Renewable Energy Revenues, Carbon Credits, and Subsidies in Agricultural Waste Treatment Economic Decisions [abstract]

Only abstract of poster available.Track III: Energy InfrastructureAll environmental waste has societal cost, and mitigation is difficult to transfer into benefits that economically justify action. Current subsidies and carbon credit financing have grown to developed within our society to actually put economic resources that are representative of the benefits, and now advanced waste treatment is viable through new economic possibilities related to methane capture and energy production. An economic model was constructed to evaluate the financial potential of anaerobic digestion for swine waste considering initial investments, the associated costs and new revenue streams of carbon credits, renewable energy credits, electricity sales and current available subsidies. The model was formulated based on case-specific inputs and was applied to three case studies in central Missouri. The model inputs were also evaluated by experienced vendors (who have developed similar projects) for validity. The results revealed that the present prices of carbon credits and electricity are not enough to prove the financial feasibility of applying AD technology in all cases without the availability of subsidies. The endeavor also showed that electricity prices have modest impacts on the corresponding Net Present Value of the projects. On the other hand, the carbon credit market projections affect the NPV to a greater degree. Clearly, carbon credit markets may play a pivotal role in widespread development and implementation of the technology. In all the three scenarios the projects were profitable with the presence of the current state and federal subsidies. However, since the subsidies may not be available for many years, high Carbon Credit and electricity prices are needed for future profitability of the technology

Phytoremediation: Plant Uptake of Atrazine and Role of Root Exudates

Phytoremediation is an Emerging Technology for Degradation of Organic Chemicals. the Potential of Phytoremediation in the Cleanup of Contaminated Sites and Prevention of Non-Point-Source Pollution Was Examined with the Pesticide Atrazine in Two Experimental Systems. Uptake Was Determined in Batch Experiments with 14C Ring-Labeled Atrazine and Hybrid Poplar Trees Grown in Two Soil Types. Mineralization Was Studied Utilizing Soil Microcosms with the Addition of Root Exudates. Results Indicate that Poplar Cuttings Were Able to Uptake the Majority of Applied Atrazine that Was Not Tightly Sorbed to the Organic Fraction of the Soil, with No Detectable Adverse Effects to the Trees. the Addition of Root Exudate to Microcosms Showed Slight Stimulation and the Addition of Ground-Up Root Biomass Revealed Large Stimulation of Mineralization to 14CO2. from Experimentally Acquired Data, a Mathematical Model Was Developed to Obtain Kinetic Rate Constants. This Research Indicates that Vegetative Uptake and Degradation in the Rhizosphere Can Play a Major Role in Remediation at Hazardous Waste Sites. © ASCE

Mineralization and Uptake of Triazine Pesticide in Soil-Plant Systems

Deep-Rooted Trees Planted as a Buffer Zone Can Intercept Runoff and Eroded Sediments, Thus Reducing Non-Point-Source Pollution Due to Agricultural Chemicals. in This Study, Populus Sp. Were Grown in Bioreactors with an Agricultural Soil (Silt-Loam) and in a Silica-Sand Media; Both Were Spiked with 14C Uniformly Ring-Labeled Atrazine. the Plants Took Up over 11% of the 14C Labeled Atrazine Applied to the Silt-Loam Soil and over 91% of that Applied to the Silica Sand Media, with the Majority of the 14C Accumulating as Nonphytotoxic Metabolites in the Leaves. Research Suggests that, in Addition to Nutrient Uptake, Poplar Tree Buffer Strips May Be Effective in Removing Atrazine from Agricultural Percolation and Runoff Water. © ASCE

Joel Burken Podcast

Professor of Architectural and Environmental Engineering Joel Burken discusses environmental effects of the Renewable Fuel Standard, which requires the U.S. to produce 36 billion gallons of biofuels by 2022

A State-Sponsored Renewable Energy Demonstration Project [abstract]

Only abstract of poster available.Track I: Power GenerationHistorically renewable energy has been adopted by consumers at varying levels across the United States. For example, California is well-known for initiatives which have resulted in thewidespread acceptance and use of wind and photovoltaic systems at all levels from utilities toindividual households. Missouri has focused on biofuels, and wind development and solar development are not widespread. In response to an initiative to reduce the State's utility costs,the Missouri Office of Administration sponsored a demonstration of the use of a 10 kW-rated wind turbine and a 2-kW photovoltaic system at a regional Highway Patrol headquarters. Both systems are interconnected with the local utility provider. The project also include environmental and system instrumentation. The straightforward demonstration project has resulted in several tangible benefits in addition to than the planned cost reduction: outreach to thegeneral public as well as precollege outreach for potential university students; identification of liability issues related to utility interconnection permits; familiarization of facility tenants andstate employees with renewable energy systems; familiarization of utility personnel withrenewable energy systems; identification of unanticipated costs; collection of data to be used for performance prediction research; training of local tradesmen in relevant construction practices;and providing graduate and undergraduate education opportunities

Vapor-Phase Exchange of Perchloroethene Between Soil and Plants

Tree core concentrations of tetrachloroethylene (perchloroethene, PCE) at the Riverfront Superfund Site in New Haven, MO, were found to mimic the profile of soil phase concentrations. the observed soil-tree core relationship was stronger than that of groundwater PCE to tree core concentrations at the same site. Earlier research has shown a direct, linear relationship between tree core and groundwater concentrations of chlorinated solvents and other organics. Laboratory-scale experiments were performed to elucidate this phenomenon, including determining partitioning coefficients of PCE between plant tissues and air and between plant tissues and water, measured to be 8.1 and 49 L/kg, respectively. the direct relationship of soil to tree core PCE concentrations was hypothesized to be caused by diffusion between tree roots and the soil vapor phase in the subsurface. the central findings of this research are discovering the importance of subsurface vapor-phase transfer for VOCs and uncovering a direct relationship between soil vapor-phase chlorinated solvents and uptake rates that impact contaminant translocation from the subsurface and transfer into the atmosphere

Assessment of Subsurface Chlorinated Solvent Contamination Using Tree Cores At the Front Street Site and a Former Dry Cleaning Facility At the Riverfront Superfund Site, New Haven, Missouri, 1999-2003.

Tree-core sampling has been a reliable and inexpensive tool to quickly assess the presence of shallow (less than about 30 feet deep) tetrachloroethene (PCE) and trichloroethene (TCE) contamination in soils and ground water at the Riverfront Superfund Site. This report presents the results of tree-core sampling that was successfully used to determine the presence and extent of chlorinated solvent contamination at two sites, the Front Street site (operable unit OU1) and the former dry clean-ing facility, that are part of the overall Riverfront Superfund Site. Traditional soil and ground-water sampling at these two sites later confirmed the results from the tree-core sampling. Results obtained from the tree-core sampling were used to design and focus subsequent soil and ground-water investiga-tions, resulting in substantial savings in time and site assessment costs.The Front Street site is a small (less than 1-acre) site located on the Missouri River alluvium in downtown New Haven, Missouri, about 500 feet from the south bank of the Missouri River. Tree-core sampling detected the presence of sub-surface PCE contamination at the Front Street site and beneath residential property downgradient from the site. Core samples from trees at the site contained PCE concentrations as large as 3,850 μg-h/kg (micrograms in headspace per kilogram of wet core) and TCE concentrations as large as 249 μg-h/kg. Soils at the Front Street site contained PCE concentrations as large as 6,200,000 μg/kg (micrograms per kilogram) and ground-water samples contained PCE concentrations as large as 11,000 μg/L (micrograms per liter). The former dry cleaning facility is located at the base of the upland that forms the south bank of the Missouri River alluvial valley. Tree-core sampling did not indi-cate the presence of PCE or TCE contamination at the former dry cleaning facility, a finding that was later confirmed by the analyses of soil samples collected from the site. The lateral extent of PCE contamination in trees was in close agreement with the extent of subsurface PCE contamina-tion determined using traditional soil and ground-water sampling methods. Trees growing in soils containing PCE concentrations of 60 to 5,700 μg/kg or larger or overlying ground water containing PCE concentrations from 5 to 11,000 μg/L generally contained detectable concentrations of PCE. The depth to contaminated ground water was about 20 to 25 feet below the land surface. Significant quantitative relations [probability (p) values of less than 0.05 and correlation coefficient (r2) values of 0.88 to 0.90] were found between PCE concentrations in trees and subsurface soils between 4 and 16 feet deep. The relation between PCE concentrations in trees and underlying ground water was less apparent (r2 value of 0.17) and the poor relation is thought to be the result of equilibrium with PCE concentrations in soil and vapor in the unsaturated zone. Based on PCE concentrations detected in trees at the Front Street site and trees growing along contaminated tributaries in other operable units, and from field hydroponic experiments using hybrid poplar cut-tings, analysis of tree-core samples appears to be able to detect subsurface PCE contamination in soils at levels of several hundred micrograms per liter or less and PCE concentrations in the range of 8 to 30 μg/L in ground water in direct contact with the roots.Loss of PCE from tree trunks by diffusion resulted in an exponential decrease in PCE concentrations with increasing height above the land surface in most trees. The rate of loss also appeared to be a function of the size and growth characteristics of the tree as some trees exhibited a linear loss with increasing height. Diffusional loss of PCE in small (0.5-inch diameter) trees was observed to occur at a rate more than 10 times larger than in trees 6.5 inches in diameter. Concentrations of PCE also exhibited directional variability around the tree trunks and con-centration differences as large as five-fold were observed around the trunks of several trees. The directional differences were attributable to spatial differences in PCE concentrations in soils around the trees and to natural “twisting” of the tree trunks. The directional differences also may be caused by diffusion of PCE vapors in the unsaturated zone into the tree roots. Comparison of PCE concentrations in core and sap samples confirms laboratory sorption studies and indicates that the vast majority (greater than 95 percent) of the PCE and TCE reside in the wood phase and not the transpiration stream

Persistence and Microbial Source Tracking of Escherichia Coli at a Swimming Beach at Lake of the Ozarks State Park, Missouri

The Missouri Department of Natural Resources (MDNR) has closed or posted advisories at public beaches at Lake of the Ozarks State Park in Missouri because of Escherichia coli (E. coli) concentration exceedances in recent years. Spatial and temporal patterns of E. Coli concentrations, microbial source tracking, novel sampling techniques, and beach-use patterns were studied during the 2012 recreational season to identify possible sources, origins, and occurrence of E. coli contamination at Grand Glaize Beach (GGB). Results indicate an important source of E. coli contamination at GGB was E. coli released into the water column by bathers resuspending avian-contaminated sediments, especially during high-use days early in the recreational season. Escherichia coli concentrations in water, sediment, and resuspended sediment samples all decreased throughout the recreational season likely because of decreasing lake levels resulting in sampling locations receding away from the initial spring shoreline as well as natural decay and physical transport out of the cove. Weekly MDNR beach monitoring, based solely on E. coli concentrations, at GGB during this study inaccurately predicted E. coli exceedances, especially on weekends and holidays. Interestingly, E. coli of human origin were measured at concentrations indicative of raw sewage in runoff from an excavation of a nearby abandoned septic tank that had not been used for nearly two years