Dutch scientist Gatze Lettinga has been awarded the Tyler Environmental Prize for a wastewater treatment system that is making an impact in the developing world. Mike O'Sullivan reports, the process offers inexpensive treatment of industrial waste and sewage in countries that cannot afford centralized systems.
The world needs to become more sustainable, say Gatze Lettinga, and his system helps by removing pollutants from sewage, wasting less water than conventional treatment, while extracting useful resources from the waste.
"We consider waste as a resource, so what we want using the system is to valorize, put to value, all kinds of residues which we indicate as waste, including wastewater," said Gatze Lettinga.
The process is anaerobic, which means it relies on bacteria that exist without oxygen. The system, called Upflow Anaerobic Sludge Blanket or UASB, produces energy in the form of methane, and extracts ammonia, phosphate and potassium, which can be used as fertilizer. Lettinga says there were technological hurdles, but the basic process is simple, and that so-called waste digesters can be placed in a large building, in a village or neighborhood.
He says the system was developed for agricultural industries in Holland, and there are industrial installations around the world today.
"Brazil, they have installations," he said. "India, China. Developing countries are going to use it for industrial wastewater treatment."
Just as importantly, he says, developing countries are using the system to treat domestic waste, and a demonstration facility has been built in Cali, Colombia.
The Tyler Prize is administered by the University of Southern California and overseen by environmental researcher Linda Duguay. She says the process developed by Lettinga and his team conserves precious water by processing waste close to its point of origin, and also reduces pollution.
"His engineering work basically developed a system that was very economical, very effective, and he had been educating people from the developing world and having those systems built in the developing world," said Linda Duguay.
Lettinga refused to patent the system so it would be freely available throughout the developing world.
The system is being used in an experimental village in Holland, a collection of houses and greenhouses that together form an independent energy zone. Waste from the homes is collected and processed to create bio-gas, which produces electricity. Nutrients from the waste are used as soil conditioners. Carbon dioxide from the process is introduced into the greenhouses to help the vegetation. The sun provides heat, and an aquifer helps regulate temperature.
The scientist wants sustainable systems like this to become the norm.
"That is what I hope," he said. "I think we have to move for our children everywhere in a kind of a society, a social system, which is really more democratic, I mean bottom up with respect to all kind of important basic things for citizens, that we can decide ourselves."
Lettinga says in this age of globalization, some of the best solutions to our environmental problems may be locally implemented.
