Only 20% of the wastewater is treated in Latin America
Blanca Valadez, Millennium, December 4, 2012, Mexico City
The study in Mexico, Dominican Republic, Colombia, Brazil, among other countries in the Americas, indicates that only 20 percent of wastewater is treated, the remaining liquid is discharged into water bodies or, in some measure, be for irrigation. We found that the technologies used are stabilization ponds, followed by activated sludge and UASB reactors, which account for 80 percent of the infrastructure of municipal wastewater treatment in Latin America and the Caribbean.
A diagnostic inventory of the technologies used in municipal treatment plants water in Latin America (LA) and the Caribbean found that in the region, including Mexico, only 20 percent of wastewater is treated, particularly the methane dissolved in effluents, which may lead to the spread of infectious diseases, said Adalberto Noyola Robles, director of the Institute of Engineering of UNAM. Municipal wastewater are treated about 20 percent the rest is discharged into water bodies or, in some measure, is used for irrigation and untreated raw liquid, a common practice in countries like Mexico. The countries covered in this study were Mexico, Dominican Republic, Colombia, Brazil, Guatemala and Chile, with the help of consultants in each of them, and using public information websites of the agencies responsible for managing the resource.We obtained a sample of two thousand 734 treatment plants.
It was found that the technologies used are stabilization ponds, followed by activated sludge and UASB reactors, which account for 80 percent of the infrastructure of municipal wastewater treatment in Latin America and the Caribbean. Therefore it is necessary to invest in research to develop more effective mitigation technologies, Noyola said Robles, who made a calculation to quantify the emission of greenhouse gases (GHG), as part of the research project IDRC-UNAM. There is much to invest and build in the area, however, should be considered for treatment infrastructure contributes to GHG emissions. One example is the methane which is produced according to the type of operation and the technology used, although it depends on the correct operation of the plant.
According to the Intergovernmental Panel on Climate Change (IPCC, for its acronym in English), seven percent of atmospheric methane comes from sewage waste. So build systems must meet certain technical criteria, economic and environmental, in particular, now that there national and international commitments. According to the analysis, it was determined that the scenarios that generate less total GHG emissions are the UASB, only if the biogas is captured and burned correctly. However, stabilization ponds have a high mitigation potential, because they can be covered to recover and eventually seize the generated gas to produce electricity. This, he said, represents an opportunity to identify the technological processes that could have a low carbon footprint to help combat climate change in the region.
In this regard, Patricia Güereca, researcher, said that technologies activated sludge to generate greater environmental acidification, abiotic resource depletion, deterioration of the ozone layer, eutrophication and photo-oxidants, all due to the use of electricity. Energy efficiency and the use of biogas as an alternative within the plants, help to lessen the impact on all categories analyzed.