Sea Brine Research Articles

Simulation of stable and metastable sea-type carbonate systems for optimization of MgCO3·3H2O precipitation from waste sea brines

The thermodynamic simulation of the systems Na+, Mg2+/Cl−, CO32−//H2O and Na+, Mg2+/SO42−, CO32−//H2O using the Pitzer method at 25°C revealed that both stable and metastable crystallizations take place in these systems. MgCO3·3H2O is always a metastable phase. Thermodynamic modeling of Mg2+ removal as a part of desalination of hyper-saline sea-salt waste brines, which can be described by these systems, pointed to the co-precipitation of various salts. Ensuing from the obtained data and considering the crystal chemistry and kinetic crystallization of the co-crystallizing salts we designed the precipitation of MgCO3·3H2O from sea-salt brines avoiding its further transformation to metastable 4MgCO3·Мg(ОН)2·4H2O and stable MgCO3. Our experimental studies confirmed the designed method and optimized the conditions for precipitation of high-purity MgCO3·3H2O with good filtration characteristics.

Long-term freshening of the Dead Sea brine revealed by porewater Cl− and [formula omitted] in ICDP Dead Sea deep-drill

The geological evolution of the unique Dead Sea Ca-chloride brine has been the focus of many research efforts for several decades. These studies relied on the information obtained from sedimentary exposures of the marginal terraces of the modern Dead Sea, mostly documenting the history of the surface lake brine during its high stands periods. The present study is the first attempt to establish the history of the deepest part of the lake by direct measurements of the chemical and isotopic composition of pore-fluids that were extracted from cores drilled during 2011 by ICDP in the deep basin of the Dead Sea at water depth of 300 m. The vertical profiles of chloride (Cl−) and oxygen isotopes (δO18) in pore brines reveal a substantial decrease in the salinity of the hyper-saline lake during the last glacial and particularly during MIS2 (∼31–17 kaBP). The Cl− concentration of the deep brine in the lake decreased gradually, reaching a minimum of less than 2/3 of its present value while the δO18 increased to maximum of ∼7‰ (3‰ higher than today). The low Cl− indicates significant dilution of the bottom water mass (hypolimnion) of Lake Lisan (the last glacial predecessor of the modern Dead Sea) during its highest stand period. Beforehand, during the interglacial and later during the post-glacial and the Holocene the Cl− concentrations and δO18 values were similar to those of the modern Dead Sea. The slow dilution of the deep Ca-chloride brine was caused probably by continuous turbulent mixing of the hypolimnion with the less saline high δO18 epilimnetic brine, across the epilimnion/hypolimnion interface (EHI). While the increase in δO18 during the salinity decrease of Lake Lisan is a result of “normal” evaporation of the less saline epilimnetic brine, the post-glacial δO18 decrease (contemporaneous with salinity increase) is attributed to the “reversed” behavior of δO18 during evaporation of high salinity brine. During the long freshening period the hypolimnion was enriched with dissolved sulfate supplied by the freshwater and transported by the turbulent mixing across the EHI until reaching gypsum saturation that commenced massive gypsum deposition at the end of this period, when full overturn took place.

Physical controls on the storage of methane in landfast sea ice

Abstract. We report on methane (CH4) dynamics in landfast sea ice, brine and under-ice seawater at Barrow in 2009. The CH4 concentrations in under-ice water ranged from 25.9 to 116.4 nmol L−1sw, indicating a supersaturation of 700 to 3100% relative to the atmosphere. In comparison, the CH4 concentrations in sea ice ranged from 3.4 to 17.2 nmol L−1ice and the deduced CH4 concentrations in brine from 13.2 to 677.7 nmol L−1brine. We investigated the processes underlying the difference in CH4 concentrations between sea ice, brine and under-ice water and suggest that biological controls on the storage of CH4 in ice were minor in comparison to the physical controls. Two physical processes regulated the storage of CH4 in our landfast ice samples: bubble formation within the ice and sea ice permeability. Gas bubble formation due to brine concentration and solubility decrease favoured the accumulation of CH4 in the ice at the beginning of ice growth. CH4 retention in sea ice was then twice as efficient as that of salt; this also explains the overall higher CH4 concentrations in brine than in the under-ice water. As sea ice thickened, gas bubble formation became less efficient, CH4 was then mainly trapped in the dissolved state. The increase of sea ice permeability during ice melt marked the end of CH4 storage.

Chemical Parameters of Brine at Various Stages of Solar Salt Production in South Tamil Nadu, India

It deals with the chemical parameters of brine at various stages of four selected salt production works, two from Kanyakumari District (SW1,SW2) and other two from Tuticorin District (SW3,SW4) Tamil Nadu. Estimation of ionic content of the various ions like chloride, sulphate, fluoride, calcium, magnesium, sodium and potassium were studied. The mean and standard deviation value of chloride, sulphate, fluoride, calcium, magnesium, sodium and potassium content (gl-1) at various stages of salt production process of the selected salt works were evaluated. The concentration of different ions in each samples were almost same. The calcium ion content was minimum in bittern stage of sub soil brine and below the detection level in sea brine.

Mining a database of single amplified genomes from Red Sea brine pool extremophiles-improving reliability of gene function prediction using a profile and pattern matching algorithm (PPMA).

Reliable functional annotation of genomic data is the key-step in the discovery of novel enzymes. Intrinsic sequencing data quality problems of single amplified genomes (SAGs) and poor homology of novel extremophile's genomes pose significant challenges for the attribution of functions to the coding sequences identified. The anoxic deep-sea brine pools of the Red Sea are a promising source of novel enzymes with unique evolutionary adaptation. Sequencing data from Red Sea brine pool cultures and SAGs are annotated and stored in the Integrated Data Warehouse of Microbial Genomes (INDIGO) data warehouse. Low sequence homology of annotated genes (no similarity for 35% of these genes) may translate into false positives when searching for specific functions. The Profile and Pattern Matching (PPM) strategy described here was developed to eliminate false positive annotations of enzyme function before progressing to labor-intensive hyper-saline gene expression and characterization. It utilizes InterPro-derived Gene Ontology (GO)-terms (which represent enzyme function profiles) and annotated relevant PROSITE IDs (which are linked to an amino acid consensus pattern). The PPM algorithm was tested on 15 protein families, which were selected based on scientific and commercial potential. An initial list of 2577 enzyme commission (E.C.) numbers was translated into 171 GO-terms and 49 consensus patterns. A subset of INDIGO-sequences consisting of 58 SAGs from six different taxons of bacteria and archaea were selected from six different brine pool environments. Those SAGs code for 74,516 genes, which were independently scanned for the GO-terms (profile filter) and PROSITE IDs (pattern filter). Following stringent reliability filtering, the non-redundant hits (106 profile hits and 147 pattern hits) are classified as reliable, if at least two relevant descriptors (GO-terms and/or consensus patterns) are present. Scripts for annotation, as well as for the PPM algorithm, are available through the INDIGO website.

Host-induced increase in larval sea bass mortality in a gnotobiotic challenge test with Vibrio anguillarum

Vibrio anguillarum is the major cause of haemorrhagic septicaemia, vibriosis, which is a severe disease affecting marine fish. In this work, it was found that the mortality of gnotobiotic sea bass larvae challenged with V. anguillarum was dependent on the number of dead fish in the vials at the moment of challenge. Based on this finding, the effect of dead hosts (homogenised sea bass larvae or brine shrimp) on the virulence of V. anguillarum towards sea bass larvae was further investigated. Addition of homogenised hosts led to significantly increased larval mortality of challenged larvae, and this was observed for 3 different V. anguillarum strains, i.e. 43, NB 10 and HI 610. In contrast, the addition of similar levels of tryptone had no effect on mortality. In line with this, the motility of all 3 V. anguillarum strains was significantly increased by the addition of homogenised hosts but not by tryptone. These results suggest that dead hosts increase infectivity of V. anguillarum, not merely by offering nutrients to the bacteria, but also by increasing virulence-associated activities such as motility.

Detection of Saline Groundwater Bodies between the Dead Sea and the Mediterranean Sea, Israel, Using the TDEM Method and Hydrochemical Parameters

A Time Domain ElectroMagnetic (TDEM) survey coupled with hydrogeological information was carried out along the Be’er Sheva valley between the Mediterranean Sea and the Dead Sea base levels, aiming to obtain the subsurface distribution of the different fresh and saline water bodies. Hydrochemical considerations and previous TDEM results hinted that the previously accepted model of an upper fresh water body underlain by solely Dead Sea (R-type) brines in the east and C-type brines in the west does not match the actual observations. Thus, the suggested working hypothesis of additional intruding seawater from the Mediterranean Sea to the Dead Sea base level was checked by the TDEM method. The results, indeed, exhibit an upper high resistivity fresh water body, an underlying low resistivity brine body and a moderate resistivity body in between. The origin of this body is not uniquely determined based on the geophysical measurements alone. Analysis of borehole data testifies that hydrochemical parameters of the body cannot be solely interpreted as a mixture of the above two end members, but rather calls for an additional contribution of intruding seawater. The suggested configuration consists of an upper fresh water body flowing to both base levels in the west and the east. Underneath there is a saline body resulting from seawater intrusion reaching from the Mediterranean to the Dead Sea base level. At the bottom there is a third body of the westward density driven Dead Sea brine. The entire configuration is supported by results of subsurface flow modeling.

The hydrogeochemistry of subsurface brines in and west of the Jordan–Dead Sea Transform fault

AbstractThis study is based on 113 analyses of brines with Cl > 0.57 mol l−1 (modern seawater), which were collected and analysed mostly during several decades of exploration for gas and oil in Israel. Based on critical evaluation of correlations of elements and ionic ratios and on spider patterns, six different brine events or source brines were identified in the Phanerozoic: the Triassic, Lower Cretaceous and the Mio/Pliocene brine families which were identified in boreholes Sdom‐1, Sdom Deep‐1 and Ha'on, and the Holocene Dead Sea brines. The Triassic brines are nowadays also encountered in under‐ and overlying rock units such as the Paleozoic Negev‐Yam Suf and the Jurassic Arad Groups, respectively. The southern Jordan–Dead Sea Transform (also known as the Rift) hosts the Mio‐Pliocene Sdom Deep and Sdom brine families. Brine bodies not sufficiently isolated by impervious sedimentary layers were flushed out during the Pliocene when the southern Valley drained north‐ and westwards through the Yizre'el Valley to the Mediterranean Sea. In the northern Rift Miocene to Pliocene seawater evaporated and infiltrated into the Rift sediments and into adjacent rocks. Further diluted by freshwater, it emerges as the Ha'on brine. Together with its derivatives, they form the Ha'on family. The derivatives of the Holocene Dead Sea brine family occur along the shoreline of the recent Dead Sea. Apart of all these evaporation brines, brines deriving from dissolution of evaporites locally occur in the area. The time‐bound chemical composition of paleoseawater is considered when discussing the ionic ratios of brines generated during different geological periods. Spider patterns of each brine family are compared and, where necessary, the relationship of brines to distinct families of brines is supported by inverse modelling.

Diversity and distribution of eukaryotic microbes in and around a brine pool adjacent to the Thuwal cold seeps in the Red Sea

A hypoxic/suboxic brine pool at a depth of about 850 m was discovered near the Thuwal cold seeps in the Red Sea. Filled with high concentrations of hydrogen sulfide and ammonia, such a brine pool might limit the spread of eukaryotic organisms. Here, we compared the communities of the eukaryotic microbes in a microbial mat, sediments and water samples distributed in 7 sites within and adjacent to the brine pool. Taxonomic classification of the pyrosequenced 18S rRNA amplicon reads showed that fungi highly similar to the species identified along the Arabic coast were almost ubiquitous in the water and sediment samples, supporting their wide distribution in various environments. The microbial mat displayed the highest species diversity and contained grazers and a considerable percentage of unclassified species. Phylogeny-based methods revealed novel lineages representing a majority of the reads from the interface between the sea water and brine pool. Phylogenetic relationships with more reference sequences suggest that the lineages were affiliated with novel Alveolata and Euglenozoa inhabiting the interface where chemosynthetic prokaryotes are highly proliferative due to the strong chemocline and halocline. The brine sediments harbored abundant species highly similar to invertebrate gregarine parasites identified in different oxygen-depleted sediments. Therefore, the present findings support the uniqueness of some microbial eukaryotic groups in this cold seep brine system.

Impact of sea‐ice processes on the carbonate system and ocean acidification at the ice‐water interface of the Amundsen Gulf, Arctic Ocean

From sea‐ice formation in November 2007 to onset of ice melt in May 2008, we studied the carbonate system in first‐year Arctic sea ice, focusing on the impact of calcium‐carbonate (CaCO3) saturation states of aragonite (ΩAr) and calcite (ΩCa) at the ice‐water interface (UIW). Based on total inorganic carbon (CT) and total alkalinity (AT), and derived pH, CO2, carbonate ion ([CO32−]) concentrations and Ω, we investigated the major drivers such as brine rejection, CaCO3 precipitation, bacterial respiration, primary production and CO2‐gas flux in sea ice, brine, frost flowers and UIW. We estimated large variability in sea‐ice CT at the top, mid, and bottom ice. Changes due to CaCO3 and CO2‐gas flux had large impact on CT in the whole ice core from March to May, bacterial respiration was important at the bottom ice during all months, and primary production in May. It was evident that the sea‐ice processes had large impact on UIW, resulting in a five times larger seasonal amplitude of the carbonate system, relative to the upper 20 m. During ice formation, [CO2] increased by 30 µmol kg−1, [CO32−] decreased by 50 µmol kg−1, and the ΩAr decreased by 0.8 in the UIW due to CO2‐enriched brine from solid CaCO3. Conversely, during ice melt, [CO32−] increased by 90 µmol kg−1 in the UIW, and Ω increased by 1.4 between March and May, likely due to CaCO3 dissolution and primary production. We estimated that increased ice melt would lead to enhanced oceanic uptake of inorganic carbon to the surface layer.

Induction of apoptosis in cancer cell lines by the Red Sea brine pool bacterial extracts

BackgroundMarine microorganisms are considered to be an important source of bioactive molecules against various diseases and have great potential to increase the number of lead molecules in clinical trials. Progress in novel microbial culturing techniques as well as greater accessibility to unique oceanic habitats has placed the marine environment as a new frontier in the field of natural product drug discovery.MethodsA total of 24 microbial extracts from deep-sea brine pools in the Red Sea have been evaluated for their anticancer potential against three human cancer cell lines. Downstream analysis of these six most potent extracts was done using various biological assays, such as Caspase-3/7 activity, mitochondrial membrane potential (MMP), PARP-1 cleavage and expression of γH2Ax, Caspase-8 and -9 using western blotting.ResultsIn general, most of the microbial extracts were found to be cytotoxic against one or more cancer cell lines with cell line specific activities. Out of the 13 most active microbial extracts, six extracts were able to induce significantly higher apoptosis (>70%) in cancer cells. Mechanism level studies revealed that extracts from Chromohalobacter salexigens (P3-86A and P3-86B(2)) followed the sequence of events of apoptotic pathway involving MMP disruption, caspase-3/7 activity, caspase-8 cleavage, PARP-1 cleavage and Phosphatidylserine (PS) exposure, whereas another Chromohalobacter salexigens extract (K30) induced caspase-9 mediated apoptosis. The extracts from Halomonas meridiana (P3-37B), Chromohalobacter israelensis (K18) and Idiomarina loihiensis (P3-37C) were unable to induce any change in MMP in HeLa cancer cells, and thus suggested mitochondria-independent apoptosis induction. However, further detection of a PARP-1 cleavage product, and the observed changes in caspase-8 and -9 suggested the involvement of caspase-mediated apoptotic pathways.ConclusionAltogether, the study offers novel findings regarding the anticancer potential of several halophilic bacterial species inhabiting the Red Sea (at the depth of 1500–2500 m), which constitute valuable candidates for further isolation and characterization of bioactive molecules.

Isolation and characterization of a heavy metal-resistant, thermophilic esterase from a Red Sea Brine Pool

The Red Sea Atlantis II brine pool is an extreme environment that displays multiple harsh conditions such as high temperature, high salinity and high concentrations of multiple, toxic heavy metals. The survival of microbes in such an environment by utilizing resistant enzymes makes them an excellent source of extremophilic enzymes. We constructed a fosmid metagenomic library using DNA isolated from the deepest and most secluded layer of this pool. We report the isolation and biochemical characterization of an unusual esterase: EstATII. EstATII is thermophilic (optimum temperature, 65°C), halotolerant (maintains its activity in up to 4.5 M NaCl) and maintains at least 60% of its activity in the presence of a wide spectrum of heavy metals. The combination of biochemical characteristics of the Red Sea Atlantis II brine pool esterase, i.e., halotolerance, thermophilicity and resistance to heavy metals, makes it a potentially useful biocatalyst.

Mercury uptake within an ice algal community during the spring bloom in first‐year Arctic sea ice

In this study, we examine mercury bioaccumulation by a first‐year sea‐ice (FYI) algal community in the western Canadian Arctic during the spring of 2008. Total mercury concentration in bottom sea‐ice particulate ([PHg]T) ranged 0.004–0.022 µg/g dw and was limited by the amount of mercury available for uptake when the spring bloom commenced. Mercury in ice algae originated from a combination of brine and seawater as sources, while atmospheric mercury depletion events did not appear to significantly contribute as a source in a coupled manner. We show that the bottom sea‐ice brine presents a chemically and biologically unique niche from which inorganic Hg makes its way into the food web. Once incorporated into algae, mercury can be transported spatially and trophically within the ecosystem by a range of processes including grazing, resuspension, remineralization, and sedimentation. Ice algae contribute 10–60% of the annual primary production in the Arctic and are thought to become even more productive and abundant under a mild climate change scenario. Replacement of multiyear ice with FYI in the Beaufort Sea alone could result in an additional influx of ∼48 kg/yr of particle bound Hg. Further studies are thus warranted to elucidate mechanisms by which mercury transformation processes and transfer into the Arctic marine food web are impacted by the interaction between sea ice, brine, and seawater.

Application of ocean manganese nodules for the adsorption of potassium ions from seawater

Extracting potassium from seawater has great economic potential, although conventional methods offer low separation capacity and selectivity. In this study, a series of novel potassium ionic sieves (PISs) were synthesized using ocean manganese nodules (OMN) as raw materials. The PISs were characterized by XRD, SEM, and nitrogen adsorption–desorption. The potassium adsorption capacities and separation factors of PISs and OMN in KCl solution and sea brine showed that KMnO4 treatment will result in the highest adsorption and separation performance. The resulted sample OMN-C exhibit major composition of birnessite-type potassium manganese oxides and high micropore volumes. The adsorption capacities of OMN-C to K+ in KCl solution and sea brine were 35.2mgg−1 and 22.1mgg−1, respectively. The separation factor of OMN-C was α(K+/Na+)=108.6 and the sieve did not adsorb Mg2+, indicating its relatively high separation selectivity to K+. Therefore, OMN-C can selectively extract potassium from sea brine effectively. This study not only utilized the abundant OMN resources, but also prepared effective PISs, which showed great potential in the utilization of seawater.

海水、かん水中に溶存するマグネシウムおよびカルシウムの直接電解分離に関する研究 (第1報)

海水、かん水中に溶存するマグネシウムおよびカルシウムの直接電解分離に関する研究 (第1報)

かん水,「にがり」のpHについて (第1報)

かん水,「にがり」のpHについて (第1報)

Mg 1-naphthy amine-8-sulfonateによる海かん水中のナトリウムの重量分析

Mg 1-naphthy amine-8-sulfonateによる海かん水中のナトリウムの重量分析

The physical structures of snow and sea ice in the Arctic section of 150°-180°W during the summer of 2010

The physical structures of snow and sea ice in the Arctic section of 150°–180°W were observed on the basis of snow-pit, ice-core, and drill-hole measurements from late July to late August 2010. Almost all the investigated floes were first-year ice, except for one located north of Alaska, which was probably multi-year ice transported from north of the Canadian Arctic Archipelago during early summer. The snow covers over all the investigated floes were in the melting phase, with temperatures approaching 0 °C and densities of 295–398 kg/m3. The snow covers can be divided into two to five layers of different textures, withmost cases having a top layer of fresh snow, a round-grain layer in themiddle, and slush and/or thin icing layers at the bottom. The first-year sea ice contained about 7%–17% granular ice at the top. There was no granular ice in the lower layers. The interiormelting and desalination of sea ice introduced strong stratifications of temperature, salinity, density, and gas and brine volume fractions. The sea ice temperature exhibited linear cooling with depth, while the salinity and the density increased linearly with normalized depth from 0.2 to 0.9 and from 0 to 0.65, respectively. The top layer, especially the freeboard layer, had the lowest salinity and density, and consequently the largest gas content and the smallest brine content. Both the salinity and density in the ice basal layer were highly scattered due to large differences in ice porosity among the samples. The bulk average sea ice temperature, salinity, density, and gas and brine volume fractions were −0.8 °C, 1.8, 837 kg/m3, 9.3% and 10.4%, respectively. The snow cover, sea ice bottom, and sea ice interior show evidences of melting duringmid-August in the investigated floe located at about 87°N, 175°W.

PH evolution in sea ice grown at an outdoor experimental facility

The pH of sea ice and brine was experimentally determined during initial ice growth and melt at the Sea-ice Environmental Research Facility (SERF), an outdoor experimental sea ice facility in Winnipeg, Canada. pH measurements were performed potentiometrically and spectroscopically at near-freezing temperatures. Vertical pH profiles from bulk ice cores revealed a consistent C-shaped pattern during columnar ice growth, with highest pH values (>9) in both exterior (top and bottom) ice sections and in frost flowers, and lowest pH (~7) in interior ice sections. Brine pH typically remained below that of the source seawater pH (~8.4). The distinct differences between these ice features and the underlying seawater source demonstrate the effect of the natural freezing process and associated changes in the CO2-carbonate system on the pH of the sea ice environment. Interpreting this effect provides new insight into the conditions leading to CO2 exchange across the ocean–sea ice–atmosphere interface. A conceptual model of pH evolution in seawater, sea ice and brine, and frost flowers is proposed to explain the observed pH characteristics of seawater components during sea ice growth and melt.

Autotrophic Microbe Metagenomes and Metabolic Pathways Differentiate Adjacent Red Sea Brine Pools

In the Red Sea, two neighboring deep-sea brine pools, Atlantis II and Discovery, have been studied extensively, and the results have shown that the temperature and concentrations of metal and methane in Atlantis II have increased over the past decades. Therefore, we investigated changes in the microbial community and metabolic pathways. Here, we compared the metagenomes of the two pools to each other and to those of deep-sea water samples. Archaea were generally absent in the Atlantis II metagenome; Bacteria in the metagenome were typically heterotrophic and depended on aromatic compounds and other extracellular organic carbon compounds as indicated by enrichment of the related metabolic pathways. In contrast, autotrophic Archaea capable of CO2 fixation and methane oxidation were identified in Discovery but not in Atlantis II. Our results suggest that hydrothermal conditions and metal precipitation in the Atlantis II pool have resulted in elimination of the autotrophic community and methanogens.