scholarly journals Irrigation management strategies through the combination of fresh water and desalinated sea water for banana crops in El Hierro, Canary Islands

Author(s):  
Sergio J. Álvarez-Méndez ◽  
Isidro Padrón-Armas ◽  
Jalel Mahouachi

Abstract The current lack of natural water resources, mainly due to the absence of sufficient precipitation and the deterioration of irrigation water (IW) quality, urges to search for alternative resources, especially in arid and semiarid areas. Desalination of sea water is well established in numerous regions where water is scarce. To investigate the effects of the combination of regular fresh water and desalinated sea water (DSW) on mineral nutrient changes in crops, an experimental system based on Musa acuminata AAA plants was performed in Frontera (El Hierro, Canary Islands). Data showed that banana crops irrigated with a mixture of fresh water and DSW exhibited an adequate nutritional status and did not suffer any injuries of salt ions (Na+ and Cl−) or B toxicity. Moreover, plants may tolerate higher concentrations of these elements and a major supply of the other essential micronutrients. The obtained results suggest that irrigating crops with a combination of fresh water and DSW is a good strategy to respond to the high water requirements, at least under the tested experimental conditions. This strategy could be very helpful in arid regions, as well as in other areas where precipitation is seasonal and scarce, like the Mediterranean or the Canaries.

1951 ◽  
Vol 8b (3) ◽  
pp. 164-177 ◽  
Author(s):  
Virginia Safford Black

Changes in body chloride, density and water content of chum and coho salmon fry were measured when these fish were transferred from fresh water to sea water, and the reverse. Both species tolerated 50% sea water (8–9‰ Cl). Chum fry survived direct transfer from fresh water to sea water (15–17‰ Cl), but showed a marked increase in body chloride during the first 12 hours, followed by a return to the normal range between 12 and 24 hours. Coho, however, died within the first 36 hours, after a 60% increase in chloride. Coho fry lost more water than chum fry after introduction to sea water. The density of both species approximated that of the water within an hour of transfer to the new medium. When returned to fresh water after 12 hours in sea water the body chloride, density, and water content of both species regained normal levels within 10 hours. Chum salmon go to sea as fry, whereas cohos remain in fresh water a year or more. Although coho fry seem capable of some adjustment to sea water after a preliminary period in 50% sea water, permanent acclimatization could not be demonstrated under the experimental conditions.


1964 ◽  
Vol 41 (3) ◽  
pp. 665-677
Author(s):  
MARY E. TODD

1. Osmotic balance was studied in Hydrobia ulvae and Potamopyrgus jenkinsi over the range 100% sea water to fresh water, by determining the freezing-point depression of the urine in the different solutions. 2. Hydrobia ulvae was slightly hyperosmotic from 100 to 50% sea water, and sometimes initially markedly hyperosmotic in 25% sea water at 5°C. The urine was always markedly hyperosmotic relative to fresh water, and the animals were withdrawn. Experiments with phenol red indicated that the tissues were not shut off from the medium. 3. Potamopyrgus jenkinsi was hyperosmotic from fresh water to 100% sea water. Osmotic balance in fresh water is maintained in part by the excretion of a urine hypo-osmotic relative to the blood. 4. There was some variation in the reaction of different ecological groups of Hydrobia ulvae and Potamopyrgus jenkinsi to the experimental conditions. 5. In the Hydrobiidae, whether transformed from a lower to a higher salinity or vice versa, survival outside the viable range was longer at 5°C. than at 15°C., although, within the range, activity occurred more rapidly at 15°C. 6. In fresh water, winter animals of both species had a higher osmotic concentration of the urine than summer animals, but no differences in osmotic concentration correlated with temperature were demonstrated.


Author(s):  
Olga Mashukova ◽  
Olga Mashukova ◽  
Yuriy Tokarev ◽  
Yuriy Tokarev ◽  
Nadejda Kopytina ◽  
...  

We studied for the first time luminescence characteristics of the some micromycetes, isolated from the bottom sediments of the Black sea from the 27 m depth. Luminescence parameters were registered at laboratory complex “Svet” using mechanical and chemical stimulations. Fungi cultures of genera Acremonium, Aspergillus, Penicillium were isolated on ChDA medium which served as control. Culture of Penicillium commune gave no light emission with any kind of stimulation. Culture of Acremonium sp. has shown luminescence in the blue – green field of spectrum. Using chemical stimulation by fresh water we registered signals with luminescence energy (to 3.24 ± 0.11)•108 quantum•cm2 and duration up to 4.42 s, which 3 times exceeded analogous magnitudes in a group, stimulated by sea water (p < 0.05). Under chemical stimulation by ethyl alcohol fungi culture luminescence was not observed. Culture of Aspergillus fumigatus possessed the most expressed properties of luminescence. Stimulation by fresh water culture emission with energy of (3.35 ± 0.11)•108 quantum•cm2 and duration up to 4.96 s. Action of ethyl alcohol to culture also stimulated signals, but intensity of light emission was 3–4 times lower than under mechanical stimulation. For sure the given studies will permit not only to evaluate contribution of marine fungi into general bioluminescence of the sea, but as well to determine places of accumulation of opportunistic species in the sea.


2018 ◽  
Vol 3 (2) ◽  
pp. 38-47
Author(s):  
Muhammad Abdul Azis ◽  
Nuryake Fajaryati

This research aims to create a Reosquido desalination tool for evaporation methods using a microcontroller. This tool can control the temperature to speed up the evaporation process in producing fresh water. The method applied to Reosquido desalination uses Evaporation. The first process before evaporation is the detection of temperature in sea water that will be heated using an element heater. The second process of temperature measurement is to turn off and turn on the Arduino Uno controlled heater, when the temperature is less than 80 ° then the heater is on. The third process is evaporation during temperatures between 80 ° to 100 °, evaporation water sticks to the glass roof which is designed by pyramid. Evaporated water that flows into the reservoir is detected by its solubility TDS value. The fourth process is heater off when the temperature is more than 100 °. Based on the results of the testing, the desalination process using a microcontroller controlled heater can speed up the time up to 55% of the previous desalination process tool, namely manual desalination prsoes without using the heater element controlled by the temperature and controlled by a microcontroller which takes 9 hours. Produces fresh water as much as 30ml from 3000ml of sea water, so that it can be compared to 1: 100.


Geomorphology ◽  
2021 ◽  
Vol 381 ◽  
pp. 107661
Author(s):  
Mauro Rossi ◽  
Roberto Sarro ◽  
Paola Reichenbach ◽  
Rosa María Mateos

Membranes ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 377
Author(s):  
Federico Leon ◽  
Alejandro Ramos-Martin ◽  
Sebastian Ovidio Perez-Baez

The water situation in the Canary Islands has been a historical problem that has been sought to be solved in various ways. After years of work, efforts have focused on desalination of seawater to provide safe water mainly to citizens, agriculture, and tourism. Due to the high demand in the Islands, the Canary Islands was a pioneering place in the world in desalination issues, allowing the improvement of the techniques and materials used. There are a wide variety of technologies for desalination water, but nowadays the most used is reverse osmosis. Desalination has a negative part, the energy costs of producing desalinated water are high. To this we add the peculiarities of the electricity generation system in the Canary Islands, which generates more emissions per unit of energy produced compared to the peninsular generation system. In this study we have selected a desalination plant located on the island of Tenerife, specifically in the municipality of Granadilla de Abona, and once its technical characteristics have been known, the ecological footprint has been calculated. To do this we have had to perform some calculations such as the capacity to fix carbon dioxide per hectare in the Canary Islands, as well as the total calculation of the emissions produced in the generation of energy to feed the desalination plant.


Author(s):  
Juan C. Santamarta ◽  
Luis E. Hernández-Gutiérrez ◽  
Jesica Rodríguez-Martín ◽  
Anastasia Hernández Alemán ◽  
José Luis Gutiérrez Villanueva ◽  
...  

2014 ◽  
Vol 592-594 ◽  
pp. 2409-2415 ◽  
Author(s):  
S. Naga Sarada ◽  
Banoth Hima Bindu ◽  
Sri Rama R. Devi ◽  
Ravi Gugulothu

In recent years with the exacerbation of energy shortage, water crisis increases around the world. With the continuous increase in the level of greenhouse gas emissions, the use of various sources of renewable energy is increasingly becoming important for sustainable development. Due to the rising oil price and environmental regulations, the demand of utilizing alternative power sources increased dramatically. Alternative energy and its applications have been heavily studied for the last decade. Energy and water are essential for mankind that influences the socioeconomic development of any nation. Pure water resources become more and more scarce every day as rivers, lakes wells and even seawater pollution rapidly increases. Solar energy is one promising solution to secure power and potable water to future generation. The process of distillation can be used to obtain fresh water from salty, brackish or contaminated water. Water is available in different forms such as sea water, underground water, surface water and atmospheric water. Clean water is essential for good health. The search for sustainable energy resources has emerged as one of the most significant and universal concerns in the 21st century. Solar energy conversion offers a cost effective alternative to our traditional usages. Solar energy is a promising candidate in many applications. Among the alternative energy sources used for electricity production, wind and solar energy systems have become more attractive in recent years. For areas where electricity was not available, stand alone wind and solar systems have been increasingly used. The shortage of drinking water in many countries throughout the world is a serious problem. Humankind has depended for ages on river, sea water and underground water reservoirs for its fresh water needs. But these sources do not always prove to be useful due to the presence of excessive salinity in the water. To resolve this crisis, different methods of solar desalination have been used in many countries. Distillation is a well known thermal process for water purification, most importantly, water desalination. Most of the conventional water distillation processes are highly energy consuming and require fossil fuels as well as electric power for their operation. Single basin solar still is a popular solar device used for converting available brackish or waste water into potable water. Because of its lower productivity, it is not popularly used. Numbers of works are under taken to improve the productivity and efficiency of the solar still. There are large numbers of PCMs that melt and solidify at wide range of temperatures, making them attractive in a number of applications. PCMs have been widely used in latent heat thermal storage systems for heat pumps, solar engineering and spacecraft thermal control applications. The use of PCMs for heating and cooling applications for buildings has been investigated within the past decade. The experimental results computed in the field of water distillation process using solar energy in the presence of energy storage materials sodium sulphate and sodium acetate are discussed in this paper. Keywords: solar energy, saline water, distillation, phase change material.


2014 ◽  
Vol 199 (3) ◽  
pp. 1739-1750 ◽  
Author(s):  
Araceli García-Yeguas ◽  
Jesús M. Ibáñez ◽  
Ivan Koulakov ◽  
Andrey Jakovlev ◽  
M. Carmen Romero-Ruiz ◽  
...  

2013 ◽  
Vol 40 (12) ◽  
pp. 4411-4419 ◽  
Author(s):  
Alejandra C. Ordóñez ◽  
M. Arnay-de-la-Rosa ◽  
R. Fregel ◽  
A. Trujillo-Mederos ◽  
J. Pestano ◽  
...  

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