MATURE PETROLEUM HYDROCARBONS CONTAMINATION IN SURFACE AND SUBSURFACE WATERS OF KIZILIRMAK GRABEN (CENTRAL ANATOLIA, TURKEY): GEOCHEMICAL EVIDENCE FOR A WORKING PETROLEUM SYSTEM ASSOCIATED WITH A POSSIBLE SALT DIAPIR

Abstract. The Arctic Ocean accounts for only 4% of the global ocean area but it contributes significantly to the global carbon cycle. Recent observations of seawater carbonate chemistry in shelf waters of the Western Arctic from 2009 to 2011 indicate that extensive areas of the benthos are exposed to bottom waters that are seasonally undersaturated with respect to calcium carbonate (CaCO3) minerals, particularly aragonite. Our observations indicate seasonal reduction of saturation states (Ω) for calcite (Ωcalcite) and aragonite (Ωaragonite) in the subsurface in the Western Arctic by as much as 0.9 and 0.6, respectively. Such data indicates that bottom waters of the Western Arctic shelves are already potentially corrosive for biogenic and sedimentary CaCO3 for several months each year. Seasonal changes in Ω are imparted by a variety of factors such as phytoplankton photosynthesis, respiration/remineralization of organic matter and air-sea gas exchange of CO2 – combined these processes either increase or enhance Ω in surface and subsurface waters, respectively. These seasonal physical and biological processes also act to mitigate or enhance the impact of Anthropocene ocean acidification (OA) on Ω in surface and subsurface waters, respectively. Future monitoring of the Western Arctic shelves is warranted to assess the present and future impact on Ω values from ocean acidification and seasonal biological/physical processes on Arctic marine ecosystems.

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Investigation of the activity of Rn-222 along a small stream in the Representative Basin of Juatuba - MG

RBRH ◽

10.1590/2318-0331.231820180009 ◽

2018 ◽

Vol 23 ◽

Cited By ~ 1

Author(s):

Vinícius Verna Magalhães Ferreira ◽

Cláudio José Chagas ◽

Rubens Martins Moreira ◽

Zildete Rocha ◽

Talita de Oliveira Santos ◽

...

Keyword(s):

Surface Waters ◽

Human Consumption ◽

Southeastern Part ◽

Small Stream ◽

Radon Activity ◽

Subsurface Waters ◽

Main Instrument ◽

Natural Tracer ◽

Effective Radiation ◽

Surface And Subsurface Waters

ABSTRACT For thousands of years, water has been the focus of experimentation toward solving the challenges associated with human water supply, navigation, irrigation, and sanitation. The use of tracers to study water resources is an efficient approach that can facilitate the modeling of many hydrological scenarios. The goal of this paper is to show results of research that tracked the presence of Rn-222, a natural tracer, in the surface waters of a small watercourse in southeastern part of Brazil. RAD 7, which is an electronic and portable radon detector, was the main instrument used in this survey. We analyzed 117 water samples and converted the radon activity results to effective radiation doses with respect to the hypothetical human consumption of these waters. We also analyzed the sediments of the watercourse. The obtained data showed that the radon activity in the studied waters varies between 0.52-76.96 Bq/m3. We determined the effective dose of all samples to be less than 1 mSv y−1, and its consumption to present no risk to human health. The existence of connections between surface and subsurface waters in the stream is possible, and radon peaks may indicate the existence of discharge zones into the surface water body.

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Groundwater Inflows to the Columbia River Along the Hanford Reach and Associated Nitrate Concentrations

Frontiers in Water ◽

10.3389/frwa.2021.574684 ◽

2021 ◽

Vol 3 ◽

Author(s):

Abigail Conner ◽

Michael N. Gooseff ◽

Xingyuan Chen ◽

Evan Arntzen ◽

Vanessa Garayburu-Caruso

Keyword(s):

River Water ◽

Agricultural Land ◽

Columbia River ◽

Pollution Source ◽

Land Uses ◽

Sources Of Pollution ◽

Subsurface Waters ◽

Hydrologic Exchange ◽

June July ◽

Surface And Subsurface Waters

Healthy river ecosystems require the interaction of many physical and biological processes to maintain their status. One physical process supporting biogeochemical cycling is hydrologic exchange (i.e., hydrologic exchange flows, HEFs) between relatively fast-flowing channel waters and slower-flowing surface and subsurface waters (lateral and vertical). Land uses adjacent to rivers have the potential to alter the water quality of off-channel surface and subsurface waters, and HEFs therefore have the potential to deliver solutes associated with river-adjacent land uses to rivers. HEFs can be nonpoint, diffuse sources of pollution, making the ultimate pollution source difficult to identify, especially in large rivers. Here, we seek to identify HEFs in the Columbia River near Richland, WA by looking for anomalies in temperature and electrical conductivity (EC) along the bed of the river in February, June, July, August, and November 2018. These are ultimately the “ends” of HEFs as they are locations of subsurface inflow to the river. We found these anomalies to be a combination of warmer or colder and higher (but not lower) EC than river water. We identified a majority of warm anomalies in February and July 2018, and majority cold anomalies in June, August, and November 2018. High-EC anomalies were found mostly in February, August, and November. Combined, we observe a shift from warm, high EC anomalies dominating in February to equivalent EC, warm anomalies in June, to equivalent EC, cool anomalies dominating July. In August, we also measured dissolved nitrate (NO3-) in-situ to determine whether anomalies were associated with increased NO3- loading to the river, especially along the eastern shoreline, which is dominated by agricultural land use. Inflows along the eastern shoreline have greater concentrations of nitrate than river water (up to 10 mg N–NO3-/L). This research demonstrates that HEFs are temporally and spatially dynamic transferring heat and solutes to rivers.

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