The PhD central activity will be the study of the most important residual coming from the Integrated Water Cycle: the sludge material. Management of sludge, as a solid matrix coming from wastewater treatment plants, is very important both from a technological and economical point of view.
The work will be performed by a collaboration between the Polytechnic Department of Engineering and Architecture and the DI4A of the University of Udine, and the IRCSS “Mario Negri” Institute of Milan.
A series of experimental and “on the field” sampling are forecasted to seek new solutions to characterize and to evaluate toxicity of sludge coming from small and large municipal wastewater treatment plant. The sludge will be considered as a potential soil emending material studying safety and weaknesses of this concept, introducing new perspective in analyzing real and forecastable characteristics.
The PhD work will lead a proposal for a new way to characterize and control sludge coming from wastewater treatment plants of selected Integrated Water Cycles in Friulian territory.
Municipal wastewater is conveyed via the sewerage system to a centralized wastewater treatment plant. The rejuvenated water is released to streams and rivers and the residual that is produced during the treatment, called sewage sludge, should be disposed.
Land application of sewage sludge has proven as a cost effective and environmentally safe disposal method by beneficially recycling of organic matter and nutrients and improving soil quality.
By considering the importance of sewage sludge characterization before disposal or application to the farm land, during the first year of PhD I’ve focused on extraction and characterization of Humic substances to emphasize the role of this recalcitrant fractions in the evaluation of the quality of composts and sewage sludge for their use in agriculture. This compounds were extracted and analyzed through TOC analyzer, UV-Visible Spectroscopy, fluorescence Spectroscopy and FTIR spectroscopy in following samples:
• Elliot soil (United state)
• Drinking water production residuals (Netherlands)
• Sludge from livestock wastewater treatments (Netherlands)
• Sphagnum moss and two peats at different stages of decomposition
• Sludge from municipal wastewater treatment plants (FVG)
Ali Khakbaz, Carlo Bravo, Marco Contin, Daniele Goi, Maria De Nobili, "Extraction of humic substances: facts or artefacts?" (Poster), XXXV Convegno Nazionale SICA-Udine, 11-13 september 2017.
Gianni Tassan Mazzocco, Stefano Mazon, Raffaela Petris, Ali Khakbaz, Marco Contin, Efficenza della concimazione organo-minerale: prove in microcosmo e in lisimetro" (Poster), XXXV Convegno Nazionale SICA-Udine, 11-13 september 2017.
A. Khakbaz, C. Bravo, M. Contin, D. Goi, M, De Nobili, Integrity of the use of humic substances (HS) as tracers of biological transformation during storage of treated sludge, 19th International Conference of Humic Substances and their Contribution to the Climate Change Mitigation, 16–21 September 2018, Albena Resort, Bulgaria, Editors Prof. Dr. Ekaterina Filcheva, BOOK OF ABSTRACTS, Bulgarian Humic Substances Society Sofia, 2018, ISBN 978-619-90189-3-4.