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Activated carbons application to remove non ionic surfactants drom wastewater produced by an italian metallurgic plant
Full text linkThe performance of different activated carbons for the removal of nonionic
surfactants from metallurgic wastewater was assessed through lab scale
experiments. Two different matrices were used: a simple one, obtained by
dissolving different amounts of a single nonionic surfactant (Triton X100) in
distilled water, and a complex matrix, prepared as above but using surfactantsfree
wastewater from an Italian metallurgic plant as solvent. In this way the main
operative parameters that affect the adsorption process in the simple matrix have
been studied avoiding the interference due to the complex matrix; then the results
were utilized to define and optimize the tests carried out on the complex matrix.
The adsorption equilibrium experimental data were best fitted with a Langmuir
isotherm, allowing defining the contact time and the proper design parameters for
the adsorption column. The different tests were performed on four different
activated carbon types, and the removal efficiency and the treatment cycle
duration for each of the tested carbons were discussed and compared. Theexperimental results showed that the saturation adsorption capacity is not
notably correlated either with the pH value or with the water matrix, whereas the
slope of the isotherm, defined by the Henry constant, is sensibly higher at strong
acidic or alcaline conditions, with a minimum value at nearly neutral pH.
Therefore, it was concluded that the removal efficiency is maximized when the
operative pH was in the 2–4-unit value range. The best activated carbon, in terms
of removal efficiency, resulted to be a mineral activated carbon, characterized by
the highest iodine number, and thus with the largest porosity. Removal
efficiencies were in the 60 to 80% range
Diabetes mellitus after liver transplantation: a possible relation with the nutritional status
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A comparative study of metabolic and hormonal responses to somatostatin and propranolol in man
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Vita da hijra: amore e passioni oltre i margini
No full textThe hijras are members of traditional Indian communities of transgender women, who historically have occupied marginal and liminal roles within Indian culture. The historical analysis of the roles and rituality of hijra communities is conducted through the constant reference to the particular emotional universe that unfolds with respect to the choices and fractures that influence the lives of these individuals, insisting above all on the knot of love and erotic passion, which, in contrast to the ascetic imagery to which the hijra communities traditionally refer, strongly marks the lives of these people, often in new and unexpected ways
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