SAF Plants

Submerged Aerated Filters (SAF) are a well proven technology for wastewater treatment. The BrightwaterTM HSAF® unique SAF design provides a versatile static bed process, using the BMax® floating media, which can be configured for biological wastewater treatment in aerated mode or as a suspended solids filter in unaerated mode. A version enabling the operator to switch between these treatment modes is available. All variants utilise periodic media bed cleaning cycles. These units offer the following system advantages:

The Features

  • High quality effluent - for example the BrightwaterTM HSAF® can achieve 1mg/l ammonia in tertiary mode.
  • Small footprint - The BrightwaterTM Bmax® media provides a high specific surface area (700m²/m³).
  • No sludge buildup - Automated cleaning cycle periodically removes excess sludge whilst maintaining sludge age.
  • Low power usage - The high efficiency of the process air system ensures a low air and power requirement.
  • User Friendly - Proven, simple & robust process requires virtually no maintenance during normal operation.

The Process

The BrightwaterTM HSAF® is a biological process unit designed to enable BOD and / or ammonia reduction.

In most applications the flow is pumped to the unit. The flow passes up through the aerated biological treatment zone of BMax® media where the active bacterial population metabolises the effluent to reduce the ammonia and / or the overall Biological Oxygen Demand (BOD). The air for the biological treatment is evenly distributed through each reactor by passing through a process air grid located at the base of the aerated biological treatment zone.

BMax® media is a buoyant plastic media made from 100% recycled materials which can also be recycled at the end of the plant’s design life. Biomass grows on, within and between the media, providing treatment. Suspended solids will also become entrapped by the biomass, and the media voidage. Treated effluent is collected through a simple launder system at the top of the reactor.

Over time biomass and feed solids accumulate in the reactor and need to be removed. An automated clean cycle is used. The clean cycle consists of an air scour and one or more desludge stages. The air scour works by passing additional air through the air scour grid located at the base of each reactor. The scour air creates turbulence and fluidises the media releasing the excess solids and biomass. The reactor then undergoes a settlement period enabling the media bed to repack and the solids to collect at the base of the reactor. The solids are then removed from the base of the reactor prior to the reactor being put back online.

During normal operation the HSAF® plant is a completely automated process and requires little maintenance or operator intervention.

Design & Performance

Effluent performance can be engineered to suit particular applications. In tertiary mode for example, a Brightwater® HSAF® would readily achieve discharge consents of

The Applications

The BrightwaterTM HSAF® is suitable for use in a number of applications on site as illustrated below. Should your requirement be outside these standard applications then please do not hesitate to contact us so we can discuss your requirement in further detail.

The Standard Product Range