Tata Group boss Ratan Tata launches the purifier

The Indian industrial conglomerate Tata Group has launched a new low-cost water purifier, aimed at lower-income households in rural areas.

The Tata 'Swach' purifier is less than one metre tall, and does not need running water or electricity to work.

The firm is hoping to revolutionise the business of providing clean water, a lack of which affects almost one billion people globally.

Tata says the device is the result of a decade of research and development.

The Tata Group includes India's largest carmaker Tata Motors, and also has interests in steelmaking, IT, and chemicals.

Major hurdle

Its Swach water device - named after the Hindi word for clean - will cost under 1,000 rupees ($21.50; £13), according to one Indian report.

This is opening up a complete new market Tata Chemicals' boss R. Mukundan Water shortages forge huge market

According to the latest Indian government survey of rural wages, in 2007/08, daily pay in rural areas can range from about 45 rupees a day for herd-keeping, to about 110 rupees a day for well digging.

The Swach uses ash from rice milling to filter out bacteria, and also uses tiny silver particles to kill harmful germs that can lead to diseases like diarrhoea, cholera and typhoid.

The health consequences of poor water quality are enormous for developing countries like India, with millions of people affected.

Trying to provide safe drinking water for them has cost the government billions of rupees, but it continues to be a major hurdle.