Subsequent to the increasing diffusion of wastewater treatment, particularly in high- and middle-income countries, the sewage sludge generated should be treated and valorised in an ecological and economic way, thus contributing to the circular economy. In this study, the monitoring of Heavy Metals (HM), Extractable Organic Halogens (EOX) and Linear Alkylbenzene Sulphonate (LAS) in sewage sludge from 10 different wastewater treatment plants located in Friuli Venezia Giulia (Italy) was reported, and their macronutrient content provided. The obtained results showed, for all tested samples, that HM content in sewage sludge was below the maximum permitted limits provided for by Italian and European regulations for agricultural reuse. Comparison with a similar monitoring campaign carried out in 2006 revealed how, while wastewater treatment plants efficiently resolved water pollution, they accumulated heavy metals and other persistent toxic compounds in sludge, thus restricting their potential reuse. Consequently, consistent and regular sludge monitoring should be undertaken to prevent soil and groundwater contamination. These outcomes could be of particular relevance for the future perspective of agricultural reuse of sewage sludge in waste management practices.
The continuous use of Cu-based fungicides in viticulture has caused Cu accumulation in soils, which represents a major environmental and toxicological concern. The purpose of this study was to verify whether the organic management would be more resilient to temperature and moisture stresses in comparison to conventional practices. Two organic and two conventional vineyard soils, contrasting in pH, were exposed for six months to temperature stress (29 °C), moisture stress (10% water holding capacity—WHC), and combined stresses (29 °C—10% WHC). Main soil properties, Cu speciation, bioavailability, and leaching were monitored before and after 6 months’ incubation. Results confirm that the increase of temperature caused a decrease in both total organic carbon (TOC) and dissolved organic carbon (DOC) (up to 19% and 49%, respectively), a decrease in available ammonium, and an increase in nitrate. Moisture stress tends to mitigate some of these changes. Despite that, changes of Cu bioavailability and leaching were limited and rarely significant. Moreover, no regular trends between conventional and organic management could be observed. Changes in soil pH and total N (TN) appeared as the most influencing properties to regulate Cu behavior in vineyard soils. Calcareous soils were more resistant to environmental stresses compared to acid soils, regardless of the type of management (conventional or organic).