This paper studies the influence of temperature and of rainfall intensity and the effect of such variations on the treatment efficiencies and on the electrical consumptions in seven medium-large size Wastewater Treatment Plants (WWTPs) in Apulia in South Italy (Bari, Barletta, Brindisi, Lecce, Foggia, Andria and Taranto). It has been observed, in the considered WWTPs, a slight but clear increase of the incoming flow due to the increase in rainfall intensity, which results to an increase of the energy consumption per incoming volume. The impact of the climate change to the incoming flow, during the last five years (2016-2020), has been assessed indicating that an increase in rainfall intensity results to an increase of the WWTPs energy consumptions per wastewater treated volume. More specifically, for a specific WWTP (Lecce) it was found that the electrical consumption increases from 0.36 kw/m³ to 0.51 kw/m³ when the rainfall intensity was increased from 0.8 mm/min to 2.9 mm/min. Some adaption measures have been considered to upgrade the existing WWTP so to mitigate the energy increase and to limit the global effects of climate change.

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.

The Phyllostachys pubescens macrophyte, known also as Moso Bamboo, was evaluated in laboratory conditions for its potential to renovate copper-polluted soil. Pot experiments were conducted to determine Phyllostachys pubescens’ growth, tolerance and phytoextraction potential capacity to restore copper-contaminated soil in Mediterranean conditions. Data collected evidenced that the Phyllostachys pubescens evolution rate was 0.47 cm/day on average, with a 1.644 mm/d irrigation flow. Moso Bamboo tolerance was tested over a twelve-week irrigation period, while adding copper-polluted water. Copper removal from soil was 51.4% and the quantity of copper per gram of root/rhizome was equal to 1.18 mg Cu/g, while the amount of copper per gram of stem/leaves was 0.50 mg Cu/g, after 12 weeks. The conducted laboratory experiments show that environmental restoration using the phytoextraction technique, and using Phyllostachys pubescens, should be considered for the restoration of copper-contaminated soils.