Investigation of the treatment of textile wastewater containing of indigo and yellow 2G dyes by using of constructed wetlands

In the concept of the study; the feasibility of constructed wetland systems for the treatment of denim dyeing textile wastewaters that have substantial place in Turkey and commercial Indigo and Yellow 2G dyes which are mostly used in this industry was investigated. This lab-scaled study was used to examine the effects of different filter media and plant species on the removal of organic materials, nitrogen, phosphorus and color by vertical-flow systems. Zeolite (clinoptilolite), which is effective on removal of ammonium and phosphorus, had been used as a filter media besides sand and gravel and pumice stone, was used as a filter media in this system for the first time. Control reactors have also been used in this study to determine the effects of plants on removal of pollutants. Canna indica and Typha angustifolia plant species that are widely used in constructed wetland systems were selected as test plants in this study. COD, NH4-N, NO2-N, NO3-N, PO4-P, color, turbidity, pH, ORP and EC were determined for input and output samples of both raw wastewater and synthetic wastewaters that were prepared from commercial Yellow 2G and Indigo dyes. The results indicated that considerable amount of color and organic matters could be removed from raw textile wastewater and textile dyes by using vertical flow wetland systems. Moreover, the results showed that vegetation in constructed wetlands was effective especially in the removal of ammonia. However, it was observed that this effect was not significant for the removal of phosphorus. Results showed that the structural decompositions caused by the plants for Indigo dye was lower than the decomposition of Yellow 2G dye. So, there is a significant difference between planted and unplanted reactors for the pollutants removal at Set 2 which treated the Yellow 2G dye effectively. SEM results showed biofilm formations and FTIR analysis confirmed the existence of decomposition end-products of dyes in the anaerobic environment. It was observed that using pumice stone and zeolite, together, as filtering media was beneficial. In this study carried out with uses of Canna indica and Typha angustifolia in this study showed that the type of plant is not significant factor for the pollutant removal.