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1.
Anesth Analg ; 131(1): 288-297, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32543805

RESUMO

BACKGROUND: The inhalation anesthetics are potent greenhouse gases. To reduce the global environmental impact of the health care sector, technologies are sought to limit the release of waste anesthetic gas into the atmosphere. METHODS: Using a photochemical exhaust gas destruction system, removal efficiencies for nitrous oxide, desflurane, and sevoflurane were measured at various inlet concentrations (25% and 50%; 1.5%, 3.0%, and 6.0%; and 0.5%, 1.0%, and 2.0%, respectively) with flow rates ranging from 0.25 to 2.0 L/min. To evaluate the economic competitiveness of the anesthetic waste gas destruction system, its price per ton of carbon dioxide equivalent was calculated and compared to other greenhouse gas abatement technologies and current market prices. RESULTS: All inhaled anesthetics evaluated demonstrate enhanced removal efficiencies with decreasing flow rates (P < .0001). Depending on the anesthetic and its concentration, the photochemical exhaust gas destruction system exhibits a constant first-order removal rate, k. However, there was not a simple relation between the removal rate k and the species concentration. The costs for removing a ton of carbon dioxide equivalents are <$0.005 for desflurane, <$0.114 for sevoflurane, and <$49 for nitrous oxide. CONCLUSIONS: Based on this prototype study, destroying sevoflurane and desflurane with this photochemical anesthetic waste gas destruction system design is efficient and cost-effective. This is likely also true for other halogenated inhalational anesthetics such as isoflurane. Due to differing chemistry of nitrous oxide, modifications of this prototype photochemical reactor system are necessary to improve its removal efficiency for this gas.


Assuntos
Anestésicos Inalatórios/efeitos adversos , Anestésicos Inalatórios/química , Gases de Efeito Estufa/efeitos adversos , Gases de Efeito Estufa/química , Resíduos Perigosos/efeitos adversos , Fotoquímica/métodos , Anestesia por Inalação/efeitos adversos , Anestésicos Inalatórios/análise , Gases de Efeito Estufa/análise , Resíduos Perigosos/análise , Humanos
4.
Infez Med ; 26(3): 210-215, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30246763

RESUMO

A possible tool to reduce nosocomial infections is to identify unknown sources of contamination and then to provide a measure for controlling the related infections. In this study, solid hospital waste was considered a potential source of contamination, and a strategy to reduce the potential risk of pathogen contamination was tested. This paper describes a novel technique for waste management in healthcare settings with a view to facilitating infection prevention and control. We explored the innovative use of sodium dichloroisocyanurate (NaDCC) by investigating the microbicidal activity of chlorine, which derives from the hydrolysis of NaDCC mediated by humidity, and by testing its effect on the inhibition of microorganism growth. NaDCC was inserted in a solid hospital waste bin containing also Lauria-Bertani agar plates, with different dilutions of a known titre of three different microorganisms, namely Escherichia coli, Staphylococcus aureus and Aspergillus brasiliensis. The plates were incubated in the container with or without the antimicrobial agent (control, CNT) at room temperature for 5 days. The number of colony-forming units (CFUs) present on each plate was then counted. Microorganisms capable of proliferating in the CNT waste bin were not able to grow in the presence of NaDCC. Furthermore, the molecular chlorine which developed and was released in the waste bin under the experimental conditions (T=20°C, t=5 days) was quantified using iodometric titration. NaDCC hydrolysis, mediated by humidity, has a strong and long-lasting microbicide effect. The proliferation of tested bacteria and fungi is totally inhibited. These results demonstrate the effectiveness of NaDCC in controlling and/or inhibiting microbial proliferation and support its possible use in the treatment of hospital waste to control the spread of nosocomial contamination.


Assuntos
Infecção Hospitalar/prevenção & controle , Desinfetantes/farmacologia , Microbiologia Ambiental , Resíduos Perigosos , Eliminação de Resíduos de Serviços de Saúde/métodos , Resíduos de Serviços de Saúde , Eliminação de Resíduos/métodos , Resíduos Sólidos , Triazinas/farmacologia , Aspergillus/efeitos dos fármacos , Contagem de Colônia Microbiana , Infecção Hospitalar/transmissão , Escherichia coli/efeitos dos fármacos , Resíduos Perigosos/efeitos adversos , Humanos , Resíduos de Serviços de Saúde/efeitos adversos , Eliminação de Resíduos de Serviços de Saúde/instrumentação , Estrutura Molecular , Eliminação de Resíduos/instrumentação , Resíduos Sólidos/efeitos adversos , Staphylococcus aureus/efeitos dos fármacos , Triazinas/química , Volatilização
5.
Environ Sci Pollut Res Int ; 25(9): 8592-8607, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29318484

RESUMO

Recent studies have shown that cigarette consumption affects much more than human health. Smoked cigarette butt (SCB) disposal into the environment can bring little-known negative biological consequences to mammals, since it contains many organic and inorganic toxic chemical constituents. Thus, we aim at assessing whether the ingestion of water with leached SCB for 60 days by female Swiss mice changes their defensive behavioral response to potential predators (cats and snakes). We worked with the following groups of animals: control (pollutant-free water), water with environmental concentration of SCB (1.9 µg/L of nicotine), and concentration 1000 times higher (EC1000×). Our data show that the treatments did not cause locomotor, visual, auditory, and olfactory deficit in the animals. However, we observed that the animals exposed to the pollutants did not present behavioral differences in the test session with or without the snake. On the other hand, animals in all groups showed defensive behavior when the test was conducted with the cat in the apparatus. However, female mice presented weaker response than the control. Thus, our data point towards the potential neurotoxic damage caused to mice who have ingested water with SCB residues, even at low concentrations.


Assuntos
Exposição Ambiental/efeitos adversos , Reação de Fuga/efeitos dos fármacos , Resíduos Perigosos/efeitos adversos , Produtos do Tabaco/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Feminino , Camundongos , Modelos Teóricos
6.
Environ Health ; 16(1): 107, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-29020961

RESUMO

Waste is part of the agenda of the European Environment and Health Process and included among the topics of the Sixth Ministerial Conference on Environment and Health. Disposal and management of hazardous waste are worldwide challenges. We performed a systematic review to evaluate the evidence of the health impact of hazardous waste exposure, applying transparent and a priori defined methods. The following five steps, based on pre-defined systematic criteria, were applied. 1. Specify the research question, in terms of "Population-Exposure-Comparators-Outcomes" (PECO). POPULATION: people living near hazardous waste sites; Exposure: exposure to hazardous waste; Comparators: all comparators; Outcomes: all diseases/health disorders. 2. Carry out the literature search, in Medline and EMBASE. 3. Select studies for inclusion: original epidemiological studies, published between 1999 and 2015, on populations residentially exposed to hazardous waste. 4. Assess the quality of selected studies, taking into account study design, exposure and outcome assessment, confounding control. 5. Rate the confidence in the body of evidence for each outcome taking into account the reliability of each study, the strength of the association and concordance of results.Fifty-seven papers of epidemiological investigations on the health status of populations living near hazardous waste sites were selected for the evidence evaluation. The association between 95 health outcomes (diseases and disorders) and residential exposure to hazardous waste sites was evaluated. Health effects of residential hazardous waste exposure, previously partially unrecognized, were highlighted. Sufficient evidence was found of association between exposure to oil industry waste that releases high concentrations of hydrogen sulphide and acute symptoms. The evidence of causal relationship with hazardous waste was defined as limited for: liver, bladder, breast and testis cancers, non-Hodgkin lymphoma, asthma, congenital anomalies overall and anomalies of the neural tube, urogenital, connective and musculoskeletal systems, low birth weight and pre-term birth; evidence was defined as inadequate for the other health outcomes. The results, although not conclusive, provide indications that more effective public health policies on hazardous waste management are urgently needed. International, national and local authorities should oppose and eliminate poor, outdated and illegal practices of waste disposal, including illegal transboundary trade, and increase support regulation and its enforcement.


Assuntos
Resíduos Perigosos/efeitos adversos , Exposição Ambiental/efeitos adversos , Europa (Continente) , Locais de Resíduos Perigosos , Humanos
7.
Environ Res ; 158: 531-541, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28711809

RESUMO

Assessment of the health impacts related to hazardous waste is a major scientific challenge with multiple societal implications. Most studies related to associations between hazardous waste and public health do not provide established of mechanistic links between environmental exposure and disease burden, resulting in ineffective waste management options. The exposome concept comes to overhaul the nature vs. nurture paradigm and embraces a world of dynamic interactions between environmental exposures, endogenous exposures and genetic expression in humans. In this context, the exposome paradigm provides a novel tool for holistic hazardous waste management. Waste streams and the related contamination of environmental media are not viewed in isolation, but rather as components of the expotype, the vector of exposures an individual is exposed to over time. Thus, a multi-route and multi-pathway exposure estimation can be performed setting a realistic basis for integrated health risk assessment. Waste management practices are thus assessed not only regarding their technological edge and efficacy but also their effects on human health at the individual and community level, considering intra-subject variability in the affected population. The effectiveness of the exposome approach is demonstrated in the case of Athens, the capital of Greece, where the health effects associated to long term and short term exposure to two major waste management facilities (landfill and plastic recycling) are presented. Using the exposome analysis tools, we confirmed that proximity to a landfill is critical for children neurodevelopment. However, this effect is significantly modified by parameters such as parental education level, socioeconomic status and nutrition. Proximity to a plastics recycling plant does not pose significant threats under normal operating conditions; yet, in the case of an accidental fire, release of persistent carcinogenic compounds (dioxins and furans) even for a short period results in increased lifelong risk, especially for breast feeding neonates.


Assuntos
Saúde da Criança , Exposição Ambiental , Saúde Ambiental , Resíduos Perigosos/efeitos adversos , Gerenciamento de Resíduos , Criança , Pré-Escolar , Cidades , Feminino , Grécia , Humanos , Masculino , Medição de Risco
8.
Artigo em Inglês | MEDLINE | ID: mdl-28604580

RESUMO

In the present work, thermal treatment was used to stabilize municipal solid waste incineration (MSWI) fly ash, which was considered hazardous waste. Toxicity characteristic leaching procedure (TCLP) results indicated that, after the thermal process, the leaching concentrations of Pb, Cu, and Zn decreased from 8.08 to 0.16 mg/L, 0.12 to 0.017 mg/L and 0.39 to 0.1 mg/L, respectively, which well met the limits in GB5085.3-2007 and GB16689-2008. Thermal treatment showed a negative effect on the leachability of Cr with concentrations increasing from 0.1 to 1.28 mg/L; nevertheless, it was still under the limitations. XRD analysis suggested that, after thermal treatments, CaO was newly generated. CaO was a main contribution to higher Cr leaching concentrations owing to the formation of Cr (VI)-compounds such as CaCrO4. SEM/EDS tests revealed that particle adhesion, agglomeration, and grain growth happened during the thermal process and thus diminished the leachability of Pb, Cu, and Zn, but these processes had no significant influence on the leaching of Cr. A microbial assay demonstrated that all thermally treated samples yet possessed strong bactericidal activity according to optical density (OD) test results. Among all samples, the OD value of raw fly ash (RFA) was lowest followed by FA700-10, FA900-10, and FA1100-10 in an increasing order, which indicated that the sequence of the biotoxicity for these samples was RFA > FA700-10 > FA900-10 > FA1100-10. This preliminary study indicated that, apart from TCLP criteria, the biotoxicity assessment was indispensable for evaluating the effect of thermal treatment for MSWI fly ash.


Assuntos
Cinza de Carvão/análise , Resíduos Perigosos/análise , Incineração , Metais Pesados/análise , Cinza de Carvão/efeitos adversos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Resíduos Perigosos/efeitos adversos , Temperatura Alta , Metais Pesados/toxicidade , Resíduos Sólidos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
9.
G Ital Dermatol Venereol ; 152(4): 379-382, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28209048

RESUMO

BACKGROUND: Waste is a composite mixture of different substances including endotoxins, organic dust and bio-aerosol stuffed with micro-organisms, and various toxic organic and inorganic chemicals, which may be intrinsically hazardous to human health. Therefore, health risks may derive from direct or indirect contact with garbage. EVIDENCE ACQUISITION: We searched for English-language literature describing the relationships between garbage and skin diseases in order to provide a state-of-the-art review on what is currently known about waste exposure effects on skin health. EVIDENCE SYNTHESIS: Most of the data regarding the possible relationship between garbage exposure and skin diseases are mainly gathered from studies conducted on subjects living near dumping sites and landfills as well as on workers engaged in solid waste collection, processing and/or disposal. Literature data are controversial since some studies did not show any significant association between cutaneous diseases and garbage whereas other authors reported significant connections with conditions such as skin infections, skin rashes and systemic lupus erythematosus. CONCLUSIONS: Despite deficiency in garbage collection and waste overproduction are becoming more and more common problems worldwide, to date only few surveys have been conducted to investigate on the relationship between garbage exposure and cutaneous diseases. Indubitably, more efforts and research are needed to elaborate this emerging issue and seek to drive authorities for the organization of controlled action and health risk reduction behaviors models to face possible waste related health risk.


Assuntos
Exposição Ambiental/efeitos adversos , Resíduos Perigosos/efeitos adversos , Dermatopatias/etiologia , Resíduos de Alimentos , Humanos , Doenças Profissionais/epidemiologia , Exposição Ocupacional/efeitos adversos , Dermatopatias/epidemiologia
10.
Environ Monit Assess ; 189(1): 45, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28039661

RESUMO

This study is the first to investigate the contamination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) on surface soils in the vicinity of the first hazardous waste incinerator of Turkey. In the study, 24 soil samples were taken from a 1625-m-radius circle whose center is the stack of the incinerator. This process was repeated 1 year later. Since the acquired average PCDD/F concentrations of the two sampling campaigns (0.05 and 0.02 ng WHO-toxic equivalent (TEQ)/kg) were meaningfully low compared to the related literatures, a new sampling campaign was carried out to control this inconsistency, but this time in a foreign laboratory (0.56 ng WHO-TEQ/kg). In the same period, eight gas samples were taken from the stack under different operational conditions of the facility. According to the evaluations of the findings, the geographical-meteorological data of the study area and the specific operational conditions of the facility corroborate the concentrations of the first and the second soil samplings rather than the third one. The major underlying reason for the inconsistency of the soil concentrations may be the fact that the data analysis procedures used by the laboratories are different. The author suggests a hypothesis which argues that the soils in the vicinity of a hazardous waste incinerator may have significantly lower concentration levels than in related literatures.


Assuntos
Dibenzofuranos Policlorados/análise , Monitoramento Ambiental , Resíduos Perigosos/efeitos adversos , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , Solo/química , Geografia , Incineração , Turquia , Gerenciamento de Resíduos
11.
Regul Toxicol Pharmacol ; 84: 105-115, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27998719

RESUMO

Risk assessment (RA) of manufactured nanomaterials (MNM) is essential for regulatory purposes and risk management activities. Similar to RA of "classical" chemicals, MNM RA requires knowledge about exposure as well as of hazard potential and dose response relationships. What makes MNM RA especially challenging is the multitude of materials (which is expected to increase substantially in the future), the complexity of MNM value chains and life cycles, the accompanying possible changes in material properties over time and in contact with various environmental and organismal milieus, and the difficulties to obtain proper exposure data and to consider the proper dose metric. This article discusses these challenges and also critically overviews the current state of the art regarding MNM RA approaches.


Assuntos
Exposição Ambiental/efeitos adversos , Substâncias Perigosas/toxicidade , Nanoestruturas/toxicidade , Nanotecnologia/métodos , Exposição Ocupacional/efeitos adversos , Testes de Toxicidade/métodos , Fluxo de Trabalho , Local de Trabalho , Animais , Relação Dose-Resposta a Droga , Resíduos Perigosos/efeitos adversos , Humanos , Reciclagem , Medição de Risco , Fatores de Risco , Fatores de Tempo , Gerenciamento de Resíduos
12.
Environ Int ; 97: 37-44, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27771564

RESUMO

In May 2016, a fire occurred in one of the largest landfills in Europe (Seseña, Toledo, Spain), where 70,000-90,000tons of tires had been illegally accumulated for >15years. Because of the proximity of population nuclei and the duration of the episode (>20days), we conducted a preliminary human health risk assessment study just after the tire fire. Samples of air and soil were collected in 3 areas surrounding the landfill (El Quiñón, at only 500m, and Seseña Nuevo and Seseña Viejo, both at 4km), as well as in background sites. In addition, samples of crops (barley, wheat, cabbage and lettuce) were also obtained from local farmers. The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and a number of trace elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl, and V) were analyzed in all the samples. The concentrations of all the target pollutants, excepting PAHs, were relatively similar at the different sampling zones, irrespective of the distance to the landfill. In turn, a significant increase of PAHs was noted near the tire landfill, with air levels up to 6-times higher than those found at 4km (134 vs. 19.5-22.7ng/m3). Similarly, PAH concentrations in lettuce were relatively higher than those typically found in monitoring programs of food safety. Because of the increase of airborne PAHs, cancer risks due to exposure to environmental pollutants for the population living at El Quiñón, near the landfill, were between 3- and 5-times higher than those estimated for the inhabitants of Seseña. After this preliminary study, further investigations, focused only on PAHs, but more extensive in terms of number of samples, should be conducted to assure that PAHs have been progressively degraded through time.


Assuntos
Poluentes Atmosféricos/análise , Poluentes Ambientais/análise , Fogo , Resíduos Perigosos/análise , Dibenzodioxinas Policloradas/análise , Poluentes do Solo/análise , Oligoelementos/análise , Poluentes Atmosféricos/toxicidade , Poluentes Ambientais/toxicidade , Resíduos Perigosos/efeitos adversos , Humanos , Veículos Automotores , Bifenilos Policlorados/análise , Bifenilos Policlorados/toxicidade , Dibenzodioxinas Policloradas/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Medição de Risco , Poluentes do Solo/toxicidade , Espanha , Oligoelementos/toxicidade , Instalações de Eliminação de Resíduos
13.
Artigo em Inglês | MEDLINE | ID: mdl-27618082

RESUMO

Although medical waste usually accounts for a small fraction of urban municipal waste, its proper disposal has been a challenging issue as it often contains infectious, radioactive, or hazardous waste. This article proposes a two-level hierarchical multicriteria decision model to address medical waste disposal method selection (MWDMS), where disposal methods are assessed against different criteria as intuitionistic fuzzy preference relations and criteria weights are furnished as real values. This paper first introduces new operations for a special class of intuitionistic fuzzy values, whose membership and non-membership information is cross ratio based ]0, 1[-values. New score and accuracy functions are defined in order to develop a comparison approach for ]0, 1[-valued intuitionistic fuzzy numbers. A weighted geometric operator is then put forward to aggregate a collection of ]0, 1[-valued intuitionistic fuzzy values. Similar to Saaty's 1-9 scale, this paper proposes a cross-ratio-based bipolar 0.1-0.9 scale to characterize pairwise comparison results. Subsequently, a two-level hierarchical structure is formulated to handle multicriteria decision problems with intuitionistic preference relations. Finally, the proposed decision framework is applied to MWDMS to illustrate its feasibility and effectiveness.


Assuntos
Tomada de Decisões , Lógica Fuzzy , Resíduos Perigosos/efeitos adversos , Eliminação de Resíduos de Serviços de Saúde/métodos , Animais , Humanos , Modelos Teóricos , Reprodutibilidade dos Testes
14.
Regul Toxicol Pharmacol ; 80: 125-33, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27346665

RESUMO

A method for determining a safety range for non-cancer risks is proposed, similar in concept to the range used for cancer in the management of waste sites. This safety range brings transparency to the chemical specific Reference Dose or Concentration by replacing their "order of magnitude" definitions with a scientifically-based range. EPA's multiple RfCs for trichloroethylene (TCE) were evaluated as a case study. For TCE, a multi-endpoint safety range was judged to be 3 µg/m(3) to 30 µg/m,(3) based on a review of kidney effects found in NTP (1988), thymus effects found in Keil et al. (2009) and cardiac effects found in the Johnson et al. (2003) study. This multi-endpoint safety range is derived from studies for which the appropriate averaging time corresponds to different exposure durations, and, therefore, can be applied to both long- and short-term exposures with appropriate consideration of exposure averaging times. For shorter-term exposures, averaging time should be based on the time of cardiac development in humans during fetal growth, an average of approximately 20-25 days.


Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/efeitos adversos , Locais de Resíduos Perigosos , Resíduos Perigosos/efeitos adversos , Tricloroetileno/efeitos adversos , Animais , Técnicas de Apoio para a Decisão , Relação Dose-Resposta a Droga , Monitoramento Ambiental/normas , Poluentes Ambientais/análise , Resíduos Perigosos/análise , Humanos , Exposição por Inalação/efeitos adversos , Valores de Referência , Medição de Risco , Gestão da Segurança , Fatores de Tempo , Testes de Toxicidade , Tricloroetileno/análise
15.
Environ Pollut ; 214: 713-721, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27149148

RESUMO

Fly ashes generated by municipal solid waste incinerator (MSWI) are classified as hazardous waste and usually landfilled. For the sustainable reuse of these materials is necessary to reduce the resulting impact on human health and environment. The COSMOS-rice technology has been recently proposed for the treatment of fly ashes mixed with rice husk ash, to obtain a low-cost composite material with significant performances. Here, aquatic biotoxicity assays, including daphnidae and zebrafish embryo-based tests, were used to assess the biosafety efficacy of this technology. Exposure to lixiviated MSWI fly ash caused dose-dependent biotoxic effects on daphnidae and zebrafish embryos with alterations of embryonic development, teratogenous defects and apoptotic events. On the contrary, no biotoxic effects were observed in daphnidae and zebrafish embryos exposed to lixiviated COSMOS-rice material. Accordingly, whole-mount in situ hybridization analysis of the expression of various tissue-specific genes in zebrafish embryos provided genetic evidence about the ability of COSMOS-rice stabilization process to minimize the biotoxic effects of MSWI fly ash. These results demonstrate at the biological level that the newly developed COSMOS-rice technology is an efficient and cost-effective method to process MSWI fly ash, producing a biologically safe and reusable material.


Assuntos
Cinza de Carvão/efeitos adversos , Exposição Ambiental/efeitos adversos , Resíduos Perigosos/efeitos adversos , Oryza , Eliminação de Resíduos/métodos , Resíduos Sólidos/efeitos adversos , Peixe-Zebra , Animais , Cinza de Carvão/química , Crustáceos/embriologia , Incineração/métodos , Sementes , Tecnologia , Teratogênios , Peixe-Zebra/embriologia
16.
Bioresour Technol ; 193: 156-63, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26133472

RESUMO

The combustion characteristics for three kinds of antibiotics residue (AR) materials were investigated by TG-FTIR and Py-GC/MS technique. The TG results indicated that AR combustion involved three stages, and correlation between the H/C atomic ratio of the raw materials and peak temperature of weight loss for the second stage was obtained. The FTIR spectra identified evolving gaseous products as CO2, CH4, HCNO, NH3, HCN, and NO. An AR material with a low H/C ratio promoted the formation of CO2 and HCN, but suppressed the yields of NH3 and CH4. The Py-GC/MS results suggested that abundant volatiles can be produced, including alkenes, benzene, phenols, furans, acid, and heterocyclic-N, nitrile-N and amine-N compounds, and confirmed the FTIR absorption characteristics in the low temperature range. A possible pathway for the AR combustion was also tentatively presented.


Assuntos
Antibacterianos/química , Resíduos Perigosos/análise , Fermentação , Cromatografia Gasosa-Espectrometria de Massas/métodos , Gases/química , Resíduos Perigosos/efeitos adversos , Incineração/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura
20.
PLoS One ; 10(3): e0120001, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25781032

RESUMO

The distribution, sources and potential ecological risk of heavy metals in the sediment of lakes in eastern China and other areas of the world that have undergone rapid economic development have been widely researched by scholars. However, this is not true for heavy metals in the sediment of rump lakes in the arid regions of China and world-wide. Because of this, we chose Aibi Lake to serve as a typical rump lake in an oasis in an arid area in northwest China for our study. Sediment samples were collected from the lake and then the quantities of the heavy metals Pb, Ni, Cd, Cu, Zn, Hg and Cr were measured. Then using a variety of statistical methods, we analyzed the distribution, sources, pollution status and the potential ecological risk of these metals. The results show that: (1) The amounts of the seven heavy metals all fell within the Second Soil National Standard, but the average and maximum values were all higher than the background values of Xinjiang in northwest China. (2) Multivariate statistical analysis determined that the Cd, Pb, Hg and Zn in the sediment were mainly derived from man-sources, and Cu, Ni, and Cr were mainly from the natural geological background. (3) Enrichment factor analysis and the geo-accumulation index evaluation method show that Cd, Hg and Pb in the surface sediment of the Aibi Lake were at low and partial pollution levels, while Zn, Cr, Ni and Cu were at no and low pollution levels. (4) Calculation of the potential ecological hazards index found that, among the seven tested heavy metals, Cd, Hg and Pb were the main potential ecological risk factors, and the contribution of each was 42.6%, 28.6%, and 24.0%, respectively. Cd is the main potential ecological risk factor, followed by Hg and Pb. This work revealed that recent economic development of the Aibi Lake Basin has negatively influenced the accumulation of heavy metals in the sediments of the lake, and, therefore, we should pay increasing attention to this problem and take effective measures to protect the ecology of the Aibi Lake Basin. This work can provide a scientific basis for an early warning of heavy metal pollution and for protection of the environment. Furthermore, it can serve as a reference when creating policies for the economic development in Aibi Lake Basin and environmental protection of rump lakes in arid regions of northwest China and other areas of the world.


Assuntos
Sedimentos Geológicos/química , Lagos/química , Metais Pesados/análise , China , Resíduos Perigosos/efeitos adversos , Metais Pesados/toxicidade
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