Process Description

The plant receives flows from the catchment area. The influent is screened to 6mm in 2 dimension by a Haigh screen before entering a combined inlet pumping station and storm tank. Pumps transfer FFT to the MBR plant via a Huber grit plant and a 3mm 2d screen. Surplus flows build-up in the storm tank. The hydraulic design of the plant then allows gravity flow through the MBR plant to the main outfall without the need for inter-stage pumping.

The main membrane treatment structure, constructed in steel, is divided into two membrane bioreactor tanks. The structure also comprises common flow split, permeate collection and sludge re-cycle tanks. This main treatment structure is approximately 10m long, 8m wide and 4m high.

Flow from the 3mm 2d screen discharges into a flow distribution chamber where it is mixed with return actived sludge. Flow gravitates to the two MBR tanks, each of which contains 6 ES150 membrane units. Permeate is collected by gravity through the membranes.

Return activated sludge gravitates to a sludge recirculation tank where it is pumped back to the flow distribution chamber.

Following treatment in the MBR plant, the permeate is discharged direct to the local watercourse.

Surplus sludge is removed from the process at upto 1.8% dry solids. This is pumped to membrane sludge thickening system (FS50 membrane units) and thickened to 4% dry solids before transfer to thickened sludge storage tanks, before tinkering away for further treatment.

Design data Population Equivalent Peak Flow: Average Flow: Assumed BOD load: Assumed Average Nitrogen load:

2,000 1,123 m3/day 375 m3/day 120 kg/d 16.2 kg/d

Plant data Each Tank dimensions: No of membrane units: Membrane surface area:

6.6 x 3.4 x 4.0m 12 x 150 panels 1,440 m2