Advanced Purification of Industrial and Mixed Wastewater by Combined Membrance Filtration and Sonochemical Technologies

Abstract

The textile sector plays a critical role in this context, because textile companies are large users
of water - typically 0.2-0.5 m3 are needed to produce 1 kg of finished product [1] – and they
are historically concentrated in districts (e.g. Prato in Italy) located in Southern Member
States, such as Italy, Spain and Portugal, which are facing more and more longer periods of
drought and therefore are strongly in the need to preserve the availability of water for potable
use. The finishing processes (i.e. pre-treatment, dyeing, printing and special finishing) are
especially polluting and resource consuming in terms of water, energy and chemicals. Almost
the entire of water used in textile production is discharged and, on average, the effluents
volume covers 90-95% of the water used [2].
According to that, a new Ultrafiltration/Sonichemical combined process has been investigated
on textile wastewater by evaluating the reduction of the pollution load induced by physical
separation and by chemical oxidation promoted by Ultrasound cavitation. The experimental
campaign carried out at the Municipal Wastewater treatment Plant in Prato showed that the
quality of the treated water reaches the target reported in literature [3] for textile
manufacturing sectors. An estimation of the costs of the purified water has been assessed and
the combined process seems to be promising for further development.
The authors would like to thank the European Commission to funding this project (contract
number LIFE07/IT/000439) within the LIFE+ Environmental Policy and Governance 2007
Programme.