A blog from University of Borås

Tuesday, September 21, 2010

Biological Superabsorbents from fungi cell wall

Zygomycetes are a class of saprophytic fungi, which can grow on different waste materials. We are working on this class since 1999, and have several publications. They can grow in harsch conditions and produce several metabolites such as ethanol and lactic acid, or different enzymes. However, their cell mass has about 20% cell wall, which compose mainly of chitosan. Our PhD student Akram Zamani worked for several years on these fungi, in order to characterize their cell wall and produce superabsorbents from them. She defend her thesis soon. Let's wish her a good success during the defense and afterward in her life!

(The cover of her thesis, which shows the steps from fungi to superabsorbents)

Thursday, September 9, 2010

Viva scavengers

Latin America with 524 million population, produces about 130 million tons wastes per year. Brazil with 1.152 kg/day/person wastes stands for haft of this wastes. This wastes is practically dumped, and just about 2% is recycled. This recycling is carried out mainly by scavengers that are about 100,000 families in Latin America, of which 10-30% are children and are working with slavery conditions, as we heard from our friends both at Rio de Janeiro and Sao Paulo universities. Recognition of their work by the governments in the region and more attention in the media and help by people, may help to increase their recycling from 2% to the corresponding level in Sweden which is about 35%.

(Treatment and final deposition of wastes in Brazil, Ref: Alvaro Cantanhede, UFRJ, Brazil)

Friday, September 3, 2010

Good business with landfill gas in Brazil

Together with our friends from University of Sao Paulo in Brazil, we visited today the old landfill of Sao Paulo named "Bandeirantes". This landfill received 50 million tons wastes in 1979-2007, and converted a valley to a hill with 150 m height of the wastes. The landfill is now closed to new wastes and covered. A company named "Biogas" collect the landfill gas via 300 wells and convert them to electricity via engines. They had about 14000 m3/h gas with about 49% methane, which is now reduced to about 6000 m3/h. They sells 10 MW electricity now. In addition, the company is registered to CDM to sell also the carbon emission credits, which was 2000 tons/day in 2007 and 700 tons/day now. The price of each ton equivalent CO2 saving is about 8-10 Euro. The company says its 50 million USD investment was paid back in 2 years. Good investment for both the companies involved and also the environment!

(Bandeirantes landfill in Sao Paulo, Brazil with 1.2 km2 and 150 m height of the waste. The wells for gas collection are visible in the photo)