Proceedings

Abstract

MBRs are a technology seen in both domestic and industrial markets although the primary purpose is different depending upon the sector. For domestic wastewaters the main driver has been disinfection prior to discharge to bathing waters, whilst industry has looked to a belt and braces technology to guarantee compliance for total suspended solids and BOD and as a treatment step prior to water reuse; thus ensuring that Production is not adversely affected by the ‘tail wagging the dog’.

However, MBRs can be challenged with achieving the design volumetric throughput and this can be down to many factors including filterability of the mixed liquor, operating MLSS concentration, microbiology, nutrient levels, limited dissolved oxygen, cleaning regimes, surfactants and silicone based antifoams to name some.

This paper looks at techniques to assess the health of MBRs and actions taken to maximise volumetric throughput and draws upon numerous real-world examples that Aqua Enviro have worked upon, including a cross-flow MBR at the Beam Suntory, Ardmore distillery. The effluent treatment plant upgrade process, project delivery, commissioning and operation is an excellent example of long term successful MBR performance; built upon strong, collaborative relationships led by the client’s team that have and continue to engage contractor, consultant and chemical supplier.

It also shows that key to long term successful operation is understanding all parts of the puzzle and that can only be achieved with the assistance of routine analysis, of which microscopic analysis of the activated sludge is central.

Keywords
MBR, Membrane bioreactor, microscopic analysis of activated sludge, Thiothrix, Type 021N,