Science - June 10, 2004

Argentinian environmentalist helps half a million city dwellers

Whether building his own wastewater treatment-system or introducing battery recycling for half a million city dwellers, the Argentinian Dr Lucas Seghezzo, keeps on working for the common good. 'I like to apply scientific discoveries to everyday environmental policy.'

In the winter of 2002 an economic crisis hit Argentina. Lucas Seghezzo was working on his PhD project in the city of Salta, situated in the foothills of the Andes in north-western Argentina. Many people saw their savings devalue to almost nothing, but Seghezzo was lucky. With a foreseeing eye, he had changed his Argentinian pesos a few months before into hard American dollars, which he kept safe in the lab where he worked.

And as in financial matters, the 39-year old Seghezzo, who received his PhD degree from Wageningen University on 29 May, has a foreseeing eye when it comes to environmental issues. Already during his MSc study in Environmental Sciences in Wageningen from 1995 until 1997, he absorbed as much information as he could about modern waste management systems. Back in Argentina, he applied his knowledge for the benefit of the inhabitants of Salta, half a million in number.

As director of Environmental Protection of the Municipality of Salta for two years, he had the power to achieve something: “We actually came up with the first environmental policy for this town. A system for recycling organic waste was developed. And I am very happy with the new environmentally friendly landfill. In the past, waste was just dumped in various places. Liquids were not treated, which contaminated groundwater. Dump sites were full of scavengers collecting bottles. It was a very ugly situation.”

Now batteries are separated from the rest of the garbage at the landfill and better disposed of. “Actually we based the waste treatment-system on the Dutch one. We also want to separate glass and plastic, but this is not done yet. Nevertheless, at least the people of Salta know now they will have to separate more of their waste in the near future.”

What to do with solid waste is a big problem in the whole of South America says Seghezzo, but another big challenge is the massive amount of sewage water. It is the topic of his PhD research. “We see widespread discharge of raw or poorly treated sewage into rivers, lakes and open canals. Problems include serious threats to human health and loss of recreational activities like fishing and camping.”

Looking ahead, Seghezzo was already worried in the late eighties that the situation was going to get worse. As a student in Natural Resources at the National University of Salta, he built his own anaerobic digester, a biological system for treating sewage. And he kept a keen eye on the many papers of Professor Gatze Lettinga of Wageningen University, about his low-cost wastewater-treatment system that was going to spread all over the world. Seghezzo decided to study this system in Wageningen and apply it in Argentina. A pilot-scale plant has now been working successfully for seven years in Salta, the first in Argentina for treating sewage water. The filth is passed through a tank where bacteria clean it. A great benefit is that is a closed system and not much biological sludge remains. “In contrast, our open waste-stabilisation ponds create many problems: bad smells and a breeding ground for mosquitoes, spreading malaria, dengue and other diseases.”

The Argentinian cannot wait to go back to his country to work on unfinished business, although the economic and social crisis worries him. “Environmental issues are now low on the political agenda. You get new offices but not the best people. For example, our forests are being chopped down to grow soya beans because the price is high at the moment. Before the economic crisis, environmental concerns were high. I hope after the crisis they will surface again.”

Hugo Bouter

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