In order to be the best water treatment consultant, we are always looking for new or improved ways to treat water more efficiently or robustly, to reduce energy consumption and space, and to free up an operator’s time and resources.

Royal HaskoningDHV is the consultancy with the highest Research & Development expenses and most water patents.

Our technicians have expertise in all known water treatment processes:

Raw water treatment
  • Water resources
  • Intake and pumping stations
  • Conditioning
  • Pre-treatment
Industrial Water Treatment
  • Treatment & Conditioning
  • Softening & demineralisation
  • Desalination
  • Ultra-pure water
Water recycling & Advanced Treatment
  • Water recycling concepts
  • Quality control concepts
  • Advanced membrane technologies
  • Chemical & Biological oxidation
  • Evaporation
    • Membrane filtration (UF, NF,RO)
    • Disinfection (UV, chlorination)
    • Ion Exchange (IEX, Mixed Bed)

      Industrial Water Use & Transport
      • Cooling Water Systems
      • Water optimisation & de-bottlenecking
      • Process integrated treatment
      • Sewerage, distribution and piping systems
      • Scaling prevention (magnets)
      Wastewater Treatment

      • Oil removal & organic dust removal
      • Metals & anion removal
      • Suspended solids removal
      • Micro & higher organism removal
      • Sieves
      • DAF (Dissolved Air Flotation)
      • Sedimentation
      • Oil/fat/grease separation
      Physical-chemical treatment


      Biological Treatment
      • Anaerobic
      • Aerobic (Carrousel®, Nereda®, ABR®, SBR, MBR, MBBR, BABE™)
      Air treatment
      • MBTF (Moving Bed Trickling Filter)
      • Lava, compost, biofilters


      Post Treatment
      • Settling / clarifiers
      • Membrane & sand filtration
      • Revitalisation
      • Flow forms
      • Cascade
      Sludge treatment
      • Sludge thickening & storage
      • Sludge drainage (centrifuge, filter press, band filter)
      Digestion & Biogas treatment/storage
      • Ephyra & Themista


      The Crystalactor is a fluidised-bed type crystalliser for the selective removal and recovery of components from water and wastewater. In a cost-effective process a reusable product is produced instead of chemical waste. The technology is suitable for domestic and industrial applications for water softening and removal or recovery of phosphates, fluoride or heavy metals.


      The four steps found in conventional treatment processes - coagulation, flocculation, separation and dewatering – are combined into one in the Crystalactor. Water-free pellets are produced thereby eliminating troublesome and costly sludge dewatering.

      No residual waste

      A major advantage of the Crystalactor is its ability to produce virtually water-free pellets which are easy to handle.

      Advantages of The Crystalactor

      Due to their purity the water-free pellets can be recycled or reused in other applications. In the rare event that they need to be disposed of, they have the added advantages of being low volume as well as water-free - thereby avoiding bulky sludge disposal.

      Compact and cost-effective, the Crystalactor unit is compact due to the high surface loadings of 40-120 m/h. The small footprint, combined with relatively low capital and operational expenditure, results in a cost-effective solution.


      Our innovative water purification technology, Nereda leads to lower investment and operational costs and scores higher in sustainability measures whilst reducing a plant’s footprint. Nereda is a hybrid SBR process with biological purification capability for industrial and municipal waste water treatment. This technology uses granular biomass, with a granule settling speed 10 times faster than that of conventional flocks. The improved settle ability allows the process to be operated at mixed liquor concentrations comparable to that of MBR (3-4x that of conventional processes), while maintaining the high settling velocities. The aerobic granular sludge removes organic compounds as well as nutrients like nitrogen and phosphor to a high extent. Furthermore, given the high biomass concentration, Nereda only requires a compact installation with accordingly low capital investments.

      Due to the extremely short settling time, it is beneficial to operate Nereda as a Sequencing Batch process in a single reactor, which eliminates the need for separate clarifiers. By using either a buffer tank or several, parallel Nereda-reactors, the wastewater treatment system can be operated as a continuous process. Nereda is a unique process resulting in a compact treatment plant with lower energy / operational costs and also lower investment costs.


      The advantage of the Carrousel is its continuous biological process of BOD/COD removal and simultaneous nitrification and denitrification in one reactor, with only a limited amount of equipment required. The oxidation ditch is a looped channel system, featured by a central dividing wall and a surface aerator, the Oxyrator®, positioned at one or both ends of the wall. The Oxyrator is a low-speed vertical shaft surface aerator. Its function is three-fold: It adds oxygen to the treatment process, it thoroughly mixes the wastewater and the purifying biomass (‘activated sludge’) and it creates and maintains the flow circulation through the channels.

      During the past 40 years, the Carrousel has proven itself as a cost-effective, reliable and highly efficient method for the biological treatment of wastewater from both municipalities and industries. Over 1,200 systems have already been successfully implemented world-wide, with treatment capacities ranging from as little as one thousand population equivalents (p.e.) to as high as ten million p.e.


      The Anti Bulking Reactor (ABR®) is a robust solution to prevent bulking sludge problems within wastewater treatment plants, whilst effectively reducing oxygen demand and bio sludge production. In industrial wastewater treatment plants, problems with bulking sludge are often caused by easily biodegradable components. Poor settling results in reduced performance and loss of active biomass.

      The ABR biodegrades the components in a kind of chemostate with a hydraulic residence time of 4 to 20 hours. Additionally, the ABR decreases overall oxygen demand and bio sludge production by approximately 25%, whilst providing an effective oxidation of reduced sulphur compounds. The ABR process performs well at high and low temperatures. Given the compact and simple design, ABR is a very cost-effective upgrade for improving the performance of existing, overloaded, treatment plants or even as alternative to anaerobic pre-treatment. The ABR can be applied in industrial wastewater treatment processes with high C/N ratios and a COD concentration of more than 1000 mg/l. AB-Carrousel® The two Royal HaskoningDHV technologies, ABR® and Carrousel®, can be combined to form a robust treatment process for industrial wastewater: the AB-Carrousel®

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