Brine Depth Research Articles

Response of the photosynthetic characteristics and antioxidant system of Suaeda salsa to the changes of underground brine depth.

Water and salt conditions are key factors influencing vegetation growth on shell island in the Yellow River Delta. However, the effects of the depth of underground brine on the photosynthetic characteristics and antioxidant system of halophytes remain unclear. The laboratory simulation experiment was carried out to investigate the effect of the changes of underground brine depth on Suaeda salsa using four levels of groundwater: 0 cm, 15 cm, 30 cm and 45 cm. The results showed that different underground brine depths had significant impacts on the photosynthetic characteristics and antioxidant system of S. salsa, and 0-30 cm underground brine depth was suitable for S. salsa growth. The net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), light utilization efficiency (LUE) and carboxylation efficiency (CE) of S. salsa increased first and then decreased with increasing depth of underground brine. The stomatal limitation value (Ls) and WUE of S. salsa reached the peak value at the groundwater depth of 0 cm, and water use efficiency was reduced by 19.4%, 8.0% and 8.6% at 15 cm, 30 cm, and 45 cm, respectively, compared to the 0 cm treatment. With the deepening of underground brine depth, the value of LUE and CE firstly increased and then decreased, and reached the peak value when the depth was 30 cm. The antioxidant enzyme (SOD, POD and CAT) activities of S. salsa decreased and then increased with the increase of underground brine depth. The enzyme activities were the lowest when the underground brine depth was 30 cm. As the groundwater depth increased, MDA content decreased and then increased. The highest degree of membrane peroxidation in S. salsa leaves was observed at the depth of 45 cm. Our study reveals that the antioxidant capacity of S. salsa was weakened at the underground brine depth of 45 cm and the growth of S. salsa was inhibited.

Flow Field Analysis of Gas Injection and Brine Discharge in Natural Gas Storage Salt Cavern

Gas injection and brine discharge is the key link in the construction and safe operation of the salt cavern gas storage. Accurate description of the bottom flow field of the salt cavern in the process of gas injection and brine extraction is the basis and premise for determining the depth of the brine drainage string. According to the characteristics of gas injection and brine discharge, a numerical simulation calculation model of the brine flow field near the inlet of the brine discharge tubing was established. The brine flow field under different working conditions is simulated, and the safe brine drainage rate at different residual brine depths in the later stage of gas injection and brine drainage is determined, which provides technical support for the adjustment of gas injection brine drainage rate in the later stage of construction.

Experimental investigation of designed solar parabolic concentrator based desalination system for textile industry wastewater treatment

The escalation in demand for textile products increased the use of fresh water and treatment of wastewater; which escalates the search for suitable and energy-efficient technology for wastewater treatment. Solar assisted technology ( i.e. solar desalination) for the textile industry wastewater treatment is proved to be an affordable technology. The only drawback of solar desalination is its low productivity which is the major hindrance in the global acceptance of the system. In the present study, an ingenious improvement in form of a parabolic concentrator-based solar desalination system (PCB-SDS) is designed to overcome low productivity, and the simultaneous use of source textile industry wastewater for its treatment makes this study more realistic. The performance of the designed system was examined for three different brine depths i.e. 20%, 40%, and 60% for two different processing step i.e. Dyeing and Degumming. System performance was evaluated in terms of energetic, exergetic, pollutant removal, and economic analysis. The maximum output of the system was found to be around 7440 and 8330 mL/day on clear sunny days with textile dyeing wastewater (TDyWW) and textile degumming wastewater (TDgWW) at 60% depth respectively. Daily average energy and exergy efficiency of system varies in the range 39.8–51.9 and 3.6–4.8% respectively. The degumming wastewater shows 85% COD removal, whereas, around 90% of TDS and hardness removal was also recorded. The dyeing processed wastewater showed 80% COD removal efficiency, ≅90% TDS, and hardness removal. The cost per liter of distillate output produced from designed PCB-SDS was found to be 0.014 $/L.

The brine depth of the Khorat Basin in Thailand as indicated by high-resolution Br profile

Bromine contents of a 17-cm halite core from drilling hole of K203 in the Khorat Basin were analysed at 1 cm intervals (17 samples in total). The Br contents range from 99 to 184 ppm with a rapid variation. The K/Mg ratios of halite samples are tens of times higher than those of primary halite fluid inclusions. There is no positive correlation between Mg and Br contents, suggesting that fluid inclusions impose very little or negligible influence on Br contents of halites. The Br contents are not controlled by potash minerals either because the SEM examination shows no potash minerals and there is no relationship between K and Br contents. The Br contents of halite are thus primarily controlled by the Br concentrations of parent brines. The rapid variation of Br contents of halite within this section suggests a shallow saline pan wherein the giant Khorat evaporites were formed. This is contradictory to previous Br profiles of the Lower Salt Member which showed relatively stable and continuously increasing trends. The shallow saline pan model evidenced by high-resolution Br profile is consistent with sedimentary facies and salt mineral textures.

Stepped solar still: A review on designs analysis

Everyone’s rights to get clean, safe, and fresh drinking water. As we know almost 71% of water covered in the Earth's surface. It may be in the form of oceans (covers almost 96.5% of all Earth's water), rivers, lakes, glaciers, icecaps, and also exists in the form of water vapor as well as soil moistures. The percentage of freshwater on earth is about 3% in which almost 2.5% fresh water is not available (locked in polar ice caps, atmosphere, glaciers, highly polluted, in soil, or lie too deep below the surface of the earth and not to be collected at a reasonable cost. Fresh water is available only 0.5% of the earth's atmosphere. Solar desalination from a solar still is a renewable method used to fulfill the provision of safe water supply in distant locations at a very affordable cost. However, due to its lower awareness solar still technology is not standardized and commercialized. The factors that influence solar still productivity are wind velocity, solar intensity, depth of water, an inlet water temperature, ambient temperature, and absorber plate area etc. ambient temperature, solar intensities and wind velocity are unable to control because these are metrological variables while the left standing variables could be changed to enhance solar stills productivity. Water depth in solar still inversely affects solar still productivity. Investigations suggest that reduction in brine depth productivity increases, because of higher temperatures in the basin. Minimum depth is maintained by stepped solar still, so stepped solar stills can improve the distillate Productivity. Throughout this review, we attempt to study the various types of stepped solar stills.

A comparative study on shaded square pyramid shape solar still with thermo-economic analysis

ABSTRACT This study aims to decrease the temperature of the transparent plate in the square pyramid shape solar still (PSSS) by shading the transparent plate by cloth. The PSSS has the advantage of receiving solar radiation from all sides and has the higher condensation area. Two PSSS systems were fabricated with similar dimensions. The transparent plate in one of the PSSS systems was shaded (SPSSS) with cloth and the other one was used as a conventional PSSS (CPSSS) system without any shading. All the experiments were conducted for a constant brine depth of 0.02 m. Experiments were performed in the month of May 2019 at Chennai, Tamil Nadu, India. The experiment evidenced a considerable decrease in the transparent plate temperature of the SPSSS by about 7.5% compared to that of the CPSSS. The influence of shading lowered the evaporative rate by 24% in the SPSSS compared to the CPSSS. The freshwater yield of 2.66 kg/day in the CPSSS was 33% higher compared to the SPSSS. The economic analysis and payback comparison of the CPSSS and SPSSS detailed the influence of shading.

PERFORMANCE EVALUATION OF TWO DEFFERENT ACTIVE SOLAR STILLS

The main goal of this work is evaluating the performance of two solar desalination systems under active mode using an integrated solar flat plate collector (FPC). The first one included a glass covered pyramid solar still (PSS) combined with FPC, whilst the second is consists of a greenhouse solar still (GSS) with the same area of brine basin and provided with transparent acrylic cover and connected to another similar FPC. The two systems were fully powered by solar energy using photo voltaic (PV) system. The pre-experiment was performed to evaluate the thermal performance of FPC to determine the optimum hot water flow rate to be used in the main experiment. The main experiment aims to investigate the performance of the two active solar stills under different brine depths and salinity levels. The effect of using basin auxiliary materials including black wick clothes (BWC) and black rubber mat (BRM) on the performance of solar stills was studied with taking into consideration the performance indicators. The obtained results revealed that, the water flow rate of 0.30 l/min achieved the highest values of maximum and average thermal efficiency for the solar FPC. Furthermore, there was no remarkable difference in the hourly productivity and accumulated yield for active PSS and GSS under the best operating condition of brine depth 1cm, salinity level 10000 ppm using BWC and water flow rate 0.30 l/min. Nevertheless, the instantaneous efficiency of active PSS was higher than active GSS, particularly at noon. The cost of distilled water unit is approximately equal for both stills. In conclusion, the two designs of stills proved a good performance with advantages of lightweight, durability and formability for the transparent acrylic cover of GSS over the fragile glass cover of PSS.

Experimental study of single slope solar still coupled with parabolic trough collector

After a comprehensive review, it was found that very few research has been conducted on single slope solar still coupled with parabolic trough collector. In this research article, the behavior of parabolic trough collector integrated solar still was experimentally evaluated. An experimental study dealing with the energy analysis of a single slope solar still coupled with a parabolic trough collector was investigated for three different brine depths (5 cm, 10 cm and 15 cm) and results are presented. Three different brine depths of 5 cm, 10 cm and 15 cm water level were configured for flow rates of 4.1 l/m2, 3.645 l/m2 and 3.2 l/m2, respectively and daily productivity was investigated. The energy analysis includes annual energy output, energy payback period, CO2 mitigation, and embodied energy. It was observed that the annual energy output, energy payback time and CO2 mitigation decrease with increasing water depth while a reduction in water level from 15 cm to 5 cm showed an increased in daily energy yield of 22%. The embodied energy of the experimental setup is estimated at 856.72 kWh, and 5 cm of water depth resulted in the highest range of carbon credit earned (₹10,169.86–₹40,679.44). Energy and economic analysis were also conducted for parabolic trough collector integrated solar still to evaluate the viability of the developed system. The payback period of the setup was found to be 246 days, 253 days, and 341 days at 5 cm, 10 cm and 15 cm water level, respectively.

A DEVELOPED SOLAR COMBINATION UNIT FOR COOKING AND WATER DESALINATION

A solar combination unit was developed be suitable for cooking and water desalination. Ordinary solar box cooker was developed to be accommodate for desalination and cooking. Different configurations were carried out under study as: Cooker without mirror reflector (C1), Cooker with mirror reflector (C2), Cooker integrated with flat-plate solar collector (C3) and Cooker integrated with mirror reflector and flat-plate solar collector (C4). Fourth merit figure and overall thermal cooking efficiency were applied under water load densities of 1.0, 1.5, 2.0 and 2.5 L to select the highest system performance. Preliminary experiments clarified that using C4 system and 1.5 L of water gave the highest efficiency compared to other treatments. Thermal analysis was done based on internal and external heat transfer to predict the used C4 behavior. The performance evaluation was conducted as a function of change in different brine depths of 1, 2 and 3 cm under conditions of groundwater desalination, cooking rice (T1), potato (T2), cake (T3) and egg + potato + rice (T4) and desalination-cooking combined systems. This is in terms of system productivity, internal and instantaneous thermal efficiencies and cooking time. Experimental results revealed that the use of desalination-cooking combined system gave the highest distillate water productivity (9.38 L/m2·day) as well as internal and instantaneous efficiencies (60.17 % and 41.43%), added to that decreased the cooking time; T1 (39 min), T2 (43 min), T3 (49 min) and T4 (100 min) under condition of 1 cm brine depth.

A Comparative Analysis and Effect of Water Depth on the Performance of Single Slope Basin Type Passive Solar Still Coupled with Flat Plate Collector and Evacuated Tube Collector

Many experimental and numerical works have been done on different configurations of solar stills to optimize the design by investigative the effect of climatic, operational and design parameters on its performance. One of the most important of the operational parameters that has received a considerable attention in the literature is the brine depth. A study was subsequently conducted to verify this trend by an experimental investigation on three types of solar still that was fabricated with an area of 1 m2 and tested in the composite climate of Coimbatore, Tamilnadu, India, (Latitude: 11°N; Longitude; 77°E and an altitude of 409 m above sea level) with five different brine depths, namely 1, 4, 6, 8 and 10 cm. The present study clearly validated that the decreasing trend in productivity with the increase of brine depth.

Experimental investigation of corrugated absorber solar still with wick and reflectors

The performance parameters of the corrugated solar still (CrSS) and conventional solar still (CSS) are investigated experimentally from another point of view. The authors' view concerns with using the double layer wick material and also reflectors together inside the CrSS. In addition, the influence of saline water depth (1, 2, and 3cm) on CrSS performance was also investigated. Results indicated an enhancement in the total productivity and efficiency of the CrSS. During experimentations, the productivities of CrSS with wick and reflectors are about 145.5% higher than the CSS, at a brine depth of 1cm, and the daily efficiency of CrSS and CSS are approximately 59% and 33%, respectively.

Improving the double slope solar still performance by using flat-plate solar collector and cooling glass cover

Thermal analysis, for double slope solar still, was carried out based on internal and external heat transfer and energy balance equations to predict its performance. Depending on the thermal analysis, passive and active solar stills were installed (solar still and solar still integrated with flat-plate solar collector) to use solar desalination technology for producing fresh water. Water temperature as well as both internal and external temperatures of glass cover, added to ambient temperature was measured with hour intervals, under all experimental conditions, for both solar stills. Performance of both solar stills was studied as a function of change in basin brine depth and glass cover thickness under conditions of applying glass cover cooling (flash tactic) or without cover cooling. Performance of solar stills was evaluated in terms of recorded temperatures, instantaneous and internal thermal efficiencies and system productivity. The experimental results revealed that active solar still maximizes both fresh water productivity (10.06l/m2·day) as well as internal thermal efficiency (80.6%) compared with passive solar still (7.8l/m2·day productivity and 57.1% internal efficiency) under conditions of 1cm basin brine depth and 3mm glass cover thickness and by applying flash tactic cover cooling with 5min on and 5min off.

Experimental investigation of the effect of solar collecting area on the performance of active solar stills with different brine depths

Solar collecting area is one of the most important operating parameters of active solar stills. No experimental work has been performed to investigate the effect of this parameter to date. Furthermore in all of previous theoretical studies the effect of solar collecting area was examined during only the first 24-hour period of the operation of stills with one specified brine depth. However the present work experimentally studies the long-term simultaneous effects of collector area and brine depth on the performance of active solar stills. For this purpose four parallel active solar stills with different collector areas were fabricated and experiments were conducted for 5 consecutive days during which different amounts of brine depth were considered for active solar stills. The present results indicated that the overall trend of distilled water production and efficiency lessened with decreased brine depth for all solar collecting areas. Moreover, as the solar collecting area increased, water production of stills increased but their efficiency decreased for all brine depths. Furthermore the current results showed that for active solar stills with low brine depth and high solar collecting area the brine may boil and this boiling decreases the efficiency of active solar stills.

Topologies of velocity-field stagnation points generated by a single pair of magnets in free-surface electromagnetic experiments.

The velocity fields generated by a static pair of magnets in free-surface electromagnetically forced flows are analyzed for different magnet attitudes, ionic currents, and brine depths. A wide range of laminar velocity fields is obtained despite the forcing simplicity. The velocity fields are classified according to their temporal mean flow topology, which strongly depends on the forcing geometry but barely on its strength, even through the bifurcation to unsteady regimes. The mean flow topology possesses a major influence on the critical Reynolds number Rec under which the steady velocity fields remain stable. The qualitative comparison of the dependence of Rec on the topology is in agreement with previous works. The unsteady configurations evidence the advection of smaller flow structures by the largest scales, commonly known as "sweeping."

A thorough investigation of the effects of water depth on the performance of active solar stills

One of the most important operating parameters which affects the performance and efficiency of active solar stills is brine depth. In all of the previous experimental or theoretical studies, effects of water depth were investigated during only the first 24-hour period (or even shorter periods) of the operation of active solar stills. In other words, only the first day was taken into account. However, the production of an active solar still depends on several parameters such as brine temperature at sunrise (initial temperature), which are all affected by the depth variation after the first day of operation. However, the present research experimentally investigates the long-term effects of water depth on the performance of active solar stills for the first time. For this purpose, two parallel active solar stills coupled with solar collectors with different surface areas were fabricated and an experiment was conducted for 10 continuous days. Unlike previous studies, results indicated that the overall trend of distilled water production and efficiency increased with increased water depth. Hence, higher water depth is recommended for practical uses of solar stills (more than two days).

Critical variables in the performance of a productivity-enhanced solar still

A new and sustainable modification has been introduced into the conventional solar still, considerably increasing its productivity. This enhancement in the solar still productivity is achieved without forsaking the basic features of the still such as low cost, ease of handling, sustainability, water quality, material availability, low maintenance and space conservation. The introduced modification is in the form of a slowly rotating hollow drum within the still cavity that allows the formation of thin water films, which evaporate rapidly. Several environmental and operational parameters attribute to the optimization of the new still design. Environmental factors refer primarily to weather conditions such as solar intensity, relative humidity, ambient temperature and wind speed and direction. Operational variables include drum speed, brine depth in the basin, cover cooling and other related parameters such as the materials used and the still configuration. The influence of these parameters is discussed and their impact on productivity is investigated in detailed order to identify existing correlations and optimize design and operation of the new system. An error analysis was conducted for all experimental data obtained from this study.

The promotion of salt quality through optimizing brine concentration a new technique “bidirectional brine concentration”

The commonly accepted brine concentration practice in most Chinese Northern solar works is to pump the sea water into salt works and then let it go through a physical changing process of natural evaporation, condensation and crystallization, during which, weather factor and the soil nature have to be taken into consideration when determining the technologic parameters such as brine depth, brine protection area, fresh water drainage rate and so on. Meanwhile, different methods should be employed according to various weather conditions, for example, brine is concentrated with decided depth and salinity over periods of stable weather conditions (Spring); rapid brine concentration by deep storage and lower depth brine should be used during rainy seasons; and in winters, the amount should be increased to keep the salinity. However, accompanying this physical changing process of salt production is balancing process of the amount of multi-biology in brine. Every salt work fosters an ecosystem, which includes algae, bacteria, protoza, menatoza, artemia, sea weed and fish communities. The low salinity brine is featured of a myriad of algae, which are able to synthesize and accumulate pigments, elevate the brine’s absorbency of solar energy and quicken the evaporation speed; the algae, bacteria, organic and inorganic substances on the salt ponds floor may form a biological pad, performing the functions of brine purifying, soil improvement and leakage protection. At the same time, the biological pad can block out large amount of elements and trace elements in the mud on the salt pond floor and the bacteria can effectively decompose organic crumbs of the solar salt works ecosystem. The medium salinity brine is dominated by artemia, who are good at sieving the algae, organic and inorganic substances in brine so as to purify it. The artemia corpse are sources of protein for red halobacteria, which are capable of increasing the brine staining ability, purifying brine and promoting the evaporation amount and the salt quality. In conclusion, a balanced ecosystem is beneficial to salt industry by : A. culturing bentic communities, available for seizing nutrition and controlling leakage; B. staining brine to enhance the absorbency of solar energy and evaporation rate; C. being able to decompose most of its self-generated organics. The Bidirectional Brine Concentration Technology is meant supplementing the ordinary brine concentration with ecosystem management, namely, through the artificial adjustment of the amount of biology to reach the eco-balance. This is composed of two parts: A. The bio-management of artemia. Combining the concentrated multiplication with culturing during the whole production process to adjust the community density to a suitable level and keep the eco-balance in line with scientific standards. As long as the brine salinity reaches certain level and the artemia food chain starts loosing balance, we will fish over-thick community and let the resting artemia die in the high salinity area and their corpse will be used for the source of protein for halobecteria. B. Selecting and culturing excellent breed of halobacteria.. Let red halobacteria reproduce in saturated brine and crystallizers and contact a corresponding scientific surveillance. This helps heighten the brine transparency, lower the brine stickiness and promote the salt quality.

Performance correlation for single-basin double-slope solar still

In this study, an attempt has been made to develop a new correlation for the productivity of a single-basin double-slope solar still using experimental results obtained for different brine depths (0.01, 0.02, 0.03, 0.04, 0.05, and 0.06 m) in the basin in Coimbatore, Tamilnadu, India. The proposed correlation has been validated with the experimental results for one of the typical days in Coimbatore, Tamilnadu, India. A concluding correlation has been developed by including the results mentioned in the literature regarding double-slope solar still alone and the proposed correlation. The concluding correlation is compared with the correlation developed by the researcher based on the results in the literature regarding both single- and double-slope solar stills. The results indicate that

IMPROVING THE PERFORMANCE OF A PYRAMID-SHAPED SOLAR STILL

The main goal of this study is to improve the performance of a pyramid-shaped solar still by studying some effective parameters on the still distillate yield and still instantaneous efficiency including solar radiation intensity, brine depth, water salinity, temperature difference between the glass cover and the brine. Thus a simple basin pyramid- shaped solar still with total area of 0. 64 m2 covered with four triangle clear sheets of glass with 3 mm in thickness without frame was fabricated and tested with auxiliary black materials in basin from 8 am to 6 pm under Zagazig city local climatic conditions (Latitude 30.5° N). The solar still performance was evaluated under three levels of brine depth (4 ,8 and 10 cm),two levels of water salinity (15000 and 35000 ppm) intended to simulate brackish water and seawater respectively using auxiliary black materials including black sponge cubes and black stones. The results showed that around the noon hour, using the black sponge cubes at water depth of 4 cm and water salinity of 15000 ppm gave the highest still instantaneous efficiency of 46.15 %, the highest temperature difference between the glass cover and the brine of 32.40 °C, the highest distillate and accumulated yield of 630.40 ml/h and 3620.45 ml respectively. Hence, it is recommended to operate the solar still at brine depth of 4 cm and water salinity of 15000 ppm using black sponge cubes to obtain the highest values of the distillate yield, accumulated yield and the instantaneous efficiency.

Performance correlations for basin type solar stills

Many experimental and numerical studies have been done on different configurations of solar stills to reach the optimum design by examining the effect of climatic, operational and design parameters on its performance. Some of the most important parameters investigated were solar radiation, cover tilt angle, brine depth, and using dyes with the brine. The majority of the investigators presented their results in scatter diagrams rather than correlations. Four correlations are derived in this work to illustrate the effect of solar radiation, dyes, cover slope and brine depth on the productivity of the basin type solar still using the available data given by the different investigators. The correlations developed illustrate that the still productivity could be influenced by the brine depth alone by up to 33% and by the tilt angle alone by up to 63%. A cover tilt angle of about 30° gives the highest productivity. The still productivity could be enhanced by adding dark soluble dye to the brine by up to 20%. The still productivity increases with the increase of insulation thickness of the still and the solar radiation received.