Issue 4

The potential regional future changes in seasonal (winter and summer) temperature and
precipitation are assessed for the greater area of Greece over the 21st century, under A2, A1B and
B2 future emission scenarios of IPCC. Totally twenty-two simulations from various regional climate
models (RCMs) were assessed; fourteen of them with a spatial grid resolution of 50km for the period
2071-2100 under A2 (9 simulations) and B2 (5 simulations) scenarios and eight of them with an
even finer resolution of 25km under A1B scenario for both 2021-2050 and 2071-2100 time periods.
The future changes in temperature and precipitation were calculated with respect to the control
period (1961-1990). All the models estimated warmer and dryer conditions over the study area. The
warming is more intense during the summer months, with the changes being larger in the continental
than in the marine area of Greece. In terms of precipitation, the simulations of the RCMs estimate a
decrease up to -60% (A2 scenario). Finally it is shown that the changes in the atmospheric
circulation over Europe play a key role in the changes of the future precipitation and temperature
characteristics over the domain of study in a consistent way for the different emission scenarios.

Literature reports have indicated that Particulate Matter (PM) concentrations in the atmosphere over
the major urban centres of Greece are high compared to other European cities of the same size. The
great majority of these reports are based on measurements that have been conducted over a limited
amount of time. This study provides an overview of the temporal variation that shows the trends of
PM10 concentrations in the two major urban centres of Greece (Athens and Thessaloniki) during the
last decade (i.e., from 2001 to 2010). Annual average PM10 concentrations at the urban monitoring
stations in Athens range from 32.3 to 62.5 μg m-3, and at the suburban stations from 21.5 to 62.9 μg
m-3. In Thessaloniki the respective values range from 41.7 to 70.8 μg m-3 for the urban stations, and
from 23.4 to 51.5 μg m-3 for the suburban. The highest and the lowest monthly average PM10
concentrations at the urban stations in Athens are observed during the autumn/winter and the
summer months, respectively. For the suburban stations the highest values are observed during the
spring and the lowest during the winter. In Thessaloniki, autumn exhibits the highest and summer the
lowest PM10 values both for the urban and the suburban stations.

Improving the treatment efficiency of a primary wastewater treatment plant(WWTP),in Alexandria,
Egypt,was studied.In order to improve the treatment efficiency of the plant, different improving
scenarios were proposed and evaluated. The improvement scenarios are: scenario 1,use of
engineered wetland instead of the current treatment system, scenario 2, use of the engineered
wetland as a secondary treatment after the existing treatment system and scenario 3,replace the
existing treatment system with a secondary WWTP. The scope of this study is to environmentally
assess the existing primary WWTP, in addition to assess the possibility of using the engineered
wetland for improving the primary WWTP. To evaluate the performance of each treatment system,
Life Cycle Assessment (LCA) approach was applied.

Based on the results, the main improvement achieved in all the scenarios is in the category of
eutrophication and acidification, as the three scenarios have higher removal efficiency for the
nutrients than the current system. Unlike the total reduction in the environmental impact, scenario 3
gave the highest reduction in the category of eutrophication and acidification (25%) followed by
scenario 2 (24%) and the lowest reduction achieved by scenario 1 (13%). The analysis revealed that
the use of combined system from natural and traditional systems (scenario 2) is the best scenario.
However, scenario3 achieved a very close result.

Electrically and ionically conducting graphite powder beds interposed between the anode and
cathode inside an electrolytic setup are used as intermediate bipolar electrodes. The beds cause
electric field discontinuity by eliminating the applied electric field locally within their mass and act as
electrostatically shielded zones – ion and ionic current sinks and thus ion concentrating
compartments, whereas the adjacent compartments become ion depleting compartments. The ion
sinks were implemented in a coupled electrostatic shielding electrodialysis/electrodeionization
process to remove ammonium nitrate from fertilizer plant wastewaters. The batch wise operated
electrostatic shielding electrodialysis of a solution containing 1310 mg L-1 ammonium nitrate
produced in 28 min at a current density of 15-30 A m-2 a concentrate ammonium nitrate solution
which could be recycled to the fertilizer plant unit and a diluate containing 50 mg L-1 ammonium
nitrate. The diluate was subsequently used as feed in the electrostatic shielding electrodeionization
process to produce pure water of a NH4
+ and NO3- ion concentration of less than 1 mg L-1
respectively with a flow rate of 5.51x10-4 dm3 s-1 and a current density of 50 A m-2.