Elisa D'Angelo - Academia.edu (original) (raw)

Papers by Elisa D'Angelo

Science of The Total Environment, 2021

Chemodenitrification-the abiotic (chemical) reduction of nitrite (NO2-) by iron (II)-plays an imp... more Chemodenitrification-the abiotic (chemical) reduction of nitrite (NO2-) by iron (II)-plays an important role in nitrogen cycling due in part to this process serving as a source of nitrous oxide (N2O). Questions remain about the fate of NO2- in the presence of mineral surfaces formed during chemodenitrification, such as iron(III) (hydr) oxides, particularly relative to dissolved iron(II). In this study, stirred-batch kinetic experiments were conducted under anoxic conditions (to mimic iron(III)-reducing conditions) from pH 5.5-8 to investigate NO2- reactivity with goethite (FeOOH(s)) and Fe(II)-treated goethite using wet chemical and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Nitrite removal from solution by goethite was more rapid at pH 5.5 than at pH 7 and 8. Spectral changes upon nitrite adsorption imply an inner-sphere surface interaction (monodentate and bidentate) at pH 5.5 based on ATR-FTIR spectra of the nitrite-goethite interface over time. In iron(II)-amended experiments at pH 5.5 with high aqueous Fe(II) in equilibrium with goethite, nitrous oxide was generated, indicating that nitrite removal involved a combination of sorption and reduction processes. The presence of a surface complex resembling protonated nitrite (HONO) with an IR peak near ~1258 cm-1 was observed in goethite-only and iron(II)-goethite experiments, with a greater abundance of this species observed in the latter treatment. These results might help explain gaseous losses of nitrogen where nitrite and iron(II)/goethite coexist, with implications for nutrient cycling and release of atmospheric air pollutants.

Environmental Earth Sciences, 2016

In this study, volatile organics and other relevant constituents in soil and water were analyzed ... more In this study, volatile organics and other relevant constituents in soil and water were analyzed at two fires in eastern Kentucky (the Truman Shepherd fire in Knott County and the Lotts Creek fire in Perry County). The samples were analyzed for a number of relevant constituents, notably benzene, toluene, ethyl benzene, and xylenes (BTEX); and polycyclic aromatic hydrocarbons (PAHs). No water contamination was noted at either site and relatively low levels of soil contamination [defined as exceeding EPA soil screening levels (SSLs)] were observed at Truman Shepherd, but numerous Lotts Creek soil samples exhibited PAH concentrations above EPA SSLs. Specifically, benzo (a)anthracene, considered a highly carcinogenic PAH, was found at over 7000 times higher than the EPA SSL for soil (32 mg/kg). BTEX concentrations were low even where PAH and other constituents were high. This is likely due to the low atomic masses and high volatilities of BTEX compounds. The PAHs with the highest concentrations at Lotts Creek were in the mid-to high atomic mass range. The discrepancy in soil contamination between the two sites is consistent with differences in total organic carbon concentrations, which may reflect differences in soil cover.

Wetlands Ecology and Management, 2008

The use of periphyton nitrogenase activity (biological N 2 fixation) as an indicator of wetland P... more The use of periphyton nitrogenase activity (biological N 2 fixation) as an indicator of wetland P impact was assessed using patterns of nutrient content (C, N, P, Ca, Mg, K, Fe, and Mn) and acetylene reduction (AR) in floating cyanobacterial periphyton mat (metaphyton) communities of a P-enriched portion of the Florida Everglades, USA (Water Conservation Area-2A, WCA-2A). Spatial patterns of nutrients indicate the enrichment of floating mat periphyton N, P, Fe, and K, and the reduction of Mn and TN:TP in enriched marsh areas. In highly enriched areas, floating mat periphyton AR was approximately threefold greater than that in less enriched, interior marsh zones. Multiple regression models indicated AR dependence on P in eutrophic WCA-2A areas while the AR of more interior marsh periphyton mats was more closely related to tissue levels of Ca and Fe. Nitrogenase activity of floating mat periphyton from P-loaded mesocosms revealed a significant enhancement of N 2 fixation in samples receiving approximately 2-3 mg P m-2 of cumulative P dosing or with biomass TP content of 100-300 mg kg-1. At P contents above the optimum, mat periphyton AR was suppressed possibly as a result of changes in species composition or increased levels of NH 4 +. After 3 years of dosing, consistently high AR occurred only at low rates of P enrichment (0.4-0.8 g P m-2 yr-1), and the patterns appeared to be seasonal. These findings agree with the hypothesis that P availability is a key determinant of nitrogenase activity in aquatic systems, and thus, may support the use of periphyton nitrogenase to indicate P impacts in P-limited systems. These results also demonstrate the potential existence of a P threshhold for biogeochemical alteration of periphyton mat function in the Everglades, and that cumulative loading of limiting nutrients (i.e., P), rather than instantaneous concentrations, should be considered when evaluating nutrient criteria.

Toxicological & Environmental Chemistry, 2005

Polychlorinated biphenyls (PCBs) are a mixture of 209 individual chlorinated compounds commonly k... more Polychlorinated biphenyls (PCBs) are a mixture of 209 individual chlorinated compounds commonly known as PCB congeners. These compounds are hydrophobic and are persistent in the environment. Their use was banned in the US a few decades ago because of ...

Soil Science Society of America Journal, 1993

Internal N cycling processes in sediments and the overlying water column may contribute to the eu... more Internal N cycling processes in sediments and the overlying water column may contribute to the eutrophication of lake systems. One of the major mechanisms for N loss in these systems is through biological oxidation and reduction of N species in the aerobic and anaerobic sediment zones, coupled with exchange processes between these zones. These mechanisms were measured using flooded, intact sediment columns and batch incubations with bulk sediments collected from a hypereutrophic lake. In continuously stirred batch incubations with aerated sediment, NHJ oxidation to NOj (nitrification) showed twophase, zero-order kinetics. The rapid first phase of nitrification (0.36 mg N L-' h-1) was due to the oxidation of NHJ initially present in the sediment, while the slower second phase (0.15 mg N L ' far 1) was limited by the rate of production of NHJ during ammoniflcation of organic N. Denitriflcation as determined by the C 2 H 2-blockage technique was found to be limited by NOj availability. Under NOj nonlimiting conditions, the denitriflcation rate was 0.11 mg N L~' h-1 , but a fivefold decrease was measured at low NOj concentration (1 mg NO, L-'). Denitriflcation was the major NOj reductive process in the surface 27-cm sediment depth. Assimilatory 15 NOj reduction into the organic I5 N fraction was also a significant NOj loss mechanism at the sediment surface. Dissimilatory 15 NOj reduction to 15 NH J became the dominant NOj reductive pathway at sediment depths >27 cm. Losses of up to 90% of the floodwater 15 NH} or 15 NO j was largely attributed to sequential nitrification-denitrification reactions.

Journal of Environmental Quality, 1990

Laboratory experiments were conducted to determine the effectiveness of three floating and six em... more Laboratory experiments were conducted to determine the effectiveness of three floating and six emergent aquatic macrophytes in improving domestic wastewater quality, based on their capacities for O2 transport into the effluent. Oxygen transport into the rooting zone of the plants created an oxidized microenvironment, thereby stimulating C and N transformations critical to wastewater treatment. Plants were cultured in flasks containing deoxygenated primary and secondary sewage effluent for an 8-d period. Oxygen transport by the plants was measured in terms of both O2 consumed by the effluent (biological 02 demand reduction-BODs) and increased effluent dissolved 02. Two floating plants, pennywort (Hydwcotyle nmbellata L.) and waterhyacinth [Eichkornia crasslpes (Mart.) Solms], and the emergent plants pickerelweed (Pontederla cordata L.) and common arrowhead (Sagittaria latifolia L.), were superior in improving primary sewage effluent quality, by reducing BOD5 up to 88%, NH4-N up to 77%, and increasing dissolved O2 up to 6.1 mg L-I. Nitrification rates in pennywort-and water hyacinth-based water treatment systems were calculated to be in the range of 12 to 47 kg NH 4-N ha-1 d-!. Oxygen transport through plants accounted for up to 90% of the total O2 transported into the effluent. In separate batch experiments, the effectiveness of diffuse mechanical aeration (5 and 50 mL air mint) and of biological aeration (02 transport by selected plants including pennywort, waterhyacinth, pickerelweed, and common arrowhead) on the rate of contaminant removal from deoxygenated primary sewage effluent were compared for a 26-d period. Biological and mechanical aeration effected similar BODs removal. First-order reaction rate constants for BOD~ removal were from 0.0066 to 0.0079 h-~ and from 0.0041 to 0.0051 h-1 for biological and mechanical aeration, respectively. Rate constants for NH4-N removal were from 0.0024 to 0.0107 h-~ for the plant treatments. Virtually complete BOD~ removal occurred in biological and mechanical aeration treatments within 20 d. Complete nitrification of NH4-N had occurred within 12 d after mechanical aeration was initiated, but subsequent N-loss by denitrification was inhibited. In the biological aeration treatments, negligible effluent (NO 3 + NO2)-N levels were measured, but 65 to 100% NH4-N loss occurred both by plant assimilation and by sequential nitrification-denitrification reactions. A QUATIC PLANTS rooted in anaerobic sediments and anoxic waters transport 02 through stems and leaves into their rooting zones. The mechanism ofO2 transport through aquatic plants into the rooting zone has been demonstrated by several researchers

Aquatic Geochemistry, 2008

Redox potentials (Eh) were monitored bimonthly and porewater chemistry was analyzed seasonally at... more Redox potentials (Eh) were monitored bimonthly and porewater chemistry was analyzed seasonally at three slightly-acidic, high-elevation Kentucky wetlands that differed in hydrology, parent materials, and vegetation. At all sites, Eh values were below 300 mV, which indicated that reducing conditions persisted within the upper 90 cm and fluctuated mainly within the range of iron and sulfate reduction. Significant relationships of Eh values with depth were observed only at the Martins Fork wetland, where precipitation was the primary water source. The strongest and most stable reducing conditions, observed at the Kentenia site, reflected consistently high water levels, which were sustained by ground water. The third wetland (Four Level) was distinguished by irregular Eh fluctuations coinciding with strong seasonal groundwater upwelling. Although Fe 3+ and SO 4 2were the primary terminal electron acceptors in all wetlands, porewater chemistry also varied significantly by season and soil depth in response to piezometric water level fluctuations. Additional factors that influenced porewater chemistry included: (1) the presence of limestone parent materials that affected porewater pH, Ca 2+ , and Mg 2+ ; and (2) the prevalence of sphagnum moss or graminoid species that influenced dissolved organic carbon, CO 2 , and CH 4. Results from this study indicated the diverse range and importance of multiple factors in controlling biogeochemical processes and properties in small, highelevation Appalachian wetlands.

Open Journal of Soil Science, 2013

The broiler (Gallus gallus domesticus) industry in the United States and several other countries ... more The broiler (Gallus gallus domesticus) industry in the United States and several other countries routinely includes subtherapeutic levels of antibiotics such as roxarsone, virginiamycin, and bacitracin in the feed to improve bird growth yields. Large fractions of the antibiotics fed to the birds are excreted in manure (litter), which is often applied to soils to improve fertility. Some concerns with this practice are antibiotic-induced alterations in microbially-mediated nutrient cycling, which could influence plant productivity and environmental quality. To investigate this possibility, a series of lab experiments were conducted to determine the effects of increasing levels of the three livestock antibiotics on nitrification, denitrification, and microbial community composition (fatty acid methyl ester profiles) of soils collected along a catena. Roxarsone and virginiamycin significantly influenced microbial community composition and inhibited nitrification in the soils, but only at levels that were several-fold higher than expected in poultry litter-applied soils. Bacitracin did not affect microbial growth, microbial community composition, or nitrification at any concentration tested (up to 500 mg•kg −1). None of the antibiotics influenced denitrification at environmentally-relevant concentrations. Amounts of antibiotics in soil solution were greatly reduced by sorption, which followed Freundlich models in the concentration range of 1-500 mg•L −1. Results from this study indicated that addition of roxarsone, virginiamycin, or bacitracin to these soils at environmentally-relevant concentrations would not likely impact microbial community composition, nitrification or denitrification due to intrinsic resistance/insensitivity of microorganisms to these antibiotics and reductions in the bioavailable amounts due to sorption by soil surfaces.

Science of The Total Environment

Soil Science Society of America Journal, 2000

Strategies to enhance biotransformation of pentachlorophenol (PCP) in a spectrum of wetland soils... more Strategies to enhance biotransformation of pentachlorophenol (PCP) in a spectrum of wetland soils were investigated under laboratory conditions, which included manipulations of electron acceptors and donors, and PCP concentrations. Maximum transformation rates were found at PCP concentrations <10 jxA/ (methanogenic conditions) and >6 \iM to >23 \s,M (aerobic conditions). Differences in PCP toxicity and sorption among soils and treatments were largely governed by the activities of microbial groups. Within this concentration range, transformation was observed in soils under aerobic and methanogenic conditions, but was inhibited under denitrifying and SOa-reducing conditions. Aerobic PCP transformation initially produced small amounts of pentachloroanisole (PCA). However >75% of both chemicals disappeared in 30 d from five soils. Measured soil properties were not significantly correlated to aerobic transformation rates. Under methanogenic conditions, PCP was reductively dechlorinated to yield a mixture of tetra-, tri-, and dichlorophenols in eight soils, with rates strongly correlated to measures of electron donor supply (total C, N, organic C mineralization rates) and microbial biomass. Addition of protein-based electron donors enhanced reductive dechlorination in a soil low in organic matter and microbial biomass. Results demonstrated the widespread occurrence of PCP transforming microorganisms in soils, which may be promoted by manipulating environmental conditions. C ONTAMINATION of the environment with polychlorinated phenols (CPs) is of global concern because of their widespread distribution and universal toxicity to life (Escher et al., 1996; ATSDR, 1998). The most common usage of CPs is treatment of wood against fungi and insects, but other sources include production from chlorine bleaching of pulp (Kringstad and Lindstrom, 1984), combustion of organic matter and municipal solid waste (Kanters et al., 1996), and partial transformation of phenoxy pesticides such as 2,4-D and 2,4,5-T (Mikesell and Boyd, 1985). Chlorophenols that enter nontarget upland, wetland, and aquatic environments associate with colloidal and particulate matter and, if not photodegraded, eventually settle onto surface soils (Shiu et al., 1994). There they may be biodegraded, depending on whether degrading microorganisms are present and whether appropriate conditions exist for expression of this activity. There is still much controversy about whether the presence of microbial populations or environmental conditions lim

Potential rates of aerobic respiration, denitri®cation, sulfate reduction and methanogenesis were... more Potential rates of aerobic respiration, denitri®cation, sulfate reduction and methanogenesis were investigated in 10 dierent wetland soils with a wide range of biogeochemical characteristics, with the objective of determining relationships between process rates and soil properties. Electron acceptor amendments to methanogenic soils caused gradual (1±13 d) to immediate transitions in electron¯ow from methanogenesis to alternate electron acceptors. Rates of organic C mineralization ranged between 0.2 and 34 mmol C g À 1 d À 1 and averaged three times faster with O 2 as compared to alternate electron acceptors. There was no signi®cant dierence between rates of organic C mineralization (CO 2 + CH 4 production) under denitrifying, sulfatereducing and methanogenic conditions, indicating that soil organic carbon availability was similar under the dierent anaerobic conditions. Rates of electron acceptor consumption ranged between 1 and 107 mmol g À 1 d À 1 for O 2 , 0.5 and 9.3 mmol g À 1 d À 1 for NO 3 À , 0.1 and 11.1 mmol g À 1 d À 1 for SO 4 2À and 0.1 and 6.2 mmol g À 1 d À 1 for CO 2. Heterotrophic potentials in wetland soils were strongly correlated with inorganic N and several available C indices (total, dissolved and microbial C), but not with pH or dissolved nutrients (P, Ca 2+ , Mg 2+ , Fe(II)). Microbial activity±soil property relationships determined in this study may be useful for predicting the fate of pollutants that are in¯uenced by microbial oxidation±reduction reactions in dierent types of wetland soils.

Science of The Total Environment, 2012

Manure and bedding material (litter) generated by the broiler industry (Gallus gallus domesticus)... more Manure and bedding material (litter) generated by the broiler industry (Gallus gallus domesticus) often contain high levels of arsenic (As) when organoarsenical roxarsone and p-arsanilic acid are included in feed to combat disease and improve weight gain of the birds. This study was conducted to determine As levels and species in litter from three major broiler producing companies, and As levels in soils, corn tissue (Zea mays L.), and groundwater in fields where litter was applied. Total As in litter from the three different integrators ranged between &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;1 and 44 mg kg(-1). Between 15 and 20% of total As in litter consisted of mostly of arsenate, with smaller amounts of roxarsone and several transformation products that were extractable with phosphate buffer. Soils amended with litter had higher levels of bioavailable As (extractable with Mehlich 3 solution and taken up by corn leaves). Arsenic concentrations in plant tissue and groundwater, however, were below the World Health Organization thresholds, which was attributed to strong sorption/precipitation of arsenate in Fe- and Al-rich soils. Ecological impacts of amending soils with As-laden litter depend on the As species in the litter, and chemical and physical properties of soil that strongly affect As mobility and bioavailability in the environment.

Encyclopedia of Environmental Microbiology, 2003

Wetlands, 2005

A central tenet of wetland mitigation is that replacement wetlands can sequester nutrients and pe... more A central tenet of wetland mitigation is that replacement wetlands can sequester nutrients and perform other functions at the same level as natural wetlands. This study evaluated phosphorus (P) sorption capacity and P exchange in flooded soil microcosms obtained from eight early successional (ES) mitigated and eight late successional (LS) bottomland forest wetlands in western Kentucky, USA. The LS soils had three times greater capacity to remove and retain soluble inorganic P than ES soils, which was mostly due to higher amounts of amorphous aluminum (Al) oxides (oxalate extractable), organically-bound Al (CuCl 2 extractable), and organic carbon in LS soils. Phosphorus exchange rates between the soil and water column were not significantly different in LS and ES microcosms, but rates in both systems were strongly related to the molar ratio of Mehlich III extractable P to Al ϩ Fe in the soil (r 2 ϭ0.64). Relationships between P sorption/exchange and organic C, Mehlich III-and oxalate-extractable forms of P, Al, and Fe determined in this study could be useful for (i) identifying suitable mitigation sites that would be P sinks rather than P sources to the water column and (ii) determining replacement ratios that would fairly compensate for P retention capacity losses caused by destruction/alteration of Kentucky bottomland hardwood forest wetlands.

Soil Science, 2009

... Technical Article. Carbon Sequestration Processes in Temperate Soils With Different Chemical ... more ... Technical Article. Carbon Sequestration Processes in Temperate Soils With Different Chemical Properties and Management Histories. D'Angelo, Elisa M.; Kovzelove, Caitlin A.; Karathanasis, Anastasios D. Article Outline. Collapse Box Author Information. ...

Soil Science Society of America Journal, 2003

ant between the solid phase and dissolved phase (sorption), which is governed by the physical and... more ant between the solid phase and dissolved phase (sorption), which is governed by the physical and chemical Sorption of four chlorophenols (CPs) was studied in ten wetland properties of the solute, the sorbent, and the solvent. soils with organic C contents between 1 and 44%, which were incu-Much research on organic pollutant sorption has dembated under aerobic or anaerobic conditions to simulate wetland conditions. The objectives of the study were to (i) determine the influence onstrated a strong link between the distribution ratio of aerobic and anaerobic processes on sorption, and (ii) develop sorp-(K p) and the lipophilicity of hydrophobic organic polluttion models to predict the distribution coefficient based on chemical ants, as expressed by its K ow , and the fractional amount characteristics of soils and compounds. Aerobic soils consistently had of organic C of the sorbent (f oc): lower pH than anaerobic treatments, which was a function of the amount of oxidizable constituents present in the sample. Depending K p ϭ f oc ϫ a(K ow) b [1] on the pK a of the compound relative to the pH shift, a greater fraction where a and b are empirical constants that differ deof the CP was in the neutral form in the aerobic treatments, which pending primarily on the nature of the pollutant. The was sorbed to a much greater extent than the ionic form (by about relationship has been very useful for predicting sorption 25 times). The organic C normalized distribution coefficient (K oc) was of many hydrophobic organic pollutants by a wide varistrongly related to the octanol-water distribution coefficient (K ow) and soil pH. Sorption models accurately predicted distribution coefficients ety of sorbents; on occasion, however, it has been found within a factor of 2 from the K ow and pK a of the compounds and the to be deficient for ionizable organic compounds such pH and organic C content of the sorbent. The role of sorption on CP as CPs. retention was partially negated by the formation of the nonseparable In studies on the sorption of CPs in soils and sediphase, which composed up to 8.6% of the total solid mass (depending ments, Schellenburg et al. (1984) and Lagas (1988) on the soil redox status) and had similar distribution coefficients as found that the model for hydrophobic compounds had the separable phase. This study demonstrated that microbial redox limited application because it did not account for the processes significantly influenced the soil properties and CP retention contribution of both the neutral species and the phecharacteristics, and should be considered when designing a bioremedinolate anion to overall sorption. Shimizu et al. (1992) ation plan for these compounds. derived a model that accounted for the contribution of both species to the distribution coefficient of PCP (pK a ϭ 4.74

Soil Biology and Biochemistry, 2007

... additional microcosms for each soil type were prepared with either distilled water (no amendm... more ... additional microcosms for each soil type were prepared with either distilled water (no amendment treatment) or by autoclaving and adding Hg (121 °C, 0.10 MPa, 1 h on 2 separate days followed by HgCl 2 additions to achieve 100 mg Hg kg −1 soil) (Wolf and Skipper, 1994). ...

Soil Biology and Biochemistry, 1999