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Elmosa Seawater Intake and Outfall systems, American Eco systems, LLC.Linden NJ 07036 USA , t: +1 908‐342‐0240, e. [email protected] www.amecosys.com/elmosa
Modeling dispersion of brine waste discharges from a SWRO desalination plant using the US
EPA VPRO concentrate 90 ppt, T 35◦C and
ambient 45 ppt and T 33◦ C
Reverse Osmosis Desalination RO Brine Dispersion Modeling using the US EPA VPRO concentrate 90 ppt, T 35◦C and ambient psu 45 and T 33◦ C
The O&M‐Free InvisiHead Brine Diffuser Gravity Driven System – No pumping.The InvisiHead needs no maintenance or any parts replacement or any costs associated with the O&M process for life
The discharge to the environment of large capacities of highly concentrated saline water with a 90ppt TDS is one of the major problems associated with the desalination industry. The US EPA Visual Plume modeling is used here to demonstrate how the InvisiHead technology has succeeded in spreading, mixing, and diluting the brine within a limited area and reaching ambient TDS conditions of 45ppt early in the near field mixing zone. All international environmental regulations regarding desalination brine disposal are met and satisfied.
Dispersion is gravity‐driven. No pumping is involved. The extremely low InvisiHead discharge velocity allows fluids to slowly spread and disperse to reach a high dilution ratio within the vicinity of the diffuser structure. A 1,000,000 m3/d RO desalination plant working in the Gulf with a brine TDS of 90,000 ppm would reach a dilution ratio of about 35.84 and dilute to 46.36 ppt in 2.32m away from the point of release. The plume hits the bottom at 11m away reaching a dilution of 79 and a TDS of 45.61 or 3.6% over the 45 ppt ambient. All mixing zone environmental regulations are satisfied, see Tables 1 and 2, and http://www.amecosys.com/elmosa/BSP‐780‐EN‐REP‐0110.pdf
Figure 1: The effluent fades away into the ambient soon after release
Depth, m Plume diam, m
Dilution rate
Brine dilution, ppt +amp
Distance from exit, m calculated y,x
Exit, 3.5 0.0005 1 92 0
3.491 0.0399 7.47 51.49 +6.49 0.101
3.306 0.0903 35.84 46.36 +1.36 2.32 Max dilution reached
3.096 2.058 54.33 45.9 +0.9 5.275
2.885 3.998 76.1 45.64 +0.64 10.16 Acute zone
2.87 4.322 79.17 45.61 +0.61 11 Bottom hit
Table 1: Visual Plumes 90ppt Brine Dispersion output
Table 2: Visual Plumes 90ppt brine dispersion selected actions Figure 2 -
Predicting the Near field brine discharge using Visual Plumes EPA Model
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Just before getting to the IH design phase, the company sends a data collector to gather site and application information needed to integrate natural intelligence into the InvisiHead. The IH, upon receiving pump pulses will recognize the site and assume flow management accordingly. If working as a diffuser, it disperses flow in multi layers of plumes spread over the vertical and horizontal planes. The paraboloidal configuration shaped to match the site and applications conditions, will work to minimize the area of influence of the brine discharge tothe absolute minimum. As for this example, the environmental requirements are satisfied within the first 10m after concentrate release. Dilution rate of more than 79 is achieved as soon as the bottom part of the lowest layer of flow plumes hits the bottom 11m away from the diffuser structure.
How the InvisiHead forms horizontal and vertical layers of flow plumes and gently disperses effluents providing the necessary residence time to mix and dilute with the ambient water and comply with all environmental standards – the US EPA Visual Plumes Model tells the story
Figure 3: Plume hits sea bottom 12m away from diffuser
By nature of the design, the InvisiHead diffuser releases effluent in spatial and temporal fashion or in a 4‐D space + time domain that makes the flow to funnel out in a 360◦ round surround, 180◦ up, sideways, and down.
It discharges, funnels out and disperses, spreads, mixes and dilutes effluents to reach the required dilution within the vicinity of the diffuser early in the mixing zone; radial diffusion of effluents with multi directionality is what the InvisiHead exactly made to do.
(Figure 3),
Figure 2‐Horizontal plane. 360◦ round surround, funneling out brine diffusion
Figure 4‐Vertical plane. 180◦ up, sideways, and down brine diffusion
US EPA Visual Plume UM3 demonstrates how the InvisiHead disperses, spreads, mixes and dilutes 90 psu in the Gulf 45 psu ambient seawater .
The InvisiHead dispersion process of the brine insures a high degree of mixing that substantially reduces adverse impacts on the local environment reaching 79 dilutions in less than 11m away from the diffuser.
This shows one layer of a vertical band of plumes at the 0◦ degree position
This shows one plume of the bottom layer of the horizontal band of plumes hitting the floor 12m away from the IH exit
This shows one layer of the horizontal band of plumes covering all the 360◦ degree round surround spectrum
At the 12m away from the diffuser exit plumes dilute to about 80 to achieve a 45.6 ppt, ambient is 45ppt
The near field behavior of negatively buoyant discharges
12m
8m
5m4m21 Progressive
dilution takes place as the plumes funnel out and away from the IH exit
5m IH
Contouring the 90ppt terrain of RO brine leaving the InvisiHead in a 45,000 ppm 33◦C ambient
The round surround InvisiHead plume terrain