UF/MBR wastewater reuse technology developed in UK
UK company Aquabio, which has specialised in industrial water reuse since 1998, uses its own crossflow membrane bioreactors (MBRs) as the 'core' process in a trio of wastewater treatment alternatives utilising ultrafiltration (UF).
The three types of system are:
AMBR - which uses high crossflow to achieve high flux rates. The bioreactor can be operated at high biomass suspended solids concentrations (MLSS). The technology is aimed at lower flow and higher strength wastewaters. Plants are extremely compact, with very low membrane area and low membrane replacement costs.
The membrane banks are operated automatically based on level in the bioreactor and hence are utilised, as required, to match the inlet flow. When not required individual membrane banks are automatically shutdown, auto-flushed to remove biomass and await re-start thus saving energy when the plant is not running at full design, or when membrane flux is higher than design. AMBR plants are modular, can be containerised and are relatively low in capital investment cost.
AMBR LE - which uses intermittent backflushing for the control of membrane fouling and hence allows a reduction in crossflow velocity and a significant saving in energy. Medium/high MLSS concentrations are accommodated and AMBR LE is aimed at medium/high flow and low/high strength wastewater. With variable speed recirculation pumps, the system allows for a 'managed' flux rate which is used to optimise energy consumption relative to the plant load.
Plants remain very compact, with low membrane area and moderate membrane replacement costs. Plants also operate on a direct link to level in the bioreactor, automatically adjusting membrane permeate production (and energy use) to suit the inlet flow conditions. AMBR LE is particularly suited to applications with inconsistent or variable wastewater flows, high peak or seasonal loads, or when electricity costs are moderate to high.
BIOVERT® - which incorporates vertically mounted modules and uses air injection to further reduce energy consumption. This process allows for medium MLSS concentrations and is aimed at higher flows and low/medium strength (ie, mainly larger municipal applications). Plants are compact and have more installed membrane area.
Plants operate on a more constant level in the bioreactor, with controlled air injection at either the top or the bottom of the membrane tubes. Air scour and turbulence reduces surface fouling and energy use is very low. BIOVERT® plants are particularly suited to applications with large consistent wastewater flows and when electricity costs are high.
For more information, contact: Steve Goodwin, Aquabio Ltd
Tel: +44 1905 641 966
Email : firstname.lastname@example.org