Samuel J Traina

University of California, Merced | UCM · Life and Environmental Sciences and Environmental Engineerig

Wildland fire is an important ecological process in the California Sierra Nevada. Personal accounts from pre-20th century describe a much smokier environment than present day. The policy of suppression beginning in the early 20th century and climate change are contributing to increased megafires. We use a single particulate monitoring site at the w...

Senate Bill 4 (SB 4) requires an independent study to assess current and potential future well stimulation practices in California, including the likelihood that these technologies could enable extensive new petroleum production in the state; impacts of well stimulation technologies (including hydraulic fracturing, acid fracturing and matrix acidiz...

Smoke from wildfires can expose individuals and populations to elevated levels of particulate matter (PM) and ozone (O 3). Between 21 July and 26 August 2002, the McNally Fire burned over 150 000 acres (61 000 ha). The fire occurred in the Sequoia National Forest, in the southern Sierra Nevada of California. This study evaluated the effects of the...

Two-week average concentrations of ozone (O3), nitric acid vapor (HNO3) and ammonia (NH3) were measured with passive samplers during the 2002 summer season across the central Sierra Nevada Mountains, California, along the San Joaquin River drainage. Elevated concentrations of the pollutants were determined with seasonal means for individual sites r...

Produced from incomplete combustion of biomass and fossil fuel in the absence of oxygen, black carbon (BC) is the collective term for a range of carbonaceous substances encompassing partly charred plant residues to highly graphitized soot. Depending on its form, condition of origin and storage (from the atmosphere to the geosphere), and surrounding...

The purpose of this study was to characterize the cyanuric acid amidohydrolase reaction in Ralstonia basilensis M91-3, an atrazine-mineralizing soil bacterium. This ring fission reaction is the last aromatic step in the degradative pathway of atrazine and other s-triazines. The products and molar stoichiometry of the cyanuric acid amidohydrolase re...

Quinoline is an N-containing heterocyclic contaminant associated with creosote wastes and may be biologically degraded under aerobic and anaerobic conditions. Quinoline-degrading bacteria were utilized to investigate the rate of quinoline desorption from smectite clay at low surface concentrations and its subsequent mineralization. Fluorescence spe...

Black carbon (BC) plays a significant role in the carbon cycle, simultaneously influencing the quality of air from local to regional scales from its point of origin. We are investigating these influences with respect to BC recently produced in the Central Valley and Sierra Nevada Forest area of California. Surface biomass, charred matter and soil (...

Lead (Pb) sorption onto oxide surfaces in soils may strongly influence the risk posed from incidental ingestion of lead-contaminated soils. In this study, Pb was sorbed to a model soil mineral, birnessite, and was placed in a simulated gastrointestinal tract (in vitro) to simulate the possible effects of ingestion of a soil contaminated with Pb. Th...

Organic acids are essential in the cycling and environmental fate of many elements. Their ability to solubilize and complex key elements confer them a major role in the bioavailability of otherwise insoluble nutrients. The ligand-promoted dissolution of goethite as a primary source for Fe(III) has been investigated in the presence of adsorbed urany...

The pathway of actinides through the soil column hinges on many intricate processes with soil constituents. These processes often involve the bioactivity of the microenvironment conferring the biosphere a crucial role in the natural attenuation of radionuclide contaminants in soils. In order to investigate the bioavailability of uranium, sorption e...

Magnetite is a redox active Fe oxide common in most soil and sedimentary environments. In this study, we investigated magnetite transformations under extreme alkaline conditions (0.1−2 mol l−1 NaOH) similar to those found under high-level radioactive waste storage tanks at the Hanford site in the State of Washington, USA. X-ray diffraction (XRD) an...

To investigate the sonochemical dissolution of cinnabar, sulfur oxidation products (S(ox)) and dissolved Hg(II) released into the aqueous solution were determined. Detected S(ox), in the presence of ultrasound suggests that dissolution of cinnabar occurred. Terephthalic acid (TA) used to scavenge *OH in bulk solution formed from sonication showed t...

The effects of pH, Cl-, and humic acid (HA) on sonolytic desorption of Hg(II) from aluminum oxide were examined. Results showed that Hg(II) desorption was achieved by lowering the pH from 7.0 to 4.0. Ultrasound enhanced Hg(II) release at short times compared to both hydrodynamic mixing and that expected on the basis of the pH-dependent Hg(II) adsor...

To investigate the sonochemical dissolution of cinnabar, sulfur oxidation products (S-ox) and dissolved Hg(II) released into the aqueous solution were determined. Detected S-ox in the presence of ultrasound suggests that dissolution of cinnabar occurred. Terephthalic acid (TA) used to scavenge center dot OH in bulk solution formed from sonication s...

Lead (Pb) sorption onto oxide surfaces in soils may strongly influence the risk posed from incidental ingestion of Pb-contaminated soil. Lead was sorbed to model oxide minerals of corundum (alpha-Al(2)O(3)) and ferrihydrite (Fe(5)HO(8).4H(2)O). The Pb-sorbed minerals were placed in a simulated gastrointestinal tract (in vitro) to simulate ingestion...

Reverse-phase HPLC methodology was developed for resolution and quantitative analysis of dicamba (3,6-dichloro-2-methoxybenzoic acid) with a C-18 column and acetonitrile-phosphate buffer as the mobile phase under isocratic conditions. This solvent system was also suitable for mixtures containing dicamba, 2,4-dichlorophenoxyacetic acid (2,4-D), and...

Organic ligands affect the sorption and mobility of radionuclides in soils. Batch desorption experiments on goethite particles reveal the extent of uranyl desorption and hence bioavailability with different organic acids. The desorptive strength increases in the following order: background electrolyte < Na-alginate < desferrioxamine B (DFO-B) < oxa...

The risk posed from incidental ingestion to humans of arsenic-contaminated soil may depend on sorption of arsenate (As(V)) to oxide surfaces in soil. Arsenate sorbed to ferrihydrite, a model soil mineral, was used to simulate possible effects on ingestion of soil contaminated with As-(V) sorbed to Fe oxide surfaces. Arsenate sorbed to ferrihydrite...

Arsenate adsorbed to oxide surfaces may influence the risk posed by incidental ingestion of arsenic-contaminated soil. Arsenate sorbed to corundum (alpha-Al2O3), a model Al oxide, was used to simulate ingested soil that has As-V sorbed to Al oxides. An in vitro assay was used to simulate the gastrointestinal tract and ascertain the bioaccessibility...

Fifty-nine coal combustion products were collected from coal-fired power plants using various dry flue gas desulfurization (FGD) processes to remove SO2. X-ray diffraction analyses revealed duct injection and spray dryer processes created products that primarily contained Ca(OH)2 (portlandite) and CaSO3·0.5H2O (hannebachite). Most samples from the...

The effects of elevated pH, ionic strength, and temperature on sediments in the vadose zone are of primary importance in modeling contaminant transport and understanding the environmental impact of tank leakage at nuclear waste storage facilities like those of the Hanford site. This study was designed to investigate biotite dissolution under simula...

The Department of Energy has a goal of decontaminating an estimated 180,000 metric tons of metal wastes in various surplus facilities. Uranium (U) and other radioactive actinides and lanthanides are embedded within the mixed oxide structures of the passivity layers of corroded iron and steel. These toxic metals can be dissolved out of the surface l...

This study investigated Cr(VI) reduction and immobilization by magnetite under alkaline pH conditions similar to those present at the Hanford site. Compared to acidic and neutral pH, chromium(VI) reduction by magnetite at high pH conditions is limited (<20% of potential reduction capacity), and the extent of reduction does not vary significantly wi...

As discrete particles and/or as coatings on other mineral surfaces in natural systems, aluminum (hydr)oxides are efficient sinks for Hg(II). Ultrasound at 20 kHz was applied to enhance the desorption of Hg(II) from aluminum oxide particles (5.0 micromol of Hg g(-1)). Results showed that at short times ultrasound enhanced Hg(II) release at pH 4.0 co...

Beneficial and environmentally safe recycling of flue gas desulfurization (FGD) products requires detailed knowledge of their chemical and physical properties. We analyzed 59 dry FGD samples collected from 13 locations representing four major FGD scrubbing technologies. The chemistry of all samples was dominated by Ca, S, Al, Fe, and Si and strong...

Here we examine both the short- (~ 1 year) and long-term (~ 4 years) behavior of fixated flue gas desulfurization (FGD) material grout following placement within an underground coalmine. Immediately after grout injection, significant increases in acidity, Fe, Al, S, and Ca were observed for most of the surface and groundwater monitoring locations n...

This study investigated Cr(VI) reduction by dissolved Fe(II) in hyperalkaline pH conditions as found in fluid wastes associated with the U.S. nuclear weapons program. The results show that Cr(VI) reduction by Fe(II) at alkaline pH solutions proceeds very quickly. The amount of Cr(VI) removed from solution and the amount reduced increases with Fe(II...

Pentachloronitrobenzene is a fungicide that is degraded in anoxic soils and sediments through unknown processes that are often thought to be biologically mediated. The present research describes the kinetics for the abiotic reduction of this compound in aqueous Fe(II)/goethite systems at near-neutral pH values. The results provide evidence for a ra...

In this research, we examine the long-term (4 years behavior of fixated flue gas desulfurization FGD material grout following placement within the Roberts–Dawson underground coal mine. Surface water and groundwater samples were collected to examine the impact of grouting on water quality, and core samples were obtained to assess the geochemical sta...

The objective of this study was to examine the mineralogy and geochemical stability of ochreous sediments accumulated in a compost wetland constructed in 1990 for acid mine drainage treatment. Intact sediment cores were collected in 1996 and 2000 from an area that had accumulated 33 cm of ochre. Solids and pore waters were subsequently separated by...

Radioactive core samples containing elevated concentrations of Cr from a high level nuclear waste plume in the Hanford vadose zone were studied to asses the future mobility of Cr. Cr(VI) is an important subsurface contaminant at the Hanford Site. The plume originated in 1969 by leakage of self-boiling supernate from a tank containing REDOX process...

The purpose of this study was to characterize the phylogenetic and phenotypic traits of M91-3, a soil bacterium capable of mineralizing atrazine (2-chloro-4-N-isopropyl-6-N-ethyl-s-triazine). The isolate was identified as Ralstonia basilensis based on 99.5% homology of the 16S rRNA sequence and various chemotaxonomic data. The isolate used atrazine...

Pro has been shown to play an important role in ameliorating environmental stress in plants and microorganisms, including heavy metal stress. Here, we describe the effects of the expression of a mothbean delta(1)-pyrroline-5-carboxylate synthetase (P5CS) gene in the green microalga Chlamydomonas reinhardtii. We show that transgenic algae expressing...

Reactions of bisulfide and polysulfides with alachlor, propachlor, and metolachlor were examined in aqueous solution to investigate the role reduced sulfur species could play in effecting abiotic transformations of chloroacetanilide herbicides. Experiments at 25 degrees C demonstrated that reactions were approximately first-order in HS- concentrati...

Biosorption of aqueous Cd by Chlamydomonas reinhardtii was examined. Cd uptake increased from pH 2 to 10, and was measured at different initial Cd concentrations (0.09 – 8.75 mM). Proton affinity models of potentiometric titration data indicated the presence of two major functional group clusters on the cell walls, corresponding to ionic strength d...

The purpose of this study was to determine whether there was an association between kinetics of atrazine mineralization, the number and type of atrazine-degrading microorganisms, and the presence of three genes representing different steps in the degradative pathway of atrazine in three soils with different histories of atrazine application. Compos...

This research examined the fate of polydimethylsilicones (PDMS) in agricultural test plots amended with municipal biosolids. This 4 yr field study involved addition of 0, 15, and 100 Mg ha(-1) of municipal biosolids, which contained ambient concentrations of PDMS (1272 mg kg(-1) biosolids), to corn and soybean test plots. Soil samples collected at...

The distribution of aqueous Pb(II) sorbed at the interface between Burkholderia cepacia biofilms and hematite (alpha-Fe(2)O(3)) or corundum (alpha-Al(2)O(3)) surfaces has been probed by using an application of the long-period x-ray standing wave technique. Attached bacteria and adsorbed organic matter may interfere with sorption processes on metal...

Cyanuric acid amendment was tested for potential enhancement of atrazine mineralization activity because this compound is the metabolite in the degradation pathway of s-triazines prior to ring-cleavage. The effect of cyanuric acid on: (i) subsequent atrazine mineralization kinetics and (ii) the detection of a hybridization signal to the s-triazine...

In this paper, a field study was carried out to examine the effect of flue gas desulfurization (FGD) by-product on water quality at an underground coal mine in central-eastern Ohio. Flue gas desulfurizalion by-product was injected into the down-dip portions of the Robert-Dawson mine in an attempt to seal major seeps exiting the mine and to coat exp...

Specific objectives are to investigate (1) the effect of aging on the stability of sorption complexes on Al-oxide and Al-oxyhydroxide surfaces formed from neutralization and homogeneous nucleation of alkaline aluminate solutions; (2) the sorption/coprecipitation of these elements in solids formed from reaction of alkaline aluminate solutions with s...

Organic matter–mediated root rot suppression is unpredictable in field soils. This study was conducted to determine whether particulate organic matter (POM) composition and content were related to Pythium damping‐off (DO) incidence in a sand amended with sawdust‐bedded dairy manure compost (15% compost:85% sand, v/v) incubated in pots for 506 d. Su...

Organic matter-mediated root rot suppression is unpredictable in field soils. This study was conducted to determine whether particulate organic matter (POM) composition and content were related to Pythium damping-off (DO) incidence in a sand amended with sawdust-bedded dairy manure compost (15% compost:85% sand, v/v) incubated in pots for 506 d. Su...

The degradation of organic matter was evaluated by a quantitative Fourier transform infrared spectroscopy (FTIR) analysis technique. The degradation process was conducted in a bench-scale reactor under controlled operational conditions of 50 degrees C, with 50-60% moisture content, and subjected to uniform aeration for 325 h. During the composting...

Apatite has been Used to remediate Pb contamination; apatite dissolution releases phosphate, which combines with Pb to form highly insoluble Pb-phosphate minerals. This research focused on the effects of aqueous Pb (initial [Pbaq] = 0.185 mM) on the kenetics of apatite dissolution. Synthetic microcrystalline hydroxylapatite (HAP) and natural chlora...

The effects of sorption on the bioavailability of 2-methylpyridine (2-MP) were investigated by determining the biodegradation of 2-MP by an Arthrobacter sp. in aqueous suspensions of reference clay minerals and a synthetic cation exchange resin. Adsorption of 2-MP on kaolinite, illite, hectorite, montmorillonite, and Dowex® was determined by the ba...

The effects of sorption on the bioavailability of 2-methylpyridine (2-MP) were investigated by determining the biodegradation of 2-MP by an Arthrobacter sp. in aqueous suspensions of reference clay minerals and a synthetic cation exchange resin. Adsorption of 2-MP on kaolinite, illite, hectorite, montmorillonite, and Dowex(R) was determined by the...

Organotin-humic substance (OT-HS) binding constants ( Kdoc) were determined by equilibrium-binding studies using dialysis techniques. The OT-HS binding was characterized by linear isotherms. The Kdoc values measured in this study were several orders of magnitude greater than would be predicted based only on nonpolar interactions with HS (as estimat...

Organotin-humic substance (OT-HS) binding constants (K-doc) were determined by equilibrium-binding studies using dialysis techniques. The OT-HS binding was characterized by linear isotherms. The K-doc values measured in this study were several orders of magnitude greater than would be predicted based only on nonpolar interactions with HS las estima...

Apatites provide a mechanism for in-situ remediation of Pb-contaminated sites, by supplying phosphate which combines with dissolved Pb to form highly insoluble pyromorphite. This study expanded upon previous research using hydroxylapatite (HAP), to focus on how the surface properties of natural chlorapatite (CAP) and fluorapatite (FAP) affect pyrom...

There are many compounds that are naturally occurring biodegradable organic chelates (siderophores) and appear to be more effective at oxide dissolution and actinide complexation than ethylenediaminetetraacetic acid (EDTA) or other organic acids currently used in decontamination processes. These chelates bind hard acids [Fe(III) and actinides(IV)]...

The effects of the presence of a cationic surfactant on the sorption of two typical nitrogen heterocyclic compounds (NHCs) on swelling and nonswelling phyllosilicates were investigated. The addition of a cationic surfactant to a NHC-phyllosilicate system can either solubilize the sorbed NHC molecules or immobilize the suspended NHC molecules, depen...

The purpose of this study was to assess the biodegradation of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] under different redox conditions in the presence and absence of an electron donor (glucose) and electron acceptors (oxygen, NO3/-). Experiments were conducted in sand-column systems saturated with a liquid medium and charac...

Polydimethylsiloxane (PDMS) is a widely used silicone polymer that is introduced into wastewater treatment systems where it is removed with sludge. PDMS subsequently enters the terrestial environment as a result of sludge amendment to soil. Laboratory studies have shown that PDMS extensively breaks down into monomeric units when in contact with dry...

The authors examined the suitability using a flue gas desulfurization grout (FGDG) for the attenuation and abatement of acidic mine drainage (AMD). The FGDG used was a mixture of fly ash (FA) and filter cake (FC) with a FA/FC ratio of 1:1 to improve handling. Five percent of lime (CaO) was added to improve strength development and allow the use of...

Many soils developed from volcanic rocks in southern Brazil exhibit spontaneous magnetization caused by the presence of fine-grained maghemite (gamma-Fe2O3), but few attempts were made to quantify or characterize this important soil component. To that end, clays were separated from freely drained soils derived from acid (greater than or equal to 63...

Aluminum is highly abundant in the Earth's crust where it is present in a wide variety of primary and secondary aluminosilicate minerals, amorphous phases, and aqueous solution species. The speciation and coordination of Al in many of these phases, particularly those that are X-ray amorphous or present as thin surface coatings, are often unknown or...

Biofilms form ubiquitous organic coatings surfaces in soil and aquatic environments. In order to understand the chemical speciation of heavy metals (such as Pb) sorbed to minerals colonized by bacteria, it is essential to evaluate the coupled biotic and abiotic sorption by such heterogeneous systems. We have used EXAFS spectroscopy to quantitativel...

A bacterium capable of degrading 2-methylpyridine was isolated by enrichment techniques from subsurface sediments collected from an aquifer located at an industrial site that had been contaminated with pyridine and pyridine derivatives. The isolate, identified as an Arthrobacter sp., was capable of utilizing 2-methylpyridine, 2-ethylpyridine, and 2...

The aqueous concentrations of heavy metals in soils, sediments, and aquatic environments frequently are controlled by the dissolution and precipitation of discrete mineral phases. Contaminant uptake by organisms as well as contaminant transport in natural systems typically occurs through the solution phase. Thus, the thermodynamic solubility of con...

The present study focused on understanding the sorption characteristics of acridine (AcN) and acridine-9-carboxylic acid (AcNCOOH), two typical nitrogen heterocyclic compounds (NHCs), on well-characterized phyllosilicates (hectorite, saponite, and muscovite). Results presented in this article show that the degree of sorption of NHCs on phyllosilica...

Flue gas desulfurization (FGD) scrubbing technologies create several types of by-products. This project focused primarily on by-product materials obtained from what are commonly called ''dry scrubbers'' which produce a dry, solid material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Prior to th...

New flue gas desulfurization (FGD) scrubbing technologies create a dry, solid by-product material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Generally, dry FGD by-products are treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are c...

We have compared the growth rates and cadmium binding capacity of wild-type and transgenic Chlamydomonas reinhardtii cells expressing a foreign class-II metallothionein. We observed that cells expressing metallothionein grew to significantly higher cell densities than wild-type cells in the presence of a toxic cadmium concentration (40 μM). When gr...

Cadmium (Cd), atomic number 48, is in Group IIb of the Periodic Table of the elements. It is greatest in chemical similarity to the other Group IIb elements, zinc (Zn) and mercury (Hg), with which it is commonly associated in natural geologic settings. The ground state electronic configuration of Cd can be listed in an abbreviated form as [Kr].4d 1...

Arsenate (AsO43−) is a common species in oxidizing aquatic systems and hydrothermal fluids, and its solubility and partitioning into different mineral phases are determined by the nature of AsO43− coordination, solution pH, type of soluble cations, and H2O structure at the mineral-fluid interfaces. While the vibrational spectroscopy has been widely...

The abundances, molecular weights, molar absorptivities, and polydispersities of sediment pore water dissolved organic matter (DOM) and ferrous iron, Fe(II), were measured from three sites within a freshwater wetland (Old Woman Creek) adjacent to Lake Erie. DOM concentrations (expressed as organic carbon) increased with depth. Number-average molecu...

The effectiveness of an Eu3+luminescence technique to describe metal complexation reactions in humic substances was evaluated. The molecular uncertainties intrinsic to humic substances were circumvented by using polyacrylic acid (PAA) and polyvinylsulfonic acid (PVS) as probes. An adequate determination of the Eu3+–citrate affinity constant suggest...

Recent increases in land application of sewage sludge have raised concerns over the potential introduction of contaminants into the human food chain.The establishment of sound regulation requires knowledge on the fate and distribution of contaminants in sludge amended soils. Humic substances play a crucial role in trace element bioavailability and...

The solubility and weathering reactions of ettringite, (Ca6Al2(SO4)3(OH)12·26H2O), were used to study the geochemical equilibria of the Ca(OH)2–Al2(SO4)3–H2O system at environmental pH conditions. Ettringite is a stable mineral above a pH of 10.7 and dissolved congruently with a log Ksp of −111.6 (±0.8). Between pH 10.7 and 9.5, ettringite underwen...

Results of in situ atomic force microscopy (AFM), ex situ AFM, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction were combined with previous macroscopic investigations to characterize aqueous Pb(NO3)2 reaction with hydroxylapatite (Ca5(PO4)3OH) (HAP). Experiments were conducted by immersing part...

 The purpose of this work was to assess the influence of redox conditions on benzoate biodegradation coupled with oxygen and nitrate as electron acceptors. A benzoate-degrading, facultatively denitrifying bacterium was isolated from a sediment sample and was tentatively identified as Comamonas terrigena (strain J92-6). The experimental system was b...

The chemical implications of the fitting parameters employed by two empirical models on the characterization of complexation reactions by dissolved humic substances were evaluated on various polyelectrolyte systems. Potentiometric titrations of polyacrylic acid (PAA), and different mixtures of PAA and polyvinylsulfonic acid, were conducted at diffe...

A combination of atomic force microscopy, scanning election microscopy, transmission electron microscopy, energy dispersive spectroscopy, electron diffraction, and X-ray diffraction were used to study reactions of 0.5-500 mg/L aqueous Pb with Ca 5 (PO 4 ) 3 OH, hydroxylapatite (HAP), at pH 6 and 22 degrees C. Following 2 h reaction time, concentrat...

 The stimulatory effect of earthworms (Lumbricus terrestris L.) on soil microbial activity was studied under microcosm-controlled conditions. The hypothesis was tested that microbial stimulation observed in the presence of a soil invertebrate would be due to the utilization of additional nutritive substances (secretion and excretion products) that...

Trace metal pollution is among the most pervasive and serious environmental problems facing the biosphere. In 1988, global releases of lead, mercury, cadmium, copper, and zinc were estimated to be: 1,160; 11; 30; 2,150; and 2,340 thousand metric tons/year, respectively (Nriagu & Pacyna, 1988). The largest sources of trace metal pollution were minin...

The adsorption of Suwannee River fulvic acid (SRFA) and a synthetic organic polymer, polymaleic acid (PMA) by geothite was studied. The adsorption density of the sorbates decreased with increasing pH, and the data could best be described by the Langmuir adsorption equation. The number- and weight-averaged molecular weights, Mw and Mn, of the sorbat...

The chemical interactions of hydrophobic organic contaminants (HOCs) with soils and sediments (geosorbents) may result in strong binding and slow subsequent release rates that significantly affect remediation rates and endpoints. The underlying physical and chemical phenomena potentially responsible for this apparent sequestration of HOCs by geosor...

Phosphate compounds of Pb [e.g., pyromorphite Pb5(PO4)3(X) where X = OH, F, or Cl] are comparatively insoluble, and inducing their formation in contaminated soils may be a means of reducing the bioavailability and chemical lability of Pb in soil. Previous research has documented the formation of pyromorphite subsequent to the addition of phosphates...

The functional group chemistry and coordination of AsO43−-sorption complexes in ettringite [Ca6Al2(SO4)3(OH)12·26H2O] were evaluated as a function of sorption type (adsorption, coprecipitation) and pH using Raman and Fourier Transform infrared (FTIR) spectroscopies. The reactive functional groups of ettringite, ≡Al-OH, ≡Ca-OH2, and ≡Ca2-OH exhibit...

Acid Mine Drainage (AMD) from abandoned underground coal mines in Ohio is a concern for both residents and regulatory agencies. Effluent from these mines is typically characterized by low pH and high iron and sulfate concentrations and may contaminate local drinking-water supplies and streams. The objective of this project is to demonstrate the tec...

Arsenate sorption by ettringite [Ca6Al2(SO4)3(OH)12·26H2O] is examined as adsorption and coprecipitation systems at alkaline pH (10.0−12.5) and for a wide range of As(V) concentration (<1 μM−15 mM). The mode of sorption and sorbate and sorbent concentrations controlled the nature of solid-phase As(V) speciation. Although high pH increased ettringit...

Atrazine (6-chloro-N-ethyl-N''-(1-methylethyl)-1,3,5-triazine-2,4- diamine) mineralization rates were measured in surface soils with different agricultural management practices at the Ohio Management Systems Evaluation Area (Ohio MSEA) site in Piketon, OH. Two management practices were studied at this site: (i) a continuous-corn (Zea mays L.) plot...