Bill Gates opens the HiTech toilet fair

Bill Gates, a billionaire and philanthropist, opened a new toilet fair in Beijing. The founder and former director of Microsoft's technological giant said the technologies to be presented at a three-day event are the most important advances in the sewers in nearly 200 years.

More than 20 companies and academic institutions present technology, from independent toilets to small plants in their waste management facility.

The Bill and Melinda Gates Foundation have spent more than $200m since 2011 to encourage research and development of a secure channeling technology.

U n NICEF estimates that 480,000 children die of diarrhea each year, often caused by food or water contaminated by sewage