**1. Introduction**

Textile is an ancient industry that goes back to the beginning of the history of humanity, and its products range from products of daily usage to technical ones. All kinds of garments obtained by processing knitted, woven and nonwoven fabrics are categorized as the apparel sector. Actually, textile production is one of the main industries that affect global environmental pollution, as both the production and the processing of the necessary raw materials are contributing factors to pollution. Another important aspect of the problem is the waste that results from both production and consumption of the textile goods. Though technically all waste in the textile and garment sector can be recycled, unfortunately, only a small amount is recycled. As long as the linear system currently utilized in the production goes on, it seems that we will not be able to use the resources efficiently and reduce the environmental pollution.

Given that the current global trends persist, by 2050, the textile sector is expected to represent a quarter of the world carbon budget—26%, to be precise. The figures are colossal: If the current trends do not shift, the textile and apparel sector's nonrenewable raw material usage will reach 300 million tons and the amount of microplastic released to the oceans will reach 22 million by 2050 [1].

One key concept to analyze and understand the situation is the linear economy. As the dominant model of production at least since the Industrial Revolution, linear economy basically works as "subtract the raw material from the source, convert it into a product, sell the product to the consumer, which eventually gets disposed of by the consumer after usage." Under this model, products discarded by the consumer become waste and are generally disposed of ending up in landfills or by incineration [2].

The basis of the linear economy approach is the consumption of the raw material required for production. It seems that the limited resources available to us in the world will not provide the conditions for the current dominant economic model to go on as today. The actual perception of raw materials is not sustainable. Moreover, linear economy-oriented production and business models become a burden for the environment—the environmental aspect, the damages they cause and the waste that results from them are generally not considered.

An alternative to this traditional production model is what is called a "circular economy": "A circular economy is based on the principles of designing out waste and pollution, keeping products and materials in use, and regenerating natural systems" [3].

In contrast to the negative aspects of the linear economic approach, the circular economy is seen as a sustainable development model for the future and increasingly stands out as an approach that is becoming widespread in the world. The circular economy is a systems model in which every part of a product is considered as a valuable resource that should be handled with care and resources are circulated again and again through closed loops.

The basis of the circular economy model is to expand the life-span of a product via repair, reuse, remanufacturing and recycling, so that resources are used more efficiently and the need for new products and virgin raw material is reduced or ideally eliminated [2].

In order to ensure sustainability and reduce environmental impacts in the textile and apparel sector, utilizing a circular economy model is of utmost importance. Recycling of textile waste is a requirement for the implementation of a circular model. This study presents a general evaluation of recycling of textile wastes, in terms of ensuring sustainability and minimizing environmental impacts.
