The city's largest supplier of used alkaline batteries under a government recycling scheme has called on the authorities to expand the programme to cover acid batteries to minimise industrial waste.
The MTR Corporation, which will have contributed seven tonnes or about 1,500 alkaline batteries from last April to this July, is the city's largest contributor to the Environmental Protection Department's rechargeable battery recycling plan.
MTR rolling stock manager Morris Cheung Siu-wa said the company hoped to contribute another 50 tonnes of alkaline batteries in the next three years with the gradual replacement of old alkaline batteries on its various lines.
Mr Cheung hopes the government will consider recycling acid batteries in the near future. 'Our acid batteries are used mainly at train platforms and make up about 5 per cent of the company's rechargeable battery consumption.
'The [battery recycling] programme currently does not cover this and I would like to see that as the next step,' he said.
A government spokeswoman said the situation was being reviewed by the Environmental Protection Department to see if a 'separate community programme' for acid batteries should be implemented.
'The collection and recycling of acid batteries are very much different to those of rechargeable batteries, hence they are not included in the [programme]. There is some commercial recycling of acid batteries to recover lead,' she said.
The government has recovered 40 tonnes or 600,000 rechargeable alkaline batteries and has met its 10 per cent recovery target, Environmental Protection Department deputy director Michael Chiu Tak-lun said. The recovery target for the next two years would be 15 to 20 per cent, with 38 participating companies.
So far, 26 tonnes have been shipped to a contractor in South Korea where cobalt, nickel, cadmium and other metals will be recovered from the batteries and sold for reuse in stainless steel production, as magnetic alloys and in cadmium batteries, Dr Chiu said.
The MTR's seven tonnes of used alkaline batteries come from its Tung Chung and Airport Express lines, Mr Cheung said. The batteries are installed underneath carriages for use as backup lighting and control during power shortages.
Mr Cheung said that each of the MTR's 132 trains had three sets of 72 batteries, which can provide 110 watts of power for about 90 minutes. The batteries need to be changed every 15 years.
The railway company also recycles scrap metal.