Environmental hazard assessment of coal fly ashes using leaching and ecotoxicity tests.

The environmental hazard of six coal fly ash samples collected from various coal incineration plants were examined in the present study, using various leaching tests along with physicochemical and ecotoxicological analyses. Physicochemical analyses indicated that the concentration of Ba, Cr, Mo, Se, sulfates and total dissolved solids (TDS) exceeded the threshold values, according to the European Council decision 2003/33/EC for inert, non-hazardous or hazardous waste. The highest sensitivity, among examined organisms, was presented by Daphnia magna and was ascribed to the lowest tolerance of the organism to Cr. The toxic effect profile of the leachates toward Vibrio fischeri revealed that its bioluminescence was significantly altered by the presence of heavy metals in the leachates (such as Cu, Ni and Zn) in low or sub-lethal doses. Although the toxicity of the leachates toward Pseudokirchneriella subcapitata was relatively high, the correlation between the toxicity and heavy metals concentration was rather poor, indicating the significance of the bioavailability of constituents and the importance of toxicity testing. Based on the classification of the samples resulted by physicochemical analyses of the leachates and the results of ecotoxicity tests, Physicochemical and Ecotoxicological indices were also defined, for an overall evaluation of the environmental impact assessment of fly ashes. The suggested indices showed that ecotoxicity tests were in some cases inconsistent with the outcome of waste classification based on physicochemical analyses. Moreover, the examination of leaching protocols and obtained results showed that one stage leaching test (L/S=10 L/kg) underestimated the fly ash classification, when compared with the two stage test EN 12457-3 at the cumulative ratio L/S=10 L/kg. In addition, the application of availability test NEN 7341 provided useful results about the ecotoxicity wastes. Thus, NEN 7341 is strongly suggested for the implementation of such studies, since the bioavailability of constituents may not be altered by pH adjustment tactics and pH-originated toxicity effects may be avoided.

Assessment of wastewater effluent quality in Thessaly region, Greece, for determining its irrigation reuse potential.

The objective of the present study is to assess wastewater effluent quality in Thessaly region, Greece, in relation to its physicochemical and microbiological burden as well as its toxic potential on a number of organisms. Wastewater may be used for agricultural as well as for landscape irrigation purposes; therefore, its toxicity potential is quite important. Thessaly region has been chosen since this region suffers from a distinct water shortage in summer period necessitating alternative water resources. During our research, treated effluents from four wastewater treatment plants operating in the region (Larissa, Volos, Karditsa, and Tirnavos) were tested for specific physicochemical and microbiological parameters [biochemical oxygen demand (BOD(5)), chemical oxygen demand (COD), total suspended solids (TSS), pH, electrical conductivity, selected metals presence (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn, As), and fecal coliforms' (FC) number]. The effluents were also tested for their toxicity using two different bioassays (Daphnia magna immobilization test and Phytotoxkit microbiotest). The findings were compared to relative regulations and guidelines regarding wastewater reuse for irrigation. The results overall show that secondary effluents in Thessaly region are generally acceptable for reuse for irrigation purposes according to limits set by legislation, if effective advanced treatment methods are applied prior to reuse. However, their potential toxicity should be closely monitored, since it was found that it may vary significantly in relation to season and location, when indicator plant and zooplankton organisms are used.

Marginalised social groups in contemporary weee management within social enterprises investments: A study in Greece.

This paper deals with the creation of appropriate conditions aimed at developing social services for reuse and recycling of waste electrical and electronic equipment (WEEE), by the inclusion of handicapped and Roma people in the workforce. Application areas for the project are the Hellenic (Greek) regions of Thessaly and North Aegean, where these groups suffer from professional and social exclusion. The efforts to reduce unemployment in the two aforementioned groups, together with the efforts to implement related Greek and European legislation for sustainable WEEE management, are examined here. Furthermore, networking and cooperation at local, regional and central levels between small enterprises, entrepreneurships and local authorities are examined, so that these social enterprises and their corresponding investments may support the development of the Greek alternative WEEE recycling system.