Turn factory effluent into clean water & biogas

The Client

Located in the Middle East, a leading multinational has their own production facility in Dubai, United Arab Emirates (UAE) which manufactures, imports and sells a range of several world famous chocolate products. The factory opened in 1998.

The Background

Energy is a key issue given the region’s warm climate. By implementing an anaerobic treatment system to treat the approx. 100 m3/d factory effluent, the customer includes energy-saving measures in their factory site and reduces the environmental impacts.

In 2013 (phase 1), Nijhuis improved the 2 existing anaerobic treatment tanks, which deliver biogas to the boilers, including the delivery and realization of the additional polishing steps and decanter package (phase 2). In 2015 (phase 3), Nijhuis extended, improved and retrofitted the existing WWTP system to treat the additional factory effluent of approx. 25 m3/d.

Installation Facts

  • Industry: Confectionary (chocolate)
  • Location: Dubai, United Arab Emirates (UAE)
  • Design Flowrate: 100 m3/d (phase 1 & 2), extended to125 m3/d (phase 3)
  • Nijhuis Delivery:

    • Contract type: Contractor as process delivery andrealization.
    • Added value services: Design, project managementand engineering, manufacturing, delivery, supervision during installation & commissioning, and operator training.
    • Solution (after phase 3): 1x Filter (NZB600S), Balance tank, 2x Digester (AECOMIXTM-DGF), 1x Dissolved Biogas Flotation (AECOMIXTM-DGF), 1x Aerobic tank + 1x DAF(BIOCTOR-CONTINIOUS + NFA-S + GDF 003), 2x Sand Filter, 2x CarboPure.
    • Start date: 2013, extension in 2015.


    Since the extension, improvement and retrofit solution of the WWTP in 2015, the system now consists of a pre-filter, anaerobic/aerobic treatment and polishing steps. The plant treats approx. 125 m3 factory effluent per day with a COD concentration varying between 10.000 and 60.000 mg/l of COD at an average of 37.000 mg/L.

    After passing through the Nijhuis curved screen filter (NZB 600S) and balance tank, the water enters 2 AECOMIXTM-DGF anaerobic treatment tanks of approx. 750 m3 each in series with mechanical mixing.

    The effluent discharged from the Dissolved Biogas Flotation (DBF) system is achieving high removal percentages for COD, generally well in excess of 95%. Also, TSS removal in the DGF is on average more than 95%. The digested water will then enter a continuous aerobic tank (BIOCTOR-CONTINUOUS) with the retrofitted Nijhuis DAF (GDF 003) as activated sludge flotation unit. The water in the aerobic tank is treated with 1 surface aerator (NFA-S). Finally, the effluent will be polished with 2 Sand Filters and 2 CarboPures in order to achieve the effluent discharge requirements.

    Customer Benefits

    1. Turn factory effluent into biogas and clean water.

    2. Nijhuis retrofit application knowledge.

    3. Engineering according to customer specifications.

    4. Nijhuis standardized products, manufacturing and flexibility.

    5. > 95% COD removal out of AECOMIXTM-DGF.