Textile Wastewater Treatment Using Iron-Modified Clay and Copper-Modified Carbon in Batch and Column Systems

Textile wastewater was treated by adsorption in batch and column systems using electrochemically modified montmorillonite clay and activated carbon. Textile wastewater was obtained from a denim manufacturing process; according to the characterization of wastewater, non-biodegradable organic matter was found and it limits the application of biological treatments, and then an alternative method was evaluated. The adsorption process was performed with natural and modified materials; iron-modified montmorillonite was prepared at pH 7 using iron electrodes and activated carbon was treated with copper electrodes at pH 2, and 10-12 % of iron and copper respectively were found in the modified materials. Adsorption kinetics and isotherms of chemical oxygen demand (COD), color, and total organic carbon (TOC) were evaluated; the adsorption capacities for color were 50, 37, and 44 U PtCo/g for natural clay, activated carbon, and iron-modified clay, respectively. Adsorption kinetics of COD, color, and TOC data were best adjusted to Elovich model and isotherms data to Freundlich model, indicating chemisorption on heterogeneous materials. The regeneration of materials was performed in the presence and absence of hydrogen peroxide. Continuous systems were evaluated for color and TOC. Fe-modified clay was the best adsorbent, and data were best adjusted to Thomas and Yoon-Nelson models.