Interrelationships of pollution load index, transfer factor, and concentration factor under the effect of sludge

A greenhouse experiment was conducted during 2010–2011. A complete randomized blocks design was used including seven treatment levels of sludge(tons per hectare), i.e., 0, 6, 12, 18, 24, 30, and “30+ treated wastewater”, in four replications. Lettuce (Lactuca sativa L var longifolia) was chosen as a test plant. The purpose of the experiment was to study the relationships between soil Pollution Load Index, heavy metal transfer factor, and concentration factor and to determine optimum concentration factor values. The following were found: several mathematical relationships were established between the above parameters that could be used for the study of heavy metal accumulation in soils and plants under the effect of the applied sludge. They can be also used for the calculation of one of the above parameters as a function of the others. Based on the experimental data, the optimum concentration factor for several heavy metals were determined by multiple linear regression analysis, expressing the concentration factor as a function of the maximum dry lettuce matter yield, and of optimum/minimum heavy metal content of plant dry matter. The mean value of the calculated concentration factor obtained for each separate metal was: Zn, 2.93; Cd, 0.39; Co, 1.47; and Ni, 0.52.     

Evaluating contamination of dredges and disposal criteria in Greek coastal areas

Sediments were collected from areas that were going to be dredged located at six small Greek ports, as well as from possible disposal areas. In order to assess the contamination level of dredged material, the samples were analysed for pH, organic matter, the metals Cd, Pb, Hg, Cr, Ni, Cu, Zn and major organic compounds (PAHs, PCBs). The sediments' quality was evaluated by two approaches: (i) by classifying each area according to two sets of Sediment Quality Guidelines (SQGs) and (ii) by calculating the contamination factors and degree for each area. The results showed that organic compounds were detected in trace amounts in 14% of the port samples belonging to the PAHs group. The characterization of the sediment samples was based on the metals' concentration showing that the majority of the areas to be dredged (80%) are classified as of medium-low contamination according to the SQGs. However, according to the contamination degree, only 30% of the areas are classified as of low contamination, while 40% as of moderate contamination and 30% of the areas as of considerable contamination. From the point of view of "no disturbance" of the ecosystem, decisions about dumping should be taken only after evaluating the material to be dredged. If the SQGs are exceeded, dumping must be forbidden. Otherwise, further evaluation is needed based on the comparison with the receiving area, i.e. by estimating the contamination degree. Dumping could be allowed if the contamination degree is found to be below moderate.     

Concentrations of persistent organic pollutants and organic matter characteristics as river sediment quality indices

Selected persistent organic pollutants – polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides – were determined in sediments, soils, and crops from the Asopos River area, Greece. The river has been receiving industrial effluents for the last 40 years and has been recently found to be polluted with metals. Sediments were collected in the dry (May) and wet (February) season. Agricultural soils and cultivated crops were sampled from adjacent fields. Polychlorinated biphenyls were below the limit of detection in all samples. In one tomato and two soil samples, DDT and DDE were found. Polycyclic aromatic hydrocarbons were observed in 5% of the sediments and in concentrations ranging from 4 to 57 μg kg^?1 dry weight, quite below sediment quality guidelines. Diagnostic ratios of polycyclic aromatic hydrocarbons indicated a strong influence of petrogenic point discharges. In the sediments, silicate minerals dominate over carbonates and the organic carbon content ranges from 0.4% to 3.5%, more than 70% being of natural origin. Compared to other rivers worldwide, the Asopos River was found to be not contaminated with persistent organic pollutants. Point loadings of organic pollutants were evident but continuous discharge is not occurring throughout the river basin.     

Towards the harmonization of water-related policies for managing drought risks across the EU

Drought is recognized as a major issue in the EU, particularly in the Mediterranean region, posing risks to the environment as well as to local and regional economies. The EU policy on water management is continuously evolving, particularly in relation to water scarcity and drought. Starting with the Water Framework Directive (2000/60/EC), which sets the general policy framework for water management across the EU, the EC Communication on Water Scarcity and Drought COM(2007) 414 final set the priorities for managing water scarcity and drought risks. Three follow-up reports (COM(2008) 875 final, COM(2010) 228 final and COM(2011) 133) highlighted achievements and yearly progress within the context of the implementation of the Water Framework Directive, whereas guidance has further been provided through the issue of Technical Reports (e.g. the EC Water Scarcity Drafting Group Technical Report 2008–023 on Drought Management, Including agricultural, drought indicators and climate change aspects). The 2012 EU Water Review (“Blue Print for Safeguarding European Waters” will assess achievements and identify further requirements towards long-term sustainable water use across the EU. However, a harmonized approach on drought risk management at the EU level is still lacking, whereas drought risk in several countries and regions has not been yet fully integrated in water management and relevant sectoral policies.This paper focuses on a proposed paradigm shift from crisis to risk management, which is currently gaining ground as a means of reducing societal vulnerability to droughts. The paper underlines the importance of engaging into risk assessment and management practices and identifies policy gaps and requirements for further improvement of the drought management policy framework at all levels of governance: at the EU, at the national and at the river basin and regional levels.     

On the use of metal-organic frameworks for the extraction of organic compounds from environmental samples

Environmental Science and Pollution Research - The determination of trace metals and organic contaminants in environmental samples, such as water, air, soil, and sediment, is until today a...     

Greenhouse gas emissions from two hydroelectric reservoirs in Mediterranean region

Water reservoirs are used for many purposes, such as water supply, irrigation, flood mitigation, and hydroelectric energy generation. Although hydroelectric energy is considered “green,” many studies show that the construction of a reservoir enhances greenhouse gas (GHG) emissions at the transformed area. These emissions, mainly of CO₂, CH₄, and N₂O gases, depend on the age of the reservoir, landscape and soil composition, fauna and flora remnants of the impounded area, climatic conditions, and basin runoffs. Consequently, GHG emissions significantly vary between reservoirs and depending on local specificities. Several studies have investigated GHG emissions from reservoirs around the world, focusing mainly on reservoirs located in cold regions, temperate regions, and tropical regions. Research is lacking for reservoirs in Mediterranean countries, like Greece, and similar regions. This work initially assesses the net GHG emissions of a newly created reservoir (Ilarion est. 2012) in Western Macedonia, Greece. The methodology for net GHG emission calculation was based on the use of literature data concerning pre-impoundment emission factors and local specificities of the reservoir (terrain type, canopy cover), as well as on the 2-year measurement data that were collected using a “static floating chamber.” Furthermore, in this work, the gross GHG emissions of an older, in-line reservoir (Polyfytos est. 1974) were also calculated, based on 2-year measurement data. The results show that the global warming potential (GWP) of the reservoirs is dictated by methane emissions; it minimizes during winter and spring and maximizes during summer and autumn. Hydroelectric energy production at Ilarion Reservoir results in 32 to 97 times less total CO₂ equivalent emissions in comparison to fossil fuels, while at Polyfytos Reservoir only 8 to 24 times less (based on gross emissions). It appears that the impact of a reservoir’s morphology on GHG emissions is more significant than that of a reservoir’s age.     

Occurrence of endocrine disrupters and selected pharmaceuticals in Aisonas River (Greece) and environmental risk assessment using hazard indexes

Purpose

The presence of four phenolic endocrine disrupting compounds (EDCs: nonylphenol [NP], NP monoethoxylate[NP1EO], bisphenol A [BPA], triclosan, [TCS]) and four nonsteroidal anti-inflammatory drugs (NSAIDs: ibuprofen[IBF], ketoprofen [KFN], naproxen [NPX], diclofenac [DCF]) in a Greek river receiving treated municipal wastewater was investigated in this study.

Methods

Samples were taken from four different points of the river and from the outlet of a sewage treatment plant (STP) during six sampling campaigns, and they were analyzed using gas chromatography?Cmass spectrometry.

Results

According to the results, EDCs were detected in almost all samples, whereas NSAIDs were detected mainly in wastewater and in the part of the river that receives wastewater from the STP. Among the target compounds, the highest mean concentrations in the river were detected for NP (1,345?ng?L^?1) and DCF (432?ng?L^?1). Calculation of daily loads of the target compounds showed that STP seems to be the major source of NSAIDs to the river, whereas other sources contribute significantly to the occurrence of EDCs. The environmental risk due to the presence of target compounds in river water was estimated, calculating risk quotients for different aquatic organisms (algae, daphnids, and fish). Results denoted the possible threat for the aquatic environment due to the presence of NP and TCS in the river.     

On the use of PAH molecular diagnostic ratios in sewage sludge for the understanding of the PAH sources. Is this use appropriate?

The concentrations ratios of specific pairs of polycyclic aromatic hydrocarbons (PAHs) are widely used for the qualitative determination of the PAHs sources. These ratios are called PAHs molecular diagnostic ratios and are commonly used for PAHs concentrations in air, soils and sediments. Some scientists have extended the use of these ratios also for sewage sludges, suggesting that calculation of these ratios by individual PAHs concentrations can be as effective as in soils or sediments. This paper describes the reason why the PAH molecular ratios calculated from sewage sludge concentrations should not be used for the understanding of the PAH sources.     

Derivation of ozone flux-yield relationships for lettuce: a key horticultural crop

Ozone flux-response relationships were derived for lettuce, employing a multiplicative approach to model the manner in which stomatal conductance is influenced by key environmental variables, using a dataset collected during field experimentation in Crete and yield-response relationships derived from parallel open-top chamber experiments. Regional agronomic practices were adopted throughout. Computed versus measured data revealed that the derived model explained 51% (P<0.001) of the observed variation in stomatal conductance. Concentration-based indices were compared with flux-based indices. Analyses revealed a significant relationship between accumulated stomatal ozone flux and yield employing flux threshold cut-offs up to 4 nmol m(-2) s(-1). Regressions employing very low or zero flux thresholds resulted in the strongest yield-flux relationships (explaining approximately 80% (P<0.05) of the variation in the dataset).