What makes a volatile organic compound a reliable indicator of insect herbivory?
Douma, Jacob C. ; Ganzeveld, Laurens N. ; Unsicker, Sybille B. ; Boeckler, Andreas ; Dicke, Marcel - \ 2019
Plant, Cell & Environment 42 (2019)12. - ISSN 0140-7791 - p. 3308 - 3325.
biogenic volatile organic compound (BVOC) - emission - herbivore induced plant volatile (HIPV) - hydroxyl radical - nitrate radical - oxidation - ozone - Populus nigra
Plants that are subject to insect herbivory emit a blend of so-called herbivore-induced plant volatiles (HIPVs), of which only a few serve as cues for the carnivorous enemies to locate their host. We lack understanding which HIPVs are reliable indicators of insect herbivory. Here, we take a modelling approach to elucidate which physicochemical and physiological properties contribute to the information value of a HIPV. A leaf-level HIPV synthesis and emission model is developed and parameterized to poplar. Next, HIPV concentrations within the canopy are inferred as a function of dispersion, transport and chemical degradation of the compounds. We show that the ability of HIPVs to reveal herbivory varies from almost perfect to no better than chance and interacts with canopy conditions. Model predictions matched well with leaf-emission measurements and field and laboratory assays. The chemical class a compound belongs to predicted the signalling ability of a compound only to a minor extent, whereas compound characteristics such as its reaction rate with atmospheric oxidants, biosynthesis rate upon herbivory and volatility were much more important predictors. This study shows the power of merging fields of plant–insect interactions and atmospheric chemistry research to increase our understanding of the ecological significance of HIPVs.
Balance of Emission and Dynamical Controls on Ozone During the Korea-United States Air Quality Campaign From Multiconstituent Satellite Data Assimilation
Miyazaki, K. ; Sekiya, T. ; Fu, D. ; Bowman, K.W. ; Kulawik, S.S. ; Sudo, K. ; Walker, T. ; Kanaya, Y. ; Takigawa, M. ; Ogochi, K. ; Eskes, H. ; Boersma, K.F. ; Thompson, A.M. ; Gaubert, B. ; Barre, J. ; Emmons, L.K. - \ 2019
Journal of Geophysical Research: Atmospheres 124 (2019)1. - ISSN 2169-897X - p. 387 - 413.
air quality - Asia - data assimilation - emission - ozone - satellite
Global multiconstituent concentration and emission fields obtained from the assimilation of the satellite retrievals of ozone, CO, NO2, HNO3, and SO2 from the Ozone Monitoring Instrument (OMI), Global Ozone Monitoring Experiment 2, Measurements of Pollution in the Troposphere, Microwave Limb Sounder, and Atmospheric Infrared Sounder (AIRS)/OMI are used to understand the processes controlling air pollution during the Korea-United States Air Quality (KORUS-AQ) campaign. Estimated emissions in South Korea were 0.42 Tg N for NOx and 1.1 Tg CO for CO, which were 40% and 83% higher, respectively, than the a priori bottom-up inventories, and increased mean ozone concentration by up to 7.5 ± 1.6 ppbv. The observed boundary layer ozone exceeded 90 ppbv over Seoul under stagnant phases, whereas it was approximately 60 ppbv during dynamical conditions given equivalent emissions. Chemical reanalysis showed that mean ozone concentration was persistently higher over Seoul (75.10 ± 7.6 ppbv) than the broader KORUS-AQ domain (70.5 ± 9.2 ppbv) at 700 hPa. Large bias reductions (>75%) in the free tropospheric OH show that multiple-species assimilation is critical for balanced tropospheric chemistry analysis and emissions. The assimilation performance was dependent on the particular phase. While the evaluation of data assimilation fields shows an improved agreement with aircraft measurements in ozone (to less than 5 ppbv biases), CO, NO2, SO2, PAN, and OH profiles, lower tropospheric ozone analysis error was largest at stagnant conditions, whereas the model errors were mostly removed by data assimilation under dynamic weather conditions. Assimilation of new AIRS/OMI ozone profiles allowed for additional error reductions, especially under dynamic weather conditions. Our results show the important balance of dynamics and emissions both on pollution and the chemical assimilation system performance.
Ruijven, J. van; Os, E. van; Beerling, E. ; Staaij, M. van der - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1419) - 42
kasgewassen - kassen - glastuinbouw - afvoer - zuiveren - gewasbescherming - ozon - greenhouse crops - greenhouses - greenhouse horticulture - discharge - purification - plant protection - ozone
To apply to the Dutch generic obligation to purify discharge water, each horticultural company needs to treat it’s discharge water with a technology that removes 95% of plant protection products. This report shows the process that growers need to go through to make a good choice for a purification technology: mapping of water flows, decrease the amount of discharge water, determine the strategy to apply to the generic obligation and make a choice for a purification technology. For a cucumber production company and a company that combines vegetable plant propagation and growth of potted plants this process is followed. A design for a purification system is developed and built for a semi-practice scale cucumber and sweet pepper production system. In the semi-practice scale and the cucumber production company, an ozone installation (Agrozone) is chosen, either to disinfect drain water and eventually purify discharge water. At the propagation company, an Opticlear Diamond (WaterIQ) is chosen to disinfect the drain water and eventually purify discharge water. For both installations the purification efficacy is measured. In the second part of the project the practical format for the generic obligation for discharge water purification is elaborated.
Evaluatie zuiveringstechniek voor verwijdering gewasbeschermingsmiddelen III
Ruijven, J.P.M. van; Beerling, E.A.M. ; Staaij, M. van der; Os, E.A. van - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1414) - 30
afvalwaterbehandeling - waterzuivering - afvalwater - waterverontreiniging - glastuinbouw - kassen - cultuur zonder grond - gewasbescherming - pesticiden - ozon - verwijdering - filtratie - technieken - waste water treatment - water treatment - waste water - water pollution - greenhouse horticulture - greenhouses - soilless culture - plant protection - pesticides - ozone - removal - filtration - techniques
Dutch greenhouse horticulture has to treat all discharged water from soilless cultivations for the removal of plant protection products, to meet the new Dutch Directive Hoofdlijnenakkoord (2015). Building on previous research, (1) the life span of activated carbon filters, (2) the effect of increasing concentrations of plant protection products on the removal efficacy of ozone and the removal efficacy of (3) multimedia filtration and (4) ultrasonic water treatment have been investigated. It turned out to be difficult to design an active carbon based water treatment system capable of durable treatment of greenhouse discharge water: organic and mineral material in the water blocked the pores, thereby clogging the filter system and causing leakage by pressure build-up. Activated carbon filtration (granular activated carbon, 48 min contact time, 50 μm prefiltration with sand filter) achieved a removal efficacy of >95% for up to 430 bed volumes treated. Combination with advanced oxidation improved the removal efficacy, but the removal time of the filter could not be determined due to leakage. The removal efficacy of ozone oxidation remained >98%, even at increased concentrations (factor 10 and 100) of plant protection products in the untreated water. The multimedia filter removed 75% of the plant protection products by adsorption, biological breakdown within the filter was not determined. Treatment of the water with ultrasonic waves hardly had any effect (maximum 30% efficacy) on the breakdown.
Paprikateelt in emissieloze kas haalt gelijke productie met zelfde kwaliteit : ‘bewustwording bij telers moet omhoog’
Beerling, Ellen ; Os, Erik van - \ 2016
horticulture - greenhouse horticulture - greenhouse technology - vegetables - capsicum - sweet peppers - emission reduction - agricultural research - water reuse - drainage water - water filters - disinfection - ozone - substrates - crop production
Als de proef met emissieloos telen één ding heeft duidelijk gemaakt, is het wel dat water meer vertrouwen verdient, menen Wageningen UR onderzoekers Ellen Beerling en Erik van Os. “Als we er bewust mee om gaan, neemt de noodzaak om te lozen aanzienlijk af.” De paprikateelt in het IDC Water in Bleiswijk verliep met volledige recirculatie van water en presteerde zeker niet minder dan de referentieteelt.
Exploring feedbacks between air pollution and climate policy
Chuwah, C.D. - \ 2015
Wageningen University. Promotor(en): Wilco Hazeleger; D. van Vuuren, co-promotor(en): T.P.C. van Noije. - Wageningen : Wageningen University - ISBN 9789462575547 - 122
luchtverontreiniging - klimaat - beleid - ozon - klimaatverandering - modellen - emissie - air pollution - climate - policy - ozone - climatic change - models - emission
The climate of the Earth is changing in response to natural and anthropogenic forcing agents. Emissions of greenhouse gases and air pollutants have led to significant changes in the Earth’s climate systems and projections indicate that further extensive changes are likely. Increased scientific understanding into the processes responsible for climate change and the possible consequences of assumptions regarding future climate and air pollution policy is important to formulate effective response strategies based on mitigation and adaptation. Earth System Models (ESMs) can be used to make climate projections based on emissions or concentrations projections for greenhouse gasses and aerosols derived from socio-economic scenarios. Such scenarios are produced by Integrated Assessment Models (IAMs), based on detailed descriptions of population growth, energy demand and land use.
There has been increasing interest in coupling different disciplines involved in climate research. The current cooperation efforts among scientists from different disciplines have led to an improved representation of climate forcings in ESMs, and of climate responses impacts in IAMs. In this thesis, we contribute to this cooperation by exploring the consequences of emission scenarios under different assumptions regarding air pollution and climate policy.
To do so, we utilize a set of scenarios similar to the Representative Concentration Pathways (RCPs), developed using the IAM IMAGE. These scenarios combine scenarios with radiative forcing targets in 2100 of 2.6 W/m2 and 6.0 W/m2 with different assumptions for air pollution policies (low/high). These scenarios are subsequently used in the global atmospheric chemistry and transport model TM5. Results reveal that both climate and air pollution control policies have large-scale impacts on pollutant concentrations, often of comparable magnitude. We also find that air pollution control measures could, on a global scale, significantly reduce the warming induced by tropospheric ozone and black carbon and the cooling resulting from sulphate in the coming decades. These effects tend to cancel each other on a global scale.
Next, we evaluate the equilibrium climate response to aerosol reductions in different parts of the world in 2050, using the global climate model EC-Earth. Reductions in aerosol concentrations increase downward surface solar radiation and surface temperature concomitantly in various parts of the world. The increase in surface temperature is dominated by the reduced cooling effect of sulphate which in some areas is partially compensated by the decreased warming effect of black carbon. Also, we find that aerosol reductions can significantly affect climate at high latitudes especially in the winter, mostly as a result of teleconnections between the low and high latitudes.
Due to the inhomogeneous spatial distributions of air pollutants, changes in their emissions can have strong regional climate impacts. Using EC-Earth, we assess in Chapter 4 the effectiveness of different aerosol forcing agents in causing climate change in 2050. Our results show that different anthropogenic aerosol components may have a broad range ofefficacies. The results also reveal that there are large interhemispheric differences in aerosol forcings, which result in changes in circulation patterns.
By using surface ozone concentrations simulated by TM5 as input to IMAGE, we estimate ozone impacts on crop production, and subsequent impacts on land use and carbon fluxes in 2005 and 2050. In the absence of new climate and air pollution policies, higher ozone concentrations could lead to an increase in crop damage in 2050 compared to present day. This may lead to a global increase in crop area notably in Asia. Implementation of air pollution policies and climate policies (co-benefits of reducing ozone precursor emissions) could limit future crop yield losses due to ozone in the most affected regions. At the local scale, the changes can be substantial.
Oppervlakte-ontsmetting door oxidatie met waterstofperoxide of ozon
Schoorl, F.W. - \ 2014
Lisse : Praktijkonderzoek Plant & Omgeving, Business Unit Bloembollen, Boomkwekerij & Fruit - 53
appels - peren - opslag - gewasbescherming - desinfectie - vruchtrot - toepassingen - waterstofperoxide - ozon - schimmelbestrijding - landbouwkundig onderzoek - apples - pears - storage - plant protection - disinfection - fruit rots - applications - hydrogen peroxide - ozone - fungus control - agricultural research
Het optreden van vruchtrot kan leiden tot aanzienlijke verliezen van geoogste en opgeslagen appels en peren. Fungiciden worden doorgaans gebruikt om deze verliezen te beperken. Ondanks toepassing van fungiciden komt het optreden van vruchtrot voor. Verschillende winkelketens hanteren normen met betrekking tot de aanwezigheid van residuen van gewasbeschermingsmiddelen die boven de wettelijke normen liggen. Naast wettelijke normen vormt dit een extra aanleiding om te komen tot aangepaste werkwijze ter bestrijding van vruchtrot schimmels. Meerdere schimmels zijn verantwoordelijk voor het optreden van vruchtrot. Daaronder zijn ook schimmels die via het oppervlak van de vruchten, veelal via een wond, vruchten infecteren. Bij de oogst kunnen, afhankelijk van de zorgvuldigheid waarmee geplukt wordt, wonden optreden die een invalspoort vormen voor schimmels. In dit project is aandacht besteed aan het voorkomen van infecties.
Ozon bezig aan stille wederopstanding in de tuinbouw
Ruijven, J.P.M. van - \ 2014
Kas techniek (2014)9. - p. 26 - 29.
glastuinbouw - waterzuivering - irrigatiewater - ozon - technieken - recirculatiesystemen - desinfectie - pesticiden - methodologie - greenhouse horticulture - water treatment - irrigation water - ozone - techniques - recirculating systems - disinfection - pesticides - methodology
Ozon lijkt een comeback te maken binnen de glastuinbouw. Waar de ontsmettingsinstallaties vorige eeuw nogal eens te maken hadden met storingen en veiligheidsproblemen, lijken die aspecten tegenwoordig beter onder controle. Dit maakt de weg vrij voor andere toepassingen van de techniek dan alleen ontsmetting. Agrozone onderzoekt momenteel samen met Wageningen UR Glastuinbouw wat de toepassingsmogelijkheden zijn.
Meteorology during the DOMINO campaign and its connection with trace gases and aerols
Adame, J.A. ; Martinez, M. ; Sorribas, M. ; Hidalgo, P.J. ; Vilà-Guerau de Arellano, J. - \ 2014
Atmospheric Chemistry and Physics 14 (2014). - ISSN 1680-7316 - p. 2325 - 2342.
oh reactivity measurements - particulate matter - spain - air - variability - emissions - origin - ozone - pm10 - site
The DOMINO (Diel Oxidant Mechanisms in relation to Nitrogen Oxides) campaign was carried out from 21 November to 8 December 2008 at the El Arenosillo station (SW of Spain) in a coastal-rural environment. The main weather conditions are analysed using local meteorological variables, meteorological soundings and synoptic maps, as well as back trajectories of the air masses using the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory Model) model and a high spatial resolution of meteorological fields. Measurements of the main meteorological parameters were collected both from the surface and from a tall tower. A detailed land use analysis was performed on a 80 km scale showing the main types of vegetation and land use. Also the main anthropogenic atmospheric emission sources – both industrial-urban from Huelva and from the urban Seville area – are shown. A study to identify air mass origins and their variation with height was carried out. In this intensive campaign, air masses coming from different areas with different emission sources were observed: from the NW, with a highly industrial-urban character; continental flows from northerly directions; from the NE, with a pathway starting over the Seville metropolitan area and then continuing over the Doñana National Park; and maritime air masses coming from the Atlantic Ocean. To study the chemistry in the four atmospheric scenarios identified, gas -phase measurements of primary and secondary species such as ozone, NO, NO2 and SO2, biogenic and anthropogenic VOCs (volatile organic compounds) like benzene and isoprene, as well as total particle concentration and chemical composition of the aerosols are compared and discussed. The highest levels for total particle concentration, NO, NO2, SO2, benzene, PM10, PM2.5 and chemical elements such as As or Cu were found under flows associated with industrial-urban emissions from the Huelva–Portugal sector which are transported to the site before significant removal by chemical or deposition mechanism can occur. The air masses from the north were affected mainly by crustal elements and biogenic sources, the latter being exemplified by the biogenic species such as isoprene, particularly in the first part of the campaign. The urban air from the Seville area, before arriving at El Arenosillo, traversed the Doñana National Park and therefore was affected by industrial-urban and biogenic emissions. This aged air parcel can transport low levels of NOx, total particle concentration and SO2 as well as ozone and isoprene. Marine air masses from the Atlantic Ocean influence El Arenosillo frequently. Under these conditions, the lowest levels of almost all the species – with the exception of ozone levels associated to long-range transport – were measured
TransCom model simulations of methane: Comparison of vertical profiles with aircraft measurements
Saito, R. ; Patra, P.K. ; Sweeney, C. ; Machida, T. ; Krol, M.C. ; Houweling, S. ; Bousquet, P. ; Agusti-Panareda, A. ; Belikov, D. ; Bergmann, D. ; Bian, H.S. ; Cameron-Smith, P. ; Chipperfield, M.P. ; Fortems-Cheiney, A. ; Fraser, A. ; Gatti, L.V. ; Gloor, E. ; Hess, P. ; Kawa, S.R. ; Law, R.M. ; Locatelli, R. ; Loh, Z. ; Maksyutov, S. ; Meng, L. ; Miller, J.B. ; Palmer, P.I. ; Prinn, R.G. ; Rigby, M. ; Wilson, C. - \ 2013
Journal of Geophysical Research: Atmospheres 118 (2013)9. - ISSN 2169-897X - p. 3891 - 3904.
chemical-transport model - atmospheric co2 - troposphere - stratosphere - variability - sensitivity - version - ozone - flux - air
To assess horizontal and vertical transports of methane (CH4) concentrations at different heights within the troposphere, we analyzed simulations by 12 chemistry transport models (CTMs) that participated in the TransCom-CH4 intercomparison experiment. Model results are compared with aircraft measurements at 13 sites in Amazon/Brazil, Mongolia, Pacific Ocean, Siberia/Russia, and United States during the period of 2001-2007. The simulations generally show good agreement with observations for seasonal cycles and vertical gradients. The correlation coefficients of the daily averaged model and observed CH4 time series for the analyzed years are generally larger than 0.5, and the observed seasonal cycle amplitudes are simulated well at most sites, considering the between-model variances. However, larger deviations show up below 2 km for the model-observation differences in vertical profiles at some locations, e.g., at Santarem, Brazil, and in the upper troposphere, e.g., at Surgut, Russia. Vertical gradients and concentrations are underestimated at Southern Great Planes, United States, and Santarem and overestimated at Surgut. Systematic overestimation and underestimation of vertical gradients are mainly attributed to inaccurate emission and only partly to the transport uncertainties. However, large differences in model simulations are found over the regions/seasons of strong convection, which is poorly represented in the models. Overall, the zonal and latitudinal variations in CH4 are controlled by surface emissions below 2.5 km and transport patterns in the middle and upper troposphere. We show that the models with larger vertical gradients, coupled with slower horizontal transport, exhibit greater CH4 interhemispheric gradients in the lower troposphere. These findings have significant implications for the future development of more accurate CTMs with the possibility of reducing biases in estimated surface fluxes by inverse modeling.
Consequences of human modification of the global nitrogen cycle
Erisman, J.W. ; Galloway, J. ; Seitzinger, S. ; Bleeker, A. ; Dise, N.B. ; Roxana Petrescu, A.M. ; Leach, A.M. ; Vries, W. de - \ 2013
Philosophical Transactions of the Royal Society B. Biological sciences 368 (2013)1621. - ISSN 0962-8436 - 9 p.
aquatic ecosystems - reactive nitrogen - climate-change - ozone - pollution - impact - policy - growth - oxide
The demand for more food is increasing fertilizer and land use, and the demand for more energy is increasing fossil fuel combustion, leading to enhanced losses of reactive nitrogen (Nr) to the environment. Many thresholds for human and ecosystem health have been exceeded owing to Nr pollution, including those for drinking water (nitrates), air quality (smog, particulate matter, ground-level ozone), freshwater eutrophication, biodiversity loss, stratospheric ozone depletion, climate change and coastal ecosystems (dead zones). Each of these environmental effects can be magnified by the ‘nitrogen cascade’: a single atom of Nr can trigger a cascade of negative environmental impacts in sequence. Here, we provide an overview of the impact of Nr on the environment and human health, including an assessment of the magnitude of different environmental problems, and the relative importance of Nr as a contributor to each problem. In some cases, Nr loss to the environment is the key driver of effects (e.g. terrestrial and coastal eutrophication, nitrous oxide emissions), whereas in some other situations nitrogen represents a key contributor exacerbating a wider problem (e.g. freshwater pollution, biodiversity loss). In this way, the central role of nitrogen can remain hidden, even though it actually underpins many trans-boundary pollution problems.
A meta-database comparison from various European research networks dedicated to forests sites
Danielewska, A. ; Clarke, N. ; Olejnik, J. ; Hansen, K. ; Vries, W. de - \ 2013
iForest : Biogeosciences and Forestry 6 (2013). - ISSN 1971-7458 - p. 1 - 9.
nitrogen deposition - terrestrial ecosystems - anthropogenic sources - air-pollutants - climate-change - united-states - heavy-metals - carbon - ozone - pollution
Of a wide variety of international forest research and monitoring networks, several networks are dedicated to the effects of climate change on forests, while the effects of anthropogenic pollutants on forests have been a major area for both monitoring and research for decades. The large amounts of data already obtained within existing monitoring programmes and large-scale international projects can be used to increase understanding of the state and potential of forest mitigation and adaptation to climate change in a polluted environment, and a major challenge now is to evaluate and integrate the presently available databases. We present a meta-database with the main goal to highlight available data and integrate the information about research and monitoring of selected European Research and Monitoring Networks (ERMNs). Depending on the selected ERMNs, the list of variables and the measurement units differ widely in the databases. As a result, activities related to the identification, evaluation and integration of the presently available databases are important for the scientific community. Furthermore, and equally important, the recognition of current knowledge gaps and future needed research is made easier. This analysis suggests that: ground-level ozone is under-investigated, although it is one of the pollutants of greatest concern to forests; in addition to CO2, long-term other greenhouse gasses (GHG) flux measurements should be carried out; there is still a need of improving links between monitoring of atmospheric changes and impacts on forests; research-oriented manipulative experiments in the forests are missing.
Effect van ozontoepassing in lange bewaring Conference
Geijn, F.G. van de - \ 2012
Wageningen : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research nr. 1321) - ISBN 9789461732620 - 13
fruitteelt - gewasbescherming - chemische bewaring - houdbaarheid (kwaliteit) - peren - vruchtrot - bewaarziekten - ozon - bewaarfysiologie - fruit growing - plant protection - chemical preservation - keeping quality - pears - fruit rots - storage disorders - ozone - postharvest physiology
Ozon toepassing heeft op basis van deze proef en voorliggende ervaringen geen grote effecten in de reductie van rot en schimmels bij langdurige Conference bewaring. Gezien het beperkte effect op rot onderdrukking op één van de herkomsten met een hoger aantastingspercentage rot kan ook niet gesteld worden dat ozon geheel geen effect heeft. Elektrolyse water in de kwaliteit zoals voor deze proef gebruikt heeft een sterk nadelig effect op de kwaliteit door het optreden van een schilverkleuring (scald achtig). In positieve zin zijn geen kwaliteitsvoordelen opgedaan dus kan gesteld worden dat deze techniek niet kansrijk is. In technische zin blijkt het mogelijk om CA bewaring te combineren met een dosering van ozon. Bij desgewenste hogere ozon concentraties zullen de CA condities waarschijnlijk wel beïnvloed worden door teveel O3 inbreng.
Ozon toepassing bij de lange bewaring van Rode bes
Geijn, F.G. van de; Staal, M.G. - \ 2012
Wageningen UR Food & Biobased Research : Wageningen UR - Food & Biobased Research (Rapport / Wageningen UR Food & Biobased Research nr. 1320) - ISBN 9789461732613 - 13
ribes rubrum - rode aalbessen - gasbewaring - ozon - behandeling na de oogst - bewaartijd - opslagkwaliteit - nederland - ribes rubrum - red currants - controlled atmosphere storage - ozone - postharvest treatment - storage life - storage quality - netherlands
Onderzoek naar de mogelijkheden van toepassing van Ozon in de lange bewaring van rode bessen.
A novel photocatalytic conversion of Tryptophan to Kynurenine using black light as a light source
Hamdy Mohamed Saad, M.S. ; Scott, E.L. ; Carr, R.H. ; Sanders, J.P.M. - \ 2012
Catalysis Letters 142 (2012)3. - ISSN 1011-372X - p. 338 - 344.
amino-acids - human lens - photooxidation products - wool proteins - photochemistry - constituents - degradation - ozone - mass
The photocatalytic conversion of an aqueous solution of l-tryptophan (Trp) to kynurenine (KN) was investigated under the illumination of different light sources. Results show that Trp converted to KN with a selectivity of 64% under the illumination of a medium pressure (MP) Hg lamp. KN selectivity was increased to >90% when black light (BL) was used a light source. The novel use of BL in the photocatalytic conversion of Trp to KN significantly reduces the energy consumption compared with MP light
Inverse modelling of European N2O emissions: assimilating observations from different networks
Corazza, M. ; Bergamaschi, P. ; Vermeulen, A.T. ; Krol, M.C. - \ 2011
Atmospheric Chemistry and Physics 11 (2011)5. - ISSN 1680-7316 - p. 2381 - 2398.
nitrous-oxide - atmospheric methane - ozone - gases
We describe the setup and first results of an inverse modelling system for atmospheric N2O, based on a four-dimensional variational (4DVAR) technique and the atmospheric transport zoom model TM5. We focus in this study on the European domain, utilizing a comprehensive set of quasi-continuous measurements over Europe, complemented by N2O measurements from the Earth System Research Laboratory of the National Oceanic and Atmospheric Administration (NOAA/ESRL) cooperative global air sampling network. Despite ongoing measurement comparisons among networks parallel measurements at a limited number of stations show that significant offsets exist among the different laboratories. Since the spatial gradients of N2O mixing ratios are of the same order of magnitude as these biases, the direct use of these biased datasets would lead to significant errors in the derived emissions. Therefore, in order to also use measurements with unknown offsets, a new bias correction scheme has been implemented within the TM5-4DVAR inverse modelling system, thus allowing the simultaneous assimilation of observations from different networks. The N2O bias corrections determined in the TM5-4DVAR system agree within ~0.1 ppb (dry-air mole fraction) with the bias derived from the measurements at monitoring stations where parallel NOAA discrete air samples are available. The N2O emissions derived for the northwest European and east European countries for 2006 show good agreement with the bottom-up emission inventories reported to the United Nations Framework Convention on Climate Change (UNFCCC). Moreover, the inverse model can significantly narrow the uncertainty range reported in N2O emission inventories for these countries, while the lack of measurements does not allow to reduce the uncertainties of emission estimates in southern Europe. Several sensitivity experiments were performed to test the robustness of the results. It is shown that also inversions without detailed a priori spatio-temporal emission distributions are capable to reproduce major regional emission patterns within the footprint of the existing atmospheric network, demonstrating the strong constraints of the atmospheric observations on the derived emissions
Removal of micropollutants from aerobically treated grey water via ozone and activated carbon
Hernandez Leal, L. ; Temmink, B.G. ; Zeeman, G. ; Buisman, C.J.N. - \ 2011
Water Research 45 (2011)9. - ISSN 0043-1354 - p. 2887 - 2896.
afvalwaterbehandeling - waterzuivering - verontreinigende stoffen - verwijdering - afvalwater - aërobe behandeling - ozon - actieve kool - processors - vergelijkend onderzoek - waste water treatment - water treatment - pollutants - removal - waste water - aerobic treatment - ozone - activated carbon - processors - comparative research - endocrine-disrupting chemicals - waste-water - uv filters - organic-compounds - bisphenol-a - in-vitro - pharmaceuticals - ozonation - products - vivo
Ozonation and adsorption onto activated carbon were tested for the removal micropollutants of personal care products from aerobically treated grey water. MilliQ water spiked with micropollutants (100–1600 µgL-1) was ozonated at a dosing rate of 1.22. In 45 min, this effectively removed (>99%): Four parabens, bisphenol-A, hexylcinnamic aldehyde, 4-methylbenzylidene-camphor (4MBC), benzophenone-3 (BP3), triclosan, galaxolide and ethylhexyl methoxycinnamate. After 60 min, the removal efficiency of benzalkonium chloride was 98%, tonalide and nonylphenol 95%, octocrylene 92% and 2-phenyl-5-benzimidazolesulfonic acid (PBSA) 84%. Ozonation of aerobically treated grey water at an applied ozone dose of 15 mgL-1, reduced the concentrations of octocrylene, nonylphenol, triclosan, galaxolide, tonalide and 4-methylbenzylidene-camphor to below limits of quantification, with removal efficiencies of at least 79%. Complete adsorption of all studied micropollutants onto powdered activated carbon (PAC) was observed in batch tests with milliQ water spiked with 100–1600 µgL-1 at a PAC dose of 1.25 gL-1 and a contact time of 5 min. Three granular activated carbon (GAC) column experiments were operated to treat aerobically treated grey water. The operation of a GAC column with aerobically treated grey water spiked with micropollutants in the range of 0.1–10 µgL-1 at a flow of 0.5 bed volumes (BV)h-1 showed micropollutant removal efficiencies higher than 72%. During the operation time of 1728 BV, no breakthrough of TOC or micropollutants was observed. Removal of micropollutants from aerobically treated grey water was tested in a GAC column at a flow of 2 BVh-1. Bisphenol-A, triclosan, tonalide, BP3, galaxolide, nonylphenol and PBSA were effectively removed even after a stable TOC breakthrough of 65% had been reached. After spiking the aerobically treated effluent with micropollutants to concentrations of 10–100 µgL-1, efficient removal to below limits of quantification continued for at least 1440 BV. Both ozonation and adsorption are suitable techniques for the removal of micropollutants from aerobically treated grey water.
De invloed van ozon op de alternatieve ademhaling en carbon use efficiency : evaluatie van de bevindingen van crops advance
Werf, A.K. van der; Dueck, T.A. ; Snel, J.F.H. - \ 2011
Wageningen : Plant Research International (Rapport / Plant Research International 391) - 20
plantenontwikkeling - tuinbouwgewassen - ozon - stress - ademhaling - rozen - glastuinbouw - plant development - horticultural crops - ozone - stress - respiration - roses - greenhouse horticulture
Door Crops Advance zijn waarnemingen gedaan en is onderzoek uitgevoerd waaruit blijkt dat de aanwezigheid van ozon, met name in de kritische vroeg vegetatieve groeifase van gewassen, veel grotere schade tot gevolg heeft dan tot dusver bekend is of aangenomen wordt. Een verband werd gelegd tussen het tijdstip waarop rozen worden gestekt en de groei en productie gedurende een aantal jaren. Planten die gestekt en opgekweekt werden op een tijdstip met verhoogde stress (met hogere ozonconcentraties), groeiden minder in de latere teelt(en). Voor Nederland is door het RIVM een jaarlijkse toename (2%) in ozon voorspeld, waardoor de mogelijke consequenties voor de tuinbouw alsmaar groter kunnen worden.
Small Interannual Variability of Global Atmospheric Hydroxyl
Montzka, S.A. ; Krol, M.C. ; Dlugokencky, E. ; Hall, B. ; Jöckel, P. ; Lelieveld, J. - \ 2011
Science 331 (2011)6013. - ISSN 0036-8075 - p. 67 - 69.
methyl chloroform - carbon-monoxide - tropospheric oh - (co)-c-14 - chemistry - emissions - abundance - capacity - radicals - ozone
The oxidizing capacity of the global atmosphere is largely determined by hydroxyl (OH) radicals and is diagnosed by analyzing methyl chloroform (CH3CCl3) measurements. Previously, large year-to-year changes in global mean OH concentrations have been inferred from such measurements, suggesting that the atmospheric oxidizing capacity is sensitive to perturbations by widespread air pollution and natural influences. We show how the interannual variability in OH has been more precisely estimated from CH3CCl3 measurements since 1998, when atmospheric gradients of CH3CCl3 had diminished as a result of the Montreal Protocol. We infer a small interannual OH variability as a result, indicating that global OH is generally well buffered against perturbations. This small variability is consistent with measurements of methane and other trace gases oxidized primarily by OH, as well as global photochemical model calculations.
Gerichte stress kan weerbaarheid van de plant wellicht versterken
Kierkels, T. ; Stevens, L. - \ 2010
Onder Glas 7 (2010)2. - p. 65 - 65.
stress - stressfactoren - spanningen - eiwitten - rood licht - ozon - glastuinbouw - uv-lampen - stress - stress factors - stresses - proteins - red light - ozone - greenhouse horticulture - uv lamps
Een plant die in de stress raakt, kan weerbaarheidseiwitten aanmaken. Daardoor wordt hij sterker in de straijd tegen schimmels en insecten. Wageningen UR onderzoekt hoe de plant geprikkeld kan worden om meer van die eiwitten aan te maken. Het kan misschien tot een nieuwe innovatieve tak van gewasbescherming uitgroeien