Comparison of Suspended Growth and IFAS Process for Textile Wastewater Treatment

Abstract

Water is an essential commodity that is getting scarce due to its overuse. The primary consumers of water resources are the industries, and due to industrialization, the generation of wastewater is increasing. When discharged into water bodies, this wastewater contaminates the water bodies greatly, and thus its treatment is of utmost importance. The treatment facility is not economical for small and medium-scale industries. Hence, for such industries, a Common Effluent Treatment facility (CETP) is provided where the wastewater from a cluster of industries is collected, treated and finally discharged. The present study treats CETP wastewater using a sequencing batch reactor (SBR) with suspended biomass and an SBR-IFAS, which uses a combined suspended and attached growth process. The study was done on homogeneous textile wastewater from a CETP. HRT for the system was 10 h, with 9 h aeration and 1 h settling. The pre-treated wastewater was used as an influent in the study with an inlet COD concentration varying between 600 and 1160 mg/L. After the treatment in the SBR reactor, the maximum COD removal was 65.7% for homogeneous textile wastewater. Chromium removal was 48%, at a maximum suspended MLSS of 2852 mg/L with an SVI of 30 mL/g. In SBR- IFAS, maximum COD removal was 74.28%, chromium removal was 53.33% with a suspended MLSS of 2600 mg/L and attached biomass of 6.72 mg/m with SVI of 96 mL/g. Thus, the study indicates that the IFAS system incorporated in SBR will enhance the treatment efficiency while reducing the effluent concentration and help treat a larger volume of industrial wastewater for the same footprint.