Download - Europe Direct Iasi

CLASS 1 EUROINVENT 2010 CLASA 1
Description
EN
Descriere
RO
In the textile finishing and dyeing industries, the total volume of
water consumed is around 150 millions tons/year, meaning that
very large quantities of water are processed and produced as
wastewater by textile plants worldwide. Quality indicators of textile
wastewaters, like BOD and COD, have values which, in some
cases, exceed 5 times the maximum concentration value (allowed
by the national quality standards). One of the greatest concerns in
wastewater treatment of a textile effluent is the colour, not only as
an aesthetic problem, but also as a pollution problem. Dyes and
pigments from the printing and dyeing operations are the principal
sources of colour in this type of effluents with concentrations in the
final effluent around 10 mg/L. Recovery, recycling and reuse must
be effective tools in minimizing pollutant releases in the
environment. Usually, ultrafiltration is used as a single step in
advanced wastewater treatment, either for internal or external
recycling. The aim of this study is to obtain higher removal
efficiencies of contaminants using an innovative 2 step advanced
treatment: ultrasonication, followed by ultrafiltration. During the
treatment ultrasonication destroys most of the dye molecules and
ultrafiltration retains the remaining dye molecules and suspended
solids and colloids formed in the previous process. The integrated
process of ultrasonication-ultrafiltration is proved to be very
efficient not only in the removal of dyes but also for phenolic
compounds. The removal efficiencies obtained are over 80% for
organic compounds such as dye molecules and over 98% for
suspended solids and colloids.
In industria textila, volumul total de apa consumata este de
aproximativ 150 milioane t/an, ceea ce inseamna ca o cantitate
foarte mare de apa este utilizata in procese si este apoi evacuata ca
apa uzata din unitatile industriale textile din intreaga lume.
Indicatorii de calitate ai apelor uzate din industria textila, cum ar fi
consumul biochimic de oxigen CBO 5 si consumul chimic de oxigen
CCO-Cr, au valori care, in unele cazuri, depasesc de 5 ori
concentratiile maxim admisibile (indicate de standardele nationale
de calitate).
Una dintre principalele probleme in ceea ce ce priveste epurarea
efluentilor din industria textila este culoarea, nu doar din motive
estetice, ci mai ales din motive de poluare. Colorantii si pigmentii
proveniti din operatiile de vopsire sunt principalele surse de culoare
in acest tip de ape uzate, avand concentratii in jurul valorii de 10
mg/L in efluentul final.Recuperarea, recircularea si reutilizarea
apelor epurate trebuie sa constituie instrumente eficiente in
minimizarea emisiilor de poluanti in mediu. In general, ultrafiltrarea
este utilizata ca unica treapta de epurare avansata a apelor uzate, fie
pentru recircularea interna sau externa. Scopul acestui studiu este de
a obtine grade de epurare ridicate a poluantilor, folosind un
procedeu inovativ in 2 trepte de epurare: ultrasonarea, urmata de
ultrafiltrare. In timpul procesului, ultrasonarea descompune
majoritatea moleculelor de colorant, iar ultrafiltrarea retine
moleculele de colorant ramase si solidele in suspensie si coloizii
formate ulterior. Procesul integrat de ultrasonare-ultrafiltrare este
foarte eficient nu numai pentru eliminarea colorantilor, dar si pentru
30