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Low-energy, compact, cost-effective separation for drinking water and wastewater treatment along with precious resource recovery


Expecting the future demand for clean fresh water to potentially far exceed supply, countries, communities, and corporations are working hard to find economical ways to increase sources and recover, recycle, or reuse water. In addition, regulations for discharging contaminated waters are becoming tighter, driving the cost and complexity of treatment higher. In some industries, recovery of a precious resource (e.g., algae in biofuels, biomass, metals, crude oil, etc...) or a removal of specific compounds (e.g., scalents, heavy metals, etc...) is desired.

PARC solution

PARC’s breakthrough clean water platform technology, Hydrodynamic Separation (HDS), can potentially provide multiple benefits, such as:

  • Compact form factor – ideal for space- and weight-constrained sites
  • Modular and scalable – easily increase or decrease volume capacity
  • Low energy operation – can be used in a low pressure (i.e., gravity fed)
  • Low operating and maintenance costs – contains no moving parts or physical filters
  • Reduction in cap-ex – potential reductions in real-estate needs due to small footprint
  • Separation of “neutrally buoyant” material – efficient separation of suspended particles, flocs, and organics

Potential applications include:

  • Wastewater (industrial and municipal) treatment [download fact sheet]
  • Algae dewatering [download fact sheet]
  • Process water, cooling tower, bilge water, mining water
  • Separation of oil or other emulsions from water
  • Distributed / on-site water treatment
  • Recovery of precious resources from water


how it works

Relying on no physical barriers, PARC’s HDS technology carefullyHDS how it works balances a combination of fluidic forces to separate particles (solids, flocs, and emulsions). Centrifugal force creates transverse flow patterns in a curved channel, which under certain circumstances manifest themselves as a pair of Dean vortices. As particles flow down the channel, they spiral around the Dean vortex cores while a combination of drag and shear-induced forces move them toward the channel center. Under the correct conditions (specified by channel geometry and flow rate), this dynamic causes the particles to focus into a band near the outside wall. At the end of the length of the channel, the single flow is separated into two flows: the concentrate and effluent outputs.

Although HDS technology leverages centrifugal force, it is different than centrifuges and hydrocyclones. Instead of relying on density differences between particles and fluid, HDS technology is solely based on hydrodynamic forces, resulting in a particle size dependent separation that allows for direct concentration of particles of any density, including neutrally buoyant ones.

Scaling the volume throughput can be achieved by assembling channels, in parallel, into modules, with a common source water inlet distributor and common effluent and concentrate collectors. Depending on application, modules can then be combined into compact stacks to achieve the required throughput.

HDS technology has been successfully demonstrated in our facilities with lab prototypes on a variety of water types. A pilot system has been developed and will be deployed in 2013 at a U.S. wastewater site capable of treating 10L/minute to demonstrate the technology. In addition to advancing the technology ourselves, PARC works with experienced partners who are interested in bringing advantaged water technologies to their target markets.

HDS band detail

HDS tall stack


video: demonstration