Abstract
Antiscalants are used in seawater desalination facilities and are typically discharged with the brine back into the coastal environment. We investigated the impact of two commonly-used antiscalants; polyphosphonates and polycarboxylates-based, on phytoplankton and bacterial communities in the oligotrophic Gulf of Aqaba (Northern Red Sea) using mesocosms simulating different antiscalants concentrations. Our results indicate that the addition of polyphosphonates or poly-carboxylates antiscalants significantly altered phytoplankton and bacterial growth, despite being ‘theoretically’ unavailable for microbial utilization. Specifically, the addition of polyphosphonates resulted in a significant eutrophication leading to increase phytoplankton and heterotrophic bacterial biomass. Contrary, the addition polycarboxylates antiscalants triggered a moderate increase in heterotrophic bacterial biomass and a slight phytoplankton loss, summing to a zero change in bacterioplankton's organic biomass. Altogether, the enhanced autotrophic/heterotrophic biomass attributed to the discharge of polyphosphonates-based antiscalants could impair the pretreatment procedure and increase fouling propensity on the reverse-osmosis membranes. Therefore, it is recommended to minimize/avoid the use of polyphosphonates antiscalants in P-limited oligotrophic seas if the brine is discharged into oligotrophic environments.
Original language | English |
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Article number | 118110 |
Journal | Desalination |
Volume | 592 |
DOIs | |
State | Published - 21 Dec 2024 |
Keywords
- Antiscalants
- Bacterioplankton
- Brine
- Desalination
- Oligotrophic environment
- Phytoplankton
- Polycarboxylates
- Polyphosphonates
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- General Materials Science
- Water Science and Technology
- Mechanical Engineering