European environmental legislation is driving the management of end-of-life products

away from traditional disposal methods towards increased resource efficiency and

greater sustainability through recycling. In particular, the imminent Waste Electrical

and Electronic Equipment (WEEE) Directive aims to encourage the need for higher

levels of recovery, and a target of 90 per cent has been set for all mercury-containing

lamps and bulbs.

Julia Ingleson, managing director of Recyclite, believes it is essential to

recycle every components to maximise the net gain to the environment, and avoid

landfill.

“Florescent tubes are made of several different materials. Apart from

the obvious glass and aluminium ends that can be seen, the tubes also contain

mercury vapour, a potent neurotoxin with the potential to build up in the food

chain. There is sufficient mercury in a single florescent tube to contaminate

30,000 litres of water beyond a safe level of drinking.”

Valuable resource

Florescent tubes work by passing an arc of electricity through mercury vapour

in the tube. The charged mercury atoms give off ultraviolet (UV) light, which

is then absorbed by a phosphor powder coating on the inside of the glass. When

energised these phosphors emit the white light that we see. To generate the

mercury vapour, a small amount of elemental mercury is added to each tube during

manufacture which is instantly vapourised when the lamp is turned on. It is

possible to see this small droplet of mercury by slowly tipping the tube back

and forth. Escape of mercury vapour when tubes are broken when crushed in landfill

also has implications with regard to the Pollution Prevention and Control (PPC)

regulations and Care of Substances Harmful to Health regulations. Mercury is

a valuable resource and it is therefore highly desirable to reclaim this material,

together with the glass and aluminium.

Ingleson: “The tubes are fed into a machine which crushes them in a contained

atmosphere, crudely separating the components. The glass is washed, with the

wastewater being continuously recycled, the aluminium ends separated, and a

sludge containing the mercury siphoned into a drum. This is later distilled

to extract pure mercury which can be reused to make more fluorescent tubes.

“One possible application for the recycled glass which we are currently

looking in to, is its use as ‘glasphalt’. Crushed glass can be used as a replacement

for up to 30 per cent natural aggregate in an asphalt basecourse material.”

And, in addition to providing an efficient lamp collection and recycling service,

Recyclite provides full documentary evidence that clients, anxious to prove

themselves green, can use to enhance their environmentally-friendly reputation.


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