A new research through which scientists showed that proper waste water treatment plant mud can be used as a partial alternative fuel may enable cement factories to reduce their CO2 emissions.
The research was carried out by scientists from the Rovira i Virgili University (URV) in Catalonia, an autonomous community in northeast Spain.
The scientists have carried out the first study into this method at a cement plant in Vallcarca (Catalonia), which has been producing cement for more than 100 years.
They confirm that it is "the best option for getting rid of mud that would have had to be dumped elsewhere, while also powering the plant".
"As this mud is already waste, burning it does not enter into the atmospheric CO2 emissions assigned to each country under the Kyoto Protocol," said Jose Luis Domingo, lead author of the study and director of the Toxicology and Environmental Health Laboratory at the URV.
This would enable plants producing cement, one of the most contaminating industries in terms of CO2 as well as emissions of dioxins, furans and heavy metals, to consume energy in a more environmentally friendly way.
Up to 20 percent of the fossil fuel energy used at the Catalan plant has now been substituted for the fuel from wastewater treatment plant mud.
From an economic point of view, the scientists will not say that cement plants could increase their profits by using this method, but "they will not have to pay anything to exceed their agreed emissions," the researcher points out.
The economic benefits of this system also depend on the price of fuel.
One of the most important issues for the URV scientists is the reduction in environmental impact, and consequently the health risks for people living near the plants.
The experiment with the mud has led to a 140,000 tonne reduction in CO2 emissions between 2003 and 2006, and will have limited the potential deaths from exposure to chemical pollutants.
In addition, the study shows that using this green fuel would reduce the cancer rate by 4.56 per million inhabitants.