EU Tests Ultrafiltration and Ultrasound on Textile Effluents
The PURIFAST project aims to discover whether of combination of these technologies can replace reverse osmosis in removing organic components of water.
As part of the PURIFAST project, the EU Commission has provided 2.2 million euros to help fund the development of an innovative and efficient method of treating problematic effluents such as those produced in the textile industry.
In addition to the input from Germany – comprising the ultrafiltration specialists inge watertechnologies and the Rhine-Westphalian Institute of Water Research (IWW Water Centre) – other partners in the project include GIDA, Next Technology Tecnotessile and the companies LAVO and Tintoria King Colour from Italy, as well as the University of Florence and the French company Polymem.
The PURIFAST project aims to discover whether a combination of ultrafiltration and ultrasound can replace reverse osmosis in removing organic components of water such as dyes subsequent to ultrafiltration. The goal is to establish a method of treating textile effluents that optimizes both the ecological and economic aspects.
Ultrafiltration treats water using purely physical means in order to remove suspended solids, particles and bacteria. Textile effluents feature a high degree of contamination, which poses a particular challenge to the ultrafiltration membrane. inge watertechnologies AG has been conducting research as part of the PURIFAST project in order to optimally tailor both its patented Multibore membrane and process control system to the project's requirements. The aspects being addressed include pore size and geometry, membrane hydrophilicity, determining the best flux and the optimum backflush flow rate, deploying cleaning chemicals and minimizing their use.
In order to put the new technique to the test, a facility has been set up in the textile town of Prato in Tuscany to treat the municipal wastewater, which is heavily contaminated by the textile industry. This test project involved the simultaneous installation of three, independently controlled membrane lines to enable the optimum adjustments to be identified as quickly as possible. The acid test comes next year with the installation of the process at the textile dyeing facilities of the Italian company Tintoria King Colour.
Peter Berg, chief technology officer of inge watertechnologies AG, explains further: “If we succeed in cleaning up textile effluents at a reasonable cost using ultrafiltration and ultrasound, this should lead to a boom in the recycling of industrial effluents. The treatment of organic substances such as dyes in ultrafiltered water is currently tackled by reverse osmosis. However, this is an expensive method, especially when you consider the amount of energy it requires. If ultrafiltration and ultrasound can provide a better return on investment, then nothing will stand in the way of deploying this new system on a global scale.”
In the textiles industry, large quantities of water are used in the various production processes, and it is also used to clean up machinery (for example, rinsing out dye residues). A bleach works requires 50m³ to 100m³ of water per ton of product, while a dye works uses between 20m³ and 50m³. This water ends up as effluent, and the residue of dyes and certain chemicals it contains is unavoidable. Most of the substances are of an organic nature.