Sustainable tourism management and development of a Greek coastal municipality

A process is presented to facilitate the sustainable management and development of tourist destinations. Based on a specific reforming of the Limits of Acceptable Change planning system and combined with the Tourism Carrying Capacity concept into a common framework, specific steps are described to integrate environmental, social and economic information of a tourist destination into indicators, which are afterwards compared with reference conditions. The Leopold matrix is applied to identify and classify restrictions of development and provide the basis for negotiations between managers, stakeholders and local communities. Through a feedback process of continuous monitoring and adjustment, the aim is to focus developmental activities on restricting factors until all indicators upgrade to reference. A case study at a Greek coastal municipality (Ilida – western Greece) is applied to demonstrate the process. Activity zones are identified and 18 indicators are selected. Results suggest high potential for tourism development of the area. However, low scores are assigned to 8/18 indicators, reflecting restrictions, requiring priority under a sustainable development plan. The proposed process offers managers and stakeholders the ability to easily visualize/identify restrictions and assign developmental priorities within a step-by-step upgrading process, toward the sustainable management and development of tourist destinations.     

Leaching of metals in buried industrial sludge,spiked with cadmium,chromium and lead. Results of a trial

Sludge resulting from industrial waste water treatment at the industrial area of Patras, Greece, was spiked with cadmium, chromium and lead and entrenched in 4 experimental trenches. Soil from the unsaturated zone and sludge from the trenches were sampled at successive time points over a period of 14 months to monitor the movement of metals. Results showed that 94% of cadmium and 80% of lead but only 32% of chromium migrated from the sludge just 14 months after the entrenchment.

At the end of this time the buried sludge could be considered stabilised, as indicated by the total nitrogen content. Cd content in underlying soil layers at 3 m depth showed an increase in the first 7 months followed by a decrease, afterwards. Soil Pb concentration at 3 and 6 m depth was significantly high, in relation to it's initial concentration 14 months after the entrenchment. Pb and Cd in the soil samples were negatively correlated. It is suggested that lead displaces cadmium in the sediments.     

Effect of body mass,temperature and food deprivation on oxygen consumption rate of common cuttlefish <Emphasis Type="Italic">Sepia officinalis</Emphasis>

Predictions of short and long term changes in Sepia officinalis metabolism are useful, since this species is both economically important for aquaculture and also is an ideal experimental laboratory organism. In this study standard and routine oxygen consumption rates of newly hatched and juvenile laboratory raised cuttlefish S. officinalis ranging between 0.04 and 18.48 g dry body mass (Dm), were measured over a range of temperatures (10, 15, 20 and 25°C). The mass exponent (b) ranged between 0.706 and 0.992 for standard oxygen consumption and between 0.694 and 0.990 for routine oxygen consumption. Oxygen consumption scaled allometrically (b = 0.7) with body mass for cuttlefish <2 g Dm and isometrically (b = 1) thereafter. No significant differences were apparent amongst the slopes of oxygen consumption and body mass at different temperatures for standard and routine oxygen consumption. However, the intercepts differed significantly amongst the regression lines, indicating a significant effect of temperature on the magnitude of oxygen consumption. The combined effect of temperature (T) and dry body mass (Dm) are best described by the following equations: cuttlefish <2 g, MO₂ = 0.116Dm^0.7111.086 ^T and >2 g, MO₂ = 0.076Dm^0.9831.091 ^T for standard oxygen consumption; cuttlefish <2 g, MO₂ = 0.538Dm^0.7291.057 ^T and >2 g, MO₂ = 0.225Dm^0.9621.081 ^T for routine oxygen consumption. Using these equations it was estimated that a cuttlefish of 1 g Dm held at 20°C, eating 5% Dm day⁻¹ and undergoing standard and routine metabolism consumes 21.3 and 35.4%, respectively of its total daily energy intake. Juvenile cuttlefish (3.32–5.08 g Dm) held at 15°C and deprived of food for 27 days maintained a stable standard oxygen consumption rate for the first 6 days following starvation. By the 18th day without food, oxygen consumption rate had declined by 53% and further declined to 65% below the standard oxygen consumption rate on the 27th day. Upon resumption of feeding, the respiration rate returned immediately to the initial level prior to food deprivation. The present study defines the basic energy requirements and general physiological state of young cuttlefish at temperatures of 10–25°C with and without food.     

3D numerical modelling of turbidity currents

During floods, the density of river water usually increases due to a subsequent increase in the concentration of the suspended sediment that the river carries, causing the river to plunge underneath the free surface of a receiving water basin and form a turbidity current that continues to flow along the bottom. The study and understanding of such complex phenomena is of great importance, as they constitute one of the major mechanisms for suspended sediment transport from rivers into oceans, lakes or reservoirs. Unlike most of the previous numerical investigations on turbidity currents, in this paper, a 3D numerical model that simulates the dynamics and flow structure of turbidity currents, through a multiphase flow approach is proposed, using the commercial CFD code FLUENT. A series of numerical simulations that reproduce particular published laboratory flows are presented. The detailed qualitative and quantitative comparison of numerical with laboratory results indicates that apart from the global flow structure, the proposed numerical approach efficiently predicts various important aspects of turbidity current flows, such as the effect of suspended sediment mixture composition in the temporal and spatial evolution of the simulated currents, the interaction of turbidity currents with loose sediment bottom layers and the formation of internal hydraulic jumps. Furthermore, various extreme cases among the numerical runs considered are further analyzed, in order to identify the importance of various controlling flow parameters.     

Effect of a starch-rich industrial wastewater on the acid-phase anaerobic digestion process.

This research investigated the effect of varying the starch-rich, industrial-wastewater component of mixtures with municipal wastewater fed to an anaerobic digester. A laboratory-scale, completely-mixed anaerobic digester was operated at an HRT of 30 h, an SRT of 10 d, and an ambient temperature of 21.5 +/- 1.5 degrees C. The industrial-to-municipal ratios tested were 1:3, 1:1, 3:1, and 100% industrial by volume. Steady-state, acidogenic conditions were achieved for all runs, except 100% industrial. The pH was observed to drop substantially as the industrial constituent of the feed increased. Net volatile fatty acids (VFA) production reached a plateau of approximately 800 mg/L at ratios of 1:1 and higher, while volatile suspended solids (VSS) reduction steadily increased as the industrial component rose. The specific VFA and soluble chemical oxygen demand (SCOD) production rates leveled off at approximately 0.070 mgVFA/ mgVSS.d and 0.124 mgSCOD/mgVSS.d, respectively, for all the mixtures investigated, except for 100% industrial. In this latter case, both rates dropped dramatically. Finally, acetic and propionic acid concentrations fell as the industrial proportion of the mixture increased. This was compensated by a rise in butyric acid production.     

Potentially toxic elements in groundwater: a hotspot research topic in environmental science and pollution research

Environmental Science and Pollution Research - A scientometric analysis based on the Scopus database was conducted to provide insight into research activities on the occurrence of potentially toxic...     

Biodegradation behavior of agricultural pesticides in anaerobic batch reactors

This study explored the biodegradation potential of two agricultural pesticides (2,4-D and isoproturon) as well as their effect on the performance of the anaerobic digestion process. Three 3.5 L batch reactors were used, having the same initial isoproturon concentration (25 mg/L) and different 2,4-D concentrations (i.e. 0, 100, or 300 mg/L, respectively). All systems were fed with equal amounts of primary sludge and digested sludge and operated at the low mesophilic range (32 +/- 2 degrees C). Following an acclimation period of approximately 30 days, complete 2,4-D removal was achieved, whereas isoproturon biodegradation was practically negligible. The presence of 2,4-D did not have a direct effect on acidogenesis since soluble organic carbon [expressed either as volatile fatty acids (VFAs) or as total organic carbon (TOC)] peaked within the first 10 days of operation in all bioreactors. Utilization of VFAs however appeared to follow two distinct patterns: one pattern was represented by acetate and butyrate (i.e. no acid accumulation) while the other was followed by propionate, isobuturate, valerate and isovalerate (i.e. acid accumulation, duration of which was related to the initial 2,4-D concentration). On the whole, all reactors exhibited a successful digestion performance demonstrated by complete VFAs utilization, considerable gas production (containing 45 to 65% methane by volume), substantial volatile suspended solids (VSS) reduction (42 to 50%), as well as pH and alkalinity recovery.     

Methods for joint inference from panel survey and demographic data

A number of methods for joint inference from animal abundance and demographic data have been proposed in recent years, each with its own advantages. A new approach to analyzing panel survey and demographic data simultaneously is described. The approach fits population-dynamics models to the survey data, rather than to a single index of abundance derived from them and thus avoids disadvantages inherent in analyzing such an index. The methodology is developed and illustrated with British Lapwing data, and the results are compared with those obtained from existing approaches. The estimates of demographic parameters and population indices are similar for all methods. The results of a simulation study show that the new method performs well in terms of mean squared error.