The BriefMüller Milk & Ingredients, formerly Robert Wiseman Dairies and later Müller Wiseman Dairies, is the largest milk supplier and distributor in Great Britain. As one of the most efficient dairy businesses in the UK, Müller Milk & Ingredients recycles waste water at its Bridgewater processing facility.

The dairy’s wastewater is treated by dissolved air flotation (DAF) followed by a membrane bioreactor (MBR). A new MBR wastewater treatment plant was required to comply

with discharge consent and Jacopa were commissioned to design and build the new plant.

The SolutionProcess waste is gravity fed to the works from The Process Building. Any flows in excess of 60l/sec are diverted into the Final Divert Tank to be returned once the peak has subsided. Flows below 60l/sec are lifted from the Inlet Influent Sump, and screened using duty/standby Noggerath 3mm Nogostrainer screens discharging into the Screened Effluent Sump. The screened effluent is then lifted into the Balance Tank. Any high strength flow is diverted into the High Strength Divert Tank. The flow is then forwarded at 10 - 14 l/s to the DAF Plant.

The effluent is the neutralised and any fats are removed and pumped to the DAF sludge storage tank, for removal by tanker. The outlet from the DAF discharges into the second transfer sump, and is passed forward to the Anoxic tank, then on to the FBDA Tanks and finally via a flow distribution tank, to the MBR treatment tanks.

Permeate flows out from the MBR plant via flow meters and control valves and discharges into the Permeate Discharge & Reuse Sump. Final discharge from the plant is pumped at 10l/sec to the outfall point at the far end of the site. The sump also provides facility for total reuse at

JacopaCase Study

Müller Milk & Ingredients – MBR Wastewater Treatment plant – Bridgewater

MBR Wastewater Treatment plant - Bridgewater• Designed to treat effluent from milk reception and

processing plant.

• Plant includes chemical neutralising, DAF and membrane treatment

• Plant also includes for total permeate reuse, including vehicle washing

• Equivalent population of 16,180

• 1200 m3/d flow to full treatment

• High quality discharge parameters

Contact Jacopa: Tel: +44 (0) 121 511 2400 Fax: +44 (0) 121 511 2401 Email: info@jacopa.com jacopa.comCopyright © 2017 Jacopa. All rights reserved

Contact Jacopa: Tel: +44 (0) 121 511 2400 Fax: +44 (0) 121 511 2401 Email: info@jacopa.com jacopa.comCopyright © 2017 Jacopa. All rights reserved

JacopaCase Study

Müller Milk & Ingredients – MBR Wastewater Treatment plant – Bridgewater

10l/sec, to the truck wash, boiler room, MBR chemical make-up, screen cleaning and hose points.

The main biological treatment structure, is built in concrete, and is divided into an anoxic tank with two mixers, two FBDA tanks with 200 diffusers in each, and two membrane bioreactor tanks, fed from a common flow distribution tank. This main treatment structure is 5.5m high (top water level, TWL = 5 m).

Access to the tanks is via platforms, one over the Anoxic Tank and one between the MBR and FBDA Tanks. Access to all of the valves on the MBR Plant is from ground level. Flow from the MBR Tank can be sampled and is monitored constantly in the permeate discharge sump. The flow to outfall is monitored using a Siemens magflow meter. Any out of spec permeate is diverted into the Final Divert Tank to be tankered away or to go back through the plant.

The two membrane tanks each contain five membrane units with 200 membranes in each module. Permeate is collected by gravity through the membranes. Discharging from the tanks through the wall penetrations and into

the permeate headers. From here the outlet flow rate is controlled via flow meters and control valves and then on to the discharge sump. Following treatment in the MBR plant, the permeate is then discharged direct to the local watercourse.

Activated sludge in the MBR tank gravitates to a sludge recirculation tank, via sludge flow control valves, where it is pumped back to the Anoxic tank. This Sludge re-cycle is used to maintain a common sludge thickness throughout the five main tanks. It also allows sludge to be removed from the system at regular intervals as required to maintain the thickness of the sludge between the operating range of 12k to 15k mg/l of suspended solids. Surplus sludge is removed from the process at up to 1.8% dry solids. This is pumped to a sludge storage tank, prior to loading into a road tanker for offsite disposal.

The OutcomeThanks to the Jacopa MBR system the upgraded wastewater treatment process now produces high quality treated effluent that exceeds the standards required for river discharge.

Design data

Peak flow to treatment 90 l/s

Average flow 1000 m3/d

COD average load 3000 kg/d

BOD average load 1000 kg/d

TSS average load 200 kg/d

NH3-N average load 104 kg/d

Plant data

Each FBDA Tank: 5.225 x 11.2 x 5.5m

Diffusers in each tank: 200

Each MBR tank dimension: 5.3 x 4.1 x 4m

MBR membranes: 10 x 200 panels

MBR membranes surface area: 2900 m2