scholarly journals Characterization of the Agricultural Supply of Desalinated Seawater in Southeastern Spain

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1233 ◽  
Author(s):  
Victoriano Martínez-Alvarez ◽  
Jose F. Maestre-Valero ◽  
Manuel J. González-Ortega ◽  
Belén Gallego-Elvira ◽  
Bernardo Martin-Gorriz

The increasing shortage of water for crop irrigation in arid and semiarid regions is encouraging the use of non-conventional resources. In the last decade, seawater desalination has consolidated its position as an alternative source to increase the supply for agricultural irrigation in Spain and Israel, where the farmers’ acceptance is progressively rising, despite the supply price being much higher than that of other conventional water sources. This article describes the current situation of desalinated seawater production and supply to agriculture in the southeast of Spain, and analyzes key questions such as its role in regional water planning, the infrastructure needed for conveyance and distribution, the energy requirements, the production and distribution costs, and the final price to farmers. The study is based on descriptive and quantitative data collected from desalination plants and irrigation district managers through technical questionnaires and personal interviews. The results show how seawater desalination is effectively alleviating the regional constraints in the irrigated agriculture supply, and why it is becoming strategic to maintaining food production and socioeconomic development. However, the high-energy requirements and associated costs in comparison with other water sources limit a more widespread use for agriculture, and for this reason desalinated water still only plays a complementary role in most irrigation districts.

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2085 ◽  
Author(s):  
Sola ◽  
Sánchez-Lizaso ◽  
Muñoz ◽  
García-Bartolomei ◽  
Sáez ◽  
...  

Seawater desalination represents an alternative solution to face the challenge of water scarcity in Chile. However, the uncertainty toward potential environmental impacts of desalination plants represent a barrier to achieving water sustainability and socioeconomic development in Chile. This study aimed to assess the quality of environmental monitoring plans (EMP) and determine the aspects to be improved within it, in order to enhance the management of desalination plants during the operation phase and guarantee a sustainable development of the activity. The Environmental Impact Assessments (EIAs) and Environmental Impact Studies for seawater desalination projects published in the Environmental Impact Evaluation System (SEIA) in Chile between 1997 and 2018 were reviewed. The results of the brine production from desalination plants showed a significant increase in the last decade (about 1.6 Mm3 per year estimated according to the projects approved or under implementation). The EMPs data show heterogeneity and increasing requirements over time, which can be attributed to the governmental effort to improve environmental protection. Furthermore, a high frequency of irrelevant descriptors was identified in the current EMPs. The study thus recommended standardizing the environmental requirements included in EMPs based on empiric scientific knowledge to enhance the environmental protection programs in Chile.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 641
Author(s):  
Vânia Pôjo ◽  
Tânia Tavares ◽  
Francisco Xavier Malcata

One of the main goals of Mankind is to ensure food system sustainability—including management of land, soil, water, and biodiversity. Microalgae accordingly appear as an innovative and scalable alternative source in view of the richness of their chemical profiles. In what concerns lipids in particular, microalgae can synthesize and accumulate significant amounts of fatty acids, a great fraction of which are polyunsaturated; this makes them excellent candidates within the framework of production and exploitation of lipids by various industrial and health sectors, either as bulk products or fine chemicals. Conventional lipid extraction methodologies require previous dehydration of microalgal biomass, which hampers economic feasibility due to the high energy demands thereof. Therefore, extraction of lipids directly from wet biomass would be a plus in this endeavor. Supporting processes and methodologies are still limited, and most approaches are empirical in nature—so a deeper mechanistic elucidation is a must, in order to facilitate rational optimization of the extraction processes. Besides circumventing the current high energy demands by dehydration, an ideal extraction method should be selective, sustainable, efficient, harmless, and feasible for upscale to industrial level. This review presents and discusses several pretreatments incurred in lipid extraction from wet microalga biomass, namely recent developments and integrated processes. Unfortunately, most such developments have been proven at bench-scale only—so demonstration in large facilities is still needed to confirm whether they can turn into competitive alternatives.


Author(s):  
OO Sinitsyna ◽  
VV Turbinsky ◽  
TM Ryashentseva ◽  
EP Lavrik

Background. Uneven distribution of fresh water sources on the land surface encourages a search for effective techniques of potable water preparation by desalination of seawater. Hygienic issues of such desalination methods as distillation, reverse osmosis, electrodialysis, and ion exchange have been investigated by now and appropriate limitations, requirements, and additional measures to ensure safety of desalinated drinking water have been established. Objective. To summarize and systematize the results of studying characteristics of various methods of seawater desalination for its further use for drinking and household purposes. Materials and methods. We conducted a systematic review of studies published in Russian and in English, found in the PubMed and Web of Science databases, and selected 40 literary sources containing an empirical assessment of effectiveness of seawater desalination and preparation of drinking water. We also scrutinized regulatory documents and guidelines of domestic sanitary legislation. The research results were systematized by the main desalination methods. Results and discussion. We established that the use of seawater for the preparation of fresh water for drinking and household purposes is becoming increasingly widespread around the world. Drinking water obtained from seawater, in all cases, requires additional treatment and measures to optimize its mineral composition and protect against microorganisms. Conclusion. The main challenges of ensuring sanitary and epidemiological wellbeing of the population when using desalinated seawater for drinking and household purposes include selection of a source, arrangement of sites of water intake properly protected from natural and man-made pollution, substantiation of techniques and modes of preliminary preparation of source seawater adequate to its composition, basic desalination, ensuring safety of products of destruction and migration of toxic substances from reagents and materials of desalination plants, additional conditioning with the necessary elements and disinfection of the prepared water, as well as environmental protection from desalination waste.


Author(s):  
Prachanda Pradhan

By 2050, Asia will have to face the challenge of feeding 1.5 billion extra populations. Similarly, the population of Nepal, 26 million in 2011, will also be double by 2050. Food demand will be increasing corresponding to the increase of the population. Nepal’s irrigation sector must first be revitalized to unlock its potential by introducing innovative practices and changing the ways it is governed and managed. Irrigated agriculture holds great potentiality to meet the development challenges and key to increased agriculture production to feed the growing population of Nepal. Besides, increasing the agriculture production, irrigation helps promote Green Revolution, contributes for poverty alleviation, and helps promote rural growth, and food security among people. Dilapidated irrigation systems affects on all these fronts of development issues. It is, therefore, necessary to revitalize the irrigation sector to feed growing population, to ensure livelihood and poverty alleviation and maximize the benefit of available natural resources like water to get more production from limited land availability.Hence, the revitalizing irrigation systems to meet the food demands of the future are to be considered in an integrated manner consisting infrastructure rehabilitation, investment to raise yield productivity from irrigated land and promotion of appropriate institutions and innovative management modes. There are different agencies that influence the policy and implementation of irrigation sector of Nepal. The central agency is necessary for planning, investment, monitoring, and evaluation of the sector in the larger context. At present, one feels the absence of such central agency which overlooks the overall irrigation sector in compassing all sizes and types and technologies as the national resources.Pigs are neglected domestic animal species reared under poor care and management. Chwanche, Hurra and Bampudke are major native pigs of Nepal whereas Landrace, Yarkshire, Pakhribash Black, Tamworth and Durock are the introduced pigs. A survey was conducted in selected districts of Nepal in order to understand feeding system of indigenous pigs and also collect feed samples for chemical analysis. In all surveyed sites, the pig herd size was relatively small (2-4/farm). Kitchen waste from home or hotel, local seasonal vegetable or fruit i.e. non-consumable for human being, local sweet potato and their vines (in few areas), roots and tubers and their leaves such as- Pindalu (Clocasea sps), Sweet potato (Ipomoea batatus L), Turnip (Brassia rape) and Radish (Raphnes sativa L), rice bran and maize fl our were the major feed ingredients. Sweet potato had high energy content as compared to other roots and tubers and was comparable to rice bran and maize which are the major sources of energy in livestock feeds. Findings thus indicated that roots and tubers in rural areas could be an alternative as of energy rich feed ingredients which could be utilized if maize and rice bran are expensive and unavailable. Further research on level of feeding, conservation technique and varietals improvement is needed. DOI: http://dx.doi.org/10.3126/hn.v11i1.7202 Hydro Nepal Special Issue: Conference Proceedings 2012 pp.42-43


Author(s):  
Weerana Eh Kan ◽  
Jamil Roslan ◽  
Ruzinah Isha

<p>Conservative desalination technology including distillation requires high energy and cost to operate. Hence, pretreatment process can be done prior to desalination to overcome energy demand and cost reduction. Objective of this research is to study the effect of calcination temperature of hybrid catalyst in photocatalytic reactor system in the seawater desalination, i.e. salt removal in the seawater. The catalyst was synthesized via wet impregnation method with 1:1 weight ratio of TiO<sub>2</sub> and activated oil palm fiber ash (Ti:Ash). The catalyst was calcined at different temperature, i.e. 500 <sup>o</sup>C and 800 <sup>o</sup>C. The study was carried out in a one liter Borosilicate photoreactor equipped with mercury light of 365 nanometers for two hours with 400 rpm mixing and catalyst to seawater sample weight ratio of 1:400. The Chemical Oxygen Demand (COD), pH, dissolved oxygen (DO), turbidity and conductivity of the seawater were analyzed prior and after the testing. The fresh and spent catalysts were characterized via X-Ray Diffractogram (XRD and Nitrogen physisorption analysis. The calcination temperature significantly influenced the adsorption behaviour and photocatalytic activity. However, Ti:Ash which calcined at 800 <sup>o</sup>C has less photocatalytic activity. It might be because the surface of fiber ash was sintered after calcined at high temperature. The Ti:Ash catalyst that calcined at 500 <sup>o</sup>C was found to be the most effective catalyst in the desalination of seawater by reducing the salt concentration of more than 9 % compared to Ti:Ash calcined at 800 <sup>o</sup>C. It can be concluded that catalyst calcination at 500 °C has better character, performance and economically feasible catalyst for seawater desalination. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 22<sup>nd</sup> January 2016; Revised: 23<sup>rd</sup> February 2016; Accepted: 23<sup>rd</sup> February 2016</em></p><strong>How to Cite:</strong> Kan, W.E., Roslan, J., Isha R. (2016). Effect of Calcination Temperature on Performance of Photocatalytic Reactor System for Seawater Pretreatment. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (2): 230-237 (doi:10.9767/bcrec.11.2.554.230-237)<p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.11.2.554.230-237</p>


Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 781
Author(s):  
Federico Leon ◽  
Alejandro Ramos ◽  
S. Ovidio Perez-Baez

This article shows the optimization of the reverse osmosis process in seawater desalination plants, taking the example of the Canary Islands, where there are more than 320 units of different sizes, both private and public. The objective is to improve the energy efficiency of the system in order to save on operation costs as well as reduce the carbon and ecological footprints. Reverse osmosis membranes with higher surface area have lower energy consumption, as well as energy recovery systems to recover the brine pressure and introduce it in the system. Accounting for the operation, maintenance and handling of the membranes is also important in energy savings, in order to improve the energy efficiency. The energy consumption depends on the permeate water quality required and the model of the reverse osmosis membrane installed in the seawater desalination plant, as it is shown in this study.


2020 ◽  
Vol 165 ◽  
pp. 01003
Author(s):  
Tongyao Miao ◽  
Zheng Fang ◽  
Lingzhi Feng ◽  
Yunhui Peng

As is well-known, the problem of fresh water has always been a major problem for ocean navigation. The existing marine seawater desalination equipment generally has the disadvantages of large volume, high energy consumption and easy to pollute the environment. Based on this, we proposed a small seawater desalination system based on phase change to enhance heat transfer, which realized low temperature and low energy consumption by using the loop heat pipe technology, a new type of heat sink type spoiler evaporator and an integrated equal-heat plate fin condenser. The device is suitable for islands, fishing boats and other complicated areas where power is scarce and fresh water resources are scarce. It can also be used as fresh water emergency equipment for large ships, saving energy and being portable.


Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 858 ◽  
Author(s):  
José M. Rodríguez-Flores ◽  
Josué Medellín-Azuara ◽  
Ramón Valdivia-Alcalá ◽  
Oscar A. Arana-Coronado ◽  
Roberto C. García-Sánchez

An economic assessment of the value of agricultural water was conducted at the subdistrict (module) level within the Alto Rio Lerma Irrigation District 011 in Guanajuato, Mexico. The assessment employed positive mathematical programming (PMP), a deductive valuation methodology, which self-calibrates to baseline production input use. Production and water use values for the 2016–2017 agricultural year, and the averages of the 2014 to 2017 agricultural years for yields, agricultural commodity prices, and production costs were employed disaggregated per irrigation module. Results indicate that the economic value of water is 1.8 to 4.7 times higher than the rate currently paid by users, about US$7.89 dam−3 (cubic decameters). The differences among the rate and shadow prices could create a pricing water policy focused on water conservation and its efficient use. This work also conducts an assessment of a formal water market in the irrigation district as way to achieve economically efficient water allocations and reduce the potential economic impacts of water shortage during droughts. Modeling results show that an active water market would allow the irrigation district to adapt to scarcer water conditions by shifting cropping patterns and trading water among subdistricts, by reducing loss in net income at the irrigation district. A successful implementation of this system would be feasible, provided that the irrigation modules are able to import and export water, under water scarcity scenarios considered for the water market model. Potential distributional effects and policy insights from this assessment are discussed.


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