Brine Discharge Research Articles

Multi-objective optimization of a solar-biomass multi-generation system with dual-stage desalination for brine minimization

A hybrid solar-biomass multi-generation system feeding an off-grid community is proposed in this study. An organic Rankine Cycle (ORC) generates electricity by harnessing the thermal energy supplied by the hybrid heat generation system. Part of the produced electricity is utilized to meet the community's electricity needs, while another fraction powers a brackish water reverse osmosis unit (RO). The waste heat from the ORC is recovered to produce domestic hot water and to drive a membrane distillation (MD) unit for RO brine minimization. A multi-objective optimization of the proposed system is conducted using the NSGA-II algorithm and TOPSIS decision-making tool considering plant's overall energy efficiency, exergy efficiency, and the total exergoeconomic cost of the useful products as objective functions. The study's results indicate that the overall optimal solution is achieved using R1336mzz(Z), with corresponding energy efficiency, exergy efficiency and hourly exergoeconomic cost of 45.31%, 5.39%, and 87.68 €/h, respectively. Moreover, the unitary costs associated with the useful products are 0.207 €/kWh, 0.029 €/kWh, 0.683 €/m3, and 3.36 €/m3 for the produced electricity, domestic hot water, RO permeate and MD distillate, respectively. In terms of sustainability, the system is not only renewable-driven but also achieves a 21% reduction in brine discharge through heat recovery at the ORC condenser compared to single-stage RO desalination. Additionally, using R1336mzz(Z) with its low global warming potential of 2 significantly lowers CO2 equivalent emissions compared to R245-fa. Lastly, sensitivity analysis indicates that hybridization ratios of up to 80% can result in a 10.6% reduction in CO2 emissions originating from biomass combustion compared to biomass-only solutions.

A new type of submarine chimneys built of halite

In contrast to the subaquatic sulphide and carbonate chimneys, which are known from Mid Ocean Ridges and abyssal submarine volcanoes, chimneys built of salts have not been described yet. Here we present such halite chimneys as a new form of cold-water smokers in hypersaline environments. The here described structures rise up from the bottom of the Dead Sea and result from the submarine discharge of saturated halite-dissolution brines into the salt lake, which is at halite saturation and holds remarkable chloride excess. At the interface with the lake brine, halite precipitates instantaneously, forming chimneys up to several meters in height. The brines leading to the formation of these chimneys vary in composition, while their generation processes are similar. Fresh groundwater from surrounding aquifers enters the saline lake sediments and considerably leaches halite in the adjacencies of the lake. Simultaneously, it mixes with ancient brines before it emerges from the lake floor. The distinct differences in composition between the Dead Sea and the emerging chimney brines lead to the instantaneous crystallisation of halite and few other mineral phases. The chimney structure result from the buoyancy flow of the chimney brines, which are less dense then the ambient Dead Sea.The chimneys indicate intense cavitation of massive halite bodies in the subsurface of the Dead Sea environment, a process that leads to increasing formation of hazardous sinkholes. Since chimneys are proven in shallow water but may be expected in deeper parts too, they are comfortably mappable by echo-sounding or aerial imaging. They thus provide in the Dead Sea as in any likewise setting a potent predictive tool to locate dangerous subsurface cavitation and hence areas that are at risk of collapse in the near future.

The evolutive role of shoot apical meristems in the adaptation of angiosperms to life at sea and the jump to potential environmental biotechnology applications

Seagrasses have adapted to a submerged lifestyle in seawater through a complex set of evolutionary processes. However, they show sensitivity to increases in natural salinity levels such as those commonly found in discharges of desalination plants, which have exponentially grown due to water scarcity in highly populated temperate areas, such as the Mediterranean basin. This study assessed the effects of brine-derived hypersalinity on the Mediterranean seagrass Posidonia oceanica, focusing on the metabolic responses of shoot apical meristems (SAMs). Although most physiological and genetic studies have used leaves, SAMs are more directly correlated with plant survival and might be more responsive to salinity stress. The experiments were: a controlled mesocosm of more than six practical salinity units (psu) over natural levels using either artificial salts or desalination brine and field transplantation experiments comparing two sites following the dilution plume of the brine (+5 and + 2 psu) with control. Hydrogen peroxide (H2O2), thiobarbituric acid reactive substances (TBARS), and ascorbate were measured to determine oxidative stress and damage, as well as relative expression of genes related to osmotic regulation and oxidative responses. Overall, relative expression of genes related to osmotic regulation (SOS1, SOS3, AKT 2/3) and oxidative stress (STRK1, CAT, MnSOD, FeSOD, APX, GR) was higher in SAMs at higher brine exposures, indicating a more active metabolic response in this organ. Similarly, reactive oxygen species (ROS) production and lipid peroxidation were higher closer to brine discharge and total ascorbate lower, indicating a correlative response with stressor intensity. These findings confirm that SAMs play an essential role in P. oceanica hypersalinity responses and its adaptation to life in the marine environment. Finally, the use of P. oceanica SAMs in this study is highly recommended for an early detection of threats caused by desalination brines that may cause physiological damage and meadow regression.

Morphology of Brine‐Seawater Interface and Spatial Distribution of Submarine Groundwater Discharge Windows in the Muddy Coast

AbstractThe brine‐seawater interface (BSI) is a unique type of groundwater‐seawater interface (GSI) characterized by the higher density of underground brine compared to seawater. This study focuses on characterizing the bay‐scale BSI morphology and identifying submarine‐groundwater discharge windows using a comprehensive in‐situ geophysical detection on the south bank of Laizhou Bay. Our findings reveal that the BSI forms an extensive mixing zone (15–20 km) without distinct contours between waters of varying salinities. The discharge windows for underground brine are located in nearshore areas with fine sand distribution and offshore pockmark areas. Hydraulic and salinity gradients drive the underground brine discharge through these windows. The aquitard window is the primary area for shallow and deep brine exchange, likely evolved from paleochannels, ancient tidal creeks, or ancient underwater barriers. These findings provide crucial modeling support for analyzing environmental evolution mechanisms and theoretical basis for planning the underground brine mining in similar coastal regions.

Oil storage and debrining process in insoluble sediment voids for underground salt cavern energy storage: An experimental study

Large salt cavern oil storage is an effective underground oil storage method, which has been widely used in the United States, Germany, and France. However, the insoluble impurity sediment particles at the bottom of the salt cavern will occupy plenty of oil storage space. To enhance the oil storage capacity, the sediment void oil storage (SVOS) method was proposed. The debrining process from the sediment void prerequisite of the SVOS. It will affect the feasibility of oil injection into the sediment void and the operation efficiency of SVOS. Thus, a self-made debrining device of SVOS was built, and the dynamic debrining process in the sediment void was investigated to explore the debrining process from the sediment void. Six debrining parameters (oil-brine interface change, oil injection rate, brine discharge rate, oil viscosity, the second oil injection quantity, and ground temperature) were proposed and considered. Two kinds of oils (diesel and petrolatum) were conducted in the SVOS debrining experiments. The experimental results showed that the debrining rate remained stable, and it was relevant to the oil injection rate and the interaction of oil and sediments. The average debrining rate of the initial diesel debrining, second diesel debrining, and petrolatum debrining were 2.5 g/s, 2.55 g/s and 2.40 g/s, respectively. The 50 °C of ground temperature sped the debrining rate of high-viscosity oil storage in the sediment void. The oil-brine interface kept balance from the macro perspective, and the oil did not penetrate the inner brine. The oil-brine interface drops ratio of the initial diesel debrining, second diesel debrining, and petrolatum debrining process were 0.586 mm/s, 0.629 mm/s and 0.592 mm/s, respectively. The oil in the sediment voids generated movable and immobile bubbles. The petrolatum flow in the sediment void was easier than the diesel due to the low viscosity at 50 °C. The research has a certain reference value for the development of underground salt cavern oil storage.

A Super-Hygroscopic Solar-Regenerated Alginate-Based Composite for Atmospheric Water Harvesting.

Global water scarcity is leading to increasingly tense competition across populations. In order to complement the largely fast-depleting fresh water sources and mitigate the challenges generated by brine discharge from desalination, atmospheric water harvesting (AWH) has emerged to support long-term water supply. This work presents a novel alginate-based hybrid material comprised of porous silico-aluminophosphate-34 (SAPO-34) as fast-transport channel medium as well as hydrophilicity and stability enhancer, and graphene-based sheets as light absorber for solar-enabled evaporation, both optimally incorporated in an alginate matrix, resulting in a composite sorbent capable of harvesting water from the atmosphere with a record intake of up to 6.85 gw gs -1. Natural sunlight is solely used to enable desorption achieving increase of the temperature of the developed network up to 60°C andresulting in release of the sorbed water, with impurities content well below the World Health Organization (WHO) upper limits. After 30 cycles of sorption and desorption, the composite hydrogel displayed unchanged water uptake and stability. This work provides an impactful perspective toward sustainable generation of water from humidity without external energy consumption supporting the emergence of alternative water production solutions.

Solar-driven remediation of antibiotics in synthetic and real reverse osmosis brine: Addressing lattice oxygen demand and electron transfer for improved purification

This study investigated the significance of integrated advanced oxidation process with reverse osmosis (RO) to ensure the purification and elimination of micropollutants, primarily pharmaceuticals prior to the discharge of brine to the environment. To envisage this, TiO2 based solar driven photocatalysis was employed, highlighting the crucial role of oxygen vacancy formation in the lattice of TiO2 for enhancing the purification of antibiotic contaminants from RO brine. The study elucidated how variations in oxygen environments such as oxygen rich yellow TiO2 (Y-TiO2) and oxygen vacancy black TiO2 (B-TiO2) influence photodegradation reaction kinetics taking ofloxacin (OFX) and tetracycline (TC) as model pollutants. The B-TiO2 exhibited 8.5 times higher photodegradation for OFX compared to Y-TiO2, proving significance in tuning of oxygen environment in lattice. The photodegradation efficiency plot showcases B-TiO2′s efficacy, demonstrating 99.8 % and 99.4 % for OFX and TC, respectively. Additionally, the study investigated the photocatalytic degradation mechanism, identifying predominant charge carriers and reactive species involved, while also assessing the durability of photodegradation processes. The impact of pH on the photocatalytic performance of B-TiO2 in degrading antibiotics explored, spanning pH levels from 2.5 to 10.5. An exploration on band alignment formation in B-TiO2 explains the effectiveness of it over Y-TiO2. Lastly, efficacy of B-TiO2 in degrading antibiotics in real RO brine with high level of salinity (60,200 ppm TDS) is demonstrated, which resulted with photodegradation efficiency of 31.25 % for OFX and 67.8 % for TC, proving applicability of integrated system as a sustainable purification approach. Moreover, the blockage of chloride ions quenching demonstrated improvements in photodegradation emphasizing the influence of chloride ions in high saline conditions.

Single modular flow-electrode capacitive deionization using modified Prussian blue analogues as cation intercalation electrode for continuous water desalination.

Ion back-diffusion hinders the practical application of conventional flow-electrode capacitive deionization (FCDI) under long-term operational conditions. To address this challenge, the present study integrated cation intercalation deionization (CID) with FCDI. A novel PFCDI-CID system was developed by utilizing a modified Prussian blue analogues owing to their enhanced rheological and electrochemical properties. The PFCDI-CID system achieved a high charge efficiency of 89.77% and an energy-normalized removal salt of 0.69 mol kJ-1 in single-cycle (SC) mode with the flow electrodes mass fraction of 2% and a desalinized water chamber-to-concentrated saline water chamber ratio of 2:1. Furthermore, under continuous operation for 12 h in SC mode, the PFCDI-CID system maintained stable desalination performance within the first 2 h. Over an extended duration, the average charge efficiency of the PFCDI-CID system was maintained at 88.44%, with an average energy-normalized removal salt of 0.65 mol kJ-1. The mechanism revealed that the desalination process involving the Prussian blue analogues primarily involves Na+ intercalation, accompanied by a small amount of electro-sorption process. This system exhibits the characteristics of conventional FCDI while enabling desalination and concentration of simulated saline water during brine discharge, thereby mitigating the impact of ion back-diffusion and broadening the application scope of FCDI.

Experimental investigation on the crystallization mechanism and mitigation strategies for gas injection and brine discharge pipes in salt caverns

Salt cavern gas storage (SCGS) not only holds promise for CO2 storage but also helps combat climate change by providing a reliable and adaptable solution for storing natural gas. Herein, this capability facilitates the integration of renewable energy sources and helps decrease greenhouse gas emissions from fossil fuel-based power generation. Firstly, a physical simulation platform for gas injection and brine discharge was developed to investigate the crystallization mechanism and devise preventive measures for constructing SCGS. Secondly, the study involved analyzing the mechanism of brine crystallization and determining experimental parameters using similarity theory. Furthermore, the effects of gas/water injection temperature, brine temperature in the salt cavern, flow rate, and pipe wall roughness on brine crystallization were examined. Finally, preventive measures were suggested to address issues related to crystallization and blockage. Results indicate that a 10℃ increase in gas/ water injection temperature leads to an average decrease of 26.56 % in the crystallization rate, while a corresponding increase of 186.16 % occurs for brine temperature. Heating the injected gas/water and opting for shallow strata for SCGS construction can alleviate crystallization. The crystallization rate initially increases and then decreases with flow rate, with a preferable flow rate exceeding 96 m3/h to prevent crystal adhesion and enhance scouring effects. Therefore, crystallization in the middle of the brine discharge pipe warrants special attention. Significantly reducing pipe wall roughness can effec- tively minimize crystallization, highlighting the importance of developing erosion-resistant coatings. Moreover, a proposed small U-shaped pipe backflushing method aims to solve blockages, along with preliminary application suggestions.

Low-Resistance Membrane vs. High-Resistance Membrane Performance Utilizing Electrodialysis-Evaporator Hybrid System in Treating Reject Brine from Kuwait Desalination Plants.

This work is an effort to mitigate the existing environmental issues caused by brine discharge from Kuwait's desalination plants and to find an economical and efficient way of managing reject brine from local desalination plants. Low- and high-resistance membranes (LRMs and HRMs, respectively) were used to produce salt and low-salinity water from brine effluent utilizing an electrodialysis (ED)-evaporator hybrid system. The effect of high current densities of 300, 400, and 500 A/m2 and brine flowrates of 450 and 500 L/h on the quality of produced salt and diluate were investigated for LRM and HRM. The recovered salt purity for LRM is up to 90.58%. Results show that the low-resistance membrane (LRM) achieved higher water recovery, energy consumption, desalination rate, operation time and ion removal rate than those of the high-resistance membrane (HRM) under the same operating conditions. The difference in concentration for 300 A/m2 between LRM and HRM increased from 0.93% at 10 min to 8.28% at 140 min. The difference in diluate concentration effluent is negligible for both membranes, whereas LRM produced higher concentrate effluent than HRM for all current densities and low flowrate (400 L/h). The maximum difference between LRM and HRM (with LRM achieving higher concentrations) is 10.7% for 400 A/m2. The permselectivity of LRM for monovalent cations decreased with current density, whereas the effect on permselectivity for HRM was insignificant for the current density values. The addition of a neutral cell was effective in reducing the buildup of divalent ions on the inner membrane of the cathode side.

Model-based zero liquid discharge desalination for land-locked arid/semi-arid regions in India

The arid and semiarid regions usually are water-stressed. The available natural groundwater resources in these areas are, at times, saline and unfit for potable use. Desalination of saline water is a possible solution in such cases. However, discharge of concentrated brine is an issue, particularly in land-locked areas. In this regard, a case study has been presented for brackish water desalination in Western Rajasthan, India. As this is a land-locked desert area, zero liquid discharge (ZLD) desalination has been considered, offering a practical and sustainable solution. This study presents a novel approach to the model-based ZLD hybrid desalination system consisting of reverse osmosis and multi-effect distillation (RO-MED) systems producing drinking quality water and common salt. The simultaneous production of common salt has the potential to bring down the cost of drinking water produced by the system. A system design has been carried out for a real case based on the raw water analysis of groundwater in Western Rajasthan. Our hybrid (RO-MED-ZLD) model results indicate that RO reduced TDS from 4419 mg/l to 22 mg/l with a 67 % recovery rate. The proposed ZLD method recovers 93 % of salt crystals from MED brine solutions, potentially reaching 99 % with adjustments.

Innovations in Solar-Powered Desalination: A Comprehensive Review of Sustainable Solutions for Water Scarcity in the Middle East and North Africa (MENA) Region

Water scarcity poses significant challenges in arid regions like the Middle East and North Africa (MENA) due to constant population growth, considering the effects of climate change and water management aspects. The desalination technologies face problems like high energy consumption, high investment costs, and significant environmental impacts by brine discharge. This paper researches the relationships among water scarcity, energy-intensive desalination, and the development of renewable energy in MENA, with a particular focus on the Gulf Cooperation Council (GCC) countries. It examines innovations in solar-powered desalination, considering both solar photovoltaic (PV) and solar thermal technologies, in combination with traditional thermal desalination methods such as multi-effect distillation (MED) and multi-stage flash (MSF). The environmental impacts associated with desalination by brine discharge are also discussed, analyzing innovative technological solutions and avoidance strategies. Utilizing bibliometrics, this report provides a comprehensive analysis of scientific literature for the assessment of the research landscape in order to recognize trends in desalination technologies in the MENA region, providing valuable insights into emerging technologies and research priorities. Despite challenges such as high initial investment costs, technical complexities, and limited funding for research and development, the convergence of water scarcity and renewable energy presents significant opportunities for integrated desalination systems in GCC countries. Summarizing, this paper emphasizes the importance of interdisciplinary approaches and international collaboration by addressing the complex challenges of water scarcity and energy sustainability in the MENA region. By leveraging renewable energy sources and advancing desalination technologies, the region can achieve water security while mitigating environmental impacts and promoting economic development.

Investigation on friction pressure of oil storage and brine discharge in underground salt caverns

The design and control of oil injection and brine removal constitute a crucial task in the construction of salt cavern oil storage (SCOS). In this article, the innovation is that the SCOS pressure governing equations were established, and the impacts of salt cavern depth, crude oil viscosity, as well as injection rate on pipeline friction pressure and wellhead injection pressure were calculated and assessed. Besides, the selection principle of varying viscosity crude oil in different depths of salt caverns, as well as the implementation of an optimal oil injection rate, were proposed. The findings indicated that within the depth range of 500 ∼ 2,000 m, there was a nearly linear correlation between the increase in salt cavern depths and the corresponding rise in injection pressures. The friction pressure generated by the injection pipe constituted the predominant proportion among them, and the range of oil injection pressure was 3.4 ∼ 23.0 MPa. Additionally, the injection pressure and friction pressure were primarily influenced by the viscosity of crude oil, with cavern depth and injection displacement following suit. Shallow salt caverns are optimal for storing high-viscosity crude oil, whereas deep salt caverns are better suited for low-viscosity crude oil storage.

Mechanistic Understanding of Sieving Lithium Ions Using a Biobased Sorbent Technology for Sustainable Lithium Reclamation and Cleansing Brines.

Low-cost environmentally benign materials that can be produced in a large scale to extract lithium from brine resources could drive the lithium market toward a clean technology with high lithium recovery and production. Herein, we have investigated the utilization of a novel, environmentally benign, and low-cost biobased sorbent for the extraction of lithium from lithium-rich solutions. This biobased molecular sieving sorbent, iron(III)-tannate (Fe(III)-TA), belongs to a novel class of coordination polymer frameworks derived from a natural polyphenol-tannic acid (TA)-coordinated with iron(III) metal cations. Its lithium adsorption and kinetic isotherm studies conducted using lithium-rich aqueous solutions confirm the sorbent's dual function for lithium sieving via physisorption, chemisorption, and mass transfer diffusion processes. The adsorption equilibrium and kinetic isotherm models combined with the external and internal mass transfer diffusion models reveal a mechanistic pathway for lithium-ion adsorption. Aiding by forming a fluid film for external mass transfer diffusion of lithium ions, analytes adsorb onto the sorbent surface via physisorption and chemisorption followed by the internal mass transfer diffusion, occupying lithium ions in the sorbent's pores. The lithium adsorption efficiency studies conducted for brines with different concentrations of interference alkali and alkaline cations evidence that the sorbent's affinity for lithium ions strongly depends on the analyte concentration. The results evidence that the sorbent has the ability to lower the brine's salinity and significantly reduces the ratios of Mg/Li and Ca/Li by 4-fold and 10-fold, respectively, yielding lithium-rich solutions. Thus, implementing this innovative biobased sorbent technology as an add-in step into traditional lithium extraction and refining processes, one can design a cost-effective pathway to yield lithium-rich leachate by reducing the Mg/Li and Ca/Li ratio. Nonetheless, the present work demonstrates that Fe(III)-tannate is an effective multifunctional sorbent for sieving lithium from lithium-rich aqueous solutions as well as for desalinating brine resources to recover usable water. Thus, this biobased sorbent offers the possibility of effective application of lithium reclamation and remediation of brine, mitigating the environmental impact of brine discharge and large volume of freshwater usage for lithium extraction and refining.

Analysis of Environmental Impacts of Tuz gölü Natural Gas Storage Project on Tuz Lake

Tuz Gölü Natural Gas Storage Project is one of the most crucial projects developed by BOTAŞ within the framework of ensuring energy supply security. Within the scope of this project, artificial caverns are created for the storage of natural gas and for this purpose, salt layers located 700 to 1500 meters below the ground are leached with fresh water. The brine released as a result of the leaching is discharged into the Tuz Gölü through a 40 km pipeline. This study aims to analyze and interpret the effects of this discharge on the Tuz Gölü. pH, Electrical Conductivity, Salinity, Dissolved Solids Suspended Solids, Sulfate, Chloride Alkalinity, Nitrate, Nitrite, Ammonium Nitrogen, Sodium, Magnesium, Calcium, Oil and Gress parameters were analyzed to determine the water quality in the brine samples taken monthly from the brine discharge point from 2015 when the discharge started until 2023. Related measurements were taken monthly within the scope of this project and analyzed by an accredited laboratory. SPSS 25.0 for Windows package program was used for data analysis. Mean and standard deviation values were used to describe the data. Kolmogorov Smirnov normality test was performed to confirm conformity of the research parameters to the standard normal distribution. The present study aims to provide an environmental impact prediction for future projects.

Optimizing the Marangoni effect towards enhanced salt rejection in thermal passive desalination

Amid escalating water scarcity and rising energy prices, the scientific community strives to propose innovative and efficient water treatment solutions. In this context, solar passive technologies have attracted much attention. Furthermore, recent studies have experimentally revealed that the Marangoni effect, when leveraged in well-designed passive devices, may be a promising pathway towards long-term stable performance. This study presents a comprehensive numerical exploration of applying the Marangoni effect to mitigate salt accumulation, a challenge in long-term system operation. Through an extensive sensitivity analysis, we evaluate the solute molar outflow induced by the Marangoni effect, as different parameters vary. Specifically, the Marangoni effect induces enhanced mass transport, outperforming pure diffusive flow by over three orders of magnitude, under nighttime isothermal conditions. Furthermore, we provide a semi-empirical equation describing accurately the mass transfer versus the Marangoni number. Hence, nighttime brine discharge simulations show rapid salt reduction from the evaporator, reaching seawater-like salinity levels within two hours, setting stage for optimal daytime performance. To the best of our knowledge, this discharge time is the lowest reported in the literature under equivalent conditions. In conclusion we believe that the still poorly explored Marangoni effect may offer a durable mean of providing freshwater, particularly in emergencies.

Non-target screening and prioritization of organic contaminants in seawater desalination and their ecological risk assessment

The impact of desalination brine on the marine environment is a global concern. Regarding this, salinity is generally accepted as the major environmental factor in desalination concentrate. However, recent studies have shown that the influence of organic contaminants in brine cannot be ignored. Therefore, a non-targeted screening method based on comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS) was developed for identifying organic contaminants in the desalination brine. A total of 404 compounds were tentatively identified from four seawater desalination plants (three reverse osmosis plants and one multiple effect distillation plant) in China. The identified compounds were prioritized based on their persistence, bioaccumulation, ecotoxicity, usage, and detection frequency. Twenty-one (21) compounds (seven phthalates, ten pesticides, four trihalomethanes) were then selected for further quantitative analysis and ecological risk assessment, including compounds from the priority list along with substances from the same chemical classes. Ecologically risky substances in brine include diisobutylphthalate and bis(2-Ethylhexyl) phthalate, atrazine and acetochlor, and bromoform. Most of the contaminants come from raw seawater, and no high risk contaminants introduced by the desalination process have been found except for disinfection by-products. In brine discharge management, people believed that all pollution in raw seawater was concentrated by desalination process. This study shows that not all pollutants are concentrated during the desalination process. In this study, the total concentration of pesticide in the brine increased by 58.42%. The concentration of ∑PAEs decreased by 13.65% in reverse osmosis desalination plants and increased by 10.96% in the multi-effect distillation plant. The concentration of trihalomethane increased significantly in the desalination concentrate. The change in the concentration of pollutants in the desalination concentrate was related to the pretreatment method and the chemical characteristics of the contaminants. The method and results given in this study hinted a new idea to identify and control the environmental impact factors of brine.

Active microbial communities facilitate carbon turnover in brine pools found in the deep Southeastern Mediterranean Sea

Discharge of gas-rich brines fuels productive chemosynthetic ecosystems in the deep sea. In these salty, methanic and sulfidic brines, microbial communities adapt to specific niches along the physicochemical gradients. However, the molecular mechanisms that underpin these adaptations are not fully known. Using metagenomics, we investigated the dense (∼106 cell ml−1) microbial communities that occupy small deep-sea brine pools found in the Southeastern Mediterranean Sea (1150 m water depth, ∼22 °C, ∼60 PSU salinity, sulfide, methane, ammonia reaching millimolar levels, and oxygen usually depleted), reaching high productivity rates of 685 μg C L−1 d−1 ex-situ. We curated 266 metagenome-assembled genomes of bacteria and archaea from the several pools and adjacent sediment-water interface, highlighting the dominance of a single Sulfurimonas, which likely fuels its autotrophy using sulfide oxidation or inorganic sulfur disproportionation. This lineage may be dominant in its niche due to genome streamlining, limiting its metabolic repertoire, particularly by using a single variant of sulfide: quinone oxidoreductase. These primary producers co-exist with ANME-2c archaea that catalyze the anaerobic oxidation of methane. Other lineages can degrade the necromass aerobically (Halomonas and Alcanivorax), or anaerobically through fermentation of macromolecules (e.g., Caldatribacteriota, Bipolaricaulia, Chloroflexota, etc). These low-abundance organisms likely support the autotrophs, providing energy-rich H2, and vital organics such as vitamin B12.

The halotolerant white sea anemone Anthothoe chilensis, highly abundant in brine discharges zones, as a promising biomonitoring species for evaluating the impacts of desalination plants

Seawater desalination raises concerns about its environmental repercussions, particularly the impact of brine discharge on benthic communities. In this study, we evaluated the effects of desalination and artificial brines on the sea anemone Anthothoe chilensis, following its observed proliferation near a brine outfall from a Chilean desalination plant. We measured biomarkers for oxidative stress (ROS content, lipid peroxidation, and protein carbonylation), antioxidant response (thiols), and osmotic stress (free amino acids and proline) in individuals collected from a brine discharge pipe (∼56 psu) and compared them to a population living in natural seawater salinity. Additionally, we conducted controlled laboratory experiments where A. chilensis specimens were exposed to a control salinity of 33 psu and to elevated salinities of 37 and 42 psu for 24 and 48 h. Results revealed a significant decrease in oxidative damage biomarkers, such as protein carbonylation and ROS content, along with an increase in free amino acids, proline, and thiols content at higher salinity levels, particularly under controlled conditions. These findings demonstrate the remarkable efficient cellular stress responses of this highly halotolerant species, which could potentially promote risky A. chilensis blooms in brine discharges areas. Additionally, this study provides valuable biomarker information for assessing the short-term impacts of brine discharges, which can be used in biomonitoring programs within the desalination sector.

ГИДРАВЛИЧЕСКИЙ РАСЧЕТ ТРУБОПРОВОДА С РАССРЕДОТОЧЕННЫМ СБРОСОМ РАССОЛА В АКВАТОРИЮ

When producing water using desalination technologies, significant volumes of highly concentrated brines are formed. The solution of the problem of wastes recycling is an important global issue for water protection organizations, and the studies of the last decade confirm this. The article discusses an environmentally friendly method of dispersed uniform brine discharge into the water area, presents the developed technical solution and describes the principle of its operation. As an example, the authors calculate the hole diameters of the distribution pipeline for uniform brine discharge along the length. We calculated the radius and the scattering jet rate at a given distance from the hole in the distribution pipeline. The difference in brine salt concentrations at a depth of 20 m from the discharge point between the background concentration in the sea and the salt concentration was found to be from 0.439 % to 0.524 % along the length of the discharge pipeline. Dissolution of brines to safe concentrations becomes even more intense in the presence of sea currents. The research results can be used in the design and operation of such systems.