Treatment of Textile Wastes

Abstract

The production of a textile requires several stages of mechanical processing such as spinning, weaving, knitting, and garment production, which seem to be insulated from the wet treatment processes like pretreatment, dyeing, printing, and finishing operations. Тhere is a strong interrelation between treatment processes in the dry state and consecutive wet treatments. Most of the processes and products have a negative impact on the environment. Laws and standards for environmental protection and prescribed strict criteria, in accordance with the laws of the European Union, forced this to be in the spotlight of the textile industry. The textile industry emits a wide variety of pollutants in all stages in the processing of fibres and textile materials. They are: liquid effluent, solid waste, hazardous waste, emissions in the air and noises. Most of the textile waste is composed of natural and synthetic polymeric materials such as: cotton, polyester, nylon, and polypropylene. Recovery from the waste stream includes re-use of a product in its original form and recycling to convert the waste into a new product. Textile recycling is one of the categories for waste management in the textile industries.Typically, recycling technologies are divided into: primary, secondary, tertiary and quaternary approaches. Primary approaches involve recycling a product into its original form. Secondary recycling involves melt processing a plastic product into a new product that has a lower level of physical, mechanical and chemical properties. Tertiary recycling involves processes such as: pyrolysis and hydrolysis, which convert the plastic wastes into basic chemicals or fuels. Quaternary recycling refers to burning the textile solid waste and utilizing the heat generated. The predominant method of solid textile waste managment is landfilling. The processes of production of textiles or wet treatments and finishing processes of textile materials (finishing, dyeing, printing, etc..) are huge consumers of water with high quality. As a result of these various processes, considerable amounts of polluted water are released. There is no single effective treatment of wastewater from the textile industry and it is necessary using a combination of methods in order to achieve the required standards. End-of-pipe technologies are used for wastewater treatment and include sequential application of a set of methods: coagulation / flocculation, flotation, adsorption, evaporation, oxidation, combustion, usе of membranes, etc., that have been adapted to the particular situation of a textile plant. As a result of the extreme variety of textile processes and products, it is impossible to develop a realistic concept for an effective treatment of wastewater without a detailed analysis of the actual situation in the textile plant. It is important to explore all aspects of reducing emissions and waste products from the textile industry because it will result not only in improved environmental performance, but also in substantial savings on individual textile companies.