Mechanical Technology January 2016

Mechanical Technology — January 2016

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On the cover

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Xylem: a leading global water

technology provider

ylem (XYL) is a leading global water

technology provider, enabling customers

to transport, treat, test and efficiently use

water in public utility, residential and commercial

building services, and industrial and agricultural

settings. The company does business in more

than 150 countries through a number of market-

leading product brands, and its people bring

broad applications’ expertise with a strong focus

on finding local solutions to the world’s most

challenging water and wastewater problems.

Xylem is headquartered in Rye Brook, New

York, with 2014 revenues of $3.9-billion and

about 12 500 employees worldwide. Xylem was

named in the Dow Jones Sustainability Index

for the last four years for advancing sustainable

business practices and solutions worldwide and

the company has satisfied the requirements to

be a constituent of the FTSE4Good Index Series

every year since 2013.

UV radiation is part of the natural light spectrum. Ultra-violet light with

high energy levels and a wavelength of 254 nm is most effective for cell

inactivation for water disinfection.

Photons from the UV light causes a reaction between the thymine bases,

causing them to react with one another to form double-bonded molecules

called dimers. These molecular lesions in the cell structure prevent the

microorganism from replicating, effectively making them harmless.

Aquada UV systems can be integrated into existing water pipeline systems

without any great effort.

their by-products in the treated water,”

he adds.

WEDECO’s Aquada UV system

The light necessary for UV disinfec-

tion is generated in special UV lamps

in watertight quartz tubes surrounding

each lamp. The liquid to be disinfected

is passed through a vessel with the UV

lamp at its centre. The low-pressure gas

plasma generated in the lamp emits light

with a primary wave length of 253.7 nm,

which passes though the surrounding

water flowing through the vessel.

The power required to generate the

UV is similar to that required by light

bulbs. For the Altima series Aquada1

system, for example, the smallest system

is powered by a 35 W UV lamp, while

the largest, the Aquada10 – capable of

disinfecting up to 10.52 m

/h of water

with a dose of 300 J/m

of UV – is pow-

ered by an 85 W lamp.

When this intensive UV light reaches

the microorganisms in the water, it di-

rectly impacts their DNA without causing

any other changes to occur.

There are several benefits to using the

Aquada UV-technology for homes and

businesses. Apart from the overall water

safety being improved, it is a low cost

solution and easy to install. The Aquada

system is simply connected to the main

water supply line and then provides UV-

treated water to all the water outlets on

the premises.

There are no harmful by-products and

the taste and appearance of the water

is not affected by the UV treatment.

UV lamps are also easy to replace and

only require replacement after a full year

of use.

“In spite of the low cost of the

investment, the Aquada UV system

offers significant benefits: it’s easy to

install, eco-friendly and uses no unsafe

chemicals to eliminate

harmful bacteria, viruses

and cysts from water.

The system is suitable

everywhere that drinking

water is taken from its

own sources, residen-

tial treatment plants for

water disinfection, as

well as in schools, res-

taurants, campgrounds,

hotels, hospitals and

more,” Crous says.

Aquada UV systems

are available in three

distinct models: Altima (economy);

Proxima (medium spec); and Maxima

(high spec). Each of these is available

in five different sizes for homes and

businesses; depending on the amount

of purified water required. A hotel, for

example, would require a high specifica-

tion Maxima model, whereas an average

household might only need the economi-

cal Altima model.

“UV disinfection of drinking water

is environmentally friendly and ex-

tremely efficient, hence it is no surprise

that, globally, this treatment technol-

ogy is gaining importance year on year.

WEDECO has already been providing the

municipal drinking water market with

its larger UV solutions for more than 12

years,” adds Crous.

“Xylem Water Solutions now offers

South African clients the opportunity to

obtain affordable Aquada UV systems

throughout the country. Technological in-

novation within the water cycle is forever

top of mind for Xylem – both globally and

here in South Africa,” he says.

“The new Aquada UV systems under-

score Xylem South Africa’s commitment

to provide global technology to clients

and to ensure that tailor-made solu-

tions are available to clients operating

within every part of the water cycle,” he

concludes.

As well as WEDECO, the company

boasts a range of pump and water treat-

ment systems and the brands within its

stable include Godwin; Flygt; Leopold;

Lowara and Sanitaire.