Volume 10 - 2008

The goal of the current review is to present and analyze the known information proposed and
discussed the last few years about UFP and their possible health effects. It includes
references from 1992 to 2008. It also includes references from some fundamental studies in
the 1970's and 1980's. The review and analysis of the health hazards induced by ultrafine
particle exposure focuses on the; classification and characteristics of suspended particulate
matter (PM), features and properties of PM and, specifically, ultrafine particles (UFP), the
UFP movement and translocation from exposure sources in the environment to the human
body and the ways of absorption and deposition within the human anatomy. Also, an
extensive review of epidemiological, clinical and toxicology studies concerning possible health
effects of UFP, is included. Finally, the most recent studies suggesting extrapulmonary effects
and, especially, on the brain and central nervous system. Results have shown that there is
significant analogy between UFP exposure and related adverse health effect risk in human
beings. Cardiovascular and pulmonary systems seem to be the main targets of this exposure.
New evidence shows accumulation of UFP in regions of the cerebellum, olfactory bulb and
other areas of the central nervous system.

The traditional approach to urban water management is primarily based on a supply-oriented
approach, where water follows a one-way path from supply to a single use, treatment and
then discharged to the environment. The wide acknowledgement of the need to shift towards
more sustainable practices has led to the recognition that demand is multi-faceted; delivered
supply should correspond to the varying characteristics of users, taking into account their
actual needs in terms of quantity, quality and level of reliability. Such an approach can entail
the application of reuse and reclamation methods, which allow for the multiple use of water to
meet higher to lower quality needs.
Integrated urban water cycle modelling can be a powerful tool in estimating the potential for
the application of such options, as it considers issues related to water supply, wastewater
production and stormwater runoff in a holistic framework. This paper presents preliminary
results from the application of an integrated urban water balance model, Aquacycle, in the
Greater Athens Area. The Aquacycle model accounts for water pathways by simulating two
subsystems of the urban water cycle (the rainfall-run-off network and the water supplywastewater
network), and the interactions between them. The software package can also be
used for evaluating alternative stormwater and wastewater reuse schemes.
In this paper, Aquacycle was used for simulating water use, wastewater production and
stormwater drainage in the Greater Athens Area. For applying the model, the region was
divided into smaller – cluster – scales, according to specific structural characteristics. Then,
the model was calibrated and validated against measured data, so that model outputs can
account for the overall complexity of the Athens urban environment. Finally, three alternative
scenarios, comprising the application of on-site recycling and reuse technologies were
simulated and evaluated on the basis of three sustainability indicators (i.e. reduction of
imported freshwater, wastewater and stormwater discharge).

The effect of ultrasonic waves (US) was studied on the degradation of Malachite Green (MG)
as a model contaminant from textile industry by direct photolysis with ultraviolet (UV) radiation
and UV/H2O2 processes. The US (35 kHz) and UV (253.7 nm) radiations were carried out with
an ultrasonic bath and a 15 W low-pressure mercury lamp, respectively. Degradation of MG
follows pseudo-first order kinetics in all cases. The apparent reaction rate constant (kap) for
UV/US process is greater than sum of the UV and US processes but it is relatively low for
practical uses. However UV/H2O2 treatment more efficiently decomposes this organic
contaminant and combining this process with US can improve its efficiency. kap is influenced
by variation of operational parameters such as power density, temperature, initial
concentration of MG and H2O2 for US/UV/H2O2 process and activation energy was 9 kJ mol-1
in the range of 294-307 K for this process. UV-vis spectral change of MG showed
hypsochromic shift occurred with increasing sonication time, suggested N-demethylation
process of MG.

In the present study, the wet oxidation of zinc and copper cyanide complexes (cyanide
concentration of 1,000 mg dm-3) was conducted in a hydrothermal reactor, under oxygen
atmosphere of which the pressure was set to 1 MPa. The pH of the reaction solution was kept
in the range of 11 to 12 and the reaction temperature was changed from 383 K to 423 K. In the
experiments, mainly the effect of reaction time on the cyanide decomposition was investigated.
As a result, it was found that cyanide decomposition increased with an increase in the
temperature and cyanide decompositions of 99.9 % and 96.1 % were achieved after 8 hours at
423 K for Na2[Zn(CN)4] and Na3[Cu(CN)4], respectively. In the case of Na2[Zn(CN)4], mainly
HCOO- and NH4+ were identified as the decomposition products. By contrast, in the case of
Na3[Cu(CN)4], carbon of CN- was transformed either to H2CO3 or HCOO-, and nitrogen was
converted to NH4+, N2 or NO2-. Based on these results, the decomposition mechanisms of
Na2[Zn(CN)4] and Na3[Cu(CN)4] at a temperature of 423 K and pressure of 1 MPa were
discussed.