Mercury rising

One florescent lamp contains enough mercury to pollute 30,000 litres of water, yet they are regularly sent to landfill.

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.


Tags



Topics


Click a keyword to see more stories on that topic, view related news, or find more related items.

Comments

You need to be logged in to make a comment. Don't have an account? Set one up right now in seconds!


© Faversham House Group Ltd 2001. edie news articles may be copied or forwarded for individual use only. No other reproduction or distribution is permitted without prior written consent.