Related Experiment Video
Updated: Feb 17, 2026
Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing
Published on: February 13, 2016
Impact of poly dimethyldiallylammonium chloride on membrane fouling mitigation in a membrane bioreactor
Jia-Heng Zhou1, Chang-Hua Wu1, Gao-Feng Cheng1
1a College of Civil Engineering and Architecture , Zhejiang University of Technology , Hangzhou , People's Republic of China.
Abstract:
Poly dimethyldiallylammonium chloride (PDMDAAC) was applied in a membrane bioreactor (MBR) to study its effects on mitigation of MBR membrane fouling. Floc size, zeta potential, soluble microbial substances (SMP) and extracellular polymeric substances (EPS) secretion were studied with respect to PDMMAAC-dosing operations. Results demonstrated that a sustainable filtration cycle extended 3.3 times with the optimal PDMDAAC dosage of 90 mg L-1. The addition of PDMDAAC could increase zeta potential of sludge floc, which led to the decrease in repulsive electrostatic interactions between flocs, as well as the facilitation of flocs-to-flocs aggregation. With the optimal dosage of PDMDAAC, the mean size of sludge was 3.23 ± 0.55 times higher than the control group, resulting in higher impact resistance and better adaptive capacity to the changing environment, which led to less SMP secretion. Moreover, a high contaminants removal rate was achieved in the reactor that was dosed with PDMDAAC. The average effluent concentrations of chemical oxygen demand and total nitrogen were less than 45.6 ± 2.85 and 5.23 ± 0.61 mg L-1, respectively, and the corresponding removal rates were 93.1 ± 5.81% and 89.1 ± 9.61%.
Insights
Polydimethyldiallylammonium chloride (PDMDAAC) effectively mitigates membrane fouling in membrane bioreactors (MBRs). Optimal PDMDAAC dosage enhances sludge floc size and zeta potential, extending filtration cycles and improving contaminant removal rates.
Area of Science:
- Environmental Engineering
- Water Treatment Technologies
- Polymer Science
Background:
- Membrane bioreactors (MBRs) are crucial for wastewater treatment but suffer from membrane fouling.
- Fouling reduces MBR efficiency and increases operational costs.
- Controlling sludge properties is key to mitigating membrane fouling.
Purpose of the Study:
- To investigate the impact of polydimethyldiallylammonium chloride (PDMDAAC) on MBR membrane fouling.
- To analyze the effects of PDMDAAC on sludge characteristics, including floc size and zeta potential.
- To evaluate the efficiency of PDMDAAC in improving contaminant removal and extending filtration cycles.
Main Methods:
- PDMDAAC was added to an MBR system at varying dosages.
- Sludge floc size, zeta potential, soluble microbial substances (SMP), and extracellular polymeric substances (EPS) were measured.
- Filtration performance, including cycle duration and contaminant removal rates (COD, TN), was monitored.
Main Results:
- An optimal PDMDAAC dosage of 90 mg/L extended the sustainable filtration cycle by 3.3 times.
- PDMDAAC increased sludge floc size (3.23 times larger) and zeta potential, promoting floc aggregation.
- This led to reduced SMP secretion, enhanced impact resistance, and improved adaptive capacity of the sludge.
- High removal rates for chemical oxygen demand (93.1%) and total nitrogen (89.1%) were achieved.
Conclusions:
- PDMDAAC is an effective agent for mitigating membrane fouling in MBRs.
- Optimized PDMDAAC dosing improves sludge properties, leading to enhanced MBR performance and stability.
- The study demonstrates the potential of PDMDAAC for improving wastewater treatment efficiency and sustainability.
