Concentrations of dissolved oxygen (DO) plotted vs. dissolved organic carbon (DOC) in groundwater samples taken from a coastal plain aquifer of South Carolina (SC) showed a statistically significant hyperbolic relationship. In contrast, DO-DOC plots of groundwater samples taken from the eastern San Joaquin Valley of California (CA) showed a random scatter. It was hypothesized that differences in the bioavailability of naturally occurring DOC might contribute to these observations. This hypothesis was examined by comparing nine different biochemical indicators of DOC bioavailability in groundwater sampled from these two systems. Concentrations of DOC, total hydrolysable neutral sugars (THNS), total hydrolysable amino acids (THAA), mole% glycine of THAA, initial bacterial cell counts, bacterial growth rates, and carbon dioxide production/consumption were greater in SC samples relative to CA samples. In contrast, the mole% glucose of THNS and the aromaticity (SUVA(254)) of DOC was greater in CA samples. Each of these indicator parameters were observed to change with depth in the SC system in a manner consistent with active biodegradation. These results are uniformly consistent with the hypothesis that the bioavailability of DOC is greater in SC relative to CA groundwater samples. This, in turn, suggests that the presence/absence of a hyperbolic DO-DOC relationship may be a qualitative indicator of relative DOC bioavailability in groundwater systems.
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http://dx.doi.org/10.1111/j.1745-6584.2011.00835.x | DOI Listing |
Chemosphere
January 2025
Department of Civil and Environmental Engineering, University of Massachusetts Lowell, Massachusetts, United States. Electronic address:
There is significant interest in monitoring abiotic decomposition of chlorinated solvents at contaminated sites due to large uncertainties regarding the rates of abiotic attenuation of trichloroethylene (PCE) and perchloroethylene (PCE) under field conditions. In this study, an innovative passive sampling tool was developed to quantify acetylene, a characteristic product of abiotic reduction of TCE or PCE, in groundwater. The sampling mechanism is based on the highly specific and facile click reaction between acetylene and an azide compound to form a biologically and chemically stable triazole product.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
National Centre for Earth Sciences Studies, Akkulam, Thiruvananthapuram, 695031, Kerala, India.
The submarine groundwater discharge (SGD) into the sea is known to alter various biotic and abiotic properties of coastal waters. However, its influence on the lower trophic levels, namely, meiofauna, is poorly understood. This study highlights the impact of SGD on the density, distribution, and diversity of intertidal meiofaunal communities along the subterranean estuaries (STEs) of the southwest coast of India (Arabian Sea).
View Article and Find Full Text PDFChemosphere
January 2025
, School of Water Resources Engineering, Jadavpur University, Kolkata 700032, West Bengal, India. Electronic address:
Groundwater toxicity and water level depletion are serious concerns today. Assessing groundwater quality (GWQ) is crucial for effective planning and management due to increasing demands for drinking and irrigation water. Therefore, this study aims to analyze groundwater hydrochemistry, variability, and factors influencing quality for drinking and irrigation purposes using indices and models.
View Article and Find Full Text PDFEnviron Monit Assess
January 2025
Department of Chemistry, Vaal University of Technology, Vanderbijlpark, South Africa.
Due to incessant contamination of the groundwater system near the dumpsite in southwestern Nigeria Basement Complex, this study seeks to evaluate the impact of the Odogbo dumpsite on the local groundwater system by integrating geophysical and geochemical methodologies. Aeromagnetic data covering the study area was acquired, processed, and enhanced to delineate basement features that could potentially be passing plumes to the groundwater system. Concurrently, geoelectric methods using 2-D dipole-dipole imaging and vertical electrical sounding (VES) were utilized to characterize the vulnerability indices of the lithologies underlying the dumpsite.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Third World Center (TWC) for Science and Technology, H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan; H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan. Electronic address:
Groundwater contamination is a growing global concern. The objective of the present study is to assess the groundwater quality of Khairpur district, Sindh, Pakistan-a region which is emblematic of broad environmental and public health challenges prevalent in South Asian countries. The study also aims to comprehend the impact of arsenic (As), fluoride (F), and nitrate (NO) dynamics and its health implications.
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