Brine Effluent Research Articles

Demonstration of ultra-high-water recovery and brine concentration in a prototype evaporation unit: Towards zero liquid discharge desalination

The availability of water is still one of the most important factors affecting the sustainable growth of a country. Although many countries have free access to an inexhaustible source of water, the sea, this source cannot be used for human purposes as it is. To face this problem, desalination has been proposed for freshwater production but the generation of a waste brine effluent poses some issues of actual sustainability. In this work, the operation results of a Multiple Effect Distillation (MED) demo plant, designed for stable operation at high brine concentrations and operated as a brine concentrator, are presented. To this purpose, the integration with NanoFiltration (NF) has been implemented to minimize scaling risks, by removing bivalent ions from the feed stream. The 2-effects MED pilot unit, with a capacity of 1.7 m3/h, has been installed as part of the treatment chain of the WATER-MINING project, within the premises of the power station of the island of Lampedusa (Sicily, Italy) and is fully powered by waste heat at 70–80 °C from diesel engines. A vapor temperature of 40–50 °C allowed a perfect coupling with the low temperature waste heat source, demonstrating the possibility to produce distilled water with a conductivity between 15 and 25 μs/cm. Among the several operating conditions investigated, a recovery ratio above 80 % has been achieved and an effluent brine conductivity of 240 mS/cm was produced, very close to saturation in NaCl, thus being excellent for food-grade sea salt production in evaporative ponds. For the first time, it has been demonstrated on a pilot scale how a MED unit, supplied with waste heat, can be used efficiently as a brine concentrator, obtaining a brine concentration 8 times higher than the input concentration without any scaling problem.

A novel tool for modeling the near- and far-field dispersion of brine effluent from desalination plants

A novel tool for modeling the near- and far-field dispersion of brine effluent from desalination plants

Fluid-rock interactions during intermittent injection of supercritical CO2: An investigation for CO2 storage in the depleted Nini West oil field, Danish North Sea

CO2 that is planned to be stored in the depleted Nini West oil field will be delivered by ship which results in intermittent injection of supercritical CO2 (scCO2). It is important to investigate the effect of this injection scenario on rock specimens in the early phase of the storage program. In this regard, core flooding experiments have been conducted at current reservoir conditions of 200 bar and 60 °C. The state of plug samples pre- and post-scCO2 injection were compared by coupled scanning with the scanning electron microscope (SEM) and micro-CT scanning to track mineralogical changes at core-scale. The coupled approach shows partial dissolution of garnet, specifically almandine and carbonate minerals such as siderite, rhodochrosite and calcite in the glauconitic sandstone after 5 sets of scCO2 injection periods. Effluent brine ion content measured after each brine injection operation shows an increase in Fetot, Si+, and Mn2+ in the effluent brine compared with the injection brine, which agrees with dissolution of minerals captured by the SEM and micro-CT scan. ScCO2 effective permeability at the end of each scCO2 injection period ranges between 18 and 34 % of the initial brine permeability at 100 % water saturation (Sw). The conclusion is that CO2 permeability over these periods of injection is not affected by neither the dissolution of minerals, since these minerals are present only in low concentrations, nor the salt precipitation due to scCO2 injection.

Perspective in resource recovery from reverse osmosis brines: the case for sustainable seawater refineries for small islands

AbstractReverse osmosis has become the dominant technique for desalination while at the same time there is a steady increase in reliance on desalination systems for water production globally. Resource recovery and mitigation of adverse effects from brine discharge are important factors and are increasingly being considered by researchers and industrial actors. The island nation of Aruba, with over 100 years of commercial desalination history, is used as a case study to illustrate the possibilities of shifting from centralized seawater desalination plants to seawater refineries in which freshwater is considered only one of the possible products. We identify possible economic value from desalination plants of medium scale (as is the case in Aruba) from the production of magnesium, caustic soda, chlorine‐based products and rubidium and possible energy recovery possibilities through osmotic gradients and/or hydrogen storage while at the same time highlighting the insufficient potential for lithium harvesting from seawater desalination brines. We have found that the economic value from resources recovered from brine may be even larger than the value of the freshwater produced by these plants. Furthermore, reduction of salinity and quantity of brine can reduce the overall ecological impact from current brine effluents. © 2023 Society of Chemical Industry (SCI).

Process design and technoeconomic analysis for zero liquid discharge desalination via LiBr absorption chiller integrated HDH-MEE-MVR system

A novel multipurpose seawater desalination process is presented that integrates a Lithium Bromide (LiBr) absorption chiller, humidification-dehumidification (HDH), multi-effect evaporator, and mechanical vapor recompression (MVR) to improve the energy effectiveness of conventional desalination processes. The proposed process uses the LiBr absorption chiller cycle to preheat the seawater prior to the steam generation in the multi-effect evaporators while the MVR system activates the LiBr cycle. The integration of HDH further allows to recover the excess water in the process stream and concentrates the brine effluent for zero liquid discharge processing. A stand-alone HDH desalination is comparatively studied with the integrated system to quantify their respective performances over several metrics. Technoeconomic analysis is also performed to assess the economic feasibility and a sensitivity analysis is carried out to observe the effects of changing process variables on the overall performance of these systems. The results show that the proposed process design achieves several times higher gain-output ratio compared to a conventional HDH system of equal capacity, with a levelized water production cost of $8.4/m3 and 6 kW of cooling capacity that can be used for air conditioning.

Effects of Carbonic Acid-Rock Interactions on CO2/Brine Multiphase Flow Properties in the Upper Minnelusa Sandstones

SummaryCarbon dioxide (CO2) injection into a deep saline aquifer can dissolve into formation brine and generate carbonic acid. The resulting acid can drive fluid-rock geochemical reactions. The impact of these fluid-rock geochemical reactions on porosity, permeability, and multiphase flow responses is relevant to the determination of CO2 storage capacity of deep saline aquifers. In this research, carbonic acid flooding experiments were performed on core samples consisting of poorly sorted, quartz-rich sand with laminated bedding from a possible CO2 storage target in northwest Wyoming. Complementary pre- and post-injection porosity and permeability, thin-section, Brunauer-Emmett-Teller (BET) surface area, mercury intrusion capillary pressure (MICP), and time-domain nuclear magnetic resonance (TD-NMR) measurements were conducted. Overall, both core porosity and permeability increased after a 7-day carbonic acid injection, from 6.2 to 8.4% and 1.6 to 3.7 md, respectively. We attributed these changes to carbonate mineral dissolution, which was evidenced by the effluent brine geochemistry, pore-throat size distribution (PTSD), and BET surface area. To be more specific, within the more-permeable section of core samples containing larger pore size, the permeability increment is apparent due to dolomite mineral grains and cements dissolution. However, for the lower-permeability section corresponding to the smaller pore size, mineral precipitation possibly lessened dissolution effects, leading to insignificant petrophysical properties changes. Consequently, the observed heterogeneous carbonic acid-rock interactions resulted in alterations of CO2/brine relative permeability (i.e., the initial CO2 saturation decreased and the CO2 flow capacity was enhanced). This research provides a fundamental understanding regarding effects of fluid-rock reactions on changes in static and multiphase flow properties of eolian sandstones, which lays the foundation for more accurate prediction/simulation of CO2 injection into deep saline aquifers.

Process simulation and analysis of high‐pressure reverse osmosis (HPRO) in the treatment and utilization of desalination brine (saline wastewater)

Reverse osmosis (RO) is nowadays considered to be the most dominant desalination technology. Nonetheless, due to osmotic pressure constraints, conventional RO cannot desalinate brine effluents (>70 g/L of total dissolved solids [TDS]). Thus, high-pressure RO (HPRO), that is, RO operating at a pressure of more than 82 bar, has recently attracted the interest of the water and wastewater industry. To this aim, a process simulation for the HPRO process was implemented and several sensitivity analyses were conducted for the first time. The results showed that by increasing the recovery rate by 0.05, energy consumption decreased by 3.5%. An increase in the feed brine temperature from 5°C to 30°C increases the permeate flow rate (up to 0.929 m3/h), the permeate concentration (up to 468 mg/L TDS), and the recovery rate (up to 0.435). A 10-bar pressure increases the permeate flow by approximately 9.8% and decreases the permeate concentration by approximately 6 mg/L TDS. Moreover, the use of an energy recovery device significantly reduces energy consumption by 26% (from 4.93-5.10 to 3.65-3.78 kWh/m3). Overall, HPRO is a promising technology for brine treatment and valorization in zero liquid discharge and minimal liquid discharge systems.

Hypersalinity effects on O2 flux across the diffusive boundary layer of leaves in the tropical seagrass Thalassia testudinum

Hypersalinity is a major stressor to seagrasses, particularly in highly evaporative coastal estuaries and lagoons as well as those subjected to brine effluent from desalination systems, a condition likely to be heightened under a warming climate. While hypersalinity has been well established to cause physiological dysfunction, the effects on internal seagrass pO2 and O2 flux to the water column has not been explicitly studied. We examined the pO2 across the leaf diffusive boundary layer and estimated O2 flux rates from T. testudinum leaves at 35, 45, 55, and 65 salinity in the light and dark using O2 microsensors. Leaf segments were used to examine photophysiological responses and leaves of shoots in intact cores with multiple shoots to evaluate internal leaf pO2 flux that incorporates whole-plant sinks. Steady-state pO2 levels internally and at the leaf surface were also quantified at light saturation and in the dark. We found hypersalinity (45–65) primarily affected the O2 dynamics of T. testudinum leaves in the light based on leaf segments and whole plants. Net and gross photosynthetic rates of leaf segments were significantly lower at 55 and 65 salinities compared to controls (35), and net photosynthesis at 65 salinity was significantly lower than at 55 salinity. In contrast, the light required to compensate for leaf respiration (Icomp) was not affected by hypersalinity, and photosynthetic efficiency was only significant between 35 and 55 salinities above compensation irradiances (Φ(I comp – 200)), suggesting lesser effects of hypersalinity on photosynthesis at low irradiance below compensation (0–50 μmol photon m−2 s−1). We propose that hypersalinity, particularly ≥55 causes photosynthetic dysfunction limiting leaf O2 production, specifically Pmax at high irradiance. Further, our data indicate that with increasing hypersalinity more of the O2 produced by leaves in intact shoots is consumed by meristems and/or belowground tissues and the sediment. These O2 sinks are likely more significant than O2 lost to leaf respiration (RD) that was not shown to increase with salinity in experiments using leaves in isolation. Thus, hypersalinity not only affects the physiology, growth and reproduction of seagrasses, but also their O2 balance. For seagrass species growing at their upper salinity thresholds, a management strategy that lowers hypersalinity exposure would limit loss of seagrasses to O2 imbalance from hypersalinity effects on photosynthesis and ecosystem O2 demand.

Structure and biosynthesis of carotenoids produced by a novel Planococcus sp. isolated from South Africa

BackgroundThe genus Planococcus is comprised of halophilic bacteria generally reported for the production of carotenoid pigments and biosurfactants. In previous work, we showed that the culturing of the orange-pigmented Planococcus sp. CP5-4 isolate increased the evaporation rate of industrial wastewater brine effluent, which we attributed to the orange pigment. This demonstrated the potential application of this bacterium for industrial brine effluent management in evaporation ponds for inland desalination plants. Here we identified a C30-carotenoid biosynthetic gene cluster responsible for pigment biosynthesis in Planococcus sp. CP5-4 through isolation of mutants and genome sequencing. We further compare the core genes of the carotenoid biosynthetic gene clusters identified from different Planococcus species’ genomes which grouped into gene cluster families containing BGCs linked to different carotenoid product chemotypes. Lastly, LC–MS analysis of saponified and unsaponified pigment extracts obtained from cultures of Planococcus sp. CP5-4, revealed the structure of the main (predominant) glucosylated C30-carotenoid fatty acid ester produced by Planococcus sp. CP5-4.ResultsGenome sequence comparisons of isolated mutant strains of Planococcus sp. CP5-4 showed deletions of 146 Kb and 3 Kb for the non-pigmented and “yellow” mutants respectively. Eight candidate genes, likely responsible for C30-carotenoid biosynthesis, were identified on the wild-type genome region corresponding to the deleted segment in the non-pigmented mutant. Six of the eight candidate genes formed a biosynthetic gene cluster. A truncation of crtP was responsible for the “yellow” mutant phenotype. Genome annotation revealed that the genes encoded 4,4′-diapolycopene oxygenase (CrtNb), 4,4′- diapolycopen-4-al dehydrogenase (CrtNc), 4,4′-diapophytoene desaturase (CrtN), 4,4′- diaponeurosporene oxygenase (CrtP), glycerol acyltransferase (Agpat), family 2 glucosyl transferase 2 (Gtf2), phytoene/squalene synthase (CrtM), and cytochrome P450 hydroxylase enzymes. Carotenoid analysis showed that a glucosylated C30-carotenoid fatty acid ester, methyl 5-(6-C17:3)-glucosyl-5, 6′-dihydro-apo-4, 4′-lycopenoate was the main carotenoid compound produced by Planococcus sp. CP5-4.ConclusionWe identified and characterized the carotenoid biosynthetic gene cluster and the C30-carotenoid compound produced by Planococcus sp. CP5-4. Mass-spectrometry guided analysis of the saponified and unsaponified pigment extracts showed that methyl 5-glucosyl-5, 6-dihydro-apo-4, 4′-lycopenoate esterified to heptadecatrienoic acid (C17:3). Furthermore, through phylogenetic analysis of the core carotenoid BGCs of Planococcus species we show that various C30-carotenoid product chemotypes, apart from methyl 5-glucosyl-5, 6-dihydro-apo-4, 4′-lycopenoate and 5-glucosyl-4, 4-diaponeurosporen-4′-ol-4-oic acid, may be produced that could offer opportunities for a variety of applications.

Study and evaluation of the characteristics of saline wastewater (brine) produced by desalination and industrial plants.

Desalination and industrial plants all around the world generate large amounts of saline wastewater (brine). The discharge of brine from facilities poses a severe environmental threat, while at the same time, the opportunity to recover resources is being lost as discharged brine is rich in valuable metals that could be recovered as salts/minerals. To this aim, this study presents and analyzes for the first time the characteristics of different brine effluents (from industries such as desalination, oil and gas production, petrochemical, aquaculture, pharmaceutical, textile) to prevent environmental pollution and to recover valuable resources (i.e., salts, minerals, metals, chemicals) enabling the concept of waste-to-resource (circular water economy model). The results revealed that the common salinity values in brine effluents range from 0.5 to 150 g/L, while the only exception is the produced water from the oil and gas industry (up to 400 g/L). Brine effluents from all sectors contain sodium, chloride, calcium, and potassium ions in high concentrations, while the production of common salts such as NaCl, CaCl2, and MgCl2 from brine can be economically profitable. Besides common ions, precious metals such as lithium, rubidium, and cesium are present in low concentrations (<25 mg/L); however, their extraction from brine effluents can be significantly profitable due to their very high sale price. The treatment and valorization of brine can be implemented by the hybridization of membrane-based, chemical, biological, and thermal-based technologies/processes in minimal and zero liquid discharge (MLD/ZLD) systems.

Effect of temperature on the pH of water flood effluents and irreducible water saturation: A study with reference to the Barail sandstone outcrop of the upper Assam Basin

Low salinity water flooding (LSWF) is a promising strategy for improving oil recovery in sandstone reservoirs, and recent studies have shown that the recovery with low salinity water injection is a function of not only the salinity and ionic composition but also of the pH of injected brine, temperature, and the combined effect of both on the wetting properties of the clay mineral surfaces. Following brine flooding, the initial wettability of sandstone rock surfaces existed when crude oil, formation water (FW), and rock surface interaction were in chemical equilibrium at reservoir condition changes based on brine pH, salinity, temperature, and clay mineralogy. This study proposes pH, core flood temperature, and irreducible water saturation as key parameters in inducing wettability changes in the sandstone porous media. In the present work, the sandstone cores were subjected to flooding at temperatures of 70 °C, 85 °C, and 105 °C and measured the pH of the discharge effluents and initial or irreducible water saturation with respect to varying temperatures. This paper investigates the rise of the pH gradient and irreducible water saturation, Swir with respect to LS flooding, at increasing temperatures using a Barail sandstone core. The key results include the following:The pH of the flood effluents increases with increasing core flood temperature, which indicates a shifting of the existing wetting state of the rock.The combined effects of increasing pH and initial or irreducible water saturation pertaining to low salinity flooding at progressively increasing temperatures result in increasing water wettability of the sandstone rock. Increasing flooding temperatures cause an increase in Swir, which follows a linear relationship.The findings of the paper highlight the link of increasing pH and irreducible water saturation with the water wetting properties of the sandstone reservoir rock and hence the fluid flow or the oil–water relative permeability behaviour. This paper proposes that increased irreducible water saturation and pH of water flood effluents are connected to increasing water wetness in a sandstone rock as a function of elevated temperatures. As adequate work and consensus on the potential effects of temperature on wettability alteration under low salinity water flooding is still lacking, the current work in relation to the Barail sandstone of the upper Assam basin could be a novel reference for understanding of the importance of temperature dependent wettability alteration behaviour in sandstone cores. The findings of this study can assist in the formation of a novel approach towards considering the increasing irreducible water saturation and pH of the brine effluent as an effect of alternatively injection of low salinity water at elevated temperatures on sandstone porous rock.

Application of LCA and LCC in the early stages of wastewater treatment design: A multiple case study of brine effluents

Technological developments are opening new avenues to facilitate the circular economy through resource recovery from industrial wastewater. This paper presents the use of Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) in the development of technology solutions for the treatment of brine wastewater and recovery of by-products. Four industrial case studies are assessed that apply different innovative technology configurations, to treat the brines and recover the water, salts and mineral compounds. The assessment focusses on identifying hotspots and potential design improvements for the four case studies. In addition, the development of a unified approach for prospective LCA and LCC is illustrated to promote robustness and consistency in the analysis of the four systems. The analysis reveals that the impact and cost of treatment is highly dependent on the wastewater composition. Critically, whether the recovery of compounds and deionised water can counteract the impact and cost of the treatment systems. The early analysis suggests that this is possible for two of the cases studies. Estimates of the GHG emissions for the initial system analysis, range from 10 to 17 kg CO2e/m3, whilst costs range from €10/m3 to €25/m3. However, both are expected to decrease at full scale and are sensitive to costs of energy, chemicals and revenue from recovered by-products. The LCA's highlight chemical and energy consumption as critical hotspots. Design considerations therefore focus on the reduction of chemicals, reuse or switching to lower impact chemicals, and maximising by-product recovery, and using renewable energy.

Continuous Extraction of Black Liquor Salts under Hydrothermal Conditions

In hydrothermal valorization of black liquor (BL) from the Kraft process, the separation of inorganic salts is pivotal to prevent them from fouling downstream equipment such as reactors and for the cost-efficient recycling of salts into pulp cooking chemicals. In this work, the phase behavior of the inorganic salts present in BL was studied in supercritical water and the conditions for the separation from BL were optimized. A high-pressure differential scanning calorimetry study indicated the concomitant precipitation of salts and the formation of a second salt-rich liquid-like phase. The potassium-to-sodium ratio was found to strongly impact the phase behavior of the salt mixture. Potassium was found to prevent salt precipitation and to lead to the formation of a second liquid-like phase alone. At K/(K + Na) ≥ 0.4, a steady salt separation could be achieved, enabling the continuous extraction of up to 96% of the salts in a concentrated brine effluent.

Brine management from desalination plants for salt production utilizing high current density electrodialysis-evaporator hybrid system: A case study in Kuwait

The potential of producing salt and low salinity water by treating synthetic brine was investigated in a pilot-scale electrodialysis-evaporator hybrid system as part of brine management. An electrodialyzer with 25 cell pairs of monovalent selective anion exchange membranes (AEMs) and monovalent selective cation exchange membranes (CEMs) were used. Effect of three different current densities (300 to 500 A/m2) and two different flowrates (400 L/h and 450 L/h) on brine treatment were evaluated in the current study. The results indicated that the aforementioned membranes were efficient in separating monovalent ions over divalent ions. Moreover, higher current density operation was favoured during the electrodialysis (ED) operation as the operation time for producing salt was shorter. Flowrate is a crucial parameter for the operation of the ED system, where higher flowrate (by 12.5%) reduced the operation time (by 30 min), reduced energy consumption (by 32%) and reduced system resistance (by 32.42%) leading to an increase in current efficiency (by 31.4%). The concentrated brine effluent from ED was fed to an evaporator to produce coarse salt with 84.75% salt recovery and low salinity water of 1526 ppm. Thus, ED-evaporator hybrid system was found to be a good option to treat reject brine from desalination plants.

Multiple Salinity Equilibria and Resilience of Persian/Arabian Gulf Basin Salinity to Brine Discharge

The Persian/Arabian Gulf is the most important region for seawater desalination. Surrounding countries produce about 50 % of global desalinated seawater. If Gulf salinity significantly rises because of desalination effluent (brine), marine ecosystems and the water supply for many population centers will be threatened. In order to quantify current and future impacts of seawater desalination on Gulf salinity and avoid costly environmental problems, it is vital to first examine the present Gulf salinity state and its response to salinity perturbation (i.e. determine its stability). Here, using a coupled Gulf-Atmosphere numerical climate model, we test the hypothesis that the Gulf has a single stable equilibrium state under the current climate. Simulations with different initializations under identical external forcing show that the natural coupled Gulf-Atmosphere system may exhibit a mixture of unstable and stable equilibrium salinity states. When continuous salinity perturbation is added to the simulations, results show that the present Gulf equilibrium state, characterized by annual mean basin-average salinity of about 40.6 g/kg, is stable. We conclude that Gulf basin salinity is resilient to present brine discharge activities under the current climate.

The effect of a step change in seabed depth on spreading discharged brine effluents from a two-outfall system

Discharged brine effluents from coastal desalination plants through marine outfall systems contain some reactive chemicals that may be derived from corrosion product, toxic antifoulants, antiscalants and other chemicals used in desalinating seawater. These effluents are subject to significant loss due to temporal decay that varies with water depth as the results of consumption by bacteria or radioactive decay, heat loss or evaporation through the surface, and break up or dissolution by turbulence. A far-field model using a two-dimensional decay-advection-diffusion equation with two point sources in a simple step seabed profile is presented to study the variability of decay with water depth. Analytical solutions are illustrated graphically by plotting contours of concentration to simulate the spreading of discharged brine effluent plumes from two outfalls in coastal waters. The maximum value of the compounded concentration at the shoreline is formulated and used as a measure for assessing the quality standards of coastal waters. It is found that, for coastal effluent discharges, the modern engineering practice which installs a two-port diffuser at the end of the outfall pipeline does produce low potential environmental impact.

Oil Recovery Efficiency and Mechanism of Low Salinity-Enhanced Oil Recovery for Light Crude Oil with a Low Acid Number.

Low salinity waterflooding (low salinity-EOR) has attracted great interest from many giant oil producers and is currently under trial in some of the oil fields of the United States, Middle Eastern countries, and North Sea reservoirs. Most of the reported studies on this process were carried out for medium to relatively heavy oil with significant polar contents. In this work, we have investigated low salinity waterflooding performance for light paraffinic crude oil with a low acid number. This study has been performed using crude oil from an Indian offshore oilfield and Indian offshore seawater. Oil recovery efficiencies of seawater and its diluted versions (low salinity seawater) were evaluated through core-flooding experiments performed on a silica sand pack containing small amounts (2 wt %) of bentonite clay saturated with crude oil. Interfacial tension and wettability studies were performed to understand the associated low salinity effects on the crude oil/brine/rock properties. Effluent brine produced during the flooding experiments was also analyzed to obtain a clearer insight into the low salinity-enhanced oil recovery (EOR) mechanism. The results showed that injection of low salinity seawater can significantly increase the waterflood recovery in comparison with high salinity seawater injection. Interfacial tension and contact angle studies revealed that there is an optimum dilution level at which the interfacial tension and wettability are the most favorable for enhanced oil recovery even in the case of light paraffinic crude. These results are in line with the results obtained from the core-flooding experiments. The possible reason behind recovery improvement based on the interfacial tension and wettability studies in conjugation with the effluent brine analysis has been discussed in detail. In this study, we have observed that the enhanced oil recovery efficiency could be achieved by applying low salinity seawater flooding even in the case of light paraffinic oil with a low acid number.

The effect of a step change in seabed depth on spreading discharged brine effluents from a two-outfall system

The effect of a step change in seabed depth on spreading discharged brine effluents from a two-outfall system

Social Life Cycle Assessment of Brine Treatment in the Process Industry: A Consequential Approach Case Study

Social life cycle assessment (SLCA) was developed to complement the environmental life cycle assessment (LCA) and economic assessment. Contrary to LCA, SLCA is not yet standardized, and the consequential approach is little discussed in literature. This study aims to perform a consequential SLCA and investigate the applicability of the method in industrial decision making. The aforementioned assessment is done within the Zero Brine project, which works on zero liquid discharge technology for water, salt, and magnesium recovery from brine effluents. The developed SLCA systems are gate-to-gate, and the analysis is performed at two levels: Hotspot and site-specific. The system boundaries consist of a demineralized water (DW) production company, a chlor–alkali company, an electricity provider, a magnesium distributor in the Netherlands, and a Russian mining company. The latter exists only in the boundaries before the change due to the Zero Brine project, because recovered magnesium is expected to replace the Russian magnesium imported in the Netherlands. Within the system boundaries, the stakeholders contributing the most are the DW and the magnesium distributor companies. The former produces the brine and thus recovers the magnesium and salt. The latter is the exclusive distributor of Russian magnesium in the Netherlands. Overall, we find that the recovered magnesium results in improving social performance mainly in “Freedom of association and collective bargaining”, “Fair salary”, and “Health and Safety” due to decreasing the dependency of the Netherlands on Russia, while increasing operation in a country with much stronger environmental regulation and corporate commitment to sustainability issues. Modelling with SLCA may not result in the expected societal benefits, as the Russian community and workers may not benefit due to the large geographical boundaries of the system under study. Nevertheless, the application of the consequential approach can be considered suitable, yet complicated, for offering decision makers adequate social information. We recommend that decision makers in the DW company invest in magnesium recovery and that decision makers in the magnesium distributor company distribute the recovered magnesium.

Experimental investigation of the influence of fluid-fluid interactions on oil recovery during low salinity water flooding

This study aims to investigate the role of fluid-fluid interactions during low salinity water flooding, using crude oil from an Iranian oil reservoir. To minimize the effects of mineral heterogeneity and wettability alteration, a synthetic sintered glass core was utilized and all coreflooding experiments were performed at low temperatures without any aging process. The effect of fluid-fluid interactions were investigated in both secondary and tertiary injection modes. pH measurements as well as UV-Vis spectroscopy and interfacial tension (IFT) analysis were performed on the effluent brine samples. Resultsshow that fluid-fluid interactions, mainly the dissolution of crude oil polar components into the brine, significantly affect brine physical and interfacial properties. In secondary injection scenario, two times diluted seawater (2SW), which has the lowest IFT value, exhibits the highest (81%) oil recovery factor. While the lowest recovery factor (60.75%) was observed for the case of formation water (FW) injection. To explore the effect of contacting time, after 48 h soaking, brine injection was resumed. The effluent pH measurement at this stage showed a reduction, where the UV-Vis spectroscopy and IFT measurements confirmed dissolution of the crude oil polar components into the brine. The results showed that as brine salinity decreases, the amount of dissociated polar components increases. pH value of ten times diluted sea water (10SW) was reduced from its initial value of 7.45 to 4.22, while FW exhibits minor pH variation. Consequently, 10SW, which dissolved highest amount of polar components, depicts the highest recovery factor (6%) after soaking. Contrary to this, in tertiary injection mode, the high amount of saline brine in the core (because of FW injection at secondary stage) hinders the potential for more production for SW, 2SW and 10SW injection as all resulted to lower recovery factor compared to their secondary counterparts.