Global NEST Journal

The aim of this study is to investigate the effect of sub-irrigation with untreated and treated municipal wastewater on soil chemical parameters. Three treatments were used: untreated wastewater (U), treated wastewater (T) and tap water (W), being the control treatment, in two soil types, Sandy loam (SL) and Loamy sand (LS). A sub-irrigation system including pots filled with soil was installed in one of the greenhouses of the Agricultural University of Athens. The wastewater used was applied in the soil in pots at a depth of 10cm and 20cm. In order to determine the changes of chemical parameters at the point where the emitter was placed, the soil was divided into two zones according to depth: (zone I -upper) and (zone II-lower). The pH, CaCO3 %, K μg/g, Na μg/g, P μg/g and EC μmhos/cm, were determined. Statistically significant differences (p <0, 05) in sodium Na+ μg/g and electrical conductivity EC were observed, only in LS soil. Phosphorus and sodium increased in zone (I) for SL soil (p <0, 05). Electrical conductivity and potassium increased in zone (I), while CaCO3% and pH increased in zone (II) for LS soil (P <0, 05).

The distribution, stocks and fluxes of Mo were examined in a mountainous fir forest in Greece in two hydrological years. In both years, the fluxes of Mo in throughfall were lower than those in bulk deposition implying Mo retention and probably uptake by tree canopies. The Mo concentration was appreciable in soil solution but its fluxes were lower than those in throughfall. The Mo fluxes in both bulk and throughfall deposition were higher than those in litterfall, a finding that stresses the importance of the hydrological cycle for this metal. The Mo concentration in the older twigs in the standing trees were higher than the current year ones most probably due to the existence of dry deposition. The concentrations of total Mo in soils reflected the nature of the sedimentary rocks underlying the soil and increased with depth following the clay concentration gradient. The available (oxalate extractable) Mo in soils ranged from 3% to 14% of the total Mo. In terms of the stocks of Mo, the soil had by far the highest values in both total and available Mo. The needs of the fir plants for Mo uptake are covered by the available Mo in the mineral soil layers, whereas the Mo content in the organic horizon may not be adequate for this purpose.

The present study simulates the flow and temperature fields in a street canyon caused by solar heating of road and building surfaces, in either calm and weak wind conditions. Six scenarios, formed by changing the sources of heat fluxes, the wind speed (0, 1 and 3 m s^-1) and direction (±), are examined, at 12:00 solar time during June 21 in the city of Patras. A 1000-W m^-2 heat flux is considered to come out from the road surface and/or 400-W m^-2 heat flux from the left building face. These values correspond to the most intense solar radiation conditions. A computational fluid dynamics (CFD) simulation is performed and the results show that the weak winds cause increased temperatures near the building faces compared to calm conditions, due to intense vortices that entrap air masses, while moderate winds contribute to an improvement of temperatures below those for calm conditions. The entrapment of air masses may also cause increase of pollutant concentrations deteriorating both outdoor and indoor air quality and thermal comfort conditions.

Waste management is one of the most crucial part of the sustainability concept. In Turkey, waste management of the small household appliances under waste of electrical and electronic equipment (WEEE) category still remains as an issue to handle although its production is very large and long-established. The main reason is that many of the household appliances’ wastes are not properly treated in waste management process despite the fact that Turkey is a country which has recovery and collection targets. This outboard of wastes non-treated in an environmentally friendly way, such as recycling or reuse, gives rise to environmental damage. The aim of this paper is to integrate a system dynamics and fuzzy cognitive mapping model in order to evaluate and develop recovery options of small household appliances’ wastes which are not treated according to the regulations in Turkey. The first part of the proposed model is to build a system dynamics model by developing recovery options for small household appliances’ waste management while the second part is to evaluate the relations between supporting factors of recovery options by using Fuzzy Cognitive Mapping.