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The look of Desalination and Natural Hazards
Arregoitia Sarabia, Carla Adriana
[email protected]
Figure 1 Projected Water Scarcity in 2025 [1]
Seawater Desalination process separates saline seawater into two streams: a fresh water stream with a low concentration of dissolved salts and a
concentrated brine stream. Technologies. Classified into: Non-membrane Technologies which use thermal energy such as multi-stage flash (MSF) and multieffect distillation (MED). This is the oldest and most commonly used method of desalination, and its distillation units routinely use designs that conserve as
much thermal energy as possible by interchanging the heat of condensation and heat of vaporization. The major energy requirement in the distillation process
thus becomes providing the heat for vaporization to the feed water. Membrane technologies: A selective membrane allows water to flow from one side to the
other leaving behind all impurities. The limiting factors are: feed stream characteristics, membrane cleaning, concentration polarization and fouling. Reverse
osmosis (RO) is becoming a popular process today. Other processes such as forward osmosis (FO) and the use of alternative energies are grabbing
researchers attention. Membrane technologies are preferred over thermal ones. They allow for continuous operations close to ambient temperatures and offer
a wider selection of large equipment and modules. This makes it possible to design processes according to potable water standards and ease the use of
membranes and other separation technologies together. Hybrid systems, nuclear energy and co-generation are also contemplated.
The most important aspects for a desalination plant are the location of the plant, brine disposal management and the energy considerations. However, this
can be sometimes affected by a natural adversity if no precautions are taken and turn desalination into a thread. A natural hazard is a random natural event
of unusual intensity that threatens people's lives or their activities. Atmospheric hazards are weather-related events, whereas geologic hazards happen on or
within the Earth's surface. It is important to understand that the capricious force of nature can trigger catastrophes that could impact households, communities
and even threaten life across the world depending on the desalination plant location. Los Angeles, Mexico city and Tokyo, are examples of large cities that
are very affected by earthquakes. Desalination plants in these locations could face many challenges. Other places however could face other type of events.
OBJECTIVE
A study on desalination plants and natural hazard
because they can either be a mitigation source for
water scarcity or be turned into a greater disaster.
INTRODUCTION
Desalination is considered a source for drinking water
and a mitigation action for water scarcity. The
increase of desalination plants is due to population
growth, climate change and water management [2].
However, little work has been undertaken to explore
the impact of desalination in the presence of a natural
hazard.
Many countries have started to use this technology.
As cities continue to expand their water supply gets
more difficult. The desalination capacity has increased
in the past years being Saudi Arabia in the top of the
list followed by the US, the UAE, Kuwait, Japan and
Spain among others.
Focus of the study. Population growth in countries
like China and India will remain high compared to
Mexico, Japan and Spain. Some of these countries
are more prone to certain natural hazards such as
earthquakes, hurricanes, tsunamis, etc.
Figure 2 Population Changes in China, India, Japan, Mexico and Spain in 2050 [3]
In the presence of a natural phenomenon, plant design, risk management and decision
making influence the path of the plant operation. Hazard mitigation strategies should
also be considered. The following approaches are suggested to be considered for the
natural hazard assessment: an evaluation of the location, severity, and probable
occurrence of a hazardous event in a given time period. Each point is not exclusive and
depends on the type of hazard, technology of the plant, energy used and location:1)
The sustainability of the plant could be endangered due to energy requirements. They
could be of any form of power energy such as thermal, electrical, mechanical, or
nuclear depending on the separation process. 2) Water production might be adversely
disrupted by the effects of the demand and lead to stress of the plant. 3) Feed water
can get mix with dust, brine, or other type of contaminated water if tanks are open. 4)
Brine control can become challenging. 5) Infrastructures damages can result in
ruptures, cracks, leaks, etc. 6) Stream contamination of surrounding rivers, lakes, etc.
and the plant itself changing the quality of the feed. 7) Fire can cause a major disaster.
8) Sewage system contamination. 9) Flooding in the case of heavy precipitation. 10) A
major nuclear disaster in the case of nuclear power and co-generation.
Type
Phenomenon
Atmospheric Hailstorms, hurricanes, lightning, tornadoes, tropical storms
Seismic
Fault ruptures, ground shaking, lateral spreading, liquefaction, tsunamis, seiches
Other
Debris avalanches, expansive soils, landslides, rock falls, submarine slides,
Geologic/Hyd subsidence
rologic
Figure 3 Countries with projects in construction with a more than 150,000m3/d capacity [4]
Hydrologic
Coastal flooding, desertification, salinization, drought, erosion and sedimentation,
river flooding, storm surges
Volcanic
Tephra (ash, cinders, lapilli), gases, lava flows, mudflows, projectiles and lateral
blasts, pyroclastic flows
Figure 4 World Desalination Capacity up to 2010 [5]
Wildfire
Brush, forest, grass, savannah
Table 1 Potentially Hazardous Natural Phenomena [6]
REMARKS AND RECOMMENDATIONS
The water demand created by the world population growth together with climate change
and water management have increased the number of desalination plants in the world.
Today there are different technologies used to desalinate and countries face different
natural hazards depending on their location. Desalination should consider these events
to prevent a worse disaster situation. To fully understand the risks, vulnerability, cost
and consequences of a desalination plant in the presence of a natural hazard a more
thorough study is recommended.
A Tsunami took place in north Japan as a consequence of a
magnitude 9 Earthquake on March 11, 2011 creating a nuclear
crisis. The dramatic event was considered as the biggest
disaster since WWII [7]. Nuclear desalination plant safety
depends mainly on the safety of the nuclear reactor and the
interface between the nuclear plant and the desalination
system [8]. In Japan, there are 53 nuclear pants and some ten
desalination facilities linked to pressurized water reactors
operating for electricity production yield some 14,000 m³/day of
potable water[9].Today the problem still remains.
REFERENCES
1. Schwikert, Shane et. al. Water Scarcity: Tomorrow´s Problems. U. of Michigan.
2.Bates, B.C.,et al. 2008: Climate Change and Water. Technical Paper of the Intergovernmental
Panel on Climate Change, IPCC Secretariat, Geneva
3.United Nations. The 2008 Revision Population Database.
4.Global Water Intelligence Desalination Tracker.
5.World Desalination Capacity up to 2010. UNEP/GRID-Arendal, Water desalination,
UNEP/GRID-Arendal Maps and Graphics Library,
6.Arthur M. et. al. Department of Regional Development and Environment. Executive Secretariat
for Economic and Social Affairs Organization of American States.1990 Disaster, Planning and
Development: Managing Natural Hazards to Reduce Loss.
7. The New York Times
8. World Nuclear Association (WNA)
9. International Atomic Energy Agency IAEA
10. Lentech Technologies
11. Younos, Tamim, et. al. Overview of Desalination Techniques. Journal of Contemporary Water
Resarch & Education (Virginia Polytechnic Institute and State University), no. 132 (Diciembre
2005): 3-10.
12. Charcosset, Catherine. A review of membrane processes and renewable energies for
desalination. Desalination 245, no. 1-3 (September 2009): 214-231