simulations show that nuclides such as 182Ta may potentially create perturbations that could impair this evaluation method, and which impact needs to be further studied in future safety assessments of accidental target releases.

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Soil microbial response to silicate fertilization reduces bioavailable arsenic in contaminated paddies

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2021.108307 ◽

2021 ◽

pp. 108307

Author(s):

Suvendu Das ◽

Hyun Young Hwang ◽

Hyeon Ji Song ◽

Song Rae Cho ◽

Joy D. Van Nostrand ◽

...

Keyword(s):

Soil Microbial ◽

Microbial Response

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Plant residue chemical quality modulates the soil microbial response related to decomposition and soil organic carbon and nitrogen stabilization in a rainfed Mediterranean agroecosystem

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2021.108198 ◽

2021 ◽

pp. 108198

Author(s):

María Almagro ◽

Antonio Ruiz-Navarro ◽

Elvira Díaz-Pereira ◽

Juan Albaladejo ◽

María Martínez-Mena

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Plant Residue ◽

Chemical Quality ◽

Carbon And Nitrogen ◽

Soil Microbial ◽

Microbial Response

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Characterization of microbial response to petroleum hydrocarbon contamination in a lacustrine ecosystem

Environmental Science and Pollution Research ◽

10.1007/s11356-021-13885-8 ◽

2021 ◽

Author(s):

Emilio D’Ugo ◽

Milena Bruno ◽

Arghya Mukherjee ◽

Dhrubajyoti Chattopadhyay ◽

Roberto Giuseppetti ◽

...

Keyword(s):

Oil Spill ◽

Petroleum Hydrocarbon ◽

Oil Spills ◽

Oil Pollution ◽

Primary Source ◽

Hydrocarbon Contamination ◽

Petroleum Hydrocarbon Contamination ◽

Microbial Response ◽

Pollution Event ◽

Hydrocarbonoclastic Potential

AbstractMicrobiomes of freshwater basins intended for human use remain poorly studied, with very little known about the microbial response to in situ oil spills. Lake Pertusillo is an artificial freshwater reservoir in Basilicata, Italy, and serves as the primary source of drinking water for more than one and a half million people in the region. Notably, it is located in close proximity to one of the largest oil extraction plants in Europe. The lake suffered a major oil spill in 2017, where approximately 400 tons of crude oil spilled into the lake; importantly, the pollution event provided a rare opportunity to study how the lacustrine microbiome responds to petroleum hydrocarbon contamination. Water samples were collected from Lake Pertusillo 10 months prior to and 3 months after the accident. The presence of hydrocarbons was verified and the taxonomic and functional aspects of the lake microbiome were assessed. The analysis revealed specialized successional patterns of lake microbial communities that were potentially capable of degrading complex, recalcitrant hydrocarbons, including aromatic, chloroaromatic, nitroaromatic, and sulfur containing aromatic hydrocarbons. Our findings indicated that changes in the freshwater microbial community were associated with the oil pollution event, where microbial patterns identified in the lacustrine microbiome 3 months after the oil spill were representative of its hydrocarbonoclastic potential and may serve as effective proxies for lacustrine oil pollution.

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