Investigation of New Techniques Used in the Removal of Dyes in Textile Wastewater

Abstract

Recently, industrial development which is increasing fast gives rise to environment problems and has negative effects on all living organisms. Especially wastewaters which are originated from industries are the biggest factor of that issue. Among these industries, the textile industry being one of the most polluting industries is the source of enormous quantities of colored and toxic wastewaters; because of its need to large volumes of water is used in different production steps.

Between the various processes in the textile industry, the dyeing process uses large volumes of water for dyeing, fixing and washing. The constituents of dyeing process wastewater is characterized by suspended particles, surfactants and toxic chemicals, salts, high pH and chemical oxygen demand (COD) concentrations that discard of these toxic wastewaters to the environment will cause a major problem. Particularly, dyes are considered as important pollutants in textile wastewater.

The currently existing different treatment methods are physical, biological, chemical methods for textile industry wastewaters. However there is a need to develop innovative and alternative technologies that can remove toxic and carcinogenic dyes from environment in addition to the current techniques. Combinations of these methods which are among recent studies such as chemical coagulation/flocculation, ozonation, advanced oxidation, chemical precipitation, ionic exchange, electrochemical destruction, irradiation, reverse osmosis, ultrasound technology, nanotechnology techniques and adsorption processes are applied for the removal of dyes from dye containing wastewater.