After the initial study of the historical data from last years on sewage sludge characterization analysis from the wastewater treatment plants managed by Aqualia in the region, based on certain factors such as heavy metals content, fertilizing capability, etc., 5 WWTPs have been selected for the exhaustive characterization of the sewage sludge.

<p style="text-align: justify;"> These analysis will continue until October this year and aim at assessing the variability of the sludge regarding time, location and point of the sludge line of the process</p>