Features

Long-term monitoring of its constitution in the full-scale MBR

Reducing process aeration energy consumption in MBRs

MBRs use more energy compared with classical activated sludge (CAS) because the aeration requirements are greater. Aeration is needed both for the biological and membrane tanks for degrading the organics and scouring the membrane respectively. Typically, aeration energy consumption accounts for 70–80% of total energy used for the municipal wastewater treatment process, with 40–60% consumed by the process biology.

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Membrane operation | Process biology | Feasibility, optimisation and costs

NF testing set-up

Reuse of dairy wastewater treated by membrane bioreactor and nanofiltration: technical and economic feasibility

A study carried out by Andrade and co-authors assessed the viability of a two-stage membrane bioreactor−nanofiltration scheme (MBR−NF) for treating dairy wastewater. Of key concern was the quality of the treated water with respect to its potential reuse and the overall cost of the scheme.

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Feasibility, optimisation and costs | Pre-treatment and post-treatment | Water quality and treatability

Rotary drum screens

Kunming Underground MBR: a Chinese case study

China features many of the largest municipal wastewater MBRs in the world. Apart from their capacity, some also are ambitious in their construction. The below-ground installation at Kunming City, commissioned in 2012, is one such example. At an ADF (average daily flow) capacity of 150,000 m3/d and a peak daily flow of 195,000 m3/d, it is a substantial plant.

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Membrane operation | Feasibility, optimisation and costs | Pre-treatment and post-treatment | Water quality and treatability

OPEX vs flux at various membrane life periods

MBR OPEX − the theory of running costs

Operational costs in MBRs are marginally higher than those of conventional activated sludge (CAS). Firstly, permeating water through a membrane demands energy. In the case of the immersed technologies (iMBRs) this means that the overall specific aeration demand (SAD) is higher, since air is needed both for maintaining the process biology in the aeration tank and scouring the immersed membrane.

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Membrane operation | Process biology | Feasibility, optimisation and costs

The 2016 MBR Survey results

The 2016 MBR Survey results

Last year, we asked 'What’s the main issue with MBRs?' This time our question focused on the topic of sludge − most of your responses from the previous three surveys had been based around this topic so we felt it was worthy of further investigation.

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Surveys

Membrane technologies with modes of movement: (a) rotating and vibrating disc filters (RDF and VDF), indicating torsional motion; (b) multiple shaft disc (MSD), overlapping; (c) vibrating membrane (e.g. hollow fibre, vibrating hollow fibre membranes (VHFM)) (Zsirai et al, 2016)

Mechanical shear in membrane bioreactors

In membrane separation systems, it is probably shear which is the most significant parameter for driving the membrane process. Pressure is obviously important for forcing the water through the membrane but shear is arguably the property of the system which largely determines the rate of membrane fouling and so, ultimately, the flux.

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Feasibility, optimisation and costs | Pre-treatment and post-treatment | Water quality and treatability