Explore the vast range of titles available.

In this paper, a potassium chabazite (KCHA) zeolite membrane was prepared by coating KCHA zeolite on the surface of a porous alumina sphere. The performance of the KCHA zeolite membrane in extracting potassium from seawater and sea bittern at room temperature was studied in detail. The XRD results show that the prepared KCHA zeolite was a KCHA membrane. The EDS test indicated that the potassium content of the KCHA zeolite membrane reached a value of 18.33 wt.%. The morphology of the KCHA zeolite grown on the surface of the alumina sphere was similar to a sphere, and it had good symmetry. The potassium ion-exchange capacities of the KCHA zeolite membrane reached 32 mg/g in seawater and 77 mg/g in sea bittern at room temperature. Ion exchange between the ammonium ions and potassium ions in the KCHA zeolite membrane could be completed in a short time at room temperature. The KCHA zeolite membrane was proven to have good reusability in seawater and sea bittern. The selective ion-exchange mechanism of the KCHA zeolite membrane was controlled by a specific K+ ion memory.

Many countries import potassic fertilizers due to dearth of K-mineral deposits. Therefore processes to obtain K-nutrient sources from sea bittern were developed by our Institute. The present investigation evaluated the fertilizer potential of three different sea bittern-derived (SBD) potassium forms developed viz., potassium schoenite, potassium nitrate and potassium ammonium sulfate on maize productivity in two cropping seasons. The pot and field experiments consisted of four treatments, wherein the three K forms were applied at the recommended rate of 40 kg K O ha and were compared with commercially used sulfate of potash. The effect of these fertilizers on different parameters of plant and soil were evaluated. The application of SBD-potassic fertilizers led to enhancement in growth, productivity and quality of maize which related well with higher photosynthesis, nutrient uptake and soil quality parameters. On an average all the three forms of sea bittern-derived potash enhanced yield of maize over control by 22.3 and 23.8%, respectively, in pot and field trials. The best performance was under SBD-KNO , which also recorded the highest benefit: cost ratio of 1.76. The K-fertilizers derived from sea-bittern-a waste product of salt industry-can thus be economically used to improve crop production sustainably.

Magnesium metal is used in automobile, sports and aircraft industries. It is also used in aluminum alloys and titanium production. The main raw material for magnesium production is anhydrous magnesium chloride which can be produced from sea water bitterns, magnesite and dolomite. Sea water bitterns from Bhavanagar, Gujarat, India has been used to produce magnesium chloride in the present study using low temperature spray drying. As bitterns solution contains lot of sodium and sulfate, efforts have been made to remove both these elements before spray drying. The purified solution is subjected for spray drying and the variables covered during spray drying are feed flow rate, inlet temperature and atomization pressure. With increase in flow rate from 2 to 5 mL/min, % of magnesium chloride content in the product is reduced from 57.58 to 52.73 %. Temperature and atomization pressure are not having significant effect on percentage of magnesium chloride in the product. The spray dried powder contains moisture content which is removed by thermal decomposition. Thermal drying studies such as temperature, duration of thermal drying have been carried out. The final product of MgCl 2 1.31H 2 O is suitable for magnesium metal production using fused salt electrolysis.

* A dual \"waste-to-resource\" application of FO was proposed. * Performance of sea salt bittern as an economic FO draw solution was evaluated. * High quality struvite recovery from black water using FO was demonstrated. * Feed pH is a key factor to control the form of recovered phosphorous. A dual \"waste-to-resource\" innovation in nutrient enrichment and recovery from domestic black water using a sea salt bittern (SSB)-driven forward osmosis (FO) process is proposed and demonstrated. The performance of SSB as a \"waste-to-resource\" draw solution for FO was first evaluated. A synthetic SSB-driven FO provided a water flux of 25.67±3.36 L/m 2⋅h, which was 1.5‒1.7 times compared with synthetic seawater, 1 M NaCl, and 1 M MgCl 2. Slightly compromised performance regarding reverse solute selectivity was observed. In compensation, the enhanced reverse diffusion of Mg 2+ suggested superior potential in terms of recovering nutrients in the form of struvite precipitation. The nutrient enrichment was performed using both the pre-filtered influent and effluent of a domestic septic tank. Over 80% of phosphate-P recovery was achieved from both low- and high-strength black water at a feed volume reduction up to 80%‒90%. With an elevated feed pH (~9), approximately 60%‒85% enriched phosphate-P was able to be recovered in the form of precipitated stuvite. Whereas the enrichment performance of total Kjeldahl nitrogen (TKN) largely differed depending on the strength of black water. Improved concentration factor (i.e., 3-folds) and retention (>60%) of TKN was obtained in the high-nutrient-strength black water at a feed volume reduction of 80%, in comparison with a weak TKN enrichment observed in low-strength black water. The results suggested a good potential for nutrient recovery based on this dual \"waste-to-resource\" FO system with proper management of membrane cleaning.

The valorization of ultra-concentrated seawater brines, named bitterns, requires preliminary purification processes, such as membrane filtration, before they can be fully exploited. This study investigates the performance of an ultrafiltration pilot plant aimed at separating organic matter and large particles from real bitterns. An empirical model for the bittern viscosity was developed to better characterize the membrane. Distinct variations in permeability, fouling resistance and rejection coefficient were observed under operational pressures ranging from 2 to 4 bar. Working at low pressure (2 bar), the pilot plant achieves permeability and rejection coefficient values of 17 L/m2hbar and 95%, respectively. Foulant behavior was characterized by determining a “fouling resistance”, obtaining an average value of 1013 m−1. Tests with three distinct bittern samples were conducted to assess the influence of chemical composition and organic matter content on membrane permeability and fouling characteristics. The collected data enabled a comprehensive characterization of the ultrafiltration pilot unit working with this particular saline feed solution, which has very high technical–economic potential.

Sea-level rise, suppression of natural disturbances, and human development of coastal lands have influenced the capacity of tidal marshes to maintain quality habitat for wildlife, including coastal marsh birds. This study targeted the oligohaline marshes of the lower Mobile-Tensaw River Delta, Alabama, USA with the objective of assessing landcover and marsh bird distributional changes relative to two sampling periods, 2004 and 2015. We employed analysis of aerial imagery and standardized marsh bird surveys to derive information on the densities of common gallinule ( Gallinula galeata ), king rail ( Rallus elegans ), and least bittern ( Ixobrychus exilis ) during each sampling period. A gradient of land change was apparent where the northernmost and the southeastern portions of the study area lost land from 2006 to 2013 while the extent of emergent marsh wetland increased in the south and decreased in the north. Average densities of all three birds declined between survey periods (common gallinule 15%, king rail 50%, least bittern 38%). Changes in the distributions of these marsh birds reflected change in landform and emergent marsh habitat. This study reveals that tidal wetlands and associated communities do not change through linear processes. Rather, coastal wetlands may show distinct patterns surrounding areas of accretion, and loss.

Accelerating sea level rise (SLR) is likely to cause considerable changes to estuarine and other coastal wetlands. Efforts to forecast the effects of SLR on coastal wetland vegetation communities should be useful in making predictions for individual species that depend upon those communities. However, considerable uncertainty exists when predicting a chain of events that passes from the global climate to local effects to implications for a single species. One component of this uncertainty is the classification resolution used by SLR landscape change models such as the Sea Level Affects Marshes Model (SLAMM). To isolate and assess the effects of this kind of uncertainty on species-level SLR prediction, we analyzed surveys of birds and plants in the lower Altamaha River and its estuary in Georgia, USA. For 19 marsh and forest bird species, we tested the predictive value of three classes of covariates of site occupancy: (1) field-measured habitat variables and spatial information, (2) information available from a SLAMM map, including the spatial configuration of the SLAMM habitat classes, and (3) SLAMM habitat class alone. We found that the predictive ability of occupancy models built from these three kinds of information varies widely among species. We therefore suggest criteria for classifying species according to the amount of detail necessary to describe their habitat niche, and thus to maximize the accuracy of predictive models. We point out that for species with habitat requirements that can be represented well by SLAMM classes, such as the Clapper Rail, forecasts of SLR-induced population change are probably feasible. For species with more narrow habitat needs, however, such as the Seaside Sparrow, reasonable predictions of SLR effects may not be possible without further refinement of SLR landscape change models. We suggest that improved thematic resolution of such models should be a priority, if the implications of SLR models for individual species are to be ascertained fully.

Laboratory studies were conducted to determine the efficacy of seawater bittern as a coagulant for the treatment of municipal wastewater. Freshly collected grab samples of municipal wastewater from two different discharge points were alkalinized to pH levels of 11.4 ± 0.1 by adding slaked lime or caustic soda. Serial dosages of liquid bittern were added and the jar test technique was used to determine the effect of the process on a number of determinant parameters. Seawater, liquid bittern, and dried bittern were used as coagulating agents in one of the four test sets to determine the effect of the three magnesium ion (${\\rm Mg}^{2+}$) sources on effluent characteristics. The extent of bacterial inactivation and the use of${\\rm CO}_{2}$to control effluent pH were investigated as well. Seawater liquid bittern was found to be an effective and economic source of${\\rm Mg}^{2+}$that may be used in the treatment of municipal wastewater. Turbidity and suspended solids removal exceeded 95%. Recorded chemical oxygen demand removals were in excess of 75%, while dissolved organic carbon removals averaged approximately 30%. Very limited differences in efficiency of treatment were noted between the use of slaked lime and caustic soda as alkalinizing agents. Besides its reduced bulk when compared to seawater, liquid bittern demonstrated an added advantage (over seawater and dry bittern) in imparting the least increase in dissolved solids to treated effluent. The process is very effective in inactivating fecal bacteria. Carbonation by the addition of${\\rm CO}_{2}$in concentrations ranging between 56 and 362 mL/L (depending on initial levels of pH, alkalinity, and the nature of the alkalinizing agent used) were needed to neutralize clarified supernatants to acceptable levels.