Nieuws - 7 juni 2007

Wasting water worse than greenhouse effect

Many people have seen Al Gore's film on climate change, An Inconvenient Truth, with its images of environmental doom. ‘A waste of energy,’ was Professor Jules van Lier’s comment during his inaugural lecture to mark his appointment as Professor of Anaerobic Wastewater Treatment at Wageningen University, an endowed chair.

‘Why do we confront people with a doom scenario for something we can no longer do anything about?” The CO2 will end up in the atmosphere anyway, according to Van Lier. Whether the Netherlands reduces its greenhouse gas emissions by half or not, any savings will be negated by the fuel guzzling of the rising economies of China and India. Added to that, the climate models do not provide any conclusive evidence of the direction of the developments. ‘It’s equally possible that global warming will lead to an ice age.’

‘What’s more important is that the supply of natural resources is drying up,’ said Van Lier. ‘In a hundred years we are going to run into problems: if we don’t look for alternatives now, we are going to end up in a situation where raw materials are monopolised, and that will lead to social unrest and conflicts.’ Humanity has to think up smarter ways of using available natural resources. For example, the supply of water is not unlimited. ‘At present the western world wastes water on a massive scale through toilet use, industrial wastewater and agricultural production.’

We have to start thinking in water chains, suggested Van Lier. ‘It’s the only way we can make big savings. At present we flush toilets with water that is fit for drinking. This dilutes solid waste, which makes the wastewater much more difficult to treat than when the faecal waste remains concentrated. By simply separating faecal waste from the rest of the wastewater system and catching it in tanks, we would need less energy to treat the rest of the household wastewater. It would also then be possible to use anaerobic methods to get methane gas out of the faecal waste in the tank.’

The irony according to Van Lier is that at present the western world exports its wastewater treatment systems to third world countries through development projects. ‘The intentions are good, but this way our problems are introduced to other parts of the world. Why should sewage water in Africa be purified for drinking water if that means throwing away valuable nutrients that could be used in agriculture? It is far better to think up integral solutions with the people there that fit their situation.’ / Teun Hofmeijer - Photo Hans Dijkstra