Recent Advances in Textile Wastewater Treatment Using Nanoporous Zeolites

This review study deals with low-cost nanoporous zeolite for color removal from textile wastewaters. Wastewater from textile industries contains colorants originating from printing or dyeing processes. Basic and reactive dyes are extensively used in the textile industry due to their favorable characteristics of bright color, being easilywater soluble, simple application technique and low-energy consumption. Yet, they can not be easily removed via conventional treatment methods since they strongly resist to biodegradation in an aerobic environment. Oxidation and adsorption are two major technologies that are used for wastewater treatment in the textile industrywhile adsorption-based removal of colorants along with other organic pollutants from industrialwastewater is considered an important application. Zeolites are becoming widely used as alternative materials in areas where sorptive applications are required. Having said that, several studies have reported that zeolites are not suitable for the treatment of anionic contaminants and reactive dyes. Thus, in order to enhance the removal of anionic contaminants, modification of zeolites with quaternary amine cationic surfactants have been proposed. This review investigates the equilibrium and the dynamics of the adsorption of dye on zeolites. The dynamics of color/dye removal using bed depth service time (BDST) was modeled and design parameters of the fixed-bed system were determined. Textile and other synthetic dyes were discussed along with their removal via non-conventional low-cost adsorbents. In a nutshell, this chapter provides an updated literature on the application of nanoporous zeolites in the treatment of textile dyeing wastewaters. An extensive list of natural and modified zeolites in batch and fixed-bed systems was compiled. Dye adsorption capacities and other parameters for natural and modified zeolites were evaluated. Color removal efficiency for textile wastewater treatment systems coupled with zeolites were presented. Adsorption capacities and cost of zeolites were also reported in comparison with other adsorbents.