Physical Sciences and Mathematics Commons^™

Stable Isotope Analysis Of Organic Carbon In Small (Μg C) Samples And Dissolved Organic Matter Using A Gasbench Preparation Device, Susan Lang, S. Bernasconi, G. Früh-Green

Susan Q. Lang

No abstract provided.

Sources And Cycling Of Carbon In Continental, Serpentinite-Hosted Alkaline Springs In The Voltri Massif, Italy, E. Schwarzenbach, Susan Lang, G. Früh-Green, M. Lilley, S. Bernasconi, S. Méhay

Susan Q. Lang

No abstract provided.

Purification Of Fire Derived Markers For Μg Scale Isotope Analysis (Δ13c, Δ14c) Using High Performance Liquid Chromatography (Hplc), M. Gierga, M. Schneider, D. Wiedemeier, Susan Lang, R. Smittenberg, I. Hajdas, S. Bernasconi, M. Schmidt

Susan Q. Lang

No abstract provided.

Dissolved Organic Carbon In Ridge-Axis And Ridge-Flank Hydrothermal Systems, Susan Lang, D. Butterfield, M. Lilley, H. Johnson, J. Hedges

Susan Q. Lang

No abstract provided.

Sources Of Organic Nitrogen At The Serpentinite-Hosted Lost City Hydrothermal Field, Susan Lang, G. Früh-Green, S. Bernasconi, D. Butterfield

Susan Q. Lang

No abstract provided.

Developing Scientific Literacy In Introductory Laboratory Courses: A Model For Course Design And Assessment, Benjamin Surpless, Bushey Michelle, Mark Halx

Benjamin E Surpless

Although science educators at all levels have focused on teaching students scientific literacy for nearly five decades, studies indicate that the average student remains far from scientifically literate. To address this issue at the local level, faculty at Trinity University, in San Antonio, Texas, significantly revised the curriculum of an existing introductory physical geology laboratory course. The course, which satisfies general education requirements at Trinity, was revised to provide students learning opportunities in a scientific process context as part of a new science literacy initiative. This effort was spurred by general dissatisfaction with the existing curricular structure of the course …

Modern Strain Localization In The Central Walker Lane, Western United States: Implications For The Evolution Of Intraplate Deformation In Transtensional Settings, Benjamin Surpless

Benjamin E Surpless

Approximately 25% of the differential motion between the Pacific and North American plates occurs in the Walker Lane, a zone of dextral motion within the western margin of the Basin and Range province. At the latitude of Lake Tahoe, the central Walker Lane has been considered a zone of transtension, with strain accommodated by dip-slip, strike-slip, and oblique-slip faults. Geologic data indicate that extension and strike-slip motion are partitioned across the central Walker Lane, with dip-slip motion resulting in E–W to ESE–WNW extension along the present-day western margin of the central Walker Lane since approximately 15 Ma, and dextral strike-slip …

Volcanism And Tectonics: An Exploration Of Volcanoes And Volcanic Deposits Using Google Earth, Benjamin Surpless

Benjamin E Surpless

No abstract provided.

Crowdsourced Earthquake Early Warning, Sarah Minson, Benjamin Brooks, Craig Glennie, Jessica Murray, John Langbein, Susan Owen, Thomas Heaton, Robert Iannucci, Darren Hauser

Robert A Iannucci

Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitous. Through controlled tests of consumer devices, simulation of an Mw (moment magnitude) 7 earthquake on California’s Hayward fault, and real data from the Mw 9 Tohoku-oki earthquake, we demonstrate that EEW could be achieved via crowdsourcing.

Arsenic Mobilization In An Alluvial Aquifer Of The Terai Region, Nepal, Jasmine Diwakar, Scott Johnston, Edward Burton, Suresh Das Shrestha

Associate Professor Edward D Burton

Study Region

A shallow (<50 m) alluvial aquifer in the Terai region of Nepal.

Study Focus

We examine the hydrogeochemical characteristics of a shallow alluvial aquifer system in the Terai region (Nawalparasi district) to identify possible mechanisms and controls on geogenic As mobilization in groundwater. Groundwater and river water samples from a topo-gradient flow-path and floodplain of a minor river draining the Siwalik forehills were analyzed for physico-chemical parameters.

New Hydrological Insights for the Region

The aquifer is characterized by Ca-HCO₃ type water and is multi-contaminated, with the WHO guideline values exceeded for As, Mn and F in 80%, 70% and 40% of cases respectively. The middle portion …

A Revised Method For Determining Existing Acidity In Re-Flooded Acid Sulfate Soils, Scott Johnston, Edward Burton, Roslyn Hagan, Thor Aaso, Gerard Tuckerman

Associate Professor Edward D Burton

Titratable actual acidity (TAA) is a technique commonly used to estimate the existing pool of exchangeable H⁺ in acid sulfate soils (ASS). A widely adopted version of the TAA method involves titrating a 1M KCl suspension of oven-dry soil (1:40) with NaOH to a known pH endpoint. However, when ASS are subject to long term re-flooding during wetland remediation, former sulfuric horizons can develop substantial quantities of porewater Fe²⁺, non-sulfidic solid-phase Fe(II) and a variety of reduced inorganic sulfur (RIS) species (e.g. pyrite, mackinawite, greigite and elemental sulfur). For these sediments, an oven-drying approach may induce oxidation …

Enrichment And Heterogeneity Of Trace Elements At The Redox-Interface Of Fe-Rich Intertidal Sediments, Annabelle Keene, Scott Johnston, Richard Bush, Edward Burton, Leigh Sullivan, Matthew Dundoon, Angus Mcelnea, C Smith, Col Ahern, Bernard Powell

Associate Professor Edward D Burton

Redox-interfacial sediments can undergo radical geochemical changes with oscillating tides. In this study, we examine trace element enrichment and availability, at both landscape and pedon-scales, in the surface sediments of a remediating acidic tidal wetland. Fe-rich sediments at the surface-water interface (0–10 mm in depth) were collected across an elevation gradient spanning the supratidal to subtidal range. These sediments were analysed for solid phase Fe fractions and trace elements (As, Pb, Cr, Cu, Mn, Ni, Zn, V, B, Co, Mo, Ba and U) via dilute HCl-extractions and total digests. Their concentrations were compared with those of underlying (0.05–0.65 m in …

Landslide-Induced Iron Mobilisation Shapes Benthic Accumulation Of Nutrients, Trace Metals And Ree Fractionation In An Oligotrophic Alpine Stream, Scott Johnston, Andrew Rose, Edward Burton, Jenny Webster-Brown

Associate Professor Edward D Burton

Large alpine landslides that entrain substantial organic material below the water table and create suspended floodplains may have long-term consequences for the mobilisation of redox sensitive elements, such as Fe, into streamwaters. In turn, the cycling of iron in aquatic systems can influence the fate of nutrients, alter primary productivity, enhance accumulation of trace metals and induce fractionation of rare earth elements (REE). In this study we examine a reach of a pristine oligotrophic alpine stream bracketing a 30 year-old landslide and explore the consequences of landslide-induced Fe mobilisation for aqueous geochemistry and the composition of benthic stream cobble biofilm. …

Late Pleistocene Glacial History And Magnetic Chronostratigraphy, Western Adirondack Borderland, New York, Donald Pair

Donald L. Pair

New lines of evidence from the western Adirondack borderland have been employed to assess the style of deglaciation and reconstruct the nature and timing of associated proglacial lacustrine and marine (Champlain Sea) events. Contrasting styles of deglaciation, controlled primarily by water depth, resulted in landfast ice withdrawing gradually on the northern slope of the Adirondacks while actively calving ice, retreating rapidly in the deep water of Lake Iroquois, quickly evacuated the western St. Lawrence Lowland of ice. The extent of ice retreat from the western St. Lawrence Lowland during the life of Lake Iroquois has been estimated on the basis …

Maine's Climate Future: An Initial Assessment, George Jacobson, Ivan Fernandez, Paul Mayewski, Catherine Schmitt

Ivan J. Fernandez

Earth’s atmosphere is experiencing unprecedented changes that are modifying global climate. Discussions continue around the world, the nation, and in Maine on how to reduce and eventually eliminate emissions of carbon dioxide (CO2), other greenhouse gases, and other pollutants to the atmosphere, land, and oceans. These efforts are vitally important and urgent. However, even if a coordinated response succeeds in eliminating excess greenhouse gas emissions by the end of the century, something that appears highly unlikely today, climate change will continue, because the elevated levels of CO2 can persist in the atmosphere for thousands of years to come.

In late …

Tb134: A Laboratory Study To Assess Methods For Predicting Ph Change Of Ash Amended Forest Soils, Yvonne Unger, Ivan Fernandez

Ivan J. Fernandez

The objective of this study was to compare several commonly used lime requirement tests and soil capacity factors for their ability to predict pH change following wood-ash amendment. The ability to predict pH change is important because it is one of the criteria used to prescribe rates of ash amendment to forest soils.

Role Of Organic Amendments On Enhanced Bioremediation Of Heavy Metal(Loid) Contaminated Soils, Jin Hee Park, Dane Lamb, Periyasamy Paneerselvam, Girish Choppala, Nanthi Bolan, Jae Chung

Dr Girish Choppala

As land application becomes one of the important waste utilization and disposal practices, soil is increasingly being seen as a major source of metal(loid)s reaching food chain, mainly through plant uptake and animal transfer. With greater public awareness of the implications of contaminated soils on human and animal health there has been increasing interest in developing technologies to remediate contaminated sites. Bioremediation is a natural process which relies on soil microorganisms and higher plants to alter metal(loid) bioavailability and can be enhanced by addition of organic amendments to soils. Large quantities of organic amendments, such as manure compost, biosolid and …

Chapter Two: Chromium Contamination And Its Risk Assessment In Complex Environmental Settings, Girish Choppala, Nanthi Bolan, Jin Hee Park

Dr Girish Choppala

Chromium reaches the soil environment through waste disposal emanating from a number of industrial activities, including coal-fired power production, electroplating, leather tanning, timber treatment, pulp production, and mineral ore and petroleum refining. Of the heavy metals, chromium (Cr) is a major pollutant, poses a great threat to flora and fauna and persists for long time. The most abundant species of Cr—Cr(III) and Cr(VI)—have very different properties. The toxicity, mobility, and bioavailability of Cr mainly depend on its speciation. In the natural environment, Cr(III) is most immobile, less soluble and stable, whereas Cr(VI) is highly mobile, soluble and bioavailable. Redox reactions …

Differential Effect Of Coal Combustion Products On The Bioavailability Of Phosphorus Between Inorganic And Organic Nutrient Sources, Belaji Seshadri, Nanthi Bolan, Girish Choppala, Ravi Naidu

Dr Girish Choppala

In farming systems, all the applied phosphorus (P) is not available to plants because they are either adsorbed in soil or lost to the environment through leaching or runoff. The effect of coal combustion products (CCPs) for enhancing the bioavailability of applied phosphorus (P) in soil was examined separately for inorganic (KH₂PO₄ – PP) and organic (poultry manure – PM) P treatments, where fluidised bed combustion (FBC) ash emerged as the most effective amendment. Greenhouse study was conducted by growing mustard plants on FBC amended soils under leaching and non-leaching setups. The FBC increased the biomass yield …

Comparative Sorption Of Pb And Cd By Biochars And Its Implication For Metal Immobilization In Soils, Jin Hee Park, Girish Choppala, Seul Lee, Nanthi Bolan, Jae Chung, Mansour Edraki

Dr Girish Choppala

Biochar has great potential as a soil amendment to immobilize heavy metals, thereby reducing their bioavailability. In this study, biochars derived from chicken manure and green waste were compared with commercial activated carbon (AC) and laboratory produced black carbon (BC) for the sorption of Pb and Cd. Sorption kinetics and equilibrium sorption isotherms for Pb and Cd were obtained for the char materials and the data were fitted to kinetic and sorption isotherm models.. Chicken manure-derived biochar (CM) showed the highest sorption capacity for both Pb and Cd, and the Pb sorption by biochars was higher than the Cd sorption …

Phytocapping: An Alternative Technology For The Sustainable Management Of Landfill Sites, Dane Lamb, Kartik Venkatraman, Nanthi Bolan, Nanjappa Ashwath, Girish Choppala, Ravi Naidu

Dr Girish Choppala

Landfill remains the predominant means of waste disposal throughout the globe. Numerous landfills exist in developed and underdeveloped countries, engineered with contrasting degrees of effectiveness. Modern landfill closure in developed countries involves the conventional capping of waste with materials such as compacted clay or geosynthetic clay liners, typically overlain with other soil materials. Conventional capping technologies are now accepted to be increasingly ineffective in reducing percolation into waste. Cost-effective alternative systems are of increasing interest, including the use of plants to control and limit water entry into waste, otherwise known as “Phytocapping”. Phytocapping reduces percolation through three main mechanisms: (a) …

Comparative Sorption And Mobility Of Cr(Iii) And Cr(Vi) Species In A Range Of Soils: Implications To Bioavailability, Girish Choppala, Nanthi Bolan, Dane Lamb, Anitha Kunhikrishnan

Dr Girish Choppala

The sorption of chromium (Cr) species to soil has become the focus of research as it dictates the bioavailability and also the magnitude of toxicity of Cr. The sorption of two environmentally important Cr species [Cr(III) and Cr(VI)] was examined using batch sorption, and the data were fitted to Langmuir and Freundlich adsorption isotherms. The effects of soil properties such as pH, CEC, organic matter (OM), clay, water-extractable SO4 2– and PO4 3–, surface charge, and different iron (Fe) fractions of 12 different Australian representative soils on the sorption, and mobility of Cr(III) and Cr(VI) were examined. The amount of …

Chemodynamics Of Chromium Reduction In Soils: Implications To Bioavailability, Girish Choppala, Nanthi Bolan, Belaji Seshadri

Dr Girish Choppala

Chromium toxicity in soils can be mitigated by reduction of Cr(VI) to Cr(III) which is influenced by the presence of free Cr(VI) species in soil solution, and the supply of protons and electrons. In this study, the effects of Cr(VI) adsorption (i.e. availability of free Cr(VI) species in soil solution), soil pH (i.e. supply of protons) and three electron donor carbon sources [black carbon (BC), chicken manure biochar (CMB) and cow manure (CM)] on the reduction of Cr(VI) to Cr(III) in soils were investigated. The results indicated that the rate of Cr(VI) reduction decreased with an increase in Cr(VI) adsorption …

Phosphorus–Arsenic Interactions In Variable-Charge Soils In Relation To Arsenic Mobility And Bioavailability, Nanthi Bolan, Santiago Mahimairaja, Anitha Kunhikrishnan, Girish Choppala

Dr Girish Choppala

Phosphorus (P) influences arsenic (As) mobility and bioavailability which depends on the charge components of soil. The objective of this study was to examine P–As interaction in variable-charge allophanic soils in relation to P-induced As mobilization and bioavailability. In this work, the effect of P on arsenate [As(V)] adsorption and desorption was examined using a number of allophanic and non-allophanic soils which vary in their anion adsorption capacity. The effect of P on As uptake by Indian mustard (Brassica juncea L.) plants was examined using a solution culture, and a soil plant growth experiment involving two As-spiked allophanic and non-allophanic …

Microbial Transformation Of Trace Elements In Soils In Relation To Bioavailability And Remediation, Nanthi Bolan, Girish Choppala, Anitha Kunhikrishnan, Jin Hee Park, Ravi Naidu

Dr Girish Choppala

The term “trace elements” generally includes elements (both metals and metalloids) that occur in natural and perturbed environments in small amounts and that, when present in sufficient bioavailable concentrations, are toxic to living organisms (Adriano 2001). This group includes both biologically essential [e.g., cobalt (Co), copper (Cu), chromium (Cr), manganese (Mn), and zinc (Zn)] and nonessential [e.g., cadmium (Cd), lead (Pb), and mercury (Hg)] elements. The essential elements (for plant, animal, or human nutrition) are required in low concentrations and hence are known as “micro nutrients.” The nonessential elements are phytotoxic and/or zootoxic and are widely known as “toxic elements” …

Cellular Mechanisms In Higher Plants Governing Tolerance To Cadmium Toxicity, Girish Choppala, Saifullah, Nanthi Bolan, Sadia Bibi, Muhammad Iqbal, Zed Rengel, Anitha Kunhikrishnan, Nanjappa Ashwath, Yong Ok

Dr Girish Choppala

Cadmium (Cd) is an inorganic mineral in the earth's crust. Cadmium entry into the environment occurs through geogenic and anthropogenic sources. Industrial activities including mining, electroplating, iron and steel plants, and battery production employ Cd during their processes and often release Cd into the environment. When disseminated into soil, Cd can be detrimental to agro-ecosystems because it is relatively mobile and phytotoxic even at low concentrations. Cadmium's phytotoxicity is due to reductions in the rate of transpiration and photosynthesis and chlorophyll concentration resulting in retardation of plant growth, and an alteration in the nutrient concentration in roots and leaves. In …

Concomitant Reduction And Immobilization Of Chromium In Relation To Its Bioavailability In Soils, Girish Choppala, Nanthi Bolan, Anitha Kunhikrishnan, William Skinner, Balaji Seshadri

Dr Girish Choppala

In this study, two carbon materials [chicken manure biochar (CMB) and black carbon (BC)] were investigated for their effects on the reduction of hexavalent chromium [Cr(VI)] in two spiked [600 mg Cr(VI) kg−1] and one tannery waste contaminated [454 mg Cr(VI) kg−1] soils. In spiked soils, both the rate and the maximum extent of reduction of Cr(VI) to trivalent Cr [Cr(III)] were higher in the sandy loam than clay soil, which is attributed to the difference in the extent of Cr(VI) adsorption between the soils. The highest rate of Cr(VI) reduction was observed in BC-amended sandy loam soil, where it …

Biochar Reduces The Bioavailability And Phytotoxicity Of Heavy Metals, Jin Hee Park, Girish Choppala, Nanthi Bolan, Jae Chung, Thammared Chuasavathi

Dr Girish Choppala

Background and aims

Biochar has attracted research interest due to its ability to increase the soil carbon pool and improve crop productivity. The objective of this study was to evaluate the metal immobilizing impact of chicken manure- and green waste-derived biochars, and their effectiveness in promoting plant growth.

Methods

The immobilization and phytoavailability of Cd, Cu and Pb was examined using naturally contaminated shooting range and spiked soils. Biochar samples prepared from chicken manure and green waste were used as soil amendments.

Results

Application of biochar significantly reduced NH₄NO₃ extractable Cd, Cu and Pb concentrations of soils, …

Stabilization Of Carbon In Composts And Biochars In Relation To Carbon Sequestration And Soil Fertility, Nanthi Bolan, Anitha Kunhikrishnan, Girish Choppala, R Thangarajan, J Chung

Dr Girish Choppala

There have been increasing interests in the conversion of organic residues into biochars in order to reduce the rate of decomposition, thereby enhancing carbon (C) sequestration in soils. However energy is required to initiate the pyrolysis process during biochar production which can also lead to the release of greenhouse gasses. Alternative methods can be used to stabilize C in composts and other organic residues without impacting their quality. The objectives of this study include: (i) to compare the rate of decomposition among various organic amendments and (ii) to examine the effect of clay materials on the stabilization of C in …

Effect Of Coal Combustion Products In Reducing Soluble Phosphorus In Soil Ii. Leaching Study, Balaji Seshadri, Nanthi Bolan, Anitha Kunhikrishnan, Girish Choppala, Ravi Naidu

Dr Girish Choppala

Phosphorus (P) management in agriculture is crucial for both environmental health and future availability of P resource. Application of P as fertilisers (organic or inorganic) often results in either P accumulation in soil or loss to water bodies, rendering them unavailable to crops. In this study, the mobility of inorganic (KH₂PO₄ (PP)) and organic (poultry manure (PM)) P sources, as affected by coal combustion products (CCPs: fly ash (FA) and fluidised bed combustion ash (FBC)) application to soils, was evaluated using column leaching experiments. The incubated samples were also characterised using X-ray diffraction (XRD) and scanning electron …