In the textile industry it is advantageous to apply membrane technologies to recover water, auxiliary chemicals and energy. In this way the traditional money wasting process of pollution control can be converted in to a profitable operation. Moreover, by recycling the waste effluents all the environmental problems connected with the discharge of polluted effluents are avoided.
Innovative membranes and the relevant reverse osmosis processes have been developed. As a result hot water and auxiliary chemicals from effluents of textile plants can easily be recycled. This allows the approach to a quasi zero discharge system.
The major results are on the one hand, the development of both membranes and modules suitable for the recovery of water and chemicals from textile effluents, and on the other hand, the development and the qualification testing of the pilot plants in optimised technicoeconomical conditions. Within the framework of the project, innovative membranes, novel highly resistant asymmetric membranes in new special polyamides, as well as reverse osmosis processes well adapted to the textile industry, have been developed and tested in industrial conditions.
Morever, there is no current competing technology which combines all three recovery treatments : effluents, hot water and auxiliary chemicals.
The development of a laboratory spinning machine was carried out to spin hollow fibre membranes according to a dry jet wet process with a horizontal spinning set up and and which used stretching. To this end experiments were carried out in the following phases: developing and testing a laboratory spinning machine consisting of a spinning nozzle and a compressed air transport system for the spinning solution; formation of hollow fibres in a spinning bath; spooling of the hollow fibres.
The energy consumptions of textile processes were analysed and compared with new systems where membrane technologies have been introduced. The potential concentrations of dyes and salts have been tested in a reverse osmosis pilot plant. The hydrodynamic characteristics of the spiral wound modules used and an evaluation of their efficiency in terms of rejection, fluxes and life time of the membranes have been studied. Substitution factors related to the electrical energy consumption in reverse osmosis and in an integrated reverse osmosis membrane distillation process have been calculated and compared to cycles with and without chemical recovery.
MEMBRANE AND MEMBRANE PROCESSES HAVE BEEN DEVELOPED TO TREAT EFFLUENTS FROM TEXTILE INDUSTRIES. THE PROCESS USED IS REVERSE OSMOSIS. THE MEMBRANES CAN BE APPLIED TO REACH ONE OF MORE OF THE FOLLOWING OBJECTIVES:
1. TO RECOVER WATER AND-OR AUXILIARY CHEMICALS
2. TO ENHANCE TRADITIONAL WASTE DISPOSAL METHODS;
3. TO REDUCE THE WASTE TO BE TREATED BY CONCENTRATING IT.
THESE OBJECTIVES WERE NOT ECONOMICALLY POSSIBLE BEFORE DUE TO THE FACT THAT THE COMMERCIALLY AVAILABLE MEMBRANES WERE NOT ADEQUATE AND THE ENGINEERING OF THE PROCESS WAS NOT SUFFICIENTLY DEVELOPED.
Funding SchemeCSC - Cost-sharing contracts
87036 Commenda Di Rende Cosenza