Water is one of the vital resources for food, sanitation, production input in industry and sustainability of the world's ecosystem. Water scarcity creates challenges with national, regional and seasonal water shortages in some parts of the world. Water scarcity is increasing with the new water development costs, degradation of soil in irrigation areas, underground water depletion, degradation of water related ecosystems and industrilization. The textile industry that causes water pollution includes production processes where water consumption is the largest.
The textile sector has a heterogeneous structure that consists of many sub-sectors: synthetic fiber production, natural, synthetic fiber preparation and yarn production; fabric weaving, knitting, non-woven fabric production and carpet manufacturing processes. However, depending on the type of fiber to be processed in the industry and customer demands, dyestuff type used may differ in finishing-dyeing technique, finishing processes. The wastewater generated in the textile industry generally varies considerably in terms of quantity and composition. There are three major pollutants found in textile effluent which include color, dissolved solids and toxic metals. The differences in the operational processes and technologies that are renewed every day reflect on the composition of the wastewater. Since washing, dyeing and bleaching processes require large amounts of water, high volumes of colored and low organic matter can cause wastewater. In this wastewater, in general, many pollution parameters such as COD, pH, BOD5, color and salinity show high values and every process applied in parallel with different technologies in the industry makes it impossible to treat the released wastewater by a standard treatment method.
Textile waste waters consist of dyes, suspended solids, organic substances. When colored components in wastewater are discharged into water bodies together with wastewater, it stops the reoxygenation capacity of the receiving water and prevents absorbing sunlight. Thus, it disrupts the biological activity in the water. The variety of textile products is increasing day by day. As different variables of dyes according to chemical properties are used in the production process, textile wastewaters are difficult to treat.
Textile wastewater is one of the most polluted wastewater due to its high chemical oxygen demand (COD), intense color, high pH, high temperature and low biodegradability. Synthetic dyes in large-scale production can cause health problems (allergies and skin irritation), harm marine animals due to toxic effects (mutagenic or carcinogenic).
Fast fashion is quickly changing in the clothing industry. Clothes are designed and manufactured quickly every week. Fast fashion also describes "low-cost clothing". Affordable clothes are mainly manufactured from syntetic textile fibers that cause microplastic pollution in water.
According to the published Global Risks Report 2018, environmental risks are related to water contamination. Water risks are ranked at the top 5 global risks. The U.N. Sustainable Development Agenda aims by 2030 to improve water quality by reducing pollution, minimizing release of hazardous chemicals and substantially increase water-use efficiency across all sectors.
Sustainable fashion should include a cycle of design, production, use and disposal. The cycle consists of recycling clothes, reducing emission and water consumption, as well as less chemicals in production. Nowadays, even if sustainability seems to be crucial, recent studies shows that the fashion industry has not reached the full potential of sustainability. In the current situation, manufacturing plans are not sustainable enough to maintain water resources.