Experimental evaluation of intermittent aeration of a hollow fibre membrane bioreactor.

Intermittent membrane aeration provides a substantially improved energy efficiency in hollow fibre-based immersed membrane bioreactors (HF iMBRs). The benefits of intermittent aeration have been assessed with respect to sustaining a target flux and/or limiting the fouling rate to a sustainable level based on a small plant using full-scale HF modules. Results show that for the same specific aeration demand per unit of permeate produced (SAD(p)), fouling rates were significantly lower for 10 s filtration, 30 s relaxation ("10:30" intermittent aeration) compared to 10:10 and continuous aeration.

BSM-MBR: a benchmark simulation model to compare control and operational strategies for membrane bioreactors.

A benchmark simulation model for membrane bioreactors (BSM-MBR) was developed to evaluate operational and control strategies in terms of effluent quality and operational costs. The configuration of the existing BSM1 for conventional wastewater treatment plants was adapted using reactor volumes, pumped sludge flows and membrane filtration for the water-sludge separation. The BSM1 performance criteria were extended for an MBR taking into account additional pumping requirements for permeate production and aeration requirements for membrane fouling prevention.

The cost of a large-scale hollow fibre MBR.

A cost sensitivity analysis was carried out for a full-scale hollow fibre membrane bioreactor to quantify the effect of design choices and operational parameters on cost. Different options were subjected to a long term dynamic influent profile and evaluated using ASM1 for effluent quality, aeration requirements and sludge production. The results were used to calculate a net present value (NPV), incorporating both capital expenditure (capex), based on costs obtained from equipment manufacturers and full-scale plants, and operating expenditure (opex), accounting for energy demand, sludge production and chemical cleaning costs.

Model-based energy optimisation of a small-scale decentralised membrane bioreactor for urban reuse.

The energy consumption of a small-scale membrane bioreactor, treating high strength domestic wastewater for community level wastewater recycling, has been optimised using a dynamic model of the plant. ASM2d was chosen as biological process model to account for the presence of phosphate accumulating organisms. A tracer test was carried out to determine the hydraulic behaviour of the plant.