The present work has estimated greenhouse gas emissions in aerobic and anaerobic Wastewater Treatment Plants in Southern Italy. Greenhouse gases emissions from each treatment unit were calculated based on emission factors related to Chemical Oxygen Demand removal for biogenic CO₂ and CH₄ assessment and on Nitrogen removal for N₂O. N₂O, biogenic CO_2, and CH₄ emissions vary for aerobic and anaerobic-based WWTPs respectively from 73 kgCO_2eq/PE*y for anaerobic plants to 91 kgCO_2eq/PE*y for aerobic plants. In aerobic and anaerobic digestion systems WWTPs the contributions to CO_2eq total emissions from N₂O, CH₄, biogenic CO₂, and fossil CO₂ are 30 %-33 %, 20 %-29 %, 22 %-25 %, and 26 %-16 %, respectively. N₂O emissions from biological processes were found the most contributing sources of greenhouse gases while in the physical processes higher contribution is indirect carbon dioxide related to energy consumption. Compensatory measures are reported to reduce greenhouse gases emissions.

Nickel contamination poses a serious risk to ecosystems and human health. Phytoremediation provides a sustainable solution. This study evaluates the ability of Helinathus annuus L. to tolerate and accumulate nickel under simulated Mediterranean and semi-arid conditions, representing a short-term contamination event with nickel-enriched irrigation. Laboratory experiments assessed growth, tolerance, and Ni distribution within plant tissues. Results showed that Ni uptake increased with concentration, mainly in roots, while translocation to aerial parts remained limited. The bioconcentration factors ranged from 1.32 to 2.55, and the translocation factors from 0.46 to 0.60, indicating efficient uptake but restricted metal mobility. Higher water availability enhanced Ni absorption, suggesting that soil moisture facilitates metal transport and root activity. Helinathus annuus L. demonstrated good tolerance at moderate Ni levels but reduced growth and accumulation efficiency at higher concentrations, confirming its potential for phytostabilization in Mediterranean soils affected by metal contamination.