All

In this work the covariability of sea surface and lower troposphere temperatures (SST-AT) is investigated for
winter (DJFM) and summer (JJAS), over the whole northern hemisphere, by utilizing monthly anomalies in
grid boxes for a 22-year period. Air temperature variations in the lower troposphere are examined in terms
of 1000-500 hPa thickness. At first, factor analysis (FA) is applied on both sets of data in order to reduce their
dimensionality and to group objectively grid points with a similar long term temperature variability. Also, FA
revealed numerous teleconnections in both fields, most important being those governed by PNA in the
Pacific Ocean and NAO in the Atlantic Ocean. Then, by using the FA results as a guide, correlation coefficients
between the mean temperature time series of the subareas defined by FA in the two fields are estimated.
The highest values, up to r=0.70, were found for subareas located one over/under the other. Finally,
by introducing time lags, an attempt of forecasting either SST form AT or AT from SST is made. Although
in some cases the coefficients appear increasing, test showed that the increase is not statistically significant.
In any case, it appears that, on monthly time scale, it is the AT that controls SST and not the vice versa.

In the present work, Fourier Analysis is applied to the mean monthly NOx concentrations of the period
1989-1999, for a network of 7 stations. Treating NO and NO2 as a single primary pollutant, we succeeded
the assessment of NOx concentrations. The main causes of NOx emissions in urban areas are
the road traffic and the industrial activity.
The annual variation of NOx concentration is well described with only two harmonic components,
which explain over 90% of the total variance. The spatial distribution of the time of maximum, for every
one of the two harmonic components in Athens basin, is also presented.

The sustainable management of water resources often requires the identification of wastewater as a valued
source of water. Although the benefits of wastewater reuse and reclamation have increased significantly
in Europe because of the advances in effectiveness of wastewater treatment and disinfection technologies
there is currently no legislation nor guidelines regarding reuse. It is well known that there is a
great variation of wastewater reuse quality criteria applied, mainly related to significant differences in
socioeconomic conditions, environmental policies, available water resources. In this work the parameters
that affect the wastewater reuse criteria in Greece are evaluated, concerning among others reuse
priorities, available treatment plants and effluent characteristics and recommendations are made for
developing future guidelines or regulations for Greece in relation to reuse practices (agricultural, urban,
etc). The intention is not to propose an unquestionable and rigid set of standards, but to present them
on the basis of the rationale developed, in order to form a basis for further consultation, involving all the
interested parties. The recommendations are presented in relation to the different types of reuse, with
appropriate specific standards and recommended treatment systems wherever applicable.

This study was conducted to assess the removal efficiency of Di-n-butyl phthalate (DnBP) from aqueous
medium using the photo-Fenton process. The Fenton's reagent that consists of a mixture of hydrogen peroxide
(H2O) and ferrous ions (Fe2+) was used to generate the hydroxyl radical (OH0) that attacks the target
contaminant and degrade it. An ultraviolet (UV) source was used to provide the radiation needed in
the photo-Fenton method (i.e. UV/H2O2/Fe2+). The results demonstrated that photo-Fenton process was
more effective and faster than Fenton's reagent in removing DnBP and that photolysis by UV irradiation
was the dominant mechanism in degrading the compound. The results also showed that enhancing the
removal via UV irradiation was achieved by increasing either the temperature or the H2O2 concentration.