13,516 research outputs found

    Does ozonation enhance activated carbon adsorption of PFAS in textile wastewater?

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    Per- and polyfluoroalkyl substances (PFAS) are used in numerous industrial applications, such as in textile manufacturing, because of their special chemical properties. To avoid PFAS spread in the environment, removal strategies need to be implemented at the wastewater treatment plants (WWTP) to reduce their environmental risk on receiving water bodies. The fate of 14 PFAS in a full-scale WWTP treating textile and civil wastewater (WW) was investigated. The addition of an adsorption step before or after the ozonation process was studied through adsorption isotherms tested on the WW collected before and after the full-scale ozonation step. Ozonation is not aimed at PFAS removing, but it lowers organic matter competition towards long-chain PFAS in the following adsorption step. The removal of UVA254 seems to be a good proxy variable for PFAS adsorption, with relationships not dependent on the presence of ozonation step

    Sound velocity and absorption measurements under high pressure using picosecond ultrasonics in diamond anvil cell. Application to the stability study of AlPdMn

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    We report an innovative high pressure method combining the diamond anvil cell device with the technique of picosecond ultrasonics. Such an approach allows to accurately measure sound velocity and attenuation of solids and liquids under pressure of tens of GPa, overcoming all the drawbacks of traditional techniques. The power of this new experimental technique is demonstrated in studies of lattice dynamics, stability domain and relaxation process in a metallic sample, a perfect single-grain AlPdMn quasicrystal, and rare gas, neon and argon. Application to the study of defect-induced lattice stability in AlPdMn up to 30 GPa is proposed. The present work has potential for application in areas ranging from fundamental problems in physics of solid and liquid state, which in turn could be beneficial for various other scientific fields as Earth and planetary science or material research

    PFAS in textile wastewater: an integrated approach to reduce the environmental risk for their mixture

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    Per- and polyfluoroalkyl substances (PFAS), used in several industrial applications, are gaining increasing concern due to their spread in the environment, their stability and eco-toxicity. To avoid PFAS spread in the environment, reducing the environmental risk on receiving water bodies, removal strategies need to be implemented at both industrial and municipal wastewater treatment plants (WWTP). This study presents a case study in a textile district in northern Italy where PFAS monitoring campaigns were combined with testing at lab and pilot-scale of two promising removal processes (membrane separation, adsorption on activated carbon) and data used for environmental risk assessment. This combination was proved to be useful to support the identification of the optimal combination of prevention and treatment interventions to be applied at different system points to reduce the environmental risk

    Adsorption on activated carbon for PFAS removal: should we act at the source or before the discharge into the environment?

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    Per- and polyfluoroalkyl substances (PFAS), used in several industrial applications, such as textile production, are gaining increasing concern due to their spread in the environment, their stability and eco-toxicity. To avoid PFAS spread in the environment, removal strategies need to be implemented at both industrial and municipal wastewater treatment plants (WWTP). This study presents a case study in a textile district in northern Italy where PFAS removal in wastewater (WW) through adsorption on activated carbon was tested at lab and pilot-scale at different points of the system (textile companies and municipal WW treatment plant). This lab-testing was proved to be useful to identify where to apply such process in the system and to optimize process configuration and operating conditions

    A procedure for the fatigue life prediction of straight fibers pneumatic muscles

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    Different from the McKibben pneumatic muscle actuator, the straight fibers one is made of an elastomeric tube closed at the two ends by two heads that ensure a mechanical and pneumatic seal. High stiffness threads are placed longitudinally into the wall of the tube while external rings are placed at some sections of it to limit the radial expansion of the tube. The inner pressure in the tube causes shortening of the actuator. The working mode of the muscle actuator requires a series of critical repeated contractions and extensions that cause it to rupture. The fatigue life duration of a pneumatic muscle is often lower than traditional pneumatic actuators. The paper presents a procedure for the fatigue life prediction of a straight-fibers muscle based on experimental tests directly carried out with the muscles instead of with specimens of the silicone rubber material which the muscle is made of. The proposed procedure was experimentally validated. Although the procedure is based on fatigue life duration data for silicone rubber, it can be extended to all straight-fibers muscles once the fatigue life duration data of any material considered for the muscles is known

    Multi-wavelength analysis of the field of the dark burst GRB 031220

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    We have collected and analyzed data taken in different spectral bands (from X-ray to optical and infrared) of the field of GRB031220 and we present results of such multiband observations. Comparison between images taken at different epochs in the same filters did not reveal any strong variable source in the field of this burst. X-ray analysis shows that only two of the seven Chandra sources have a significant flux decrease and seem to be the most likely afterglow candidates. Both sources do not show the typical values of the R-K colour but they appear to be redder. However, only one source has an X-ray decay index (1.3 +/- 0.1) that is typical for observed afterglows. We assume that this source is the best afterglow candidate and we estimate a redshift of 1.90 +/- 0.30. Photometric analysis and redshift estimation for this object suggest that this GRB can be classified as a Dark Burst and that the obscuration is the result of dust extinction in the circum burst medium or inside the host galaxy.Comment: 7 pages, 5 figures, accepted for publication on A&

    An evaluation of |Vus| and precise tests of the Standard Model from world data on leptonic and semileptonic kaon decays

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    We present a global analysis of leptonic and semileptonic kaon decay data, including all recent results published by the BNL-E865, KLOE, KTeV, ISTRA+ and NA48 experiments. This analysis, in conjunction with precise lattice calculations of the hadronic matrix elements now available, leads to a very precise determination of |Vus| and allows us to perform several stringent tests of the Standard Model.Comment: LaTeX, 25 pages, 12 figures, 16 tables. Submitted to EPJC. v2: Minor changes for accepted version. No numerical results change
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