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1.
Int J Tuberc Lung Dis ; 27(11): 858-863, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37880894

RESUMO

BACKGROUND: Respiratory diseases of infectious, allergic, neoplastic or degenerative origin are due to the interaction of environmental and occupational risk factors, individual susceptibility and other co-factors and comorbidities. Asthma and other respiratory pathologies can be worsened by climate change and exposure to other agents in occupational environments.METHODS: PubMed and Scopus, and several websites on public and occupational health were queried to find publications and documents on work-related respiratory diseases, asthma, rhinitis, chronic obstructive pulmonary disease (COPD), pneumoconiosis and allergic alveolitis in association with climate change.RESULTS: Most of the retrieved articles concerned asthma (75 in Scopus), while the other topics were less frequently covered in the scientific literature, with a maximum of 29 papers for rhinitis and 23 for COPD. The most important terms highlighted by the word clouds were 'health', 'air', 'pollution', and, only for asthma and rhinitis, 'pollen' and 'allergic/allergy'. Website data on public and occupational health, and climate change were reported.CONCLUSIONS: Assessment and management of respiratory diseases that recognise occupational exposures should be improved, and more research into integrated approaches should be favoured. Health surveillance practices for workers exposed to agents that cause respiratory diseases should be implemented. The development of biomarkers of exposure, effect and susceptibility needs further study.


Assuntos
Asma , Hipersensibilidade , Doenças Profissionais , Exposição Ocupacional , Doença Pulmonar Obstrutiva Crônica , Transtornos Respiratórios , Doenças Respiratórias , Rinite , Humanos , Mudança Climática , Asma/etiologia , Asma/complicações , Hipersensibilidade/epidemiologia , Doenças Profissionais/epidemiologia , Doenças Profissionais/etiologia , Exposição Ocupacional/efeitos adversos , Doença Pulmonar Obstrutiva Crônica/complicações , Doenças Respiratórias/complicações
2.
Crit Rev Oncol Hematol ; 165: 103432, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34352361

RESUMO

BACKGROUND: Moderately hypofractionated radiotherapy (RT) currently represents the standard RT approach for all prostate cancer (PCa) risk categories. We performed a systematic review and meta-analysis of available literature, focusing on acute and late genitourinary (GU) and gastrointestinal (GI) adverse events (AEs) of moderate hypofractionation for localized PCa. MATERIALS AND METHODS: Literature search was performed and two independent reviewers selected the records according to the following Population (P) Intervention (I) Comparator (C) and Outcomes (O) (PICO) question: "In patients affected by localized PCa (P), moderately hypofractionated RT (defined as a treatment schedule providing a single dose per fraction of 3-4.5 Gy) (I) can be considered equivalent to conventionally fractionated RT (C) in terms of G > 2 GI and GU acute and late adverse events (O)?". Bias assessment was performed using Cochrane Cochrane Collaboration's Tool for Assessing Risk of Bias. RESULTS: Thirteen records were identified and a meta-analysis was performed. Risk of acute GI and GU > 2 adverse events in the moderately hypofractionated arm was increased by 9.8 % (95 %CI 4.8 %-14.7 %; I2 = 57 %) and 1.5 % (95 % CI -1.5 %-4.4 %; I2 = 0%), respectively. DISCUSSION: Overall, majority of trials included in our meta-analysis suggested that moderately hypofractionated RT is equivalent, in terms of GI and GU adverse events, to conventional fractionation. Pooled analysis showed a trend to increased GI toxicity after hypofractionated treatment, but this might be related to dose escalation rather than hypofractionation.


Assuntos
Gastroenteropatias , Neoplasias da Próstata , Radioterapia de Intensidade Modulada , Fracionamento da Dose de Radiação , Humanos , Masculino , Neoplasias da Próstata/radioterapia , Hipofracionamento da Dose de Radiação
3.
Clin. transl. oncol. (Print) ; 23(2): 364-371, feb. 2021. ilus
Artigo em Inglês | IBECS | ID: ibc-220621

RESUMO

Aims 68Ga-Prostate-specific membrane antigen (PSMA) PET/CT is widely used in patients with biochemical recurrence (BCR) after radical prostatectomy. We collected data about patients staged with PSMA PET/CT after BCR (PSA < 1 ng/ml) in four different institutes. Impact of baseline features (Gleason score, risk classification, PSA at recurrence, PSA doubling time and time to recurrence) was explored to understand predictive factors of (PSMA) PET/CT positivity. Impact of restaging on following treatment approaches was reported. Results 92 patients were included. PSMA PET/CT detection rate was 56.5% and low-volume disease (≤ 3 non-visceral lesions) was detected in 52.2% of patients. After positive scan, 13.5% of patients still lies on observation, ADT alone was administered in 30.8% of cases, Stereotactic body RT (SBRT) alone was delivered to 44.2% of patients and 11.5% of patients underwent concomitant SBRT and ADT. Seven patients underwent conventional salvage prostate bed RT. Chi-squared test showed a higher rate of positive PSMA PET/CT for patients with Gleason score > 7 (p = 0.004) and TTR < 29.5 months (p = 0.003). Conclusions PSMA PET/CT showed a high detection rate. This influenced clinical management in a significant percentage of patients, allowing treatment tailoring on the basis of imaging (AU)


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Idoso , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/cirurgia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Estudos Retrospectivos , Prostatectomia , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Antígeno Prostático Específico/sangue
4.
Clin Transl Oncol ; 23(8): 1577-1584, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33495981

RESUMO

OBJECTIVES: To report outcomes of stereotactic body radiotherapy (SBRT) in metastatic castration-resistant prostate cancer (mCRPC) patients with oligoprogression (≤ 5 metastases) during first-line treatment with androgen receptor-targeted therapy (ARTT). PATIENTS AND METHODS: Retrospective multi-institutional analysis of mCRPC patients treated with SBRT to oligoprogressive lesions during ARTT. End-points were time to next-line systemic treatment (NEST), radiological progression-free survival (r-PFS) and overall survival (OS). Toxicity was registered according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0. Survival analysis was performed using the Kaplan-Meier method, univariate and multivariate analysis (MVA) were performed. RESULTS: Data from 34 patients were analyzed. Median NEST-free survival, r-PFS, and OS were 16.97, 13.47, and 38.3 months, respectively. At MVA, factors associated with worse NEST-free survival and r-PFS were polymetastatic burden at diagnosis of metastatic hormone-sensitive disease (hazard ratio [HR] 3.66, p = 0.009; HR 3.03, p = 0.034), PSA ≤ 7 ng/ml at mCRPC diagnosis (HR 0.23, p = 0.017; HR 0.19, p = 0.006) and PSADT ≤ 3 months at mCRPC diagnosis (HR 3.39, p = 0.026; HR 2.79, p = 0.037). Polymetastatic state at mHSPC diagnosis was associated with a decreased OS (HR 4.68, p = 0.029). No patient developed acute or late grade ≥ 2 toxicity. CONCLUSION: Our results suggest that SBRT in oligoprogressive mCPRC is safe, effective and seems to prolong the efficacy of the ongoing systemic treatment positively affecting disease progression. Prospective trials are needed.


Assuntos
Antagonistas de Receptores de Andrógenos/uso terapêutico , Terapia de Alvo Molecular/métodos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/radioterapia , Radiocirurgia/métodos , Idoso , Análise de Variância , Terapia Combinada/métodos , Progressão da Doença , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Neoplasias de Próstata Resistentes à Castração/mortalidade , Neoplasias de Próstata Resistentes à Castração/patologia , Dosagem Radioterapêutica , Estudos Retrospectivos , Resultado do Tratamento
5.
Clin Transl Oncol ; 23(2): 364-371, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32602076

RESUMO

AIMS: 68Ga-Prostate-specific membrane antigen (PSMA) PET/CT is widely used in patients with biochemical recurrence (BCR) after radical prostatectomy. We collected data about patients staged with PSMA PET/CT after BCR (PSA < 1 ng/ml) in four different institutes. Impact of baseline features (Gleason score, risk classification, PSA at recurrence, PSA doubling time and time to recurrence) was explored to understand predictive factors of (PSMA) PET/CT positivity. Impact of restaging on following treatment approaches was reported. RESULTS: 92 patients were included. PSMA PET/CT detection rate was 56.5% and low-volume disease (≤ 3 non-visceral lesions) was detected in 52.2% of patients. After positive scan, 13.5% of patients still lies on observation, ADT alone was administered in 30.8% of cases, Stereotactic body RT (SBRT) alone was delivered to 44.2% of patients and 11.5% of patients underwent concomitant SBRT and ADT. Seven patients underwent conventional salvage prostate bed RT. Chi-squared test showed a higher rate of positive PSMA PET/CT for patients with Gleason score > 7 (p = 0.004) and TTR < 29.5 months (p = 0.003). CONCLUSIONS: PSMA PET/CT showed a high detection rate. This influenced clinical management in a significant percentage of patients, allowing treatment tailoring on the basis of imaging.


Assuntos
Isótopos de Gálio , Radioisótopos de Gálio , Recidiva Local de Neoplasia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata/diagnóstico por imagem , Compostos Radiofarmacêuticos , Idoso , Antagonistas de Androgênios/uso terapêutico , Antígenos de Superfície , Glutamato Carboxipeptidase II , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Recidiva Local de Neoplasia/sangue , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/terapia , Estadiamento de Neoplasias/métodos , Antígeno Prostático Específico/sangue , Prostatectomia , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Radiocirurgia/estatística & dados numéricos , Radioterapia/estatística & dados numéricos , Radioterapia de Intensidade Modulada/estatística & dados numéricos , Estudos Retrospectivos , Terapia de Salvação/métodos , Terapia de Salvação/estatística & dados numéricos , Fatores de Tempo
6.
Data Brief ; 33: 106383, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33102653

RESUMO

Flue-Gas Desulphurization (FGD) is a fundamental process commonly adopted for the treatment of exhausts deriving from both stationary and mobile sources. The removal of SO2 from flue gasses can be made through different technologies and absorption offers the highest versatility for a large spectrum of applications. The data presented in this paper derive from FGD experiments carried out in a pilot wet scrubber equipped with a structured packing (Hastelloy C-22, Mellapak 250.X). The experiments aim to determine the SO2 removal efficiency from a simulated flue-gas in different operating conditions, similar to those observed in common wet FGD processes. Experimental data are reported in terms of gas velocity, concentration of SO2 in the flue-gas, liquid/gas feed ratio, fluids temperature and pressure. The dataset also includes the measurements of several working parameters, i.e. pressure drops in the column, wash water pH, relative humidity of the outlet gas and temperatures of gas and liquid flowing out of the FGD unit. The collection of these data could be useful in future studies and in the analysis of FGD units, also to design/improve large-scale absorption columns with structured packing, using various scrubbing liquids and in different operating conditions.

7.
Hum Vaccin Immunother ; 14(4): 864-867, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29261361

RESUMO

In Italy, the National Plan for the Elimination of Measles and Congenital Rubella 2010-15 suggests offering Measles, Mumps and Rubella (MMR) vaccination to susceptible women who underwent voluntary termination of pregnancy (VTP) In Rome, S. Eugenio Hospital is one of the structures where VTP is practised in an Operative Unit called "Family Planning" The primary goal of this study was to estimate the prevalence of susceptibility to rubella, using IgG and IgM immunoassays, among women accessing VTP and to offering MMR vaccination to susceptible women. Secondarily, this study evaluated acceptance of the vaccination offer From 2013 to 2015, data were collected from 1513 voluntary termination of pregnancy (VTP) cases The results show a significant increase of 5 percent in susceptibility prevalence in the target group from 13.6% in 2013 and 2014 to 18.4% in 2015 The association between rubella susceptibility and age was statistically significant (p<0.01) Throughout the entire period, acceptance of the vaccine proposal was 19% (45/232) among susceptible women; 58% (135/232) refused the vaccine and 23% (52/232) took time to think about it This study shows an increase of 5 percent in the prevalence of rubella susceptibility over two years. This result is worrying, even considering the short span of the data collection The rate of acceptance of vaccination is unsatisfactory considering the possibility of future pregnancies This issue deserves continued action, which, going forward, might transform a "project" into a shared strategy as part of a wider network with the goal of aligning Italy with international recommendations.


Assuntos
Vacina contra Sarampo-Caxumba-Rubéola/imunologia , Sarampo/imunologia , Caxumba/imunologia , Rubéola (Sarampo Alemão)/imunologia , Adolescente , Adulto , Anticorpos Antivirais/imunologia , Feminino , Humanos , Esquemas de Imunização , Itália , Sarampo/prevenção & controle , Pessoa de Meia-Idade , Caxumba/prevenção & controle , Gravidez , Rubéola (Sarampo Alemão)/prevenção & controle , Vacinação/métodos , Adulto Jovem
8.
Klin Onkol ; 30(6): 456-459, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29271218

RESUMO

BACKGROUND: Papillary tumor of the pineal region (PTPR) is a recently defined tumor entity. Its clinical course is characterized by frequent local recurrence, and patients may experience the burden of symptoms due to the anatomical location of the growing mass. Guidelines for treatment protocols, and the role of radiotherapy are still being investigated. CASE: We report the case of a 27-year old woman who was referred to our department after she was diagnosed with PTPR and had undergone multiple surgical interventions. We delivered adjuvant conformal radiotherapy on the gross residual tumor to a total dose of 59.4 Gy (33 × 1.8 Gy). DISCUSSION: After a follow-up period of 41 months, we obtained a complete response to the treatment, according to the Response evaluation criteria in solid tumors criteria (RECIST). Radiation treatment was well tolerated, and the patient did not develop acute and late side effects. The neurological symptoms, which were documented at the diagnosis and after the surgical procedure, have not been recorded at last follow-up. CONCLUSIONS: Formal consensus for managing patients with a diagnosis of PTPR are nonexistent. Despite surgery, this tumor has a tendency to recur. Radiotherapy could have a role in the adjuvant setting and needs to be investigated in a multicenter setting with a long follow-up.Key words: radiotherapy - neurosurgery - magnetic resonance - pineal region - brain tumor.


Assuntos
Recidiva Local de Neoplasia/radioterapia , Papiloma/radioterapia , Pinealoma/radioterapia , Radioterapia Adjuvante/métodos , Adulto , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Feminino , Humanos , Papiloma/cirurgia , Glândula Pineal/patologia , Pinealoma/cirurgia
9.
Clin Ter ; 168(5): e317-e319, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29044354

RESUMO

INTRODUCTION: Chronic diseases are the leading cause of death and disability in almost all over the world; in Europe causing over 9 million deaths per year according to WHO estimates. A promising health organization model for chronic disease management is represented by the Chronic Care Model (CCM). In the 12th district of the ASL Roma 2 since 4 years was implemented a CCM for the management of patients affected by diabetes and/or at high cardiovascular risk. OBJECTIVE: Aim of this study is to evaluate the effectiveness of the Chronic Care Model (CCM) for the management of chronic disease in terms of mortality reduction, avoidable hospitalizations reduction and improvement of clinical parameters. MATERIALS AND METHODS: A retrospective cohort study will involve patients of 12th district of the ASL Roma 2 affected by diabetes and at high cardiovascular risk assisted through the CCM. Their health outcomes will be compared with those of patients in the same clinical conditions, residents in the same district but not assisted with CCM. The sample will be composed by adults (> 18 years) with a diagnosis of diabetes mellitus type 2 (DM2) or metabolic syndrome and / or arterial hypertension (IT) and two or more risk factors. Outcomes will be mortality from all causes and from causes related to DM and IT, preventable hospitalizations as defined in the Prevention Quality Indicators (PQI) by the Agency for Healthcare Research and Quality, and 10 clinical parameters. The data sources will be the records of causes of death (RENCAM), the hospital discharge records (SDO) and information systems for primary healthcare. CONCLUSION: Data from the experience of CCM in Tuscany seem promising especially in the evaluation of patient satisfaction and clinical outcomes particularly on cardiovascular and neurological complications and long-term mortality.


Assuntos
Doença Crônica/terapia , Assistência de Longa Duração , Modelos Organizacionais , Adulto , Doenças Cardiovasculares/terapia , Doença Crônica/mortalidade , Estudos de Coortes , Diabetes Mellitus Tipo 2/terapia , Europa (Continente) , Hospitalização , Humanos , Hipertensão/terapia , Síndrome Metabólica/terapia , Satisfação do Paciente , Atenção Primária à Saúde , Estudos Retrospectivos , Fatores de Risco , Estados Unidos
10.
J Air Waste Manag Assoc ; 66(7): 698-706, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27043167

RESUMO

UNLABELLED: An activated carbon commercially available named HGR, produced by Calgon-Carbon Group, was used to adsorbe metallic mercury. The work is part of a wider research activity by the same group focused on the removal of metallic and divalent mercury from combustion flue gas. With respect to previously published papers, this one is aimed at studying in depth thermodynamic equilibria of metallic mercury adsorption onto a commercial activated carbon. The innovativeness lies in the wider operative conditions explored (temperature and mercury concentrations) and in the evaluation of kinetic and thermodynamic data for a commercially available adsorbing material. In detail, experimental runs were carried out on a laboratory-scale plant, in which Hg° vapors were supplied in a nitrogen gas stream at different temperature and mercury concentration. The gas phase was flowed through a fixed bed of adsorbent material. Adsorbate loading curves for different Hg° concentrations together with adsorption isotherms were achieved as a function of temperature (120, 150, 200°C) and Hg° concentrations (1.0-7.0 mg/m(3)). Experimental runs demonstrated satisfying results of the adsorption process, while Langmuir parameters were evaluated with gas-solid equilibrium data. Especially, they confirmed that adsorption capacity is a favored process in case of lower temperature and they showed that the adsorption heat was -20 kJ/mol. Furthermore, a numerical integration of differential equations that model the adsorption process was proposed. Scanning electron microscopy (SEM) investigation was an useful tool to investigate about fresh and saturated carbon areas. The comparison between them allowed identification of surface sites where mercury is adsorbed; these spots correspond to carbon areas where sulfur concentration is greater. IMPLICATIONS: Mercury compounds can cause severe harm to human health and to the ecosystem. There are a lot of sources that emit mercury species to the atmosphere; the main ones are exhaust gases from coal combustion and municipal solid waste incineration. Furthermore, certain CO2 capture processes, particularly oxyfuel combustion in a pulverized fuel coal-fired power station, produce a raw CO2 product containing several contaminants, mainly water vapor, oxygen, and nitrogen but also mercury, that have to be almost completely removed; otherwise these would represent a strong drawback to the success of the process.


Assuntos
Poluentes Atmosféricos/química , Carbono/química , Mercúrio/química , Adsorção , Enxofre/química , Termodinâmica
11.
J Hazard Mater ; 281: 47-55, 2015 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-25155159

RESUMO

In this work, the results of equilibrium and dynamic adsorption tests of hexavalent chromium, Cr (VI), on activated carbon are presented. Adsorption isotherms were determined at different levels of pH and temperature. Dynamic tests were carried out in terms of breakthrough curves of lab-scale fixed bed column at different pH, inlet concentration and flow rate. Both the adsorption isotherms and the breakthrough curves showed non-linear and unconventional trends. The experimental results revealed that chromium speciation played a key role in the adsorption process, also for the occurrence of Cr(VI)-to-Cr(III) reduction reactions. Equilibrium tests were interpreted in light of a multi-component Langmuir model supported by ion speciation analysis. For the interpretation of the adsorption dynamic tests, a mass transfer model was proposed. Dynamic tests at pH 11 were well described considering the external mass transfer as the rate controlling step. Differently, for dynamic tests at pH 6 the same model provided a satisfying description of the experimental breakthrough curves only until a sorbent coverage around 1.6mgg(-1). Above this level, a marked reduction of the breakthrough curve slope was observed in response to a transition to an inter-particle adsorption mechanism.


Assuntos
Carbono/química , Cromo/química , Poluentes Químicos da Água/química , Adsorção , Concentração de Íons de Hidrogênio , Modelos Teóricos , Temperatura
12.
J Hazard Mater ; 260: 451-8, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23811366

RESUMO

This work aims to the analysis of arsenic desorption from an exhaust activated carbon used for the purification of a natural water. This last was used to mimic the properties of common groundwater or drinking water. Different low-cost and harmless eluting solutions were considered, including distilled water, natural water, saline (NaCl, CaCl2 and NaNO3) and basic (NaOH) solutions. Experimental results showed that, for 1g of activated carbon with arsenic loading close to the maximum value available for the model natural water (ω ≈ 0.1 mg/g), it is possible to recover more than 80% of the arsenic using 20 ml of 0.1 M sodium chloride solution. A temperature variation within 20 and 40 °C has scarce effect on desorption efficiency. A comparison between desorption data and adsorption isotherms data suggests that arsenic adsorption is actually a reversible process. Therefore, it is virtually possible to increase arsenic recovery efficiency close to 100% by increasing the NaCl concentration or the volume of the desorption solution, but a preliminary cost benefit analysis lead to consider a NaCl 0.1M solution as an optimal solution for practical applications.


Assuntos
Arsênio/química , Carvão Vegetal/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Absorção , Adsorção , Arsênio/análise , Carbono/química , Concentração de Íons de Hidrogênio , Ferro/química , Cinética , Controle de Qualidade , Sais/química , Cloreto de Sódio/química , Hidróxido de Sódio/química , Espectrofotometria Atômica , Temperatura , Água , Purificação da Água/instrumentação
13.
J Hazard Mater ; 192(3): 1842-50, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21803490

RESUMO

Adsorption is an effective process to remove mercury from polluted waters. In spite of the great number of experiments on this subject, the assessment of the optimal working conditions for industrial processes is suffering the lack of reliable models to describe the main adsorption mechanisms. This paper presents a critical analysis of mercury adsorption on an activated carbon, based on the use of chemical speciation analysis to find out correlations between mercury adsorption and concentration of dissolved species. To support this analysis, a comprehensive experimental study on mercury adsorption at different mercury concentrations, temperatures and pH was carried out in model aqueous solutions. This study pointed out that mercury capture occurs mainly through adsorption of cationic species, the adsorption of anions being significant only for basic pH. Furthermore, it was shown that HgOH(+) and Hg(2+) are captured to a higher extent than HgCl(+), but their adsorption is more sensitive to solution pH. Tests on the effect of temperature in a range from 10 to 55 °C showed a peculiar non-monotonic trend for mercury solution containing chlorides. The chemical speciation and the assumption of adsorption exothermicity allow describing this experimental finding without considering the occurrence of different adsorption mechanisms at different temperature.


Assuntos
Cloretos/química , Mercúrio/análise , Nitratos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Carbono/análise , Técnicas de Química Analítica , Concentração de Íons de Hidrogênio , Íons , Temperatura , Água/química
14.
J Environ Manage ; 92(1): 23-30, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20846781

RESUMO

A procedure to optimize the design of a Permeable Adsorptive Barrier (PAB) for the remediation of a contaminated aquifer is presented in this paper. A computer code, including different routines that describe the groundwater contaminant transport and the pollutant capture by adsorption in unsteady conditions over the barrier solid surface, has been developed. The complete characterization of the chemical-physical interactions between adsorbing solids and the contaminated water, required by the computer code, has been obtained by experimental measurements. A case study in which the procedure developed has been applied to a tetrachloroethylene (PCE)-contaminated aquifer near a solid waste landfill, in the district of Napoli (Italy), is also presented and the main dimensions of the barrier (length and width) have been evaluated. Model results show that PAB is effective for the remediation of a PCE-contaminated aquifer, since the concentration of PCE flowing out of the barrier is everywhere always lower than the concentration limit provided for in the Italian regulations on groundwater quality.


Assuntos
Recuperação e Remediação Ambiental/métodos , Eliminação de Resíduos , Poluição da Água/prevenção & controle , Planejamento Ambiental , Itália , Permeabilidade , Solo , Tetracloroetileno , Movimentos da Água
15.
J Hazard Mater ; 169(1-3): 360-9, 2009 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-19411134

RESUMO

The design of adsorber units is mainly dependent on the equilibrium adsorption capacity of the sorbent in the working conditions. At the moment, these data are available in a limited number of experimental conditions and, for the case of activated carbon, there are no predictive models to assess the adsorption capacity as a function of the process parameters. This makes the adsorber design a complex and approximated task. In this work, a model for the description of metallic ions adsorption onto activated carbon is presented. The model starts from an evaluation of ion speciation and it considers the approach of the multi-component Langmuir model to correlate the metal uptake to the ion concentration in solution. The model has been used to analyse available experimental data on the adsorption of As(V), Cd(II), Cr(III) and Cr(VI) ions on activated carbon. A good matching between experimental results and model predictions has been obtained for all the investigated conditions.


Assuntos
Carvão Vegetal , Metais Pesados/isolamento & purificação , Modelos Químicos , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Soluções
16.
J Hazard Mater ; 160(2-3): 428-34, 2008 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-18448247

RESUMO

This work studies the reliability of an activated carbon permeable reactive barrier in removing cadmium from a contaminated shallow aquifer. Laboratory tests have been performed to characterize the equilibrium and kinetic adsorption properties of the activated carbon in cadmium-containing aqueous solutions. A 2D numerical model has been used to describe pollutant transport within a groundwater and the pollutant adsorption on the permeable adsorbing barrier (PRB). In particular, it has been considered the case of a permeable adsorbing barrier (PAB) used to protect a river from a Cd(II) contaminated groundwater. Numerical results show that the PAB can achieve a long-term efficiency by preventing river pollution for several months.


Assuntos
Cádmio/análise , Poluentes Químicos da Água/análise , Poluição Química da Água/prevenção & controle , Abastecimento de Água/análise , Adsorção , Concentração de Íons de Hidrogênio , Nitratos/química , Permeabilidade , Espectrofotometria Atômica , Termodinâmica
17.
Water Res ; 42(8-9): 2007-16, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18222519

RESUMO

In this work the adsorption of pentavalent arsenic on a granular activated carbon (GAC) has been experimentally studied. The effects of arsenic concentration, pH, temperature and salinity on equilibrium adsorption capacity have been investigated. Experimental results show that the adsorption capacity is the highest at neutral pH conditions, low salinity levels and high temperatures. A model for the description of the arsenic adsorption mechanism is reported. This is based on the multicomponent Langmuir adsorption theory applied to the ionic species in solution. The model points out that the adsorption capacity is proportional to the concentration of arsenic anions in solution and decreases by increasing the concentration of competitive ions such as hydroxides and chlorides, allowing a correct interpretation of the pH and salinity effects on the adsorption capacity. Finally, one of the main goals of the proposed model is to preserve the exothermicity of the adsorption phenomena despite the observed trend of experimental results: the increase of adsorption capacity with temperature appears to be related to a higher arsenic dissociation.


Assuntos
Arsênio/química , Carbono/química , Adsorção , Concentração de Íons de Hidrogênio , Modelos Químicos , Controle de Qualidade , Temperatura
18.
J Hazard Mater ; 145(3): 381-90, 2007 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-17169486

RESUMO

Adsorption isotherms of chromium ions in aqueous solution have been experimentally measured on a granular activated carbon (GAC) and on a char of South African coal (CSAC). Experimental results show that the adsorption capacity for the GAC strongly depends on solution pH and salinity, with maximum values around 7mg/g at neutral pH and low salinity levels. On the contrary, the CSAC shows a smaller adsorption capacity, near 0.3mg/g, which slightly decreases by increasing pH and salinity levels. Chromium adsorption mainly depends on the availability of chromium ions in solution and on the occurrence of redox reactions between the surface groups and the Cr(VI) which lead to the formation of Cr(III). The reduction of Cr(VI) and the following sorption of Cr(III) cations appears as the leading mechanism for chromium uptake on the CSAC. A similar behaviour can be observed for the GAC at pH below 3. On the contrary, at pH>7, the multicomponent competitive adsorption of Cr(VI), OH(-) and Cl(-) has to be considered.


Assuntos
Carvão Vegetal , Cromo/química , Carvão Mineral , Poluentes Químicos da Água/química , Adsorção , Técnicas de Química Analítica , Cromo/análise , Concentração de Íons de Hidrogênio , Soluções , Poluentes Químicos da Água/análise
19.
J Hazard Mater ; 132(2-3): 220-5, 2006 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-16271826

RESUMO

In this paper the technical feasibility of various adsorbents for mercury removal from contaminated waters has been studied. Adsorption isotherms of mercury ions in aqueous solution have been experimentally measured on a granular activated carbon (Aquacarb 207EA), a char, a pozzolana and a yellow tuff. The experimental evidences show that the mercury capture capacity of yellow tuff and char is of few tenths of milligrams per gram of sorbent while for the pozzolana and the activated carbon this value is of the order of 1mg/g of sorbent. Moreover, for a mercury concentration as high as 3000 microg/l the pozzolana shows the highest adsorption capacity. This result seems to be quite interesting, especially in consideration of the extremely low cost of this natural sorbent.


Assuntos
Mercúrio/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Carbono/química , Carvão Mineral , Fenômenos Geológicos , Geologia , Mercúrio/química , Purificação da Água/economia , Purificação da Água/métodos
20.
Brain Res ; 869(1-2): 56-68, 2000 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-10865059

RESUMO

Calbindin-D 28kD is a calcium binding protein reported to protect neurons from degeneration by buffering intracellular calcium. It is expressed in midbrain dopaminergic neurons reported to be relatively resistant to degeneration in Parkinson's disease and certain of its animal models. Lesions of the nigrostriatal pathway produced in rats following injection of 6-hydroxydopamine result in a neurochemical profile similar to that seen in patients with Parkinson's disease. In the present study, brains were processed to exhibit tyrosine hydroxylase- and calbindin-D 28kD immunoreactivities in sections through the ventral mesencephalon at 3, 7, 10, 14 and 21 days after 6-hydroxydopamine had been injected into the medial forebrain bundle. Numbers of ventral mesencephalic calbindin-D 28kD immunoreactive neurons were significantly reduced ipsilateral to the lesions at 3 days post-lesion and, following slight recovery, remained significantly depleted through post-lesion day 21. The densities of calbindin-D 28kD and tyrosine hydroxylase immunoreactive neurons were different only at the 3 day post-lesion time point, when the apparent loss of calbindin-D 28 kD immunoreactive profiles was significantly greater. A lesion-induced increase in the proportion of neurons exhibiting both calbindin-D 28kD and tyrosine hydroxylase immunoreactivities, expected if calbindin-D 28kD is neuroprotective, was observed in the substantia nigra, pars compacta, but not in the ventral tegmental area. It is concluded that, while the observed losses of tyrosine hydroxylase and calbindin-D 28kD immunoreactivities do not necessarily reflect neuronal degeneration, they are not consistent with CB confering a neuroprotective advantage in the ventral tegmental area following 6-OHDA lesions as administered in this study.


Assuntos
Neurônios/metabolismo , Transtornos Parkinsonianos/fisiopatologia , Proteína G de Ligação ao Cálcio S100/metabolismo , Substância Negra/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Área Tegmentar Ventral/metabolismo , Animais , Calbindinas , Contagem de Células , Dopamina/metabolismo , Masculino , Feixe Prosencefálico Mediano/efeitos dos fármacos , Feixe Prosencefálico Mediano/patologia , Feixe Prosencefálico Mediano/fisiopatologia , Neurônios/efeitos dos fármacos , Neurônios/patologia , Núcleo Accumbens/metabolismo , Núcleo Accumbens/patologia , Núcleo Accumbens/fisiopatologia , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/patologia , Ratos , Ratos Sprague-Dawley , Substância Negra/patologia , Substância Negra/fisiopatologia , Área Tegmentar Ventral/patologia , Área Tegmentar Ventral/fisiopatologia
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