**3. Conclusion**

Textile industry, which is dominated by small and medium enterprises (SMEs), has a wide variety of products with different colors, fabrics, and fabric types by its nature. Additionally, wet processes consume large amount of water, energy, and chemicals, which are expensive to separate in the treatment processes. In the last decades, the studies with environmental and financial considerations in the textile industry have been increased, and they offered cleaner production approach, such as best available techniques (BAT) referred by the European Council and the nonconventional (metaheuristic) optimization methods, instead of end-of-pipe approach.

From the literature, it was revealed that BAT actions offer a substantial water and energy savings up to 65 and 70%, respectively. However, many of the studies involve potential implementation results, not the real ones. Therefore, more implementation studies should be conducted on actual processes in order to encourage the other enterprises.

Through the age of Industry 4.0, the enterprises, which use intelligent techniques and effective planning, will survive. Consequently, the studies on the optimization of the dyeing process scheduling have become more complex and

#### *Textile Industry and Environment*

multi-objective to be solved with nonconventional optimization methods. In the literature, only a few studies were found because of the novelty of the subject. However, those studies were indicated a remarkable environmental benefit while reducing the costs of the wastewater treatment process. The reduction of water consumption was obtained up to 30% without any installations to the process.

When the literature on BAT and metaheuristic studies are compared, it is seen that the studies used BAT has more industrial sense and feedback; however, just insufficient number of studies that were used metaheuristic optimization quantified the improvement on the studied processes. The information on the application of the novel optimization methods on the actual industrial applications is necessary. Therefore, future studies on this subject will be fruitful for the literature.
