The Transboundary River Nestos and Its Water Quality Assessment: Cross-Border Cooperation between Greece and Bulgaria

Transboundary water resources require the cooperation of the countries involved, not only on the various uses of the water, but also on overall water quality and the protection of ecosystems. Transboundary rivers and their management constitute a contemporary issue of great significance. Cooperation between neighboring countries is not always easy, due to different socio-economic and political conditions. Therefore, the different needs and priorities between the countries involved need to be solved first. Since pollution does not stop at a State border, it is an example of something that can be solved only at the cross-border level. This paper presents the cross-border cooperation between two transnational Institutions; the Aristotle University of Thessaloniki (Greece) and the University of Sofia (Bulgaria), within the framework of Interreg programs. The first collaborated attempt was to carry out a coordinated program for monitoring the pollution of the Nestos River. The second was the protection and restoration of the ecosystem through the education of young engineers and the transfer of experiences and scientific knowledge across the borders.     

Solid-phase microextraction to monitor the sonochemical degradation of polycyclic aromatic hydrocarbons in water

Solid-phase microextraction (SPME) coupled with GC-MS has been used to monitor the degradation of polycyclic aromatic hydrocarbons (PAHs) by ultrasound treatment. Immersion SPME sampling enabled the fast and solventless extraction of target contaminants at the low microg l(-1) concentration level. The developed protocol was found to be linear in the concentration range from 0.1 to 50 microg l(-1) for most target analytes, with the limits of detection ranging between 0.01 and 0.70 microg l(-1) and the relative standard deviations between 4.31 and 27%. The developed SPME protocol was used to follow concentration profiles of aqueous solutions containing 16 PAHs, which were subject to low frequency ultrasonic irradiation. At the conditions employed in this study (80 kHz of ultrasound frequency, 130 W l(-1) of applied electric power density, 30 microg l(-1) of initial concentration for each of the 16 PAHs), sonochemical treatment was found capable of destroying the lower molecular weight PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene and pyrene) within 120-180 min of irradiation. The higher molecular weight PAHs were more recalcitrant to ultrasound treatment.     

Reclamation with phytoremediation of area affected by sewage sludge at the Thessaloniki Wastewater Treatment Plant in Sindos (Greece)

The present research focused on the experimental investigation of phytoreclamation of areas affected by sewage sludge disposal and improving the quality of the sludge. It was conducted in two stages: laboratory and pilot applications. This paper reports on the first stage, which tested, under greenhouse conditions, the possibility of using various species of plants cultivated in the sludge from the Thessaloniki Wastewater Treatment Plant (ThWWTP, Greece) with different amendments. The results of the 30-day experiment showed that the quality of the output sludge material varied significantly in comparison to the input sludge material. These variations were considered as positive, as the output sludge obtained texture and structure, aeration conditions were improved, and the content of some trace metals, excess nutrients (e.g., P), and salts (of Na) were reduced. These were all influenced by both the type of treatment and the plant species used. In conclusion, the best treatments, T1, T3, and T4 (soil/sludge mixture 70%/30%, soil/sludge/gravel mixture 50%/25%/25%, and soil/sludge/gravel mixture 45%/45%/10%, respectively), and the best suited plant species, Helianthus annuus L. and Zea mays L., were proposed to be used in the pilot application (in situ) at the site within the ThWWTP.     

Perspectives for integrated municipal solid waste management in Thessaloniki, Greece

Local authorities need updated and reliable data on the quantity and the quality of the waste generated in their area, in order to establish an integrated solid waste management system capable of fulfilling regional and national waste management targets. This paper presents information about the quantity and the characteristics of the municipal solid waste generated in Thessaloniki, which is the second largest city in Greece. It is based on the results of three research programs investigating the evolution of municipal solid waste. The investigations were carried out over the last 20 years at the landfill of Thessaloniki by the same research group using statistically acceptable practices for sampling and hand sorting. The results show a great increase in the incoming quantities during the last years and a significant increase of the per capita generation. There is also a significant change in the composition, demonstrated mainly by a decrease in the organic fraction followed by an increase of packaging materials (paper and plastic).     

E. coli kinetics--effect of temperature on the maintenance and respectively the decay phase

The knowledge of enteric bacteria survival kinetic is very important for environmental scientists. Enteric bacteria andspecifically the fecal indicator bacteria are typically used to measure the sanitary quality of water for recreational, industrial, agricultural and water supply purposes. They are released into the environment with feces, and are then exposedto a variety of environmental conditions that eventually causetheir death. In general, it is believed that the fecal indicatorcannot grow in natural environments, since they are adapted to live in the gastrointestinal tract. Studies have shown that fecalindicator bacteria survive from a few hours up to several daysin surface water, but may survive for days or months in lake-sediments, where they may be protected from sunlight andpredators. We assume that pathogens similar to the fecal indicator bacteria die at the same rate as fecal indicator bacteria. Therefore, if we find relatively high numbers of fecalindicator bacteria in an environment, we assume that there is anincreased likelihood of pathogens being present as well. The kinetic of enteric bacteria survival in natural waters is affected by a large number of factors. One of them is the temperature. The aim of this contribution was the experimentalresearch of the survival kinetic of enteric bacteria applying a simple mathematical formula, which describes the survival kineticpredicting the decay phase at various temperatures. We aspire that the results will lead both to the solution of many engineering problems and to future research.