Search results for " Monitoring"
showing 10 items of 3129 documents
Water balance and pollutant removal efficiency when considering evapotranspiration in a pilot-scale horizontal subsurface flow constructed wetland in…
2016
Abstract In constructed wetland systems (CWs) for wastewater treatment, the performance of the system is affected by evapotranspiration (ET). This study shows the results of a series of water balance and pollutant removal efficiency analyses taken from a pilot horizontal-subsurface flow system (HSSFs) in the West of Sicily (Italy). The system comprised three separate units, one planted with Cyperus alternifolius L., one planted with Typha latifolia L. and an unplanted unit. The system was fed with urban wastewater from an activated-sludge wastewater treatment plant. The aims of the study were to determine water balance and pollutant removal rates when considering evapotranspiration in two r…
A hydrodynamic water quality model for propagation of pollutants in rivers.
2010
Numerical modelling can be a useful tool to assess a receiving water body's quality state. Indeed, the use of mathematical models in river water quality management has become a common practice to show the cause-effect relationship between emissions and water body quality and to design as well as assess the effectiveness of mitigation measures. In the present study, a hydrodynamic river water quality model is presented. The model consists of a quantity and a quality sub-model. The quantity sub-model is based on the Saint Venant equations. The solution of the Saint Venant equations is obtained by means of an explicit scheme based on space-time conservation. The method considers the unificatio…
A sustainable on-line CapLC method for quantifying antifouling agents like irgarol-1051 and diuron in water samples: Estimation of the carbon footpri…
2016
In this work, in-tube solid phase microextraction (in-tube SPME) coupled to capillary LC (CapLC) with diode array detection has been reported, for on-line extraction and enrichment of booster biocides (irgarol-1051 and diuron) included in Water Frame Directive 2013/39/UE (WFD). The analytical performance has been successfully demonstrated. Furthermore, in the present work, the environmental friendliness of the procedure has been quantified by means of the implementation of the carbon footprint calculation of the analytical procedure and the comparison with other methodologies previously reported. Under the optimum conditions, the method presents good linearity over the range assayed, 0.05-1…
A miniaturized method for estimating di(2-ethylhexyl) phthalate in bivalves as bioindicators.
2012
This work has developed a miniaturized method based on matrix solid phase dispersion (MSPD), using C18 as dispersant and acetonitrile-water as eluting solvent, for the analysis of di(2-ethylhexyl) phthalate (DEHP) in biota samples by capillary liquid chromatography coupled to in-tube solid phase microextraction and diode array detection. Recovery studies showed that the combination of C18-Florisil® was optimal using low amount of samples (0.1 g) and with low volumes of acetonitrile-water (2.6 mL 1:3.25, v/v). The sample is processed in less than 30 min, no evaporation step is required. The proposed method was applied to the analysis of DEHP in mussels and of the coastal waters in which they…
Enzymatic biodiesel: Challenges and opportunities
2014
The chemical-catalyzed transesterification of vegetable oils to biodiesel has been industrially adopted due to its high conversion rates and low production time. However, this process suffers from several inherent drawbacks related to energy-intensive and environmentally unfriendly processing steps such as catalyst and product recovery, and waste water treatment. This has led to the development of the immobilized enzyme catalyzed process for biodiesel production which is characterized by certain environmental and economical advantages over the conventional chemical method. These include room-temperature reaction conditions, elimination of treatment costs associated with recovery of chemical…
Cost-benefit analysis: A comparison between conventional and organic olive growing in the Mediterranean Area
2015
The conversion from conventional to organic management of olive growing has many benefits, such as increase of biodiversity, reduction of soil erosion and lower environmental impact. Since olive represents a main crop in the Mediterranean area, from a social, economic as well as environmental point of view, the aim of this paper has been to determine if the conversion from conventional to organic olive growing can increase the profitability of the farmer in Sicilian farms. Economic analysis has been carried out by means of cost-benefit analysis and financial indicators (NPV, B0/C0, IRR) show that organic growing would allow a better profitability for organic olive farms respect to conventio…
Comparing modified biological monitoring working party score system and several biological indices based on macroinvertebrates for water-quality asse…
2005
Abstract Macroinvertebrate communities from the lower Nysa Klodzka River catchment, southern Poland, were analyzed seasonally, in order to assess changes in their composition and structure, in relation to water quality. Two major groups of sites, differing in both morphological structure and taxonomical composition by cluster analysis, were identified within the catchment area. Wider and deeper sites, located along the Nysa Klodzka River, were associated with the dominance of Chironomidae. Sites assigned along tributaries were characterized by a diversified structure of dominant taxa, including Oligochaeta, Hirudinea, Crustacea, Trichoptera, Ephemeroptera and Diptera. The performance of the…
Potential for large-bodied zooplankton and dreissenids to alter the productivity and autotrophic structure of lakes.
2014
While limnological studies have emphasized the importance of grazers on algal biomass and primary production in pelagic habitats, few studies have examined their potential role in altering total ecosystem primary production and it's partitioning between pelagic and benthic habitats. We modified an existing ecosystem production model to include biotic feedbacks associated with two groups of large-bodied grazers of phytoplankton (large-bodied zooplankton and dreissenid mussels) and estimated their effects on total ecosystem production (TEP), and the partitioning of TEP between phytoplankton and periphyton (autotrophic structure) across large gradients in lake size and total phosphorus (TP) co…
Effects of eutrophication and organic loading on the occurrence of profundal harpacticoids in a lake in southern Finland.
1992
Harpacticoids made up 19 and 30% of the meiobenthos proper by number and 39 and 55% by biomass at maximum depths and a depth of 20 m, respectively, in Lake Paijanne. Harpacticoids accounted for higher proportions of the total meiobenthos in oligotrophic and unpolluted areas than in polluted areas. Seven species were identified, with Canthocamptus staphylinus confined to semi-lotic areas influenced by organic pollution from a pulp mill. Other species exhibited somewhat different distributions in oligotrophic and mesotrophic areas. Harpacticoid densities were most closely correlated with oxygen content and phytoplankton biomass, and correlations with environmental values were closer at maximu…
Meiofauna ratios as environmental indicators in the profundal depths of large lakes.
1995
Two sets of samples from Lake Paijanne and one from Lake Ladoga were used to examine the relations between the meiofauna and environmental variables. The most obvious indicators of an unpolluted environment were, in order of importance, the true meiofauna/total meiofauna ratio, the proportion of Aeolosomatidae, the proportion of Harpacticoida (excluding C. staphylinus), the meiofauna/macrofauna biomass ratio, the proportion of Naididae and the A. crassa + P. schmeili/true meiofauna ratio. Conversely, the clearest indicators of a polluted environment were the proportion of resting stages of Cyclopinae, the Nematoda/non-resting Copepoda ratio, and the proportions of Tubificidae, Oligochaeta, …