Maringá, a city in the southern Brazilian state of Paraná, generates 320 tons of waste every day. And that accounts for residential waste alone. Eight tons consist solely of disposable diapers. All of that daily waste generated by the city's 330,000 inhabitants has been heading to the same place for years: the old city dump, which is now a landfill.
"A controlled landfill," according to the city's attorney, Rogel Martins Barbosa. In the landfill, the story is the same as in so many other cities: landfill waste generates leachate (a liquid produced by garbage), gases etc.
"Landfills are time bombs," says Barbosa. Well, before the time bomb in Maringá goes off, the city has gone after a solution. This year, a new technology will start being tested, which should virtually put an end to domestic waste.
The Biopuster technology, proposed by a consortium comprised of German and Brazilian companies, will transform 70% of those 300 daily tons into humus and recyclable waste (plastic, glass, paper, aluminum).
The remaining 30% will be filled-in. Or even less, according to the Germans who own the technology. And this remaining, unsolved waste will have gone through a "cleaning" process, so that even when filled-in, it will not liberate leachate or gases.
Humus, as an organic material, can be reused. And recyclable materials will then be available for sale by companies that already operate in the sector. Nevertheless, Rogel says it is still early to know how the humus generated there might be reused. That is due to the fact that the project is still a pilot, and tests will be conducted for nine months.
The city attorney explains how the technology works: "There are cells with processing capacity for up to 1,500 tons each. Eight-meter tall spears will deposit air enriched with oxygen into them, turning anaerobic air into aerobic air on the inside. All of this takes place at high temperatures, 176 degrees Fahrenheit."
With the presence of oxygen and heat, bacteria will act upon the waste, eliminating the leachate. "That will make the waste dry," he says.
Then the waste undergoes a screening process that separates humus from recyclables. "This is the big insight of this technology: first to treat, then to separate. When the garbage is separated first, the people who work with recyclables might come into contact with contaminated waste," he explains. In the end of this process, there remains the 30% that will be of no use. Simultaneously, a gas draining process takes place.
The Biopuster Consortium – their motto is: "We return the breath to mother earth – which closed the deal with the Maringá city hall, accepted to ink a risky deal, according to Rogel. They will manage the pilot project for nine months, at no costs to the city hall.
The counterpart requested by the group was for the city to build the adequate flooring for the 14 processing cells that will be built on the landfill site. Besides, they requested that the processed waste belong to them.
"They took a chance because they know that if it works out, Maringá will be a great example to Brazil," says Rogel. After all, this is the first initiative that promises to completely eliminate urban waste in the country.
Total cost during the period will be 3 million Brazilian reais (US$ 1.7 million). The city hall will spend 300,000 reais (US$ 167,000) to build the flooring. "And we will inspect and control the results."
In the future, should the project prove feasible, then the city hall will be able to use the money generated by this new waste to invest in other environmental actions. The initiative may even be submitted to the carbon credit market (Clean Development Mechanisms, established by the Kyoto Protocol), generating new revenues.
Rogel informed that the city of Maringá already has an ecological vocation. "Here we have 645 square feet of green area per inhabitant", he says. In a place where education is one of the main economic talents – there are 33,000 university student openings -, caring for the environment comes almost naturally. Still, the initiative of seeking a solution for the dump was reinforced by a "scolding" from the District Attorney's Office.
"They filed a lawsuit forcing the city hall to close the landfill," says Rogel. "And the Environmental Institute of the state of Paraná (IAP) was pushing us too."
One of the main problems in the area of over 250,000 square meters was the number of garbage collectors who picked through the residue to survive. After the dump was turned into a landfill, those people were forwarded to cooperatives that work with selective garbage collection in the city.
For more
Anba – www.anba.com.br
