Showing papers on "Saline water published in 2010"

Using microbial desalination cells to reduce water salinity prior to reverse osmosis

Abstract: A microbial desalination cell (MDC) is a new method to reduce the salinity of one solution while generating electrical power from organic matter and bacteria in another (anode) solution. Substantial reductions in the salinity can require much larger volumes of the anode solution than the saline water, but any reduction of salinity will benefit the energy efficiency of a downstream reverse osmosis (RO) desalination system. We investigated here the use of an MDC as an RO pre-treatment method using a new type of air-cathode MDC containing three equally sized chambers. A single cycle of operation using a 1 g L−1 acetate solution reduced the conductivity of salt water (5 g L−1 NaCl) by 43 ± 6%, and produced a maximum power density of 480 mW m−2 with a coulombic efficiency of 68 ± 11%. A higher concentration of acetate (2 g L−1) reduced solution conductivity by 60 ± 7%, and a higher salt concentration (20 g L−1 NaCl) reduced solution conductivity by 50 ± 7%. The use of membranes with increased ion exchange capacities further decreased the solution conductivity by 63 ± 2% (20 g L−1 NaCl). These results demonstrate substantial (43–67%) desalination of water is possible using equal volumes of anode solution and salt water. These results show that MDC treatment could be used to substantially reduce salt concentrations and thus energy demands for downstream RO processing, while at the same time producing electrical power.

Exogenous proline effects on photosynthetic performance and antioxidant defense system of young olive tree.

Abstract: The ability of exogenous compatible solutes, such as proline, to counteract salt inhibitory effects in olive plants ( Olea europaea L. cv. Chemlali) was investigated. Two-year-old olive trees were subjected to different saline water irrigation levels supplied or not with exogenous proline. Leaf water relations (relative water content, water potential), photosynthetic activity, and leaf chlorophyll content decreased under either saline water level. The proline supplement mitigated the reduction of growth and photosynthetic activity under salt stress, and the mitigating effect of proline was different among treatments. The increment rate of leaf relative water content (RWC) in the presence of 25 and 50 mM proline was 4.45 and 6.67%, respectively, in comparison to values recorded in SS1-treated plants (plants irrigated with water containing 100 mM NaCl). In SS2 (200 mM NaCl) plus proline-treated plants, this increase was 1.14 times for 25 mM proline and 1.19 times for 50 mM proline higher than those recorded in severe salt stress treatment (SS2). In response to salt stress, Chemlali olive plants seem to activate a complex antioxidative defense system that was displayed via the increase of activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) and the decrease of polyphenol oxidase (PPO) under either salt stress treatment. The exogenous application of proline improved the antioxidative enzyme activities of salt-stressed olive plants. Indeed, in young or old leaf tissues, the highest levels of these antioxidant enzymes activities were recorded in (SS2 + P2)-treated plants (plants irrigated with water containing 200 mM NaCl plus 50 mM proline). In young leaves, this increase was 2.11, 2.96, and 2.76 times, respectively, for SOD, APX, and CAT enzyme activities in comparison to their respective activities in control plants (nonstressed plants irrigated with fresh water). In old leaves, this increase was 2, 2.41, and 2.48 times, respectively, for the various enzymes. If compared to high water salinity-treated plants (SS2), this increase was 1.1, 1.3, and 1.4 times in young leaves, respectively, for SOD, APX, and CAT activities. From these results, the proline supplements seem to improve olive salt tolerance by amelioration of some antioxidative enzyme activities, photosynthetic activity, and, so, plant growth and the preservation of a suitable plant water status under salinity conditions. More to the point, the decrease of soluble sugars contents in proline treated-plants revealed the important osmoprotectant effect played by the added proline in such a way that limited the need of salt-stressed plants for soluble sugars synthesis.

A review of anaerobic treatment of saline wastewater

Abstract: Large volumes of saline (>2% w/v NaCl) wastewaters are discharged from many industries; e.g. seafood processing, textile dyeing, oil and gas production, tanneries and drinking water treatment processes. Although anaerobic treatment would be the most cost‐effective and sustainable technology for the treatment of many of these saline wastewaters, the salinity is considered to be inhibitory to anaerobic biological treatment processes. The recent applications of salt‐tolerant cultures for the treatment of wastewaters from seafood processing and ion‐exchange processes suggest that biological systems can be used to treat salty wastewaters. Additionally, organisms capable of anaerobic degradation of contaminants in saline solutions have been observed in marine sediments and have been characterized during the last two decades. This manuscript provides a review of the recent research on anaerobic treatment of saline wastewater and bacterial consortia capable of the anaerobic degradation of pollutants in saline sol...

Irrigation Water Quality Based on Hydro Chemical Analysis, Jaffna, Sri Lanka

Abstract: The hydro chemical study reveals the quality of water and its suitability for drinking, agriculture and industrial purposes. Presence of excessive quantities of salts in groundwater is one of the major constrains in agro-well farming in Jaffna Peninsula. Irrigation with poor quality waters may bring undesirable elements to the soil in excessive quantities affecting its fertility. Electrical conductivity (EC), Sodium percentage (Na %), Sodium adsorption ratio (SAR), Residual sodium carbonate (RSC) can be used as a criterion for finding the suitability of irrigation waters. The objective of this study is to evaluate the suitability of the irrigation water quality of the Jaffna Peninsula. Major cations; Na , Ca , Mg , K and major anions; Cl , SO , HCO , CO , + 2+ 2+ + - 2- - 2- 4 3 3 were determined from 34 wells, randomly located in Peninsula from October 2008 to April 2009 to assess the hazards of salinity, sodium and bicarbonate. Out of selected wells, based on EC, 44% of the wells have medium salinity water, 47 % of the wells have high salinity water and 9 % of the wells have very high salinity water. Based on percent of sodium, 3% of the wells have excellent irrigation water quality, 18 % of the wells have good irrigation water quality, 44% of the wells have permissible irrigation water quality, 32% of the wells have doubtful irrigation water quality and 3% of the wells have unsuitable irrigation water quality. Based on SAR, almost all the wells have the good quality irrigation water. Based on RSC, 61% of the wells have good irrigation water quality, 15% of the wells have doubtful irrigation water quality and 24% of the wells have unsuitable irrigation water quality. In overall assessment of tested wells, 20.6% of the wells have good quality water for irrigation, 44.1% of the wells have permissible to doubtful irrigation water quality, 35.3% of the wells have unsuitable irrigation water quality, in which bicarbonate hazard was identified as major hazard which is due to the influence of carbonate rock dissolution.

Growth and Physiological Responses of Landscape Plants to Saline Water Irrigation: A Review

Abstract: Water shortages and poor water quality are critical issues in many areas of the world. With rapid increases in population and shortage of water supplies in urban areas, use of alternative water sources such as municipal reclaimed water and other sources of non-potable waters for irrigating landscapes is inevitable. A potential concern is the elevated salt levels in these alternative waters. This article briefly summarizes general information regarding alternative water sources and general responses of landscape plants to salinity stress. Methodology of screening and evaluating salt tolerance of landscape plants are discussed. Recent research results on salt tolerance of landscape plants and their physiological responses to salinity stress are reviewed. Like agricultural crops, a wide range of salt tolerance among landscape plants has been found. In addition to plant species, dominant salt type, substrate, irrigation method and management, and environmental conditions also affect plant responses to salinity stress. A number of mechanisms of salinity tolerance have been observed among landscape species, including restriction of ion uptake, selective ion uptake, and tolerance to high internal concentrations of sodium and/or chloride.

Impact of Capillary Pressure, Salinity and In situ Conditions on CO2 Injection into Saline Aquifers

Abstract: This article presents a numerical investigation of the combined effects of capil- lary pressure, salinity and in situ thermodynamic conditions on CO2-brine-rock interactions in a saline aquifer. We demonstrate that the interrelations between capillary pressure, salin- ity, dissolution and drying-out affect CO2 injectivity and storage capacity of a saline aquifer. High capillary forces require a high injection pressure for a given injection rate. Depending on salinity, the increase in injection pressure due to capillary forces can be offset by the dissolution of CO2 in formation water and its compressibility. Higher capillary forces also reduce gravity segregation, and this gives a more homogeneous CO2 plume which improves the dissolution of CO2. The solubility of CO2 in formation water decreases with increasing salinity which requires an increased injection pressure. Higher salinity and capillary pressure can even block the pores, causing an increased salt precipitation. Simulations with various pressure-temperature conditions and modified salinity and capillary pressure curves dem- onstrate that, with the injection pressures similar for both cold and warm basins at a given injection rate, CO2 dissolves about 10% more in the warm basin water than in the cold basin. The increase in dissolution lowers the injection pressure compensating the disadvantage of low CO2 density and compressibility for storage in warm basins.

Effect of Salt Stress on Peruvian Germplasm of Chenopodium quinoa Willd.: A Promising Crop

Abstract: Soil salinity is a major problem in today's agriculture. Quinoa has become an important crop because it exhibits high levels of salinity tolerance. In addition, its seeds contain an excellent balance of carbohydrates, lipids, amino acids and proteins for human nutrition. The quinoa germplasm includes almost 2500 accessions, some of which have been tested under salt stress. Here, we report the effect of NaCl on the germination of 182 previously untested accessions. When seeds were irrigated with saline water at 30 dS m ―1 EC, the stress appeared to be too high: all accessions showed less than 60 % germination. In contrast, irrigation with 25 dS m ―1 EC saline water allowed over 60 % germination in 15 accessions. These latter accessions' agricultural traits were then evaluated. The overall coefficients of variation indicated that quinoa genotype and salt treatment dramatically influence root dry mass per plant, but do not noticeably affect the length of the plant's life cycle. Unexpectedly, salt treatment resulted in increased plant height, leaf dry mass and grain yield. Using Euclidean distance for the simultaneous selection of these five agricultural traits, accessions 100, 136, 127 and 105 proved to be the best performing genotypes under salt stress.

Salinity dynamics and the potential for improvement of waterlogged and saline land in a Mediterranean climate using permanent raised beds.

Abstract: Waterlogging and salinity in the Mediterranean climate of Western Australia (WA) have long been recognized as major constraints to the production of agricultural crops and pastures While raised beds (RB) prevent waterlogging, the impact of RB on salinity is not known Their impact on salinity was studied at 3 sites in the Wheatbelt of WA The salinity dynamics was captured through frequent soil sampling Two small trials with different mulches were also conducted to investigate possibilities to alter salinity dynamics in other ways Each of the sites responded differently to the RB At Cunderdin, being the driest site, little impact of the precipitation on the movement of salt was found, and no difference between the RB and Control The deeper salinity was found to be more associated with the presence of the shallow saline groundwater At Woodanilling, a high-rainfall site, salinity changes were governed by precipitation, and the RB greatly reduced waterlogging in the top 10 cm of the soil surface and improved productivity Little differences were found between RB and Control with respect to salinity due to the incorporation of clayey subsoil At North Stirlings with medium rainfall, the RB were very effective in reducing waterlogging, improving productivity as well as reducing salinity, following the disruption of the gravelly subsoil layer Applying a sand mulch made a bare salt scald reasonably productive again The dry-soil mulch process is also thought to be responsible for the low salt concentrations near the soil surface at Cunderdin Maintaining the physical properties of this topsoil is crucial for sustaining a productive system It is also proposed that the salinity–waterlogging interactions are not relevant to the dry-land salinity conditions in WA as the soil surface was either waterlogged or saline but not both at the same time Our findings have narrowed down the benefits of permanent RB to the waterlogged medium-to-high-rainfall area of WA in regards to waterlogging and loamy gravelly duplex soils in regards to waterlogging and salinity control As growers in a changing climate (physical and economical) become interested in cropping the waterlogged and saline areas of the valley floors in WA, RB will make that a realistic option This would equally apply to other parts of the world where waterlogging and salinity are major constraints provided due consideration is given to soil properties of the top soil, particularly the soil texture

Impact of irrigation water quality, irrigation systems, irrigation rates and soil amendments on tomato production in sandy calcareous soil

Abstract: Low quality water for irrigation can impose a major environmental constraint to crop productivity. Effects of water quality, irrigation system, irrigation rates, and type of amendment on the yield and quality of tomato plants were investigated during the 2 growing seasons of 2005/2006 and 2006/2007. Two water quality treatments (fresh water with electrical conductivity (EC) of 0.86 dS m-1, and saline water with EC of 3.6 dS m-1), 2 drip irrigation systems (surface and subsurface), 3 irrigation rates (2, 4, and 6 L h-1) and 3 amendment types (clay deposit, and organic matter and without amendment) were applied. The results revealed that the water quality significantly affected both the yield and water use efficiency (WUE). The decreases in yields due to using low quality water were 39.2% and 17.6% for the first and second season, respectively. At a high irrigation rate (6 L h-1), tomato yields were higher and decreased significantly at a low irrigation rate (2 L h-1) in both seasons. When fresh water was used, the amendment type affected both the yield and WUE in both seasons. Clay deposit increased the yield by 11.7% and 15% in the control treatments in the first and second season, respectively. Low quality of irrigation water significantly increased fruit pH, and significantly decreased the other 3 traits (average fruit weight, total soluble solid, and fruit thickness). The influence of salinity was more obvious on average fruit weight than the other 2 traits. Application of clay deposits on sandy soils modifies the distribution of soil water content in the root zone area where water could be retained by clay deposits applied in the subsurface layer. Using saline water increased the salt accumulation in the surface to about 15 dS m-1 compared with 5 dS m-1 for fresh water treatments. The clay deposit amendments for subsurface sandy soils using good irrigation water show quite valuable effects in storing irrigation water and then enhance the root growth and the yield.

Hydrogen Production Using Sea Water Electrolysis

Abstract: Electrolysis is one of the acknowledged means of generating chemical products from their native state. This is true for hydrogen production from water. The use of saline water (sea water in particular) as a feedstock for producing hydrogen by electrolysis is examined in this paper. Little consideration is given however, to the availability and the qual- ity of the raw material used in the production of hydrogen; that is water. Under normal conditions of operation, the elec- trolysis cell behaves to produce H2/Cl2 rather than H2/O2. Experimental results are presented for the electrolysis of a wide range of saline water (0.5-7.0% TDS) and interpretations are given for two main cell-operating-characteristics. These are: rate of hydrogen production and chlorine evaluation.

Geophysical investigation of saline water intrusion into freshwater aquifers: A case study of Oniru, Lagos State

Abstract: A total of five electrical imaging lines were measured using the wenner configuration. And a total of twelve VES was carried out within the area of investigation. The lines were aligned almost in a linearly NS azimuths, perpendicular to the ocean. The results were presented as profiles, multi-profiles, maps, pseudo sections and inverted sections. Interpretations of these results involve both qualitative and quantitative deductions from 1D and 2D geoelectric models. WingLink software was utilized for plotting, filtering, modeling and iterations of the resistivity data. From the quantitative interpretation and nearby well log data five distinct layers were identified. The layers are dry and unconsolidated sand, clayey sand, saline sand, saline clay and freshwater sand. The resistivity of the topsoil varies from 3259.59 Ohm-m on VES 2 - 67.04 Ohm-m on VES 12. The resistivity of the freshwater sand varies from 1649.76 Ohm-m on VES 6 - 158.28 Ohm-m on VES 10. The resistivity of the saline layer (saline sand/clay) varies from2.06 Ohm-m on VES 12 - 39.88 Ohm-m on VES 3. The depth to saline/freshwater interface varies from 12.97 m on VES 8 - 63.01 m on VES 5. The quality of groundwater varies from poor polluted saline water saturated sand/clay through intermediate water quality clayey sand/sand to freshwater sand. The interpreted results show saline water plumes where they occur in different part of the area investigated. The 1D and 2D results correlate to a very high degree indicating saline water intrusion between depth interval of 13 and 64 m in the study area. Two major freshwater aquifers (shallow 60 m) where delineated with most of them occurring unprotected. The results showed the effectiveness and usefulness of electrical resistivity and induced polarization method in mapping saline water intrusion problem in coastal areas. Key words: Geophysical investigation, saline water, aquifers, coastal terrain.

Dispersal of yellow phase Japanese eels Anguilla japonica after recruitment in the Kojima Bay-Asahi River system, Japan

Abstract: The density, size and age distribution were investigated for 233 eels, Anguilla japonica, sampled in fresh and brackish water areas of the Kojima Bay-Asahi River system, Okayama, Japan, to evaluate the possible patterns of dispersal of eels that recruit to this area. Migratory histories of 183 eels were categorized into 5 types depending on the Sr and Ca concentrations in their otoliths: (1) brackish water residents (74 fish, 40.4%), which settled in saline water and remained until capture; (2) freshwater residents (46 fish, 25.1%), which settled in freshwater and remained until capture; (3) upstream shifters (3 fish, 1.6%), which settled in saline water and moved upstream into freshwater; (4) downstream shifters (53 fish, 29.0%), which settled in freshwater and moved downstream into saline water; (5) multiple habitat shifters (7 fish, 3.8%), which shifted their habitats between freshwater and saline water more than twice. For eels captured in the brackish water area, fish density decreased with distance in the downstream direction, while the size and age of eels increased. For eels captured in the freshwater area, size and age were greater than those in the upper-most brackish site. These observations suggest that eels in this system initially accumulate in the lower reaches of the river and then disperse in both upstream and downstream directions following their growth.

Saline irrigation water management strategies for better yield of safflower (Carthamus tinctorius L.) in an arid region

Abstract: Water quality and irrigation strategies are important factors effecting crop production, especially in arid/saline soils. The effects of irrigation water salinity and irrigation management on safflower yield was studied in a field experiment in Isfahan province (central Iran). Three irrigation water salinity levels of 3.4, 8.8 and 11.2 dS m -1 , two irrigation water managements and two leaching levels of without leaching and with leaching levels of 6, 17, and 28.5 %, were used in a completely randomized block design, arranged as Split-Split plots with four replications for each treatment. The results showed that with higher levels of water salinity the yield components such as seed yield, biomass yield (dry weight), number of plant per hectare, 1000- seed weight, plant height, number of capitula per plant and capitula weight per plant were significantly decreased. Although, irrigation with high amount of salt in water (11.2 dS m -1 ) during the entire growth period reduced the yield, irrigating with water salinity of 3.4 dS m -1 , until plant emergence and then applying high irrigation water salinity levels significantly increased the yield components. Leaching application caused a significant increase in the yield and yield components, too. The salinity threshold value of 6.4 dS m -1 was obtained for safflower seed