|Abstract:||Within the master work, we were researching waste waters from textile industry of a certain company. On the basis of 10-year execution of operational monitoring of waste waters, we wanted to find out, which ecological parameters swing and are not in accordance with legal criteria regarding emissions into sewerage system. We focused on the field of waste waters after colouring aramid fibres, since nowadays they have become very interesting in different areas. A spectrum of using the aramid fibres is quite broad. Research works indicate high increase of using and producing aramids in future. We defined the ecological parameters (KPK, BPK5, TOC …) of the waste waters after colouring aramid yarn and we researched a procedure of purifying the waste waters with which we partly or completely remove an auxiliary fibre agent (benzyl alcohol, carrier). The auxiliary fibre agent (benzyl alcohol, carrier), which is used for colouring the aramid yarn, causes high values of KPK, BPK5, TOC and other ecological parameters. The ecological parameters, particularly the values of KPK and TOC, represent also a standard for defining an ecological fee. The higher the value, higher the payment of the ecological fee is and it represents a significant financial cost for a company.
We divided the experimental part of the work into two contexts. In the first one we defined the ecological parameters of the waste waters after colouring the aramid yarn in a production and a laboratory. At the laboratory colouring we used two different auxiliary fibre agents, benzyl alcohol and carrier as a possible replacement, and two different pigments. In the second context of our work we were purifying these waste waters with a membrane filtration. We used two different membranes and we filtered the waters at the same pressure – 2 bars. We anew carried out the measuring of the ecological parameters and we defined a resistance to rubbing, washing and light of the coloured aramid yarn, and we measured colour differences, which have, regarding threads, an important influence on a certain purchaser.
The results of the research work showed that the waste waters, after colouring the aramid yarn, can be purified with the membrane filtration – ultra filtration. Within the laboratory and the production colouring, we managed to reduce the ecological parameters of the waste waters for 30 %.|