1,366 research outputs found
Ecotoxicity of raw and treated effluents generated by a veterinary medicine industry
Effluents from veterinary pharmaceutical industries that formulate medicines are mainly generated during the washing of equipment. The aim of this work was to evaluate the acute toxicity to Daphnia similis and chronic toxicity to Ceriodaphnia dubia of raw and treated effluents generated by a veterinary pharmaceutical industry. The industrial effluent treatment system comprises a step of chemical treatment (coagulation-sedimentation forced) followed by aerobic biological treatment (activated sludge process). Five samplings campaigns were performed from October 2011 to July 2012. The raw effluent samples showed high acute and chronic toxicity (acute: fourth sampling with EC50 - 48-h of <0.001% and chronic: third sampling with IC50 - 7-d of <0.0001%). The chemically treated effluent samples were the most toxic with EC50 - 48-h between <0.001 and 0.1% and IC50 - 7-d between 0.00001 and 0.0001%. This increase in toxicity is probably related to the use of aluminum sulfate as flocculating agent. The biological treatment led to a small reduction in toxicity of the effluents. The selected ecotoxicological tests were adequate for detecting the effluent toxicity and useful for evaluating the efficiency of the steps of the effluent treatment. Improvements in the industrial wastewater treatment system should be implemented in order to reduce the observed toxicity of the final effluent.Efluentes de indústrias farmacêuticas veterinárias, que formulam medicamentos, são gerados principalmente durante a lavagem dos equipamentos. O objetivo desse trabalho foi avaliar a toxicidade aguda para Daphnia similis e crônica para Ceriodaphnia dubia, dos efluentes brutos e tratados gerados por uma indústria farmacêutica veterinária. O sistema de tratamento de efluentes usado é composto por uma etapa de tratamento químico (coagulação-sedimentação forçada) seguida do tratamento biológico aeróbio (processo de lodos ativados). Foram realizadas 5 campanhas de amostragens entre outubro de 2011 e julho de 2012. As amostras de efluentes brutos apresentaram elevada toxicidade aguda e crônica (aguda: quarta campanha com CE50 - 48-h de <0,001% e crônica: terceira campanha com CI50 - 7d <0,0001%). As amostras de efluentes tratados quimicamente foram as mais tóxicas com CE50 - 48-h entre <0,001 e 0,1% e CI50 - 7-d entre 0,00001 e 0,0001%, provavelmente relacionada ao uso de sulfato de alumínio como agente floculante. O tratamento biológico levou a uma pequena diminuição da toxicidade dos efluentes. Os testes ecotoxicológicos foram adequados para detectar a toxicidade dos efluentes e úteis para avaliar a eficiência das etapas do tratamento. Melhorias no sistema de tratamento de efluentes da indústria estudada deveriam ser implementadas visando à redução da toxicidade observada nos efluentes finais.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Universidade Federal de Alfenas Instituto de Ciências da NaturezaUniversidade Estadual de Campinas Laboratório de Ecotoxicologia Aquática e Limnologia Prof. Dr. Abílio LopesUniversidade Federal de São Paulo (UNIFESP) Instituto de Ciências Ambientais, Químicas e FarmacêuticasUNIFESP, Instituto de Ciências Ambientais, Químicas e FarmacêuticasSciEL
Caminhos percorridos no mapa da portuguesificação: A Linguateca em perspectiva
This study evaluated the ecotoxicity of five dyes to freshwater organisms before and during their photo-Fenton degradation. EC50 (48 h) of the five tested dyes ranged from of 6.9 to >1000 mg L-1 for Daphnia similis. In the chronic tests IC50 (72 h) varied from 65 to >100 mg L-1 for Pseudokirchneriella subcapitata and IC50 (8 days) from 0.5 to 410 mg L-1 for Ceriodaphnia dubia. Toxicity tests revealed that although the applied treatment was effective for decolorization of the dye, the partial mineralization may be responsible for the presence of degradation products which can be either more toxic than the original dye, as is the case of Vat Green 3 and Reactive Black 5, lead to initially toxic products which may be further degraded to non toxic products (acid Orange 7 and Food Red 17), or generate non toxic products as in the case of Food Yellow 3. The results highlighted the importance of assessing both acute and chronic toxicity tests of treated sample before effluent discharge. (C) 2014 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP
Ecotoxicity of raw and treated effluents generated by a veterinary medicine industry
Effluents from veterinary pharmaceutical industries that formulate medicines are mainly generated during the washing of equipment. The aim of this work was to evaluate the acute toxicity to Daphnia similis and chronic toxicity to Ceriodaphnia dubia of raw and treated effluents generated by a veterinary pharmaceutical industry. The industrial effluent treatment system comprises a step of chemical treatment (coagulation-sedimentation forced) followed by aerobic biological treatment (activated sludge process). Five samplings campaigns were performed from October 2011 to July 2012. The raw effluent samples showed high acute and chronic toxicity (acute: fourth sampling with EC50 - 48-h of <0.001% and chronic: third sampling with IC50 - 7-d of <0.0001%). The chemically treated effluent samples were the most toxic with EC50 - 48-h between <0.001 and 0.1% and IC50 - 7-d between 0.00001 and 0.0001%. This increase in toxicity is probably related to the use of aluminum sulfate as flocculating agent. The biological treatment led to a small reduction in toxicity of the effluents. The selected ecotoxicological tests were adequate for detecting the effluent toxicity and useful for evaluating the efficiency of the steps of the effluent treatment. Improvements in the industrial wastewater treatment system should be implemented in order to reduce the observed toxicity of the final effluent.Efluentes de indústrias farmacêuticas veterinárias, que formulam medicamentos, são gerados principalmente durante a lavagem dos equipamentos. O objetivo desse trabalho foi avaliar a toxicidade aguda para Daphnia similis e crônica para Ceriodaphnia dubia, dos efluentes brutos e tratados gerados por uma indústria farmacêutica veterinária. O sistema de tratamento de efluentes usado é composto por uma etapa de tratamento químico (coagulação-sedimentação forçada) seguida do tratamento biológico aeróbio (processo de lodos ativados). Foram realizadas 5 campanhas de amostragens entre outubro de 2011 e julho de 2012. As amostras de efluentes brutos apresentaram elevada toxicidade aguda e crônica (aguda: quarta campanha com CE50 - 48-h de <0,001% e crônica: terceira campanha com CI50 - 7d <0,0001%). As amostras de efluentes tratados quimicamente foram as mais tóxicas com CE50 - 48-h entre <0,001 e 0,1% e CI50 - 7-d entre 0,00001 e 0,0001%, provavelmente relacionada ao uso de sulfato de alumínio como agente floculante. O tratamento biológico levou a uma pequena diminuição da toxicidade dos efluentes. Os testes ecotoxicológicos foram adequados para detectar a toxicidade dos efluentes e úteis para avaliar a eficiência das etapas do tratamento. Melhorias no sistema de tratamento de efluentes da indústria estudada deveriam ser implementadas visando à redução da toxicidade observada nos efluentes finais.168179Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Constraining the Ratio in TeV Cosmic Rays with Observations of the Moon Shadow by HAWC
An indirect measurement of the antiproton flux in cosmic rays is possible as
the particles undergo deflection by the geomagnetic field. This effect can be
measured by studying the deficit in the flux, or shadow, created by the Moon as
it absorbs cosmic rays that are headed towards the Earth. The shadow is
displaced from the actual position of the Moon due to geomagnetic deflection,
which is a function of the energy and charge of the cosmic rays. The
displacement provides a natural tool for momentum/charge discrimination that
can be used to study the composition of cosmic rays. Using 33 months of data
comprising more than 80 billion cosmic rays measured by the High Altitude Water
Cherenkov (HAWC) observatory, we have analyzed the Moon shadow to search for
TeV antiprotons in cosmic rays. We present our first upper limits on the
fraction, which in the absence of any direct measurements, provide
the tightest available constraints of on the antiproton fraction for
energies between 1 and 10 TeV.Comment: 10 pages, 5 figures. Accepted by Physical Review
All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV
We report on the measurement of the all-particle cosmic ray energy spectrum
with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range
10 to 500 TeV. HAWC is a ground based air-shower array deployed on the slopes
of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to
gamma rays and cosmic rays at TeV energies. The data used in this work were
taken from 234 days between June 2016 to February 2017. The primary cosmic-ray
energy is determined with a maximum likelihood approach using the particle
density as a function of distance to the shower core. Introducing quality cuts
to isolate events with shower cores landing on the array, the reconstructed
energy distribution is unfolded iteratively. The measured all-particle spectrum
is consistent with a broken power law with an index of prior to
a break at ) TeV, followed by an index of . The
spectrum also respresents a single measurement that spans the energy range
between direct detection and ground based experiments. As a verification of the
detector response, the energy scale and angular resolution are validated by
observation of the cosmic ray Moon shadow's dependence on energy.Comment: 16 pages, 11 figures, 4 tables, submission to Physical Review
Search for very-high-energy emission from Gamma-ray Bursts using the first 18 months of data from the HAWC Gamma-ray Observatory
The High Altitude Water Cherenkov (HAWC) Gamma-ray Observatory is an
extensive air shower detector operating in central Mexico, which has recently
completed its first two years of full operations. If for a burst like GRB
130427A at a redshift of 0.34 and a high-energy component following a power law
with index -1.66, the high-energy component is extended to higher energies with
no cut-off other than from extragalactic background light attenuation, HAWC
would observe gamma rays with a peak energy of 300 GeV. This paper
reports the results of HAWC observations of 64 gamma-ray bursts (GRBs) detected
by and , including three GRBs that were also
detected by the Large Area Telescope (-LAT). An ON/OFF analysis
method is employed, searching on the time scale given by the observed light
curve at keV-MeV energies and also on extended time scales. For all GRBs and
time scales, no statistically significant excess of counts is found and upper
limits on the number of gamma rays and the gamma-ray flux are calculated. GRB
170206A, the third brightest short GRB detected by the Gamma-ray Burst Monitor
on board the satellite (-GBM) and also
detected by the LAT, occurred very close to zenith. The LAT measurements can
neither exclude the presence of a synchrotron self-Compton (SSC) component nor
constrain its spectrum. Instead, the HAWC upper limits constrain the expected
cut-off in an additional high-energy component to be less than
for reasonable assumptions about the energetics and redshift of the burst.Comment: 19 pages, 6 figures, published in Ap
Search for the standard model Higgs boson in tau final states
We present a search for the standard model Higgs boson using hadronically
decaying tau leptons, in 1 inverse femtobarn of data collected with the D0
detector at the Fermilab Tevatron ppbar collider. We select two final states:
tau plus missing transverse energy and b jets, and tau+ tau- plus jets. These
final states are sensitive to a combination of associated W/Z boson plus Higgs
boson, vector boson fusion and gluon-gluon fusion production processes. The
observed ratio of the combined limit on the Higgs production cross section at
the 95% C.L. to the standard model expectation is 29 for a Higgs boson mass of
115 GeV.Comment: publication versio
Search for the associated production of a b quark and a neutral supersymmetric Higgs boson which decays to tau pairs
We report results from a search for production of a neutral Higgs boson in
association with a quark. We search for Higgs decays to pairs with
one subsequently decaying to a muon and the other to hadrons. The data
correspond to 2.7fb of \ppbar collisions recorded by the D0 detector
at TeV. The data are found to be consistent with background
predictions. The result allows us to exclude a significant region of parameter
space of the minimal supersymmetric model.Comment: Submitted to Phys. Rev. Letter
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