ENHANCED TEXTILE DYEING WASTEWATER TREATMENT AND FOULING CONTROL USING HOLLOW FIBER ANAEROBIC MEMBRANE BIOREACTOR AND DOWNFLOW HANGING SPONGE

• Main Author: Saquib, Syed
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/85422
• Institution: Institut Teknologi Bandung

Dyeing wastewater is toxic and recalcitrant pollutants which hamper the environment. Majorly affecting the aquatic regime by discharging toxic chemical-laden wastewater. Many conventional technologies were used to control dyeing wastewater pollution. However, they are slow process, high sludge generation and have high operational and maintenance cost. Combining anaerobic-aerobic bioprocess is an effective approach for efficient wastewater treatment. This research explores the Anaerobic membrane bioreactors as the promising approach due to high treatment efficiency. However, fouling is one if the biggest challenge with AnMBRs which needed to be addressed along with enhanced pollutant removal abilities. In the present study, detailed research methodologies were taken into consideration to overcome challenges related to efficient dye pollutant removal and membrane fouling mitigation. Firstly, batch anaerobic reactors were set up to evaluate the effects of sludge and desired pH on the treatment ability of dyeing wastewater. Continuous hollow fiber submerged anaerobic membrane bioreactors (HF-sAnMBRs) were fabricated and run on variational operational flux (High, Low and moderate) to evaluate the membrane fouling mitigation and efficient RB5 dye wastewater treatment. Next phase of the thesis includes the adaptation of anaerobic-aerobic bioprocess as an effective approach for efficient wastewater treatment. Integrated HF-sAnMBR- DHS system was established under the influence of intermittent aeration in later DHS column for fast, cost-effective and enhanced textile dyeing wastewater treatment. Physical, Chemical analysis and microbiological community analysis were taken into consideration throughout the experimental phase of the present studies. The batch studies revealed that sludge alone achieved 62.3% removal of soluble chemical oxygen demand (SCOD) and 84.7 ± 1.41% decolorization. Optimal pH conditions were identified, with pH 8 resulting in 26.74% SCOD removal and pH 4 achieving 92.47% color removal efficiency. Although decolorization did not influenced significantly by pH variation as by the end of operation all the pH variation results in above 90% color removal. Anaerobic membrane bioreactors (HF-sAnMBRs) were subsequently operated at near-neutral pH for 128 days under varying flux conditions. High flux (56.92 LMH) in reactor R-1 led to rapid fouling , while low flux (3.21 LMH) in reactor R-2 exhibited minimal fouling . A median flux (14.76 LMH) in reactor R-3 resulted in no significant fouling over 117 days, demonstrating optimal long-term operation. Integrated HF-sAnMBR and downflow hanging sponge (DHS) systems with intermittent aeration showed enhanced treatment efficacy. High flux in AnMBRs resulted in superior TCOD and SCOD removal and faster decolorization compared to low flux. Spectroscopic and chromatographic analyses confirmed azo bond breakdown and presence of aromatic intermediates and mineralized byproducts. Intermittent aeration in the DHS system improved effluent quality, with increased TCOD, SCOD, and color removal. TCOD and SCOD removal achieved at 88.43 ± 1.84% and 94.20?±?2.01% with final effluent concentration at 98.35 ± 18.34 mg/l and 50.98?±?18.03 mg/l during phase 1 and 2 respectively, under the national discharge limit of 150 mg/l. Decolorization was analyzed using the Pt-Co method. The average Pt-Co concentration in the final effluent had an average concentration of 222.13± 44.41. Microbial analysis highlighted the significant role of Clostridium species in dye degradation, with diverse microbial communities supported under both anaerobic and aerobic conditions. Phytotoxicity assessment using Vigna radiata seeds indicated reduced toxicity in HF-sAnMBRtreated effluent, particularly in high flux conditions. The study underscores the importance of microbial communities in azo dye degradation and suggests optimizing anaerobic-aerobic treatment systems to enhance dye degradation and mitigate fouling .