Features

Foaming in MBRs: measurement and evaluation

Foaming of conventional activated sludge (CAS) is very common. It may happen during start-up due to the presence of surfactants, with insufficient biomass to degrade them during the early stages. However, this is normally a short-term issue. These foams (from surfactant foaming) are mostly white and can be countered with anti-foamants until there are sufficient biomass developed to degrade them.

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Process biology | Feasibility, optimisation and costs

MBR Screening Part 2: Selecting an MBR screen

Key facets to take into account when selecting a screen for your MBR design include the screenings capture ratio, screen apertures, screening flow velocity, ancillary processes and coarse suspended solids, and screen maintenance. The screenings capture ratio (SCR) represents the amount of solids removed by the screen as a proportion of the total coarse solids load, and as such is analogous to membrane rejection.

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Membrane operation | Pre-treatment and post-treatment

MBR Screening Part 1: MBR screen designs and performance – an overview

The importance of screening upstream of a membrane bioreactor remains a key concern for MBR practitioners. Screening protects the membrane from mechanical damage from sharp or abrasive particles and from clogging from hair and matted cotton fibre. While any screen is better than no screen at all, it is critically important to have a properly designed and sized screening system.

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Membrane operation | Pre-treatment and post-treatment

How much does an MBR cost? The relative cost of an MBR vs an SBR

Operational experience at La Center WWTP in Washington, USA indicates that the cost of MBR technology may be lower than that of a conventional biological treatment process, despite the higher energy demand. La Center is a small city in Clark County, Washington, USA, with a population of 3,100. The wastewater treatment works at the town was originally constructed in 1967

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Feasibility, optimisation and costs | Alternative membrane technologies and applications

Effects of ferric and ferrous iron addition on membrane bioreactor effluent quality

Municipal wastewater usually contains between 4 and 12 mg/L total phosphorus (TP) concentrations in the range 4−12 mg/L. A conventional activated sludge process (CAS) can take this down to 2−4 mg/L, or 0.5−1 mg/L if an enhanced biological phosphorus removal (BPR) process is used. To achieve the levels required to suppress eutrophication, however, demands P levels of 0.01−0.3 mg/L

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Pre-treatment and post-treatment | Water quality and treatability

The 2015 MBR Survey results

In February 2015, we asked you to contribute to our MBR survey, with a view to sharing knowledge and experiences about the common technical issues that prevent MBRs working as they should, as well as your views about the future for MBR technology.

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Surveys