Issue 4

Polycyclic Aromatic Hydrocarbons (PAHs) are one of the major categories of pollutants
entering the marine environment and finally accumulating in the sediments. Their occurrence
raises major concerns for human health, especially during coastal activities (bathing waters,
aquaculture, etc), having combined adverse effects still largely unknown when they are
present as mixtures. Moreover, during their remobilization (e.g. dredging activities), their
bioavailability can increase resulting in a risk for marine environment. Several of them are
known to be potential human carcinogens including benzo[a]anthracene, chrysene,
benzo[b]fluoranthene, benzo[a]pyrene and benzo[ghi]perylene. Therefore they have been
included in the priority list of the Water Framework Directive 2000/60/EC and also sixteen of
them have been regulated by the US EPA as priority pollutants, and their distributions in the
environment and potential human health risks have become the focus of much attention.
The determination of PAHs in environmental matrices has been subject of great scientific
attention during the latest years, as the accuracy and sensitivity of analytical methods need to
be improved in order to be able to detect the compounds of interest in a complex matrix such
as sediments. Therefore, significant research is being devoted to the optimization of analytical
methodologies. A great number of studies have been performed on PAHs analysis in marine
sediments. Various analytical procedures based on gas chromatographic analyses are
reviewed and comparatively discussed in this paper.

Saltscapes are landscapes with a long lasting salt-making activity, thus embedded with a
blend of salt-related characteristics that marked them physically, ecologically, economically,
and culturally. This study, based on a broad survey, focuses on the changing atlas of saltmaking
business and the consequent land use change in Greece within the 20th century.
Like in many Mediterranean countries, salt-making has been an important activity in Greece,
not only because salt catered for local and national needs (food condiment and preservative;
basic resource in husbandry and industry), but also because it offered significant revenues to
the Greek State. Taxed salt has been produced in 28 semi- or entirely-mechanized State
saltworks. The remaining less productive salinas operated in clandestine and were numerous:
48 in lagoons and 307 on rocks. Both salina types produced either self-formed salt or were
man-managed (primitive, artisanal). This very dense network of salt-making sites, all located
along the coastline, was in operation mostly until WW II, thereafter many sites were gradually
abandoned. Today only eight saltworks are active in Greece (dormancy 71.4%) and, despite
their increased potential, the overall saltscape loss in the country is significant. Salinas
operating in lagoons suffered a spectacular change (93.4%) compared to those on rocks
(43.0%). We discuss the reasons of abandonment, especially the role of “globalization” in
heritage loss (ecological, cultural). We compare salinas on islands and the mainland as to
typology and values and we propose ways of recuperating these threatened resources by
using them as alternative poles for local development mainly through tourism.

Recent oil tanker accidents in the sea are very serious, not only since they pollute the
environment but also because they release heavy oil. The preparation of activated carbon
from agricultural waste increases economic return and reduces pollution.
On carbonized fibers, sorption capacity for different kind of oils was determined. Fibers
extracted from bagasse and carbonized at 300◦C for 2 hr were found to have a high
performance for sorption, recovery and recycling of heavy oils, even the viscous ones.
Sorption capacity showed strong dependence on the weight of sorbent and oil film thickness.
Their recycling performance was excellent as they can be used for six cycles until they reach
50% of the sorption capacity of the 1st cycle.
Comparison between the prepared carbonized fiber and a commercial sorbent has been done
and showed that the prepared sorbent could be used as sufficient sorbent more than the
commercial sorbent used.

Artificial neural networks are one of the advanced technologies employed in hydrology
modelling. This paper investigates the potential of two algorithm networks, the feed forward
backpropagation (BP) and generalized regression neural network (GRNN) in comparison with
the classical regression for modelling the event-based suspended sediment concentration at
Jiasian diversion weir in Southern Taiwan. For this study, the hourly time series data
comprised of water discharge, turbidity and suspended sediment concentration during the
storm events in the year of 2002 are taken into account in the models. The statistical
performances comparison showed that both BP and GRNN are superior to the classical
regression in the weir sediment modelling. Additionally, the turbidity was found to be a
dominant input variable over the water discharge for suspended sediment concentration
estimation. Statistically, both neural network models can be successfully applied for the
event-based suspended sediment concentration modelling in the weir studied herein when
few data are available.