Decomposing NOx with light“The world we live in faces a wide variety of problems ofglobal magnitude, from global warming to hunger and water
shortages resulting from rapid population growth. Ushio’s
light solutions are expected to play a role in alleviating one
aspect of such problems.” So says the development
manager of Ushio’s NOx* (nitrogen oxide) decomposition
technology.
Conducting collaborative research with university
laboratories and makers of environmental plants thatprocess waste materials, Ushio succeeded in developing theworld’s first technology capable of direct denitration of NOxat room temperature without use of a catalyst.
“NOx is a substance emitted in the exhaust of automobiles
and ships, diesel engines, fossil-fuel power stations, andwaste incineration facilities. It is a pollutant that causes
photochemical smog and acid rain. ‘Denitrification’ is theprocess of decomposing this harmful pollutant into harmless
nitrogen and water vapor. A variety of denitration methods
are already in existence, but they all require the use ofexpensive consumable catalysts or high temperatures inexcess of 900 degrees Celsius, making them difficult tointroduce in a world that is imposing more stringent controls
on emissions. However, Ushio’s technology allows a compact
device to render NOx harmless at ordinary temperatures
without the use of expensive catalysts.”
This technology is capable of eliminating SOx* (sulfur■ Depiction of VUV direct denitration
VUV irradiation
Vacuum ultraviolet lamp

Exhaust gas

Mixed gas
Exhaust gas mixed withammonia gas to bringabout a reaction

Excitation of ammonia gas byVUV induces a reaction withexhaust gas, resulting indenitration

Clean gas
Exhaust gas isdenitrified and cleangas discharged

Ammonia gas
Ammonia gas is mixed with exhaust gas and irradiated with VUV,
denitrifiying NOx at room temperature.

Environmentoxides) as well as NOx, and thus is attracting a lot ofattention as a means of preventing air pollution in a variety ofapplications.

Protecting the ecosystem with water
purification
In addition to technology for treating atmosphericpollutants, Ushio has taken up the challenge of treating waterpollution, an issue that adversely affects the ecosystem.
Take, for example, ballast water from ships. When sailing
unloaded, freighters and tankers must fill their holds withseawater in order to lower the ship’s center of gravity tomaintain stability. However, when this water is discharged in
preparation for loading the vessel, the organisms it carries
are introduced into a different environment, where they canbecome an invasive species that cause harm to the localecosystem. This has become a major problem.
“Foreign organisms not only threaten local fishingindustries, but present a risk of introducing disease-causing
bacteria, such as vibrio cholerae, which can enter the humanbody and cause illness. The International Maritime
Organization (IMO) has made it mandatory for new vessels tobe equipped with systems for treating ballast water. In
anticipation of this tightening of regulations, Ushio developed
an ultraviolet lamp and supporting power supply for use in
disinfecting ballast water carried by ships. Disinfection ofwater by light does not require the use of any chemicals, andthus does not introduce pollutants into the environment.”
Ushio’s ballast water disinfection solution has alreadybeen adopted by a number of shipbuilding companies.

Towards a world without water shortages
With more than 70% of its surface covered in water, theearth is sometimes referred to as the “water planet.”
However, only a limited amount of this water is suitable fordrinking or agricultural purposes, and problems such as
population growth and desertification threaten the world withwater shortages of ever increasing severity.

* NOx and SOx are atmospheric pollutants that cause
photochemical smog and acid rain. Emissions standards
have been tightened around the world due to healthconcerns.

With air and water pollutionincreasing, now is the time for us
to listen to the earth’s cry.
We can stave off environmental
pollution using light.

Protecting with LightVUV light source unit
for decomposing NOx/SOx
The world’s first method of
denitrifying NOx and SOx without
using catalysts or hightemperatures, VUV direct
denitrification technology is making
a big impact in the industry.

UV sterilizer for water treatment
Providing excellent processing
efficiency in a compact package,helps to reduce the cost of watersterilization processing.

Ushio’s vacuum ultraviolet lamp

Excimer lamp

UV-XEFL®

“It’s said that the English word ‘rival’ has its roots in theLatin ‘rivus,’ which means brook or stream. Access to waterin streams and rivers has been a source of human conflict
since ancient times. While water shortages can sometimes
be addressed by desalinization of seawater or transport offresh water, geographical considerations make thesesolutions too expensive in some places. Recycling systems
that pump used water back underground for reuse areefficient, but can make water unusable if the used watercontains harmful substances. However, the water used inrecycling systems can be rendered safe by treating it withultraviolet light, which is capable of killing bacteria andbreaking down carcinogens and other harmful substances.
With more research, improved filtration systems can be used
together with UV treatment for even more effective waterpurification.”
UV water treatment is already used in many countries
around the world, and now the method is starting to gain
recognition in Japan.

Environment“Domestically, treatment with chlorine is the currently
accepted method of disinfecting water. However, the parasite
known as Cryptosporidium is resistant to chlorine, and canbe more effectively eliminated by treatment with ultraviolet.
Ultraviolet has also been recognized as a method of dealing
with chlorine-resistant pathogens by Japan’s Ministry ofHealth, Labour and Welfare. Ushio’s ultraviolet light helps
resolve problems related to water quality in a variety of areas
beside drinking water, including the purification of water for
use in industries such as the manufacture of semiconductors
and chemicals. Water is a precious resource that is vital to all
our lives. We would like to achieve a world in which people
do not have to fight over water, or worry about the healtheffects of the water they drink.”
While desertification is increasing around the world,flooding and torrential rains also present a challenge to thesecuring and safety of water resources. In the near future,
ultraviolet water treatment technology may help provide asafety net for the protection of water resources.

Reducing CO2 with vacuum ultraviolet
It is a known fact that a characteristic of VUV (vacuumultraviolet) is its ability to break down carbon dioxide into its
constituent elements. Some dream of taking advantage ofthis characteristic to break down CO 2 , release its oxygen
component into the atmosphere and use the carbon that isfreed as an energy source. However, coal is nothing morethan altered plant matter, transformed over long periods oftime from plants that grow by taking up carbon dioxidethrough photosynthesis. Who can say that this is only adream?
Besides prevention of pollution and purification of water,
issues related to environmental protection abound. We would
like to pass on the beauty of nature to future generations,and help build a sustainable society. The environment is aproblem that transcends national borders, and Ushio istaking up the challenge with light.