Uptake and Metabolism of Atrazine by Poplar Trees

Hybrid Poplar Trees Can Uptake, Hydrolyze, and Dealkylate Atrazine to Less Toxic Metabolites. in Whole Plant Studies, the Parent Compound Atrazine and 14C Ring-Labeled Metabolites Were Extracted from Poplar Tissues and Analyzed Via High-Pressure Liquid Chromatography (HPLC) with UV and Radiochromatographic Detectors in Series. the Concurrent Separation and Identification of These Metabolites Has Not Been Previously Reported in Higher Plants for Phytoremediation Applications. Unidentified Metabolites Were Also Detected. Metabolism of Atrazine Occurred in Poplar Roots, Stems, and Leaves and Became More Complete with Increased Residence Time in Tissues. in Poplar Cuttings Exposed to Atrazine for 50 Days, the Parent Compound Comprised Only 21% of the 14C Label in the Leaves, While It Constituted 59% of 14C Activity Remaining in the Soil. after 80 Days, the Parent Compound Remaining in the Leaves Had Decreased to Only 10% of the 14C Label Recovered in the Leaves. Preferred Metabolic Pathways Were Suggested by Relative Rates of Reaction, and a Mathematical Model Was Developed to Estimate Rate Constants for the Proposed Degradation Mechanism. This Research Provides Evidence for Vegetative Detoxification of Contaminants and Suggests that Phytoremediation of Atrazine-Contaminated Soils May Be Feasible

Poplar tree buffer strips grown in riparian corridors for non-point source pollution control and biomass production

Throughout the Cornbelt eco-region, nitratenitrogen (NO3-N) is the most frequent pollutant exceeding the U.S. Environmental Protection Agency\u27s maximum contaminant limits for municipal drinking water supplies. Agricultural fertilizers that leach or run off from row-cropped fields are the principal source of NO3-N. This potential contamination poses a health concern that is attracting increasing attention among the urban and rural populace alike

Predictive Relationships for Uptake of Organic Contaminants by Hybrid Poplar Trees

Twelve Organic Compounds Commonly Found at Hazardous Waste Sites Were Studied for Uptake by Hybrid Poplar Trees. the Vegetative Uptake of Many of These Compounds Has Not Previously Been Demonstrated for Plant Species Being Utilized for Phytoremediation, Such as Hybrid Poplar Trees. Experiments Were Conducted Hydroponically Utilizing 14C-Labeled Compounds to Ascertain Translocation and Fate. Predictive Relationships for the Translocation and Partitioning to Plant Tissues Were Developed from the Experimental Data. Translocation and Partitioning Relationships based on Compounds\u27 Octanol- Water Partitioning Coefficients (100 K(Ow)) Produced the Best Results, But the Relationships Did Not Allow for Fully Accurate Prediction of Each Contaminant\u27s Fate. Translocation and Subsequent Transpiration of Volatile Organic Compounds (VOCs) from the Leaves to the Atmosphere Was Shown to Be a Significant Pathway. as Full-Scale Phytoremediation Systems Are Deliberated; the Pathways Investigated Here Should Be Considered in Terms of a Contaminant Removal Mechanism and Potential Contamination of the Vegetation

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

Development of the combined method of hardening of the surface of aluminium

Представлены результаты, полученные при исследовании фазового и элементного состава, дефектной субструктуры поверхности технически чистого алюминия марки А7, подвергнутого комбинированной обработке, сочетающей напыление металлической пленки, электронно-пучковое перемешивание системы пленка/подложка и последующее азотирование в плазме газового разряда низкого давления. Выполнен анализ закономерностей, выявлены режимы воздействия, позволяющие кратно повышать микротвердость и износостойкость материала.The results are presented, received at research of phase and elemental composition, defective substructureof surface technically pure aluminium of the A7, subjected to the combined processing combining spraying metalfilm, electron-beam mixing of system film/substrate and subsequent nitriding in plasma of the gas discharge of lowpressure. The analysis of regularities is made, revealed the modes of influence allowing multiple to raise amicrohardness and wear resistance of material

Phytotechnologies - Preventing Exposures, Improving Public Health

Phytotechnologies Have Potential to Reduce the Amount or Toxicity of Deleterious Chemicals and Agents, and Thereby, Can Reduce Human Exposures to Hazardous Substances. as Such, Phytotechnologies Are Tools for Primary Prevention in Public Health. Recent Research Demonstrates Phytotechnologies Can Be Uniquely Tailored for Effective Exposure Prevention in a Variety of Applications. in Addition to Exposure Prevention, Plants Can Be Used as Sensors to Identify Environmental Contamination and Potential Exposures. in This Paper, We Have Presented Applications and Research Developments in a Framework to Illustrate How Phytotechnologies Can Meet Basic Public Health Needs for Access to Clean Water, Air, and Food. Because Communities Can Often Integrate Plant-Based Technologies at Minimal Cost and with Low Infrastructure Needs, the Use of These Technologies Can Be Applied Broadly to Minimize Potential Contaminant Exposure and Improve Environmental Quality. These Natural Treatment Systems Also Provide Valuable Ecosystem Services to Communities and Society. in the Future, Integrating and Coordinating Phytotechnology Activities with Public Health Research Will Allow Technology Development Focused on Prevention of Environmental Exposures to Toxic Compounds. Hence, Phytotechnologies May Provide Sustainable Solutions to Environmental Exposure Challenges, Improving Public Health and Potentially Reducing the Burden of Disease. © 2013 Copyright Taylor and Francis Group, LLC

Climate Change Impacts on Iowa, 2010

Climate change is already affecting the way Iowans live and work. Without action to mitigate these effects, our future responses will become more complex and costly . The following policy recommendations are offered as initial steps to help safeguard our state’s economy, environment, and residents

New hydroxylated metabolites of 4-monochlorobiphenyl in whole poplar plants

Two new monohydroxy metabolites of 4-monochlorobiphenyl (CB3) were positively identified using three newly synthesized monohydroxy compounds of CB3: 2-hydroxy-4-chlorobiphenyl (2OH-CB3), 3-hydroxy-4-chlorobiphenyl (3OH-CB3) and 4-hydroxy-3-chlorobiphenyl (4OH-CB2). New metabolites of CB3, including 2OH-CB3 and 3OH-CB3, were confirmed in whole poplars (Populus deltoides × nigra, DN34), a model plant in the application of phytoremediation. Furthermore, the concentrations and masses of 2OH-CB3 and 3OH-CB3 formed in various tissues of whole poplar plants and controls were measured. Results showed that 2OH-CB3 was the major product in these two OH-CB3s with chlorine and hydroxyl moieties in the same phenyl ring of CB3. Masses of 2OH-CB3 and 3OH-CB3 in tissues of whole poplar plants were much higher than those in the hydroponic solution, strongly indicating that the poplar plant itself metabolizes CB3 to both 2OH-CB3 and 3OH-CB3. The total yield of 2OH-CB3 and 3OH-CB3, with chlorine and hydroxyl in the same phenyl ring of CB3, was less than that of three previously found OH-CB3s with chlorine and hydroxyl in the opposite phenyl rings of CB3 (2'OH-CB3, 3'OH-CB3, and 4'OH-CB3). Finally, these two newly detected OH-CB3s from CB3 in this work also suggests that the metabolic pathway was via epoxide intermediates. These five OH-CB3s clearly showed the complete metabolism profile from CB3 to monohydroxylated CB3. More importantly, it's the first report and confirmation of 2OH-CB3 and 3OH-CB3 (new metabolites of CB3) in a living organism