Geophysical and geochemical study of geropotamos aquifer in the north-central coast of crete

The geological setting of Geropotamos aquifer on the north-central coast of Crete, Greece, is considered complex, while the local tectonic regime of the study area is characterized by two sets of faults orientated NW-SE and NE-SW. Investigation of the aquifer using the Transient ElectroMagnetic method (TEM) has resulted initially in 1D models of geoelectric structures and a final 3D geoelectrical model was constructed, depicting the zones of salination of groundwater in the aquifer. Groundwater samples were analysed and the most important chemical parameters were determined to provide an independent dataset for comparison with the TEM results, while Groundwater Quality Maps were produced. TEM and geochemical data correspond and provide verification of the TEM approach. As a result, saline intrusion is likely to occur along fractures in a fault zone through bedrock, and this work emphasises the critical role of fracture pathways in salination problems of coastal aquifers

Physico-chemical characteristics of particulate matter in the Eastern Mediterranean

Summarization: Particulate matter (PM10, PM2.5) measurements were performed during the period 2003–2009 at the Akrotiri monitoring station (suburban/rural) on the island of Crete, Greece. Concurrent measurements of PM10 size distribution/chemical composition were also performed at selected time intervals to determine the PM sources in the region and the factors controlling their levels. Using a beta radiation attenuation monitor, the mean PM10 concentration during the measuring period (15.04.2003–31.12.2009) was equal to 36.1 ± 9.5 μg/m3, whereas the PM2.5 concentration was equal to 23.6 ± 5.8 μg/m3. Back trajectories showed that the dominant air mass origin was from North and Northwest Europe but the intrusion of southern air masses lead to elevated PM concentrations due to Saharan dust events. The 24-h EU limit value of 50 μg/m3 (PM10) was exceeded approximately 13.5% during the measured period. Furthermore, the PM10 mass size distribution of metals, ions and organic carbon/elemental carbon (OC/EC) was characterized using a 9-stage Andersen non-viable impactor and a gravimetric sequential PM10 sampler during two selected periods. The mean PM10 concentration during the first sampling period was equal to 28.3 ± 12.4 μg/m3 (10.08.2007–28.08.2007), whereas during the second sampling period (09.07.2008–19.07.2008) was 41.6 ± 14.0 μg/m3. The measurements showed a bimodal size distribution for the aerosol mass concentration. PM2.1 accounted for 41.0% and 37.2% for PM10 during the two periods respectively. Over the measurement campaigns ions dominated the PM10 mass (50–80%) with the organic mass and metals comprising the major part of the rest. The OC concentration was equal to 2.3 ± 1.2 μg/m3, whereas the EC concentration was equal to 0.8 ± 0.2 μg/m3. Finally, black carbon concentrations were measured in August 2007 with an aethalometer. The mean daily value of black carbon was 0.69 ± 0.22 μg/m3. The measurements showed that the PM values measured at the station correspond to a background/rural station in the region and are in agreement with other measurements in the Eastern Mediterranean region.Παρουσιάστηκε στο: Atmospheric Researc

TiO2-assisted photocatalytic disinfection of spring water and biologically treated municipal wastewater

Summarization: In this study, the semiconductor photocatalytic disinfection of spring water and of secondary treated municipal wastewater was investigated. Natural water from a spring in Chania prefecture, which is used for the water supplies for the city of Chania, Crete, and samples from the effluents of the secondary settling tank of the municipal wastewater treatment plant of Chania were collected. The samples were exposed to UV-A irradiation in the presence of TiO2. The parameters examined in this study were the length of TiO2 / UV-A treatment for effective disinfection, the microorganism type (total coliforms, enterococci), the relative bactericidal activity of three different types of TiO2, the amount of the catalyst needed, and the pH of the samples. The results presented here show that commercial TiO2 powder Degussa P25 is the most effective catalyst of the three used. Enterococci showed a stronger resistance to photocatalytic disinfection, whereas small pH changes do not seem to have a significant effect on it.Παρουσιάστηκε στο: First International Conference on Environmental Management, Engineering, Planning and Economic

A study on the correlation of the properties of parent rock and soils of different geological origin

Summarization: The present study examines the nutrients and micronutrients availability of uncultivated soils originated from different parent rocks. The study areas include four types of parent rocks with different geological origin, from acidic to ultramafic. The parent rock mineralogy and the nutrients available in soils are in strong relationship. Mineralogy, particle size distribution and chemical composition of the soil samples were studied jointly with the nutrient content of soil solution. High magnesium availability in soils of Anogia area is related with the alteration products of the ultramafic rocks. Potassium content of the soils exhibits no relation with the geology of the area. Micronutrients, iron and manganese, shows strong dependence to the bulk chemistry and mineralogy of the parent rock material. In contrast no interrelation detected between zinc and copper availability in soil and parent material.Παρουσιάστηκε στο: 2nd International Conference on: "Advances in Mineral Resources Management and Environmental Geotechnolog