Founded by:

Technion Israel Ports
Desalination

Desalination

There is little dispute regarding the necessity of desalination facilities. However, desalination plants may have potentially damaging effects on the environment. As the desalination industry grows and develops, desalination plants and their work methodologies are undergoing constant improvements in an effort to ensure a green and environmentally friendly production process.

There are several environmental and operational hazards common throughout the desalination industry such as:

  • Brine, heavy metals and toxic chemical compounds released back to the sea - These compounds can jeopardize marine life and flora. Dilution and spreading solutions must be modeled to ensure their effectiveness.
  • Robustness of intake and outfall systems – Ensuring that water pumped into the plant does not contain brine or chemicals that can compromise the efficiency of the work process, the equipment, and the water quality.

CAMERI has performed the brine spreading models for all the desalination plants on the Israeli Mediterranean coast. In addition, CAMERI has modeled and analyzed the concentrations of pollutants in the vicinity of various desalination intakes.

Whether you’re interested in erecting a new facility, expanding an existing plant, examining the water quality in close proximity to the desalination plant or looking for more efficient and environmentally safe diffuser design – our engineers will gladly assist for optimal results.

Brine Spreading

The large scale Sea Water Reverse Osmosis (SWRO) desalination program in Israel was designed to provide for the growing demands on Israel’s scarce water resources, and to mitigate the drought conditions that have characterized most years since the mid-1990’s. Following the water crisis Israel encounters the National Infrastructures Ministry initiated a plan to increase the volume of water desalinated in Israel up to at least 750 mil.m3/yr. until 2020.

Salinity of brine released from desalination plants significantly exceeds the salinity of the ambient sea water. In order to assess the possible impact on the coastal ecosystems and groundwater aquifers the size of the saline plume should be estimated.

The hydrodynamics of an effluent continuously discharged into a receiving water body can be conceptualized as a mixing process occurring in two separate regions. In the first region, the initial jet characteristics of momentum flux, buoyancy flux, and outfall geometry influence the jet trajectory and degree of mixing. This region is referred to as the "near-field". As the turbulent plume/jet travels further away from the source, the source characteristics become less important and the region referred to as the “far-field” is attained. Also far-field mixing begins after the effluent flow has interacted with the water surface, bottom, pycnocline, etc. The far-field region consists of one or two mixing processes and is usually simulated with the following two conditions: (1) if it contains sufficient buoyancy (either positive or negative) there will be a density current region followed by a passive diffusion region, and (2) if it is non-buoyant or weakly buoyant there is no density current region, only a passive diffusion region.
Since the physics of near-field and far-field is different, different mathematical models are applied for the description of flow fields in these regions. CAMERI uses UM3 model of the Visual Plumes package developed by the United States Environmental Protection Agency, EPA, in near-field and CAMERI3D/HD-ST model developed by CAMERI in the far-field.

The near-field model simulations allow one to estimate the zone of initial dilution where the saline concentrations are large (more than 10%), whereas the far-field modeling indicates the size of saline plume with excess salinity larger than 5% and 1%. For convenience, the size of the plume is estimated using two main parameters: the plume equivalent diameter and the plume maximum length. These parameters are used to compare an impact of different configurations of desalination plant outfalls and intakes.