Ronald W Harvey (Former Employee)
Science and Products
Filter Total Items: 80
Adaptations of indigenous bacteria to fuel contamination in karst aquifers in south-central Kentucky Adaptations of indigenous bacteria to fuel contamination in karst aquifers in south-central Kentucky
The karst aquifer systems in southern Kentucky can be dynamic and quick to change. Microorganisms that live in these unpredictable aquifers are constantly faced with environmental changes. Their survival depends upon adaptations to changes in water chemistry, taking advantage of positive stimuli and avoiding negative environmental conditions. The U.S. Geological Survey conducted a study...
Authors
Thomas D. Byl, David W. Metge, Daniel T. Agymang, Mike Bradley, Gregg Hileman, Ronald W. Harvey
Colloid transport in saturated porous media: Elimination of attachment efficiency in a new colloid transport model Colloid transport in saturated porous media: Elimination of attachment efficiency in a new colloid transport model
A colloid transport model is introduced that is conceptually simple yet captures the essential features of colloid transport and retention in saturated porous media when colloid retention is dominated by the secondary minimum because an electrostatic barrier inhibits substantial deposition in the primary minimum. This model is based on conventional colloid filtration theory (CFT) but...
Authors
Lee L. Landkamer, Ronald W. Harvey, Timothy D. Scheibe, Joseph N. Ryan
Transport and fate of microbial pathogens in agricultural settings Transport and fate of microbial pathogens in agricultural settings
An understanding of the transport and survival of microbial pathogens (pathogens hereafter) in agricultural settings is needed to assess the risk of pathogen contamination to water and food resources, and to develop control strategies and treatment options. However, many knowledge gaps still remain in predicting the fate and transport of pathogens in runoff water, and then through the...
Authors
Scott A. Bradford, Veronica L. Morales, Wei Zhang, Ronald W. Harvey, Aaron I. Packman, Arvind Mohanram, Claire Welty
Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid
Hydroxyapatite nanoparticle (nHAP) is increasingly being used to remediate soils and water polluted by metals and radionuclides. The transport and retention of Alizarin red S (ARS)-labeled nHAP were investigated in water-saturated granular media. Experiments were carried out over a range of ionic strength (Ic, 0–50 mM NaCl) conditions in the presence of 10 mg L−1 humic acid. The...
Authors
Dengjun Wang, Scott A. Bradford, Ronald W. Harvey, Xiuzhen Hao, Dongmei Zhou
Effect of dissolved organic carbon on the transport and attachment behaviors of Cryptosporidium parvum oocysts and carboxylate-modified microspheres advected through temperate humic and tropical volcanic agricultural soil Effect of dissolved organic carbon on the transport and attachment behaviors of Cryptosporidium parvum oocysts and carboxylate-modified microspheres advected through temperate humic and tropical volcanic agricultural soil
Transport of Cryptosporidium parvum oocysts and microspheres in two disparate (a clay- and Fe-rich, volcanic and a temperate, humic) agricultural soils were studied in the presence and absence of 100 mg L–1 of sodium dodecyl benzene sulfonate (SDBS), and Suwannee River Humic Acid (SRHA) at pH 5.0–6.0. Transport of carboxylate-modified, 1.8 μm microspheres in soil columns was highly...
Authors
Arvind Mohanram, Chittaranjan Ray, David W. Metge, Larry B. Barber, Joseph N. Ryan, Ronald W. Harvey
Humic acid facilitates the transport of ARS-labeled hydroxyapatite nanoparticles in iron oxyhydroxide-coated sand Humic acid facilitates the transport of ARS-labeled hydroxyapatite nanoparticles in iron oxyhydroxide-coated sand
Hydroxyapatite nanoparticles (nHAP) have been widely used to remediate soil and wastewater contaminated with metals and radionuclides. However, our understanding of nHAP transport and fate is limited in natural environments that exhibit significant variability in solid and solution chemistry. The transport and retention kinetics of Alizarin red S (ARS)-labeled nHAP were investigated in...
Authors
Dengjun Wang, Scott A. Bradford, Ronald W. Harvey, Bin Gao, Long Cang, Dongmei Zhou
Science and Products
Filter Total Items: 80
Adaptations of indigenous bacteria to fuel contamination in karst aquifers in south-central Kentucky Adaptations of indigenous bacteria to fuel contamination in karst aquifers in south-central Kentucky
The karst aquifer systems in southern Kentucky can be dynamic and quick to change. Microorganisms that live in these unpredictable aquifers are constantly faced with environmental changes. Their survival depends upon adaptations to changes in water chemistry, taking advantage of positive stimuli and avoiding negative environmental conditions. The U.S. Geological Survey conducted a study...
Authors
Thomas D. Byl, David W. Metge, Daniel T. Agymang, Mike Bradley, Gregg Hileman, Ronald W. Harvey
Colloid transport in saturated porous media: Elimination of attachment efficiency in a new colloid transport model Colloid transport in saturated porous media: Elimination of attachment efficiency in a new colloid transport model
A colloid transport model is introduced that is conceptually simple yet captures the essential features of colloid transport and retention in saturated porous media when colloid retention is dominated by the secondary minimum because an electrostatic barrier inhibits substantial deposition in the primary minimum. This model is based on conventional colloid filtration theory (CFT) but...
Authors
Lee L. Landkamer, Ronald W. Harvey, Timothy D. Scheibe, Joseph N. Ryan
Transport and fate of microbial pathogens in agricultural settings Transport and fate of microbial pathogens in agricultural settings
An understanding of the transport and survival of microbial pathogens (pathogens hereafter) in agricultural settings is needed to assess the risk of pathogen contamination to water and food resources, and to develop control strategies and treatment options. However, many knowledge gaps still remain in predicting the fate and transport of pathogens in runoff water, and then through the...
Authors
Scott A. Bradford, Veronica L. Morales, Wei Zhang, Ronald W. Harvey, Aaron I. Packman, Arvind Mohanram, Claire Welty
Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid Transport of ARS-labeled hydroxyapatite nanoparticles in saturated granular media is influenced by surface charge variability even in the presence of humic acid
Hydroxyapatite nanoparticle (nHAP) is increasingly being used to remediate soils and water polluted by metals and radionuclides. The transport and retention of Alizarin red S (ARS)-labeled nHAP were investigated in water-saturated granular media. Experiments were carried out over a range of ionic strength (Ic, 0–50 mM NaCl) conditions in the presence of 10 mg L−1 humic acid. The...
Authors
Dengjun Wang, Scott A. Bradford, Ronald W. Harvey, Xiuzhen Hao, Dongmei Zhou
Effect of dissolved organic carbon on the transport and attachment behaviors of Cryptosporidium parvum oocysts and carboxylate-modified microspheres advected through temperate humic and tropical volcanic agricultural soil Effect of dissolved organic carbon on the transport and attachment behaviors of Cryptosporidium parvum oocysts and carboxylate-modified microspheres advected through temperate humic and tropical volcanic agricultural soil
Transport of Cryptosporidium parvum oocysts and microspheres in two disparate (a clay- and Fe-rich, volcanic and a temperate, humic) agricultural soils were studied in the presence and absence of 100 mg L–1 of sodium dodecyl benzene sulfonate (SDBS), and Suwannee River Humic Acid (SRHA) at pH 5.0–6.0. Transport of carboxylate-modified, 1.8 μm microspheres in soil columns was highly...
Authors
Arvind Mohanram, Chittaranjan Ray, David W. Metge, Larry B. Barber, Joseph N. Ryan, Ronald W. Harvey
Humic acid facilitates the transport of ARS-labeled hydroxyapatite nanoparticles in iron oxyhydroxide-coated sand Humic acid facilitates the transport of ARS-labeled hydroxyapatite nanoparticles in iron oxyhydroxide-coated sand
Hydroxyapatite nanoparticles (nHAP) have been widely used to remediate soil and wastewater contaminated with metals and radionuclides. However, our understanding of nHAP transport and fate is limited in natural environments that exhibit significant variability in solid and solution chemistry. The transport and retention kinetics of Alizarin red S (ARS)-labeled nHAP were investigated in...
Authors
Dengjun Wang, Scott A. Bradford, Ronald W. Harvey, Bin Gao, Long Cang, Dongmei Zhou