Salt Manufacturing Research Articles

Barium concentration, phytoavailability, and risk assessment in soil-rice systems from an active barium mining region

Barium (Ba) is a non-essential and toxic element. In China, intensive Ba mining and Ba salt manufacturing have led to sharp increases in Ba in the environment, but little information is available regarding Ba concentrations in paddy soil and rice. The total concentrations and phytoavailability of Ba in paddy soils and paired rice samples collected from the world's largest Ba mine in Dahebian, Tianzhu, Guizhou Province, southwestern China, were investigated. Risk assessments of Ba exposure via rice consumption were also evaluated. The results indicated that extremely high Ba concentrations existed in paddy soils, ranging between 518 mg/kg and 65,760 mg/kg, which demonstrated severe Ba contamination, as expected. The concentrations of rice Ba varied from 0.10 to 3.5 mg/kg, and a significantly positive correlation (r = 0.51, p < 0.05) between rice Ba and water-extractable Ba was observed, suggesting that water, rather than weak acid (0.43 M CH3COOH), chelating agents (DTPA) or neutral salts (0.1 M NaNO3, 0.01 M CaCl2 or 1 M NH4OAc), is a suitable extractant for predicting the phytoavailable Ba in the studied soils. Risk assessments showed that residents experienced low Ba exposure via rice consumption when considered in isolation of other sources in this study area.

Preparation of LDHs Based on Bittern and Its Flame Retardant Properties in EVA/LDHs Composites

Bittern, as a byproduct of salt manufacture, is abundant in China. The researches and developments for seawater bittern have mainly focused on the reuse of magnesium, calcium, lithium, and boron. However, the utilization rate is less than 20%. The large amount of unused bittern has become a challenge that attracts much attention in academic and industry areas. In this paper, three kinds of layered double hydroxides (LDHs) were synthesized from bittern using a coprecipitation method and characterized by X-ray diffraction (XRD). The XRD results showed that the three kinds of LDHs(MgAl-LDHs, MgFe-LDHs and MgAlFe-LDHs) were successfully synthesized. Then, the flame retardant properties and thermal properties of the three LDHs in ethylene vinyl acetate (EVA)/LDHs composites had been tested by cone calorimeter test (CCT), limiting oxygen index (LOI), smoke density test (SDT), and thermogravimetry-Fourier transform infrared spectrometry (TG-IR). The CCT results showed that the heat release rate (HRR) of all three kinds of EVA/LDHs composites significantly decreased compared with that of pure EVA, and the EVA/MgAl-LDHs composites had the lowest PHRR value of 222.65 kW/m2. The LOI results showed that EVA/MgAl-LDHs composites had the highest LOI value of 29.8%. The SDT results indicated that MgAl-LDHs were beneficial to smoke suppression. TG-IR results showed that EVA/MgAl-LDHs composites had a better thermal stability.

The Antebellum Kanawha Salt Business and Western Markets by John E. Stealey III

Reviewed by: The Antebellum Kanawha Salt Business and Western Markets by John E. Stealey III Billy Joe Peyton The Antebellum Kanawha Salt Business and Western Markets. By John E. Stealey III. (Morgantown: West Virginia University Press, 2016. Pp. x xiii, 280.) At the dawn of Kanawha salt’s rise to prominence during the War of 1812, two principal sources of domestic salt existed in the interior United States—Onondaga County, New York, and Gallatin County, Illinois. Wartime embargoes on British salt, coupled with increased demand for the mineral as a meat preservative, created a substantial Western market for Kanawha salt. Area producers developed innovative drilling techniques to tap an ancient subterranean ocean, and shortly thereafter fifty-two furnace operations produced over one million bushels of salt annually. Owing to a shortage of free labor, enslaved African Americans provided the primary workforce that enabled many salt makers to amass great wealth and local power. The slave population of Kanawha County peaked at 3,140 persons in 1850, the highest total of any Virginia county west of the Shenandoah Valley. (Only Jefferson County, with 4,341 slaves, had a higher total than Kanawha County in 1850; see US Bureau of the Census, Seventh Census of the United States, https://www2.census.gov/library/publications/decennial/1850/1850a/1850a-14.pdf.) As the author states, the resultant slave society created a unique situation whereby Southern Appalachian bondsmen produced an extractive product for interstate commerce (133). [End Page 110] Stealey originally published this detailed study of the antebellum Kanawha salt industry in 1993. Time has not diminished the relevance of his work, which remains the sole scholarly monograph focused exclusively on the history of Kanawha salt. The new edition features an updated introduction by the author, but no new primary sources or manuscript collections have been located to alter the original narrative (xi). Stealey utilizes an impressive array of previously unharvested manuscript collections and other primary source documents to tell the Kanawha salt story. Among the most relevant are the Dickinson and Shrewsbury salt company papers, death registers for the 1849 and 1850 cholera outbreak at Kanawha Salines (present-day Malden), and an obscure Virginia court case in the Library of Congress that details a previously unknown association arrangement of antebellum Kanawha salt makers between 1817 and 1851. (Stealey has published all Kanawha salt makers’ agreements of concert and combination in a separate but related work; see John E. Stealey, III. Kanawhan Prelude to Nineteenth-Century Monopoly in the United States: The Virginia Salt Combinations (Richmond: Virginia Historical Society, 2000)). The book engages readers in timely historical inquiry on the business, economic, labor, and legal history of this important industry. In so doing, it has altered existing knowledge about the application of nineteenth-century associative and contract law in the United States. In a broader context, the work is reminiscent of recent studies on the rise of the market economy, the culture of new capitalism, and slavery’s profitability and adaptability. One avenue of exploration is the influence of outside market forces on Kanawha producers, especially the importance of genealogical influences among salt makers and slave owners in the Piedmont region of Virginia. Stealey heaps praise on the “entrepreneurial acumen” of area salt manufacturers, along with their technological innovation and amazingly sophisticated worldview. Students of West Virginia history have long been aware of the claim that the Kanawha Salt Association, created in 1817, constituted the nation’s first business trust. In his updated work, Stealey reiterates the fact that “So far, no earlier examples of output pools or proposals for a trust arrangement than those on the Great Kanawha have surfaced in the legal literature” (John E. Stealey III, Kanawhan Prelude to Nineteenth-Century Monopoly in the United States, xvi). Indeed, his compelling research and analysis support this assertion, which elevates the monograph to a work of national significance on the evolution of US business organization within a legal history context. In summary, The Antebellum Kanawha Salt Business and Western Markets by John E. Stealey III is a first-rate scholarly work about an essential, but inexplicably neglected, aspect of West Virginia’s industrial past. The book [End Page 111] expertly details myriad elements...

Eighteenth- and nineteenth-century salt production in Saltville, Virginia

ABSTRACTThe geology of the Saltville Valley in southwest Virginia creates a brine with an exceptionally high concentration of sodium chloride (98.7%). Because of this resource, the town of Saltville, Virginia, became the major producer of salt for the Confederacy during the latter half of the Civil War. The wood-fired salt furnaces (as the production facilities were called) produced a maximum of four million bushels of salt from this naturally occurring brine in 1864. However, these massive nineteenth-century furnaces are no longer standing. Industrial archaeology, with its goal of chronicling and preserving the history of industrial development, is used to document two of these salt furnaces—one (44SM280) in operation in the late eighteenth century when salt production was beginning, and the other (44SM139) in operation during the Civil War. Increasing size and sophistication in the exposed foundations of these structures is illustrated by the shift from predominantly stone-walled furnaces to later, larger structures with stacked brick walls. The size of the iron kettles used to cook the brine also increased to a 100-gallon capacity. These excavations corroborate historic descriptions of salt manufacture and provide important physical evidence of nineteenth-century industrial development.

Experimental investigation and cost assessment of the salt production by solar assisted evaporation of saturated brine

The technical feasibility and economy of solar heat collection-forced evaporation process are the keys to its practicality, especially its application in strong brine treatment. The operation cost of applying solar collection in salt manufacturing through depth evaporation of brine has been studied. For Na+, K+, Mg2 +//Cl−, SO42 −-H2O salt–water system, most of the NaCl and all of the Carnallite were separated. The operation cost reached the optimum when the heat collection and evaporation were controlled at 75 and 55 °C, respectively. When the solar radiation amount was 19557 kJ·m− 2·d− 1, the solar collector area for producing Carnallite was about 34.27 m2·(t salt)− 1, and the operation cost was 13 USD⋅(t salt)− 1. The energy consumption of salt manufacturing is at least 25% higher than that of natural evaporation. Regarding the economy, the solar assisted salt manufacturing process is recommended to be performed at a production scale of more than 20 tons per day.

Unsatisfactory results of the Tunisian universal salt iodization program on national iodine levels

Lack of iodine intake may promote a spectrum of disorders termed iodine deficiency disorders. Universal salt iodization laws were adopted in Tunisia to overcome this problem. This study examines the adequacy of iodized salt in the distribution chain two decades after its last assessment. A cross-sectional design was carried out in 2012 using the multi-stage cluster sampling technique. Salt samples from 24 governorates were collected at wholesaler level (n=635), retailer level (n=1440) and household level (n=1560), and analyzed using a validated iodometric titration method. Iodine concentration at each level of distribution chain was within the recommended range of 15–27mg/kg. Iodine content in household salt was significantly different according to the salt manufacturer and also between geographical regions (p <0.0001). Moreover, an insufficient coverage of adequately iodized salt consumption (less than 90%) was found with reference to international standards (≥15mg/kg). About 85.6% (95%CI: 78.3–90.8) of analyzed samples were adequately iodized at the intermediate levels of supply-chain (wholesalers and retailers). Our study demonstrates a decrease in the availability of iodized salt in households. It can thus be concluded that universal salt iodization legislation has not been sufficient to ensure an adequate supply of iodine in the population, and an evaluation system needs to be reactivated.

「土器を用いた海水からの塩作り」の教材化と実践的研究 : 古代人の知恵から学ぶ環境教育

「土器を用いた海水からの塩作り」の教材化と実践的研究 : 古代人の知恵から学ぶ環境教育

戦前期台湾・関東州製塩業における日系資本の進出過程 : 野崎家と大日本塩業株式会社を中心に

戦前期台湾・関東州製塩業における日系資本の進出過程 : 野崎家と大日本塩業株式会社を中心に

Addressing the Challenge of Iodine Deficiency in Developing Countries

Iodine deficiency causes stunted physical and mental growth as well as infertility, lethargy and cognitive impairment. Although iodine deficiency is endemic in most countries and is therefore a public health issue, it is preventable through adequate intake of iodine in diet. Recent global data estimated that 1.88 billion people are at risk of iodine deficiency with 241 million children taking inadequate iodine in diet. Majority of these children with inadequate dietary iodine intake lives in Africa and South/South-East Asia. Gains have been made towards the eradication of iodine deficiency disorders (IDDs) through the universal salt iodisation (USI) programme which has ensured greater coverage of iodine intake throughout the world. In developing countries however, the perennial problem of weaker institutions means that much needs to be done if the goal of eradicating IDDs are to be realized. This mini-review looks at what steps could be undertaken to maximize the odds of eradicating IDD through food fortification, strengthening of regulatory institutions, empowering small-scale salt manufacturers and conscientization of the populace to patronise not only iodised salt but also iodine-fortified foods.

Basic Study for Applying the Potential Noise Technique to Monitor the Initiation of Pitting in a Salt Manufacturing Process with Bittern

Basic Study for Applying the Potential Noise Technique to Monitor the Initiation of Pitting in a Salt Manufacturing Process with Bittern

Effects of CO2 fine bubble injection on reactive crystallization of dolomite from concentrated brine

In this study, we used the minute gas-liquid interfaces around CO2 fine bubbles as new reaction fields where the crystal nucleation proceeds dominantly and developed a crystallization technique to synthesize dolomite (CaMg(CO3)2) with the desired crystal quality. CaMg(CO3)2 has a crystal structure derived from calcite by ordered replacement of the Ca2+ in calcite by Mg2+. To improve the functionality of the crystal for better utilization of the CaMg(CO3)2, an effective method for an approach to a Mg/Ca ratio of 1.0 and downsizing is indispensable in the crystallization process. In the vicinity of the minute gas-liquid interfaces, the accumulation of Ca2+ and Mg2+ is caused by the negative electric charge on the fine bubbles surface; thus, CaMg(CO3)2 fine particles with a high Mg/Ca ratio can be expected to crystallize. At a reaction temperature (Tr) of 298K and CO2 flow rate (FCO2) of11.9 mmol/(Lmin), CO2 bubbles with an average bubble diameter (dbbl) of 40–2000µm were continuously supplied to 300mL of the concentrated brine coming from salt manufacture discharge and CaMg(CO3)2 crystallized within a reaction time of 120min. Fine bubbles with dbbl of 40µm were generated using a self-supporting bubble generator by increasing the impeller shear rate under reduced pressure. For comparison, the bubbles with dbbl of 300 or 2000µm were obtained using a dispersing-type generator. Moreover, FCO2 and Tr were varied as operating parameters during the reactive crystallization supplying CO2 fine bubbles. Consequently, CO2 fine bubble injection is effective for the high-yield crystallization of CaMg(CO3)2 with a Mg/Ca ratio of 1.0 and downsizing of CaMg(CO3)2 particles owing to the acceleration of crystal nucleation caused by the local increase in the supersaturation at the minute gas-liquid interfaces.

Coverage of Adequately Iodized Salt Is Suboptimal and Rice Fortification Using Public Distribution Channels Could Reach Low-Income Households: Findings from a Cross-Sectional Survey of Anganwadi Center Catchment Areas in Telangana, India.

Food fortification is a cost-effective approach to prevent and control of micronutrient deficiencies in India. A cross-sectional survey of children 0–35 months of age residing in the catchment areas of anganwadi centers in the state of Telangana was conducted to assess the coverage of adequately iodized salt and the potential for rice fortification. Salt samples were collected and tested for iodine concentration using iodometric titration. Information on demographics, household rice consumption, and Telangana’s rice sector was collected and interpreted. In households of selected children, 79% of salt samples were found to be adequately iodized. Salt brand and district were significant predictors of inadequately iodized salt. Daily rice consumption among children and women averaged 122 grams and 321 grams per day, respectively. Approximately 28% of households reported consuming rice produced themselves or purchased from a local farmer, 65% purchased rice from a market or shop, 6% got rice from a public distribution system site, and 2% obtained it from a rice mill. In the catchment areas of Telangana’s anganwadi centers, there is significant variation in the coverage of adequately iodized salt by district. Future surveys in Telangana should measure the coverage of salt iodization in the general population using quantitative methods. Nonetheless, increasing the adequacy of iodization of smaller salt manufacturers would help achieve universal salt iodization in Telangana. Despite high consumption of rice, our findings suggest that large-scale market-based rice fortification is not feasible in Telangana due to a large proportion of households producing their own rice and highly fragmented rice distribution. Distributing fortified rice via Telangana’s public distribution system may be a viable approach to target low-income households, but would only reach a small proportion of the population in Telangana.

Comparative Study on Radio Activity Associated with Common Salt Production Process of Two Salt Works in Kanya Kumari and Tuticorin Districts, Tamil Nadu

The manufacture of Common Salt used for the sea brine contain several chemical and radioactive elements. This study estimated the gross alpha and gross beta activites from the sea brine of two salt works at Kovalam in Kanya kumari District and Vepalodai in Tuticorin District, Tamil Nadu. The gross activity was increasing at subsequent stages of production due to the concentration of brine. The sediment and gypsum samples collected at different stages were also subjected for estimation of different types of activity. 40K activity was found to increase, source to bittern from 8.60 ± 0.92 to 221.006± 21.20 Bq l-1at Kovalam salt work and 4.006 ± 0.52 to 162.16 ± 15.94 Bq l-1 at Vepalodai salt work. This study showed that the radio activity is higher in Kovalam salt work than Vepalodai salt work, indicating the influence of naturally high background radiation area.

Assessment of fertilizer potential of the struvite produced from the treatment of methanogenic landfill leachate using low-cost reagents.

Leachates generated in methanogenic landfills contain high strength of ammonium nitrogen which removal is hard to be accomplished by means of conventional techniques. The chemical precipitation of struvite, which is a mineral that could be reused as a slow-release fertilizer, is an effective process in the removal and recovery of NH4 amount of high-concentrated wastewaters. In this paper, a struvite precipitation process using unconventional reagents is proposed for a sustainable recovery of nitrogen content. In particular, seawater bittern, a by-product of marine salt manufacturing, and bone meal, a by-product of the thermal treatment of meat waste, have been used as low-cost sources of magnesium and phosphorus, respectively. The process enables the removal of more than 98 % ammonia load, the recovery about 99 and 95 % of phosphorus and magnesium, respectively, and the production of a precipitate containing struvite crystals. Heavy metals concentrations of produced precipitate were below the threshold values specified by the EC Directive for use of sewage sludges as fertilizers. Specific agronomic tests were conducted to investigate the fertilizing value of precipitate recovered from landfill leachate. The fertilizing effect of struvite deposit in cultivating Spinacia oleracea was compared with that of vegetable soil and commercial fertilizer. The growth of selected vegetable in the pots with struvite precipitate resulted significantly greater in both than those in the control pots and in the pots with the complex fertilizer. Furthermore, the struvite application as fertilizer did not result in more heavy metals in the vegetables respect those from soil and model fertilizer.

Batch ion-exchange membrane electrodialysis of mother liquid discharged from a salt-manufacturing process. Experiment and simulation

Abstract Mother liquid discharged from a salt manufacturing plant was electrodialyzed in the batch process incorporated with SO42- ion low-permeable anion-exchange membranes for decreasing Na2SO4 concentration and recovering NaCl. Energy consumption of the electrodialysis was compared with that of the cooling method to precipitate Na2SO4 as Na2SO4⋅10H2O. Energy consumption of cooling method depends largely on cooling energy for decreasing temperature. If the temperature of the discharged mother liquid cannot be cooled under 31 °C in the atmosphere, the cooling method needs much cooling energy, so the electrodialysis is advantageous. If the temperature can be decreased to lower than 31 °C in the atmosphere, cooling method is possible. Succeeding to the above investigation, mother liquid was supplied to the batch electrodialysis process in the computer simulation program. The performance changes with time were computed with an instantaneous open/shut feed operation system of a salt solution. Computation was carried out to discuss the performance of the electrodialysis experiment of the mother liquid. The computed data are generally the same as the experimental data for ion flux across a membrane pair JS, current efficiency η, solution volume circulated in the desalting side Q0, energy consumption for desalination Edes and for concentration Econc. However, the computed solution flux across a membrane pair JV and cell voltage Vcell are larger than observed ones. The computed salt concentration at the inlets of desalting cells C′in and the salt concentration at the outlets of concentrating cells C″ are less than observed ones.

Differences in the effects of age on the development of entheseal changes among historical Japanese populations.

This study aims to determine the impacts of both age and physical activity on entheseal changes at sites of muscle and ligament attachment, and proposes that the influence of age on entheseal changes may depend on specific social systems. Entheseal markers of 193 individuals excavated from archaeological sites in Japan were examined, and archaeological evidence from those sites was used to determine the subsistence activities that those individuals engaged in. Fifteenth-century samples were either fishermen or Agehamashiki salt manufacturers, while samples from between the late 17(th) century and the 19(th) century were peasants, townspeople, or samurai. Nineteen entheses were examined using the scoring method of Hawkey and Merbs (1995) to clarify the degree to which age influenced entheseal severity of a given sample as well as the differences in the degree to which age influenced entheseal changes among samples. Results indicated that age influenced entheseal changes; however, the degree to which age influenced entheseal development was dependent on the characteristic physical activities associated with an individual's class and occupation. Furthermore, in certain groups, aging did not significantly impact entheseal changes. The degree to which age influenced entheseal changes was dependent on characteristic physical activities associated with an individual's class and occupation. This indicated that physical activities and lifestyle, along with age, were major factors that contributed to entheseal changes. Based on these results, it was concluded that entheseal changes could serve as a useful tool in the reconstruction of physical activities of past populations.

Effect of strontium oxide on the formation mechanism of dicalcium silicate with barium oxide and sulfur trioxide

Belite-barium calcium sulfoaluminate cement is a new type of cement characterised by low energy consumption and low carbon dioxde emissions, but the slow hydration of the belite phase leads to a slow mechanical property gain at early ages compared with ordinary Portland cement. A doping technique has been proposed as one option to promote its reactivity. Strontium slag, a kind of chemical industrial waste produced from the manufacture of strontium salt, has a high level of emissions in China. In this study, the influence of strontium oxide on the formation mechanism of dicalcium silicate with barium oxide and sulfur trioxide, which are both in excess in belite-barium calcium sulfoaluminate cement clinker, is investigated. Results show that strontium oxide accelerates the decomposition process of calcium carbonate, and its final decomposition temperature can be lowered by 67°C. Strontium oxide decreases the formation rate of dicalcium silciate at the same temperature, but the amount of total dicalcium silicate formed can still be as high as 94·5 wt% at 1350°C. Moreover, it is revealed that strontium oxide plays a significant role in stabilising β-dicalcium silicate, and reduces γ-dicalcium silicate by about 40%. This study could lead to environmental benefits and cement performance improvement.

Studies on the Quality and Heavy Metals in Common Salt Production Using Sea Brine and Sub-Soil Brine in South Tamil Nadu, India

The manufacture of common salt using sea brine and sub-soil brine contain several chemical and trace metal elements.This study estimated the salt quality parameters like moisture content, insoluble matter, calcium sulphate, magnesium sulphate, magnesium chloride and sodium chloride content of the salt and also estimated the different trace metals like copper, iron, zinc, manganese and chromium in salts harvested from the Salt samples of two selected salt works, Kovalam SW1 (sea brine) and Puthalam SW2 (sub-soil brine) in Kanyakumari District and the two selected salt works, Vepalodai SW3 (sea brine) and Sahupuram SW4 (sub-soil brine) in Tuticorin District. The salt samples have maximum moisture content in Kanyakumari salt works than Tuticorin District because of the climatic conditions. The salt works using sea brine, harvested salt of the maximum mean sodium chloride content than sub-soil brine using salt works. In both the Districts, sea brine using salt works is having almost similar concentration of heavy metals, likewise sub soil brine using salt works.

Computer simulation of ion-exchange membrane electrodialysis for salt concentration and reduction of RO discharged brine for salt production and marine environment conservation

The salt discharged from reverse osmosis is concentrated by ion-exchange membrane electrodialysis to produce salt for industrial use and the salt concentration is reduced to seawater level for preventing environmental impact on marine ecosystems. The technology was evaluated experimentally and discussed with a computer simulation program of the electrodialysis system incorporated with U shape cells. The algorithm computes mass transport, energy consumption, electric current leakage, concentrate NaCl purity, pressure drop and limiting current density. The seawater reverse osmosis discharged brine was supplied to the electrodialysis pilot plant and it was operated changing current density and temperature taking benefit of seasoning variations.The computed energy consumption ENaCl and NaCl concentration in concentrated solutions C″NaCl using developing algorithms provided a good description of the experimentally measured values with correlation coefficients of R(r)=0.9 for ENaCl and R(r)=0.6 for C″NaCl. Then the reasonability of the developed algorithms is supported by the experimental set of data. The current leakage is nearly 3% for any electric current. The pump driving force is very low. The limiting current density is very high. In order to decrease salt concentration at the outlets of desalting cells to seawater level, it is necessary to increase desalting ratio to 0.5. This technique however increases ENaCl and decrease C″NaCl. In spite of this operating circumstance, ENaCl and C″NaCl are comparable to the data in the salt manufacturing plant operation to produce edible salt. NaCl produced from in the reverse osmosis discharged brine electrodialysis is competitive in the edible salt market.

Closed Circuit PRO Series No 5: clean energy generation from seawater and its concentrates by CC-PRO without need of energy recovery

This study explores the prospects for clean energy generation in coastal regions from salinity gradient made of seawater (SW) and its concentrates (SWC) by the CC-PRO technology of near absolute energy efficiency without energy recovery device and semi-permeable membranes such as HTI-TFC (A = 2.49 lmh/bar, B = 0.39 lmh, and S = 564 μm) of 48.3 bar maximum applied pressure and alike. This power generation process is fueled by SW as low salinity feed and SWC as high salinity feed (HSF) and the regeneration of HSF from the produced high salinity diluted feed achieved through evaporation ponds of the types extensively used by the sea salt manufacturing industry. Large-scale harvesting of clean energy from the sea could be found particularly attractive along coastlines of arid zones where climate conditions (e.g. solar radiation, temperature, wind, humidity, etc.) favor effective evaporation from reservoirs of SWC. The simulated CC-PRO process of the SW (4.2%)–SWC (25%) salinity gradient with the HTI-TFC membrane revealed maximum membrane power density of 55.6 W/m2 and net electric power density after accounting for the auxiliary pumps of 39.3 W/m2 at the hydraulic pressure difference of 48.3 bar under draw/permeation flow ratio of 5.0 and membrane actual/ideal flux ratio of 0.2 estimated from available forward osmosis data of the same membrane in the 1.0–3.0 NaCl salinity gradients range. HTI-TFC membrane surface area of 1,000 m2 should provide 943 kWh electric energy per day enough to desalinate 377 m3/d of SW (4.2%) with 50% recovery by means of the closed circuit desalination (CCD) technology (RO: 2.5 kWh/m3). The results of this study reveal that the CC-PRO technology opens the door for large-scale commercial clean power generation from SW–SWC salinity gradients already with existing PRO membranes and improved economic feasibility when PRO membrane of higher actual/ideal flux ratio and burst pressure shall become available in the near future.