Entwicklung eines Verfahrens zur direkten biologischen Umsetzung von Ammonium zu Stickstoff bei der Behandlung von Abwaessern der Anaerob-Klaerschlammfaulung - Deammonifikation Abschlussbericht

The nitrogen elimination in municipal and industrial wastewater continues to play a major role in wastewater treatment, especially since the Wastewater Directive (AbwV) from 1997 introduced several changes in the requirements and regulations in regard to the pollutant and nutrient removal. As particularly the nitrogen elimination often makes for a considerable cost factor in wastewater treatment, especially when part-streams with high nitrogen loads must be (co-)treated, there is a constant search for economically viable treatment concepts. In this research project, the method of deammonification was developed, that is the process sequence of aerobic nitritation and anoxic ammonium oxidation ('biological comproportioning' of ammonium and nitrite into molecular nitrogen), which is based completely on the metabolism processes of autotrophic micro-organisms, which leads to saving potentials, especially of the carbon demand. Because of the shortened aerobic oxidation steps and the application of biofilm technology, it is also possible to reduce the oxygen demand and the reaction volume. In regard to the purposeful application of deammonification in operation technology, the project steps were targeted to determine the process-defining parameters and to check suitable method technologies and operation control systems in greater detail. To achieve this, the crucial frame conditions for the realisation and the operation performance of the autotrophic nitrogen elimination were defined on the basis of industrial and pilot-technical examinations under consideration of the (micro-)biological connections. Eventually, directives on the establishment of a stable deammonification operation could be derived. On the one hand, we ran a stock-taking of the operation of three industrial leachate treatment plants, on the other hand we operated test-plants on sludge-water treatment. Furthermore, various examinations with different reactor configurations and purposeful initiation tests were run. Accompanying batch-tests and micro-biological analyses served mainly for the kinetic examination of the metabolisms, that is for the determination of the conversion performances and for the basic analysis of the relevant metabolism ways and the participating micro-organisms. (orig.)Die Stickstoffelimination in kommunalen und industriellen Abwaessern spielt in der Abwasserreinigung weiterhin eine bedeutende Rolle, zumal mit der Abwasserverordnung (AbwV) von 1997 einige Veraenderungen bei den Anforderungen und Regelungen hinsichtlich der Schad- und Naehrstoffentfernung vorgenommen wurden. Da gerade die Stickstoffentfernung oftmals einen erheblichen Kostenfaktor bei der Abwasserreinigung darstellt, insbesondere wenn es um die (Mit-)Behandlung hoch stickstoffbelasteter Teilstroeme geht, ist man stetig auf der Suche nach wirtschaftlichen Behandlungskonzepten. Im Rahmen des Forschungsvorhabens wurde das Verfahren der Deammonifikation entwickelt, d.h. die Prozessfolge aus aerober Nitritation und anoxischer Ammoniumoxidation ('biologische Komproportionierung' von Ammonium und Nitrit zu molekularem Stickstoff), die komplett auf den Stoffwechselprozessen autotropher Mikroorganismen beruht, wodurch sich vor allem Einsparpotentiale hinsichtlich des Kohlenstoffbedarfes ergeben. Aufgrund des verkuerzten aeroben Oxidationsschrittes und bei Anwendung der Biofilmtechnologie lassen sich zudem Sauerstoffbedarf und Reaktionsvolumen reduzieren. Im Hinblick auf einen gezielten verfahrenstechnischen Einsatz der Deammonifikation waren im Rahmen der Forschungsarbeiten die prozessbestimmenden Einflussgroessen zu bestimmen und geeignete Verfahrenstechniken und Verfahrensfuehrungen naeher zu ueberpruefen. Hierzu wurden ausgehend von gross- und pilottechnischen Untersuchungen und Erkenntnissen unter Beruecksichtigung (mikro-)biologischer Zusammenhaenge die wesentlichen Randbedingungen zur Realisierung sowie das Betriebsverhalten der autotrophen Stickstoffeliminierung definiert und letztendlich Handlungsanweisungen zur Etablierung eines stabilen Deammonifikationsbetriebes abgeleitet. Zum einen erfolgte eine Bestandsaufnahme des Betriebes dreier grosstechnischer Sickerwasserreinigungsanlagen, und zum anderen wurden gezielt Versuchsanlagen zur Schlammwasserbehandlung betrieben. Des weiteren erfolgten diverse Untersuchungen mit unterschiedlichen Reaktorkonfigurationen und gezielte Inbetriebnahmeversuche. Begleitende Batchversuche und mikrobiologische Untersuchungen dienten vor allem der kinetischen Betrachtung der Umsetzungen, d.h. der Ermittlung von Umsatzleistungen, sowie der grundlegenden Untersuchung der relevanten Stoffwechselwege und beteiligten Mikroorganismen. (orig.)SIGLEAvailable from TIB Hannover: F01B1763 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Fate of nitrogen (15N) from velvet bean in the soil-plant system Dinâmica do nitrogênio (15N) da mucuna-preta no sistema solo-planta

Because of their potential for N2 biological fixation, legumes are an alternative source of nitrogen to crops, and can even replace or supplement mineral fertilization. A greenhouse experiment was carried out to evaluate temporal patterns of velvet bean (Mucuna aterrima) green manure release of nitrogen to rice plants, and to study the fate of nitrogen from velvet bean in rice cultivation. The isotopic dilution methodology was used. Treatments consisted of a control and 10 incubation periods of soil fertilized with 15N-labeled velvet bean (0, 20, 40, 60, 90, 120, 150, 180, 210, and 240 days). The plant material was previously chopped, sifted (10 mm mesh sieve) and oven-dried (65ºC). Incubation of the plant material (2.2 g kg-1 soil) was initiated by the longest period, in order to synchronize the planting of the test crop, rice (Oryza sativa), at time zero for all treatments. Green manure incorporation promoted increases in rice dry matter yield and nitrogen uptake. These variables showed maximum values at incubation periods of 38 and 169 days, respectively. Green manure nitrogen utilization by rice plants was highest at an incubation period corresponding to 151 days. More than 60% of the green manure nitrogen remained in the soil after rice cultivation. The highest green manure nitrogen recovery from the soil-plant system occurred at an incubation period equivalent to 77 days.<br>Em função de seu potencial de fixação de nitrogênio (N), as leguminosas representam uma alternativa ao suprimento do nutriente para as culturas, substituindo ou complementando a adubação mineral. Desenvolveu-se, sob condições semi-controladas, utilizando-se de metodologia de diluição isotópica, um experimento para determinar o padrão temporal de liberação de nitrogênio da mucuna-preta (Mucuna aterrima) e estudar a dinâmica do N contido nesse adubo verde no sistema solo-planta. O estudo compreendeu um tratamento testemunha e dez períodos de incubação do solo com mucuna-preta marcada com 15N (zero, 20, 40, 60, 90, 120, 150, 180, 210 e 240 dias). O material vegetal utilizado foi picado, peneirado (peneira com abertura de malha de 10 mm) e seco em estufa. A incubação do material vegetal, na dose de 2,2 g kg-1 de solo, foi iniciada pelo período mais longo, possibilitando coincidir o plantio da cultura teste, arroz (Oryza sativa), para todos os tratamentos, no tempo zero. A incorporação de mucuna-preta promoveu aumento da produção de matéria seca e da absorção de N pelas plantas de arroz. Os valores máximos para essas variáveis foram proporcionados pelos períodos de incubação de 38 e 169 dias, respectivamente. O máximo aproveitamento de N da mucuna-preta pelo arroz correspondeu ao período de incubação de 151 dias. Mais de 60% do N do adubo verde permaneceram no solo após a colheita do arroz. A recuperação máxima de N da mucuna-preta no sistema solo-planta correspondeu a um período de incubação de 77 dias

Should kidney allografts from old donors be allocated only to old recipients?

Item does not contain fulltextIn several deceased donor kidney allocation systems, organs from elderly donors are allocated primarily to elderly recipients. The Eurotransplant Senior Program (ESP) was implemented in 1999, and since then, especially in Europe, the use of organs from elderly donors has steadily increased. The proportion of ≥60-year-old donors reported to the Collaborative Transplant Study (CTS) by European centers has doubled, from 21% in 2000-2001 to 42% in 2016-2017. Therefore, in the era of organ shortage it is a matter of debate whether kidney organs from elderly donors should only be allocated to elderly recipients or whether <65-year-old recipients can also benefit from these generally as "marginal" categorized organs. To discuss this issue, a European Consensus Meeting was organized by the CTS on April 12, 2018, in Heidelberg, in which 36 experts participated. Based on available evidence, it was unanimously concluded that kidney organs from 65- to 74-year-old donors can also be allocated to 55- to 64-year-old recipients, especially if these organs are from donors with no history of hypertension, no increased creatinine, no cerebrovascular death, and no other reasons for defining a marginal donor, such as diabetes or cancer

Jet production in highQ 2 deep-inelastic ep scattering at HERA

Two-jet production in deep-inelastic electron-proton scattering has been studied for $160<Q^2<1280$~GeV$^2$, $0.01<x<0.1$ and $0.04<y<0.95$ with the ZEUS detector at HERA. The kinematic properties of the jets and the jet production rates are presented. The partonic scaling variables of the two-jet system and the rate of two-jet production are compared to perturbative next-to-leading order QCD calculations.Comment: 26 pages, latex, 9 figures appended as uuencoded fil

Search for new Higgs bosons via same-sign top quark pair production in association with a jet in proton-proton collisions at s=13TeV

A search is presented for new Higgs bosons in proton-proton (pp) collision events in which a same-sign top quark pair is produced in association with a jet, via the pp→tH/A→ttc‾ and pp→tH/A→ttu‾ processes. Here, H and A represent the extra scalar and pseudoscalar boson, respectively, of the second Higgs doublet in the generalized two-Higgs-doublet model (g2HDM). The search is based on pp collision data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 138fb−1. Final states with a same-sign lepton pair in association with jets and missing transverse momentum are considered. New Higgs bosons in the 200–1000 GeV mass range and new Yukawa couplings between 0.1 and 1.0 are targeted in the search, for scenarios in which either H or A appear alone, or in which they coexist and interfere. No significant excess above the standard model prediction is observed. Exclusion limits are derived in the context of the g2HDM

Search for new heavy resonances decaying to WW, WZ, ZZ, WH, or ZH boson pairs in the all-jets final state in proton-proton collisions at s=13TeV

A search for new heavy resonances decaying to WW, WZ, ZZ, WH, or ZH boson pairs in the all-jets final state is presented. The analysis is based on proton-proton collision data recorded by the CMS detector in 2016–2018 at a centre-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 138fb−1. The search is sensitive to resonances with masses between 1.3 and 6TeV, decaying to bosons that are highly Lorentz-boosted such that each of the bosons forms a single large-radius jet. Machine learning techniques are employed to identify such jets. No significant excess over the estimated standard model background is observed. A maximum local significance of 3.6 standard deviations, corresponding to a global significance of 2.3 standard deviations, is observed at masses of 2.1 and 2.9 TeV. In a heavy vector triplet model, spin-1 Z′ and W′ resonances with masses below 4.8TeV are excluded at the 95% confidence level (CL). These limits are the most stringent to date. In a bulk graviton model, spin-2 gravitons and spin-0 radions with masses below 1.4 and 2.7TeV, respectively, are excluded at 95% CL. Production of heavy resonances through vector boson fusion is constrained with upper cross section limits at 95% CL as low as 0.1fb