Publications by authors named "Raymond M Flynn"
Article Synopsis
- Diverse land use activities increase the risk of microbiological contamination in stream headwaters, prompting the need for effective water quality monitoring.
- Monitoring in a 17 km² agricultural area showed no significant difference in fecal contamination levels during periods when spreading organic fertilizer was restricted compared to open periods, indicating persistent fecal pollution.
- Microbial source tracking revealed that bovine waste was more dominant during open periods, while human waste signatures were more prominent when restrictions were in place, suggesting that winter land use restrictions can help limit agricultural waste impacts on water quality.
Gravel aquifers act as important potable water sources in central western Europe, yet they are subject to numerous contamination pressures. Compositional and textural heterogeneity makes protection zone delineation around groundwater supplies in these units challenging; artificial tracer testing aids characterization. This paper reappraises previous tracer test results in light of new geological and microbiological data.
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- Particulate colloids, like latex microspheres, interact with proteins such as Bovine Serum Albumin (BSA) in sewage-impacted water, influencing their removal by iron-oxide coated sands.
- Experiments showed that when BSA was fully adsorbed, the rate of microsphere deposition decreased, indicating a relationship between BSA coverage and colloid retention.
- The findings suggest that as BSA coverage saturates, it can create attractive sites for further colloid deposition, highlighting that a single protein type can either help or hinder the mobility of colloids in saturated environments.
Attenuation processes controlling virus fate and transport in the vadose zone of karstified systems can strongly influence groundwater quality. This research compares the breakthrough of two bacteriophage tracers (H40/1 and T7), with contrasting properties, at subsurface monitoring points following application onto an overlying composite sequence of thin organic soil and weathered limestone (epikarst). Short pulse multi-tracer test results revealed that T7 (Source concentration, Co=1.
View Article and Find Full Text PDFVirus inactivation and virus adsorption, resulting from interactions with minerals, constitute important aspects of an aquifers disinfection capacity. Investigations using a 20 cm column filled with medium-grained natural sands demonstrated that the sands can attenuate up to 62% of a pulse of viruses injected. Experiments using repeatedly washed sands had significantly lower attenuation capacity than fresh sands, due to removal of fine-grained (silt and clay-sized) coatings on grain surfaces.
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