China
Africa
Explore chapters and articles related to this topic
Hybrid Energy Systems for Water Industry
Published in Yatish T. Shah, Hybrid Energy Systems, 2021
In addition to less energy efficient, conventional desalination processes have enormous impact on marine life and environment in terms of volume of brine rejection and CO2 emissions. It is estimated that the brine rejection will increase to 240 km3, and emission will be approximately 400 million tons of carbon equivalents per year by 2050. In the Gulf, 23.7 metric tons (mt) of chlorine, 64.9 mt of antiscalants, and 296 kg of copper rejection are estimated from desalination installations, and in Red Sea, these rejections are 5.6 mt of chlorine, 20.7 mt of antiscalants, and 74 kg of copper [28]. Both SWRO and thermal desalination processes showed severe impact in terms of energy consumption, chemical rejection, and CO2 emission. Impact of SWRO processes is worse than thermal processes. Therefore, energy-efficient desalination processes (innovative hybrid cycles) and transitioning toward alternate renewable energies are two key innovation pillars needed to address future sustainable desalination water supplies in the region.
The Capability of Forward Osmosis in Irrigation Water Supply
Published in Iqbal M. Mujtaba, Thokozani Majozi, Mutiu Kolade Amosa, Water Management, 2018
Alireza Abbassi Monjezi, Maryam Aryafar, Alasdair N. Campbell, Franjo Cecelja, Adel O. Sharif
The lack of freshwater resources, in conjunction with population growth, forms one of the main impediments to sustainable development, while agriculture is the main consumer of freshwater resources. Currently, the production of desalinated water is costly and its use has therefore been limited to the production of water for drinking purposes. Forward osmosis desalination promises to overcome most of the practical difficulties in the conventional reverse osmosis process such as scaling, chemical treatment, fouling and high power consumption. In addition, forward osmosis is capable of delivering higher throughput with lower environmental impact, including minimal chemical additives and less brine rejection. Hence, the forward osmosis process offers a more energy efficient, environmentally friendly and economically viable desalination method. This study presented the forward osmosis process with thermal depression regeneration, using DME as a draw solution, leading to a significantly lower energy consumption rate in comparison with conventional desalination processes. The process of modified integrated forward osmosis with thermal depression has the potential to achieve a sustainable and cost-effective desalination solution to address the increasing scarcity of water for irrigation. The specific energy consumption of the proposed process was estimated to be 2.7 KWh/m3.
Implications of Long-Term Climate Change for Biogeography and Ecological Processes in the Southern Ocean
Published in S. J. Hawkins, A. J. Evans, A. C. Dale, L. B. Firth, I. P. Smith, Oceanography and Marine Biology, 2018
With a surface area of approximately 30 × 106 km2 (El-Sayed 2005), the Southern Ocean forms over 20% of the world ocean (Tomczak & Godfrey 2013) and is one of the most important drivers of world climate (Gille 2002), particularly through its role in the formation of Antarctic bottom water. Water dense enough to form the bottom water of the ocean interior can only be formed where surface evaporation caused by cold dry winds combines with ice formation and brine rejection to produce very cold, saline water (Longhurst 1998). This occurs in few places, including the Labrador and East Greenland Sea, and is a major driving force in global thermohaline circulation (Lutjeharms 1985). Bottom water is also formed in Antarctica at the Coastal Convergence Zone, where very dense ice-shelf water is transported beneath the warmer circumpolar deep water that upwells at the Antarctic Divergence. It has been argued that physical processes in the Southern Ocean largely control nutrient distribution to the rest of the world ocean (Ribbe 2004), and models suggest that nutrients supplied by the Southern Ocean may be responsible for three-quarters of biological production north of 30°S (Sarmiento et al. 2004a,b). As one of the three major high nitrogen low chlorophyll (HNLC) regions of the ocean, the Southern Ocean is also a huge potential sink for atmospheric CO2 (Falkowski et al. 1998), though ocean-atmosphere models of global warming suggest that this may be modified as increased rainfall would lead to greater stratification and a reduction in the downward flux of carbon and loss of heat to the atmosphere, both effects reducing oceanic uptake of CO2 (Sarmiento et al. 1998).
Copernicus Marine Service Ocean State Report, Issue 4
Published in Journal of Operational Oceanography, 2020
Karina von Schuckmann, Pierre-Yves Le Traon, Neville Smith, Ananda Pascual, Samuel Djavidnia, Jean-Pierre Gattuso, Marilaure Grégoire, Glenn Nolan, Signe Aaboe, Enrique Álvarez Fanjul, Lotfi Aouf, Roland Aznar, T. H. Badewien, Arno Behrens, Maristella Berta, Laurent Bertino, Jeremy Blackford, Giorgio Bolzon, Federica Borile, Marine Bretagnon, Robert J.W. Brewin, Donata Canu, Paola Cessi, Stefano Ciavatta, Bertrand Chapron, Thi Tuyet Trang Chau, Frédéric Chevallier, Boriana Chtirkova, Stefania Ciliberti, James R. Clark, Emanuela Clementi, Clément Combot, Eric Comerma, Anna Conchon, Giovanni Coppini, Lorenzo Corgnati, Gianpiero Cossarini, Sophie Cravatte, Marta de Alfonso, Clément de Boyer Montégut, Christian De Lera Fernández, Francisco Javier de los Santos, Anna Denvil-Sommer, Álvaro de Pascual Collar, Paulo Alonso Lourenco Dias Nunes, Valeria Di Biagio, Massimiliano Drudi, Owen Embury, Pierpaolo Falco, Odile Fanton d’Andon, Luis Ferrer, David Ford, H. Freund, Manuel García León, Marcos García Sotillo, José María García-Valdecasas, Philippe Garnesson, Gilles Garric, Florent Gasparin, Marion Gehlen, Ana Genua-Olmedo, Gerhard Geyer, Andrea Ghermandi, Simon A. Good, Jérôme Gourrion, Eric Greiner, Annalisa Griffa, Manuel González, Annalisa Griffa, Ismael Hernández-Carrasco, Stéphane Isoard, John J. Kennedy, Susan Kay, Anton Korosov, Kaari Laanemäe, Peter E. Land, Thomas Lavergne, Paolo Lazzari, Jean-François Legeais, Benedicte Lemieux, Bruno Levier, William Llovel, Vladyslav Lyubartsev, Pierre-Yves Le Traon, Vidar S. Lien, Leonardo Lima, Pablo Lorente, Julien Mader, Marcello G. Magaldi, Ilja Maljutenko, Antoine Mangin, Carlo Mantovani, Veselka Marinova, Simona Masina, Elena Mauri, J. Meyerjürgens, Alexandre Mignot, Robert McEwan, Carlos Mejia, Angélique Melet, Milena Menna, Benoît Meyssignac, Alexis Mouche, Baptiste Mourre, Malte Müller, Giulio Notarstefano, Alejandro Orfila, Silvia Pardo, Elisaveta Peneva, Begoña Pérez-Gómez, Coralie Perruche, Monika Peterlin, Pierre-Marie Poulain, Nadia Pinardi, Yves Quilfen, Urmas Raudsepp, Richard Renshaw, Adèle Révelard, Emma Reyes-Reyes, M. Ricker, Pablo Rodríguez-Rubio, Paz Rotllán, Eva Royo Gelabert, Anna Rubio, Inmaculada Ruiz-Parrado, Shubha Sathyendranath, Jun She, Karina von Schuckmann, Cosimo Solidoro, Emil V. Stanev, Joanna Staneva, Andrea Storto, Jian Su, Tayebeh Tajalli Bakhsh, Gavin H. Tilstone, Joaquín Tintoré, Cristina Toledano, Jean Tournadre, Benoit Tranchant, Rivo Uiboupin, Arnaud Valcarcel, Nadezhda Valcheva, Nathalie Verbrugge, Mathieu Vrac, J.-O. Wolff, Enrico Zambianchi, O. Zielinski, Ann-Sofie Zinck, Serena Zunino
Polynyas are openings within the sea-ice cover and are categorised as either a ‘sensible-heat polynya’ formed by melting of the sea ice in a region due to heating from the water below, or a ‘latent-heat polynya’ which is mechanically forced often by wind blowing the sea ice away from the coast (also called a ‘coastal polynya’) (Morales Maqueda et al. 2004). Winter polynyas play an important climatic role, through increased air-sea heat fluxes and sea-ice formation (Morales Maqueda et al. 2004). When polynyas form in winter, the ocean becomes exposed to the overlying, colder atmosphere, leading to rapid warming of the atmosphere affecting mesoscale atmospheric dynamics (e.g. Alam and Curry 1995; Fiedler et al. 2010; Tetzlaff et al. 2015). The subsequent cooling of the ocean may enhance sea-ice production and consecutive brine rejection into the underlying ocean. Such buoyancy loss may trigger cascading of dense water off the continental shelves and into the deep ocean (e.g. Ivanov et al. 2004), which is a mechanism that provides a substantial part of the Arctic cold halocline water (e.g. Cavalieri and Martin 1994; Winsor and Björk 2000) and ventilates the deep water of the Arctic Ocean (Martin and Cavalieri 1989; Swift et al. 1997; Schauer and Fahrbach 1999; Winsor and Björk 2000).
Copernicus Marine Service Ocean State Report
Published in Journal of Operational Oceanography, 2018
Karina von Schuckmann, Pierre-Yves Le Traon, Neville Smith, Ananda Pascual, Pierre Brasseur, Katja Fennel, Samy Djavidnia, Signe Aaboe, Enrique Alvarez Fanjul, Emmanuelle Autret, Lars Axell, Roland Aznar, Mario Benincasa, Abderahim Bentamy, Fredrik Boberg, Romain Bourdallé-Badie, Bruno Buongiorno Nardelli, Vittorio E. Brando, Clément Bricaud, Lars-Anders Breivik, Robert J.W. Brewin, Arthur Capet, Adrien Ceschin, Stefania Ciliberti, Gianpiero Cossarini, Marta de Alfonso, Alvaro de Pascual Collar, Jos de Kloe, Julie Deshayes, Charles Desportes, Marie Drévillon, Yann Drillet, Riccardo Droghei, Clotilde Dubois, Owen Embury, Hélène Etienne, Claudia Fratianni, Jesús García Lafuente, Marcos Garcia Sotillo, Gilles Garric, Florent Gasparin, Riccardo Gerin, Simon Good, Jérome Gourrion, Marilaure Grégoire, Eric Greiner, Stéphanie Guinehut, Elodie Gutknecht, Fabrice Hernandez, Olga Hernandez, Jacob Høyer, Laura Jackson, Simon Jandt, Simon Josey, Mélanie Juza, John Kennedy, Zoi Kokkini, Gerasimos Korres, Mariliis Kõuts, Priidik Lagemaa, Thomas Lavergne, Bernard le Cann, Jean-François Legeais, Benedicte Lemieux-Dudon, Bruno Levier, Vidar Lien, Ilja Maljutenko, Fernando Manzano, Marta Marcos, Veselka Marinova, Simona Masina, Elena Mauri, Michael Mayer, Angelique Melet, Frédéric Mélin, Benoit Meyssignac, Maeva Monier, Malte Müller, Sandrine Mulet, Cristina Naranjo, Giulio Notarstefano, Aurélien Paulmier, Begoña Pérez Gomez, Irene Pérez Gonzalez, Elisaveta Peneva, Coralie Perruche, K. Andrew Peterson, Nadia Pinardi, Andrea Pisano, Silvia Pardo, Pierre-Marie Poulain, Roshin P. Raj, Urmas Raudsepp, Michaelis Ravdas, Rebecca Reid, Marie-Hélène Rio, Stefano Salon, Annette Samuelsen, Michela Sammartino, Simone Sammartino, Anne Britt Sandø, Rosalia Santoleri, Shubha Sathyendranath, Jun She, Simona Simoncelli, Cosimo Solidoro, Ad Stoffelen, Andrea Storto, Tanguy Szerkely, Susanne Tamm, Steffen Tietsche, Jonathan Tinker, Joaquín Tintore, Ana Trindade, Daphne van Zanten, Luc Vandenbulcke, Anton Verhoef, Nathalie Verbrugge, Lena Viktorsson, Karina von Schuckmann, Sarah L. Wakelin, Anna Zacharioudaki, Hao Zuo
The northward flow of Atlantic Water is partly compensated by southward flow of colder and denser overflow water from the Nordic Seas to the northern North Atlantic, in addition to colder and less saline surface waters carried by the East Greenland Current (see Figure 3.2.1). The overflow of dense water consists of several branches; one through the Faroe-Shetland Channel (e.g. Borenäs and Lundberg 2004), one over the Iceland Faroe Ridge (Hansen and Østerhus 2000), and one through the Denmark Strait (e.g. Jochumsen et al. 2017), with the latter being the largest accounting for about 50% of the total overflow (Jochumsen et al. 2017). The dense water overflow (defined by σθ > 27.8) through these openings represents the integrated contribution from the dense water formation within the Arctic to the Arctic-North Atlantic exchanges. Such dense water formation mainly occurs in hotspots including the banks within the Barents Sea (Midttun 1985), Storfjorden in the Svalbard archipelago (e.g. Skogseth et al. 2008) and the area surrounding the archipelagos Franz Josef Land and Severnaya Zemlya (e.g. Martin and Cavalieri 1989), although some formation also takes place in the open ocean including the Greenland and Norwegian seas (e.g. Clarke et al. 1990). However, common to all the formation sites is the availability of Atlantic-derived water masses, which yields high enough salinities (typically S > 34.9) for the water masses to become dense enough to sink into the deep ocean through cooling and/or brine rejection associated with ice freezing.