Abstract
Abstract In this work, the treatment of wastewater containing azo dye using anaerobic–aerobic sequencing batch reactor (SBR) based on mixed culture for its efficacy in decolorization and reduction in chemical oxygen demand (COD) under different operational conditions has been analyzed. Effects of hydraulic retention time (HRT), salts content and nitrate ion concentration on the rate and extent of color and COD removal through 180 days containing steady-state and acclimation periods were investigated. Solid retention time was kept constant at 20 days in all experiments. Almost complete decolorization could be achieved at dye concentrations between 5 and 500 mg/L, but the removal of COD decreased gradually from 90 to 65% with increasing dye concentration. The results indicated that color was mainly removed under anaerobic conditions and it was almost filled out within 2–3 h of the anaerobic residence time with up to 98% decolorization efficiency. Besides, cutting the cycle time from 24 to 8 h does not have an effect on color removal. Increases in HRT provide enough time for partial mineralization of COD and intermediates in SBR system. The rates of color and COD removals decreased with increasing salt content and nitrate ion concentration in the feed wastewater.
Highlights
Textile wastewater is a complex and highly variable mixture of various pollutants such as degradable organics, dyes, nutrients, salts, sulfur, toxicants and refractory organics
Start-up with the glucose as growth substrate was quite prompt and high chemical oxygen demand (COD) removal of up to 90% was achieved at two steps COD increment from 1,000 to 1,500 mg/L
The outcome of this work indicated that an anaerobic– aerobic sequencing batch reactor (SBR) system has proven to be successful and robust in achieving the complete decolorization of azo dye
Summary
Textile wastewater is a complex and highly variable mixture of various pollutants such as degradable organics, dyes, nutrients, salts, sulfur, toxicants and refractory organics. Azo dyes are characterized by the presence of one or more azo bonds (–N 1⁄4 N–) connecting aromatic rings. Wastewaters from the textile industry can produce severe. There is an urgent need for a technically feasible and cost-effective treatment method (Popli & Patel )
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
