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New titanium dioxide (TiO2) based catalysts were prepared by impregnating commercial zeolites in pellets form using a sol–gel technique. Characterization was done with chemical analysis, X-Ray diffraction, scanning electron microscopy, and BET measurements, together with volatile organic compounds (VOC) adsorption equilibrium experiments. TiO2 happened to fix on the inert binder leading to a close intimacy of mixing with the zeolites crystallites, without significant modification of support properties. A diffusion cell was used to produce dilute polluted air streams for dynamic experiments, in which adsorption and photodegradation phases were alternatively carried out. Regeneration of adsorbent was evaluated regarding experimental conditions. Through a comparison with the results obtained on impregnated mesoporous borosilicate beads, it was clarified that zeolite supports had no effect on 1-butanol (BuOH) photooxidation mechanisms. Yet, evidence for mass transfer limitation was found, and attributed to intracrystalline diffusion in zeolites. [Copyright &y& Elsevier]

[Display omitted] • Ozonation removes up to 81% of heavy coke formed on ZSM-5 during pyrolysis of LDPE. • Diffusion-reaction balance drives O 3 mass transfer (homogeneous/shrinking-core). • Thermal recombination of O 3 is marginal facing catalytic degradation and oxidation. • Radial coke profile over pellets is acquired with original analytical technique. This work focuses on regeneration of coked catalysts using ozonation as an alternative process to typical coke combustion with oxygen. Different samples of coked ZSM-5 zeolites obtained during catalytic pyrolysis of polyethylene at 450 °C were exposed to an ozone enriched stream in a fixed-bed reactor. The influence of main operating parameters (time of exposure, temperature, O 3 inlet concentration and gas volumetric flowrate) were studied by evaluating coke removal efficiency and by observing regeneration behavior both at pellet and reactor scales. These experimental results led to a better insight of the diffusion–reaction phenomena occurring during the process. Diffusion limitations were illustrated thanks to an innovative method, the analytical acquisition of carbon radial profiles on catalyst pellets, while the apprehension and quantification of competing reactivity (thermal, catalytic and oxidation) gave a better understanding of the ozonation process. Time of exposure and temperature were found to significantly affect carbon removal efficiency, while inlet ozone concentration and flowrate influence were respectively moderate and null in the investigated range. Similarly to combustion, coke ozonation is driven by a balance between diffusion and reactivity, leading to the appearance of a mix of known regeneration regimes depending on the operating conditions: homogeneous and shrinking-core. [ABSTRACT FROM AUTHOR]

In wastewater treatment facilities, air quality is not only affected by conventional unpleasant odour compounds; toxic volatile organic compounds (VOCS) are also found. In this study, the adsorptive capacity of Chilean natural zeolite toward VOC removal was evaluated. Moreover, the influence of zeolite chemical surface properties on VOC elimination was also investigated. Three modified zeolite samples were prepared from a natural Chilean zeolite (53% clinoptilolite, 40% mordenite and 7% quartz). Natural and modified zeolite samples were characterised by nitrogen adsorption at 77 K, elemental analyses and X-ray fluorescence (XRF). Chemical modifications of natural zeolite showed the important role of Brønsted acid sites on the abatement of VOCS. The presence of humidity has a negative effect on zeolite adsorption capacity. Natural zeolites could be an interesting option for benzene, toluene and xylene vapour emission abatement. [ABSTRACT FROM AUTHOR]

Removal of bio-recalcitrant and toxic compounds from wastewaters has been a major objective of industrial manufacturers for a few years. Due to the potential risk toward public health, regulations are becoming increasingly strict and classical treatments like biological treatments are not efficient. Other techniques such as incineration, oxidation or adsorption provide higher levels of removal but with a high energy and capital cost. A coupled process involving adsorption and oxidation is studied. Four adsorbents are tested and compared according to two objectives, their adsorption capacity and their capability to decompose ozone into powerful hydroxyl radicals. Two model compounds were chosen: 2,4-dichlorophenol and nitrobenzene. Experimental results allow comparing coupled process with results obtained during ozonation alone. Zeolite (Faujasite Y) gave disappointing results in term of both adsorption kinetics and ozone decomposition. On the contrary, activated carbons showed fast adsorptions and important capabilites to decompose ozone into radicals, almost in nitrobenzene experiments. S-23 activated carbon proved to be the most interesting adsorbent for better mechanical and chemical stabilities over time. Sequential adsorption/ozonation experiments were conducted, showing a strong loss of adsorption efficiency after the first operation, but the positive point is that the adsorption capacity remains almost constant during further cycles. [ABSTRACT FROM AUTHOR]

Study of the catalytic deactivation during successive uses of ZSM-5 catalysts in bench-scale pyrolysis of low-density polyethylene (200:20 g LDPE:ZSM-5) has been carried out in a semi-batch reactor at 450 °C. The correlation between coke formation over catalyst properties and selectivity during pyrolysis is observed. The loss of catalytic performances translates into a significant drop of aromatics and an increase of waxes in pyrolysis products. The observed deactivation is due to the formation of heavy coke over the catalysts, causing surface hindering, porosity blockage and acid sites diminution. The capacity of ozonation process to regenerate such coked catalysts around 100 °C is demonstrated using a fixed bed reactor. Different times of exposure are investigated to evaluate ozonation efficiency. By using this coke oxidizing treatment during 48 h, regenerated catalysts recovered their initial textural and chemical characteristics (porous volume and acidity) as well as their catalytic performances (similar aromatics proportion as the first pyrolysis). [Display omitted] • Coke formation in LDPE pyrolysis leads to lowered aromatic and gasoline fractions. • ZSM-5 microporosity and Brønsted acid sites are heavily impacted by pore blocking. • Ozonation at 100 °C allows heavy coke removal and catalytic properties regeneration. • Reuse of ozonated catalysts forms similar products as fresh ZSM-5 pyrolysis use. [ABSTRACT FROM AUTHOR]

The article presents a study which prospectively evaluates an ultrasound-based scoring system as a method for triaging asymptomatic women presenting with an adnexal mass for surgical treatment. One hundred eighty-nine asymptomatic women were included in the study, and were evaluated by transvaginal power Doppler ultrasound imaging before surgery. It was found that ultrasound-based triage of ovarian tumors in asymptomatic women is effective for providing the most appropriate surgical approach.

Ten clinical laboratories in different regions of Spain have shared the search for reference individuals and the production of reference values for quantities concerning ferritin, transferrin, rheumatoid factors, C-reactive protein and antistreptolysin O, using Tina-Quant® reagents systems and RD/Hitachi analysers. All the logistic work has been done in co-operation with the supplier of the reagents and analysers (Roche Diagnostics España, S.L., Barcelona). The reference limits produced in the virtual laboratory are derived from the blend of reference values obtained by each laboratory. The multicentric reference limits were estimated according to the recommendations of the International Federation of Clinical Chemistry. The work done is a model of co-operation between the in vitro diagnostic industry and clinical laboratories for the production of reference values. [ABSTRACT FROM AUTHOR]

An abstract of the conference paper "Ultrasound features of metastases in the ovary depending of the origin of the primary tumor," by M. Ariu and colleagues is presented.

An abstract of the conference paper "Ultrasound features of rare primary malignant ovarian tumors," by S. Guerriero and colleagues, is presented.

An abstract of the conference paper "Gray-scale ultrasound and Ca-125 levels for diagnosing ovarian cancer in more than 1700 women," by S. Guerriero and colleagues, is presented.

An abstract of the article "Additional value of CA-125 to ultrasound for predicting specific diagnosis of benign adnexal cysts in premenopausal women," by J. Minguez, M. Angiolucci and M. Garcia Manero is presented.

An abstract of the conference paper "CA-125 versus power Doppler as second step technique for predicting ovarian cancer in a large cohort of women with adnexal masses," by S. Guerriero and colleagues is presented.

An abstract of the conference paper "Transvaginal color Doppler in the detection of ovarian cancer in a large study population of postmenopausal women," by S. Guerriero and colleagues is presented.

An abstract of the conference paper "Differential diagnosis of the most common benign ovarian cysts using transvaginal ultrasonography: Results of Sardinia-Navarra (Sa.Na.) group," by S. Ajossa and colleagues is presented.

An abstract of the conference paper "Triage for surgical management of ovarian tumors in symptomatic women: Assessment of an ultrasound-based scoring system," by J. L. Alcazar and colleagues is presented.

An abstract of the article "Transvaginal color Doppler in the detection of ovarian cancer in a large study population: Results of sardinia-navarra (Sa.Na.) group," by S. Guerriero and colleagues, is presented.