Development of membrane bioreactor integrated ozonation using polyvinylidene difluoride composites for textile dyeing wastewater treatment

A laboratory-scale membrane bioreactor (MBR) has been developed for textile dyeing wastewater treatment using fine-tuned polyvinilidinedifluoride (PVDF) composite microfiltration membrane combined with ozonation. These composite membranes were prepared by blending PVDF with Polyetherimide (PEI) and tungsten oxide via phase inversion method. The composite membrane characterizations such as morphology, water uptake, surface roughness, hydrophilicity and porosity were investigated. Contact angle measurements indicated that the hydrophilic property of the PVDF/PEI composite membranes have been increased by increasing the PEI concentration in the casting solution. The membrane modules were fabricated and used for the lab scale reactor, having working volume of 20 L. The membrane performance was evaluated by filtering pure water and real textile dyeing wastewater with the hydraulic retention time of 10 h. The dark coloured real combined effluent from the textile dyeing industry has been used for carrying out the treatment systems. The optimized ozone of 250 mg/L has been given as the pre-treatment to MBR. The filtration experiments have been carried out for 15 days continuously to obtain the membrane flux. Pure water flux values have been found to increase with the modified membranes from 19 to 21 LMH. The overall flux recovery ratio has been improved with the fine-tuned membranes. Total suspended solids were removed completely after this filtration. The overall COD and colour removal efficiency achieved were 92% and 90%.

Automated summary

A laboratory-scale membrane bioreactor (MBR) with fine-tuned polyvinilidinedifluoride (PVDF) composite microfiltration membrane combined with ozonation was developed for textile dyeing wastewater treatment. The PVDF/PEI composite membranes were prepared by blending PVDF with Polyetherimide (PEI) and tungsten oxide via phase inversion method. The membrane performance was evaluated by filtering pure water and real textile dyeing wastewater with a hydraulic retention time of 10 h.