Recently a mainland landfill reportedly began leaking sewage into the Mai Po wetland, which is a timely reminder that rubbish doesn't simply disappear after it leaves our homes.
Every day an average of 13,901 tonnes of solid waste is added to Hong Kong landfills, and the government forecasts that all three will reach their maximum capacity by 2015. But not everything that ends up in our landfills is actually waste. Quite a bit of it could be put to use.
Arthur is a student from La Salle College
Although phosphorous and nitrogen can be removed by bacteria, complex synthetic products in industrial wastewater are not so easy to break down. But, in an illustration of the saying 'fight fire with fire', the ultimate solution to man-made waste may just be man-made scrap iron.
Scientists have shown that scrap iron can be used to remove toxic compounds in industrial wastewater. They discovered this remarkable solution after successfully treating industrial sewage using nano-iron. Now, with a small amount of copper chloride solution, scrap iron in landfill sites can be used to treat sewage water from factories. This method is currently used to treat industrial sewage in Shanghai.
Another problem that might have an unusual solution is the gases that are emitted from landfills.
The answer might be an abundant rock that 'eats' greenhouse gases. Peridotite is one of the main constituents of the Earth's upper mantle.
