Unconfined Dense Plunging Jets Used for Brine Disposal from Desalination Plants

Aaron C. Chow,E. Eric Adams,Bader Al-Anzi,Ishita Shrivastava,Fahed Al-Rabaie

doi:10.3390/pr8060696

Aaron C. Chow, E. Eric Adams + Show 3 more

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https://doi.org/10.3390/pr8060696

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Abstract

Laboratory experiments were conducted to measure entrained air bubble penetration depth and dilution of a dense vertical unconfined plunging jet to evaluate its performance as an outfall to dilute brine from desalination plants as well as a means to aerate water column. Experiments involved neutrally buoyant or dense plunging jets discharging in quiescent receiving water. The density difference between effluent and receiving water, the plunging jet length (height above water surface), and the receiving water salinity were varied in the experiments. Observed penetration depth for neutrally buoyant jets was somewhat greater than previously reported, and increased modestly with jet density. Increasing density also resulted in an increasing number of fine bubbles descending together with the dense plume. These observations can help guide the design of plunging jets to mitigate anoxic conditions in the water column when brine is introduced to a receiving water body, as with seawater desalination.

Highlights

This study is motivated by the potential use of plunging jets to dispose of reject desalination brine into Arabian Gulf waters, in an effort to mitigate environmental impacts caused by brine discharges from Kuwait’s desalination plants
Al Anzithe et aeration al. [22] proposed the use ofwater plunging liquid jet reactors, arranged in aabove diffuser array, to promote of the underlying via entrainment of air bubbles from the to promote the aeration of the underlying water via entrainment of air bubbles from abovewater the water to promote the aeration of the underlying water via entrainment of air bubbles from aboveofthe water surface
Results from the study are used thewith amount of aeration achievable the bubbles entrained bycurrent plunging brine jets thatto areestimate in contact a moving water achievable withwith the the bubbles entrained by plunging brine brinejets jetsthat thatare are in contact with a moving achievable bubbles entrained in comprising contact with a jets moving waterwater column

Summary

Introduction

This study is motivated by the potential use of plunging jets to dispose of reject desalination brine into Arabian Gulf (hereafter referred to as the Gulf) waters, in an effort to mitigate environmental impacts caused by brine discharges from Kuwait’s desalination plants. Brine discharge from desalination plants using reverse osmosis (RO) and multistage flash (MSF) distillation technologies may produce depressions in the dissolved oxygen (DO) level, and increased salinity and sea surface temperature (SST) [1,2]. These could potentially cause degradation of Kuwait’s marine diversity [3,4] both at the plant intakes and discharge outfalls [5] and further offshore [6,7]. In Kuwait, contaminants from RO plants are discharged to the storm drains that eventually go to the Arabian Gulf; while from

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