The technology developed by the Life Celsius project allows nitrogen removal performance like traditional systems, but with “significantly lower” costs.
The advantages of Celsius
Andrés Lara, responsible for Environment of the Technological Center of Energy and Environment (Cetenma), explained in an interview with Efeverde that the usual procedure of nitrogen removal (nitrification-denitrification) “works very well, with a very high level of removal, but it is a large consumer of oxygen”.
However, he explains that “Alternative treatments like Celsius reach the same requirements with costs, in some cases and in specific conditions, significantly lower, since they manage to reduce energy consumption by 60 percent”.
The biologist continues explaining that, on top of this, “it has the advantage of generating less sludge”, although it is more sensitive to parameters such as temperature”.
Lara explained that urban wastewater reaches the treatment plant with two main pollutants, organic matter and nutrients (nitrogen and phosphorus), and most of these facilities eliminate some compounds, although the costs highly increase in the second process.
Discharges into the environment
However, if the water resulting from the purification process is discharged into the environment (a river, for example), Lara explains that “everything possible must be eliminated to avoid serious problems such as eutrophication and hypoxia”.
According to Andrés Lara, “if in the natural environment the concentrations of these compounds rise above the level of the ecosystem itself, there are some advantageous species that take advantage of it better than others, reproduce at a higher speed and can deplete oxygen for the rest”.
For this reason, it is necessary “to preserve the biodiversity and the good ecological status of a river it is necessary to avoid, arriving through the discharges, hazardous substances, agents or compounds that are not part of the river itself”, Lara explains.
“While the water coming from the sewage treatment plant has the same or better quality, the ecosystem will not be altered”.
However, the biologist nuances: “that sewage which is not optimal for pouring to a river may be useful for agriculture”, because the fertilizers are composed essentially by nitrogen and phosphorus.
“Nutrient removal in a wastewater treatment plant increases costs and in some cases, it is not interesting to carry out this removal process”, reports Lara. “It is the concept of circular economy: take advantage of nutrients that have been generated in an urban environment and bring them back to agriculture.”
Because, Andrés Lara has indicated, “it is necessary to distinguish if the water goes to a channel, to irrigation or to recreational uses, because depending on each use, the legislation establishes the minimum quality levels that the water must have”.
The Segura River
The head of Environment of CETENMA has ensured that the Segura River “has some excellent parameters and indicators, comparing it with what it was 20 years ago, in which the urban discharges were not purified and were spilt directly to the river”.
Lara remarks that: “Nowadays, nearly hundred percent of the water to be poured to the river is eliminated or if it is intended to be used for irrigation, it undergoes a purification treatment and thus the Segura River health has notably improved in the recent years”.
Traducción: Carmen Gilson