Online elemental analysis of process gases with ICP-OES: A case study on waste wood combustion

A mobile sampling and measurement system for the analysis of gaseous and liquid samples in the field was developed. An inductively coupled plasma optical emission spectrometer (ICP-OES), which is built into a van, was used as detector. The analytical system was calibrated with liquid and/or gaseous standards. It was shown that identical mass flows of either gaseous or liquid standards resulted in identical ICP-OES signal intensities. In a field measurement campaign trace and minor elements in the raw flue gas of a waste wood combustor were monitored. Sampling was performed with a highly transport efficient liquid quench system, which allowed to observe temporal variations in the elemental process gas composition. After a change in feedstock an immediate change of the element concentrations in the flue gas was detected. A comparison of the average element concentrations during the combustion of the two feedstocks showed a high reproducibility for matrix elements that are expected to be present in similar concentrations. On the other hand elements that showed strong differences in their concentration in the feedstock were also represented by a higher concentration in the flue gas. Following the temporal variations of different elements revealed strong correlations between a number of elements, such as chlorine with sodium, potassium and zinc, as well as arsenic with lead, and calcium with strontium.     

Shoreline management and its implications for coastal processes in the eastern part of the Rhône delta

The coastal fringe of the eastern part of the Rhône delta is a large area where activities related to ecological and economical interests have increased since the beginning of the century, including the salt industry of theCompagnie des Salins du Midi et des Salines de l’Est, the industrial complex ofFos-sur-Mer, tourism managed by the local authorities ofPort-Saint-Louis andArles, and dune restoration of the La Gracieuse spit undertaken by thePort Autonome de Marseille. The vulnerability of the area for changes brought about by these activities is linked to the extent of several coastal changes, whereas these changes are related to the physical functioning of the coastal fringe, such as coastal processes, but also to external components such as relative sea-level rise, subsidence, reduction of sediment input, human impact, etc. For many decades, coastline ‘protection’ in the eastern part of the Rhône delta has been undertaken to withstand erosional processes that offset beaches and retreat of the littoral. The use of different engineering structures illustrates the heterogeneity and differences in age of the various management policies. At the eastern side of the Rhône, thePort Autonome de Marseille, dealing with management, has opted for soft engineering structures using fences for dune restoration on the La Gracieuse spit. At the western side of the mouth, theCompagnie des Salins du Midi et des Salines de l’Est has been using hard engineering structures to combat erosion (rocks, groins, tetrapods, etc.). A brief assessment of the management efficiency is presented, including an analysis of the data collected concerning the survey of the zones where the structures were built. Their varying efficiency shows the important role played by the sediment supply to the littoral (solid river discharge) and the coastal hydro-sedimentary processes. In the eastern part of the Rhône river the success of the dune restoration is mainly due to the important sediment supply transported in this area by eastern drift currents. At the western part of the mouth, the decrease of sediment supply linked to erosional processes in the shallow off-shore beach has made the structures more vulnerable, and therefore, the activities of the salt industry. For this last threatened zone, three management scenarios are discussed by taking into account economical, physical and ecological parameters.     

Tolerance of Japanese knotweed <Emphasis Type="Italic">s</Emphasis>.<Emphasis Type="Italic">l</Emphasis>. to soil artificial polymetallic pollution: early metabolic responses and performance during vegetative multiplication

The expansion of invasive Japanese knotweed s.l. is of particular concern because of its aptitudes to rapidly colonize diverse environments, especially anthropized habitats generally characterized by their pollution with heavy metals. Whether the presence of heavy metals impacts the performance traits of this plant is a central question to better understand its invasive properties, though no controlled approach to assess these effects was yet reported. In this aim, we undertook greenhouse experiments where rhizome fragments of Japanese knotweed s.l. (Fallopia japonica and Fallopia × bohemica) were grown during 1 and 3 months, in a soil pot artificially polluted or not with heavy metals added in mixture (Cd, Cr, Pb, Zn). Our results showed that (i) the presence of heavy metals delayed rhizome regeneration and induced lowered plant part weights but did not affect plant height after 3 months; (ii) the effect of metals on the metabolic profiles of belowground part extracts was only detectable after 1 month and not after 3 months of growth, though it was possible to highlight the effect of metals independently of time and genotype for root extracts, and torosachrysone seemed to be the most induced compound; and (iii) the hybrid genotype tested was able to accumulate relatively high concentrations of metals, over or close to the highest reported ones for this plant for Cr, Cd and Zn, whereas Pb was not accumulated. These findings evidence that the presence of heavy metals in soil has a low impact on Fallopia sp. overall performance traits during rhizome regeneration, and has a rather stimulating effect on plant growth depending on pollution level.     

Simultaneous voltammetric determination of four triazine herbicides in water samples with the aid of chemometrics

A novel differential pulse voltammetry (DPV) method was developed for the simultaneous analysis of herbicides in water. A mixture of four herbicides, atrazine, simazine, propazine and terbuthylazine was analyzed simultaneously and the complex, overlapping DPV voltammograms were resolved by several chemometrics methods such as partial least squares (PLS), principal component regression (PCR) and principal component–artificial networks (PC–ANN). The complex profiles of the voltammograms collected from a synthetic set of samples were best resolved with the use of the PC–ANN method, and the best predictions of the concentrations of the analytes were obtained with the PC-ANN model (%RPE_T = 6.1 and average %Recovery = 99.0). The new method was also used for analysis of real samples, and the obtained results were compared well with those from the GC-MS technique. Such conclusions suggest that the novel method is a viable alternative to the other commonly used methods such as GC, HPLC and GC-MS.     

Thermophilic adaptation of a mesophilic anaerobic sludge for food waste treatment

As opposed to mesophilic, thermophilic anaerobic digestion of food waste can increase the biogas output of reactors. To facilitate the transition of anaerobic digesters, this paper investigated the impact of adapting mesophilic sludge to thermophilic conditions. A 5L bench scale reactor was seeded with mesophilic granular sludge obtained from an up-flow anaerobic sludge blanket digester. After 13 days of operation at 35 degrees C, the reactor temperature was instantaneously increased to 55 degrees C and operated at this temperature until day 21. The biomass was then fed food waste on days 21, 42 and 63, each time with an F/M (Food/Microorganism) ratio increasing from 0.12 to 4.43 gVS/gVSS. Sludge samples were collected on days 0, 21, 42 and 63 to conduct substrate activity tests, and reactor biogas production was monitored during the full experimental period. The sludge collected on day 21 demonstrated that the abrupt temperature change had no pasteurization effect, but rather lead to a biomass with a fermentative activity of 3.58 g Glucose/gVSS/d and a methanogenic activity of 0.47 and 0.26 g Substrate/gVSS/d, related respectively, to acetoclastic and hydrogenophilic microorganisms. At 55 degrees C, an ultimate gas production (Go) and a biodegradation potential (Bo) of 0.2-1.4 L(STP)/gVS(fed) and of 0.1-0.84 L(STP) CH(4)/gVS(fed) were obtained, respectively. For the treatment of food waste, a fully adapted inoculum was developed by eliminating the initial time-consuming acclimatization stage from mesophilic to thermophilic conditions. The feeding stage was initiated within 20 days, but to increase the population of thermophilic methanogenic microorganisms, a substrate supply program must be carefully observed.     

Photo-Fenton treatment of TNT contaminated soil extract solutions obtained by soil flushing with cyclodextrin

The technical feasibility and performances of coupling flushing abilities of cyclodextrin solutions for 2,4,6-trinitrotoluene (TNT) removal from contaminated soil and the ability of Photo-Fenton treatment for final disposal of soil extract solutions containing high TNT loads have been investigated at laboratory scale. Methylated-beta-cyclodextrin (MCD) has shown better ability than hydroxypropyl-beta-cyclodextrin (HPCD) to complex TNT. The MCD solution increased the aqueous concentration of TNT in soil extract effluents as much as 2.1 times the concentrations obtained during the water flush of the soil. TNT in soil extract solution has been treated by Photo-Fenton. Our results indicate that MCD has a beneficial effect on the degradation rates of TNT. This relative improvement of TNT degradation rate (1.3 time) in presence of high amounts of hydroxyl radical scavengers can be ascribed to the formation of a ternary complex (TNT-cyclodextrin-iron) which can direct hydroxyl radical reaction toward TNT. Complete mineralization of soil extraction solutions was not achieved and TNT degradation pathway has been elucidated in order to ensure that no potential toxic intermediate is left at the end of the treatment time. After successive TNT hydroxylations, oxidative opening of the TNT aromatic ring quickly occurred, leading to the accumulation of short chain carboxylic acids such as oxalic acid and formic acid.     

Down syndrome maternal serum marker screening after 18 weeks' gestation

Women having access to prenatal care late in pregnancy may still wish to benefit from maternal serum screening for Down syndrome. Therefore, we established reference values for α-feto protein (AFP) and free β-human chorionic gonadotrophin (β-hCG), and assessed the diagnostic value of maternal serum marker screening at 18–35 weeks' gestation based upon a series of 4072 sera from unaffected pregnancies and 118 sera from pregnant women with fetuses affected by Down syndrome. Using a 1/250 risk cut-off, a detection rate of 72.9% (95% CI = 71.5–74.3%) was achieved with a false-positive rate of 7.51% (95% CI = 6.71–8.3%). This was not significantly different from the percentages observed in our 14–17 weeks routine screening (50 596 patients): 71.9% (95% CI = 71.5–72.3%) and 6.48% (95% CI = 6.28–6.68%), respectively. Detection and screen-positive rates were, respectively, 51.3% (95% CI = 35.6–67.0%) and 5.95% (95% CI = 5.12–6.68%) in women aunder 35 years of age, and 84.8% (95% CI = 76.9–92.7%) and 24% (95% CI = 20.7–27.3%) in women aged 35 years and over. In conclusion, maternal serum marker screening is feasible at 18 weeks' gestation and later, which may be of interest in selected cases. Copyright © 2002 John Wiley & Sons, Ltd.     

POND SIZING FOR RATIONAL FORMULA HYDROGRAPHS1

ABSTRACT: The Modified Rational formula hydrograph and the Yarnell generalized rainfall chart are generally accepted procedures for sizing storm water detention ponds for small drainage areas. A procedure has been developed to choose the rainfall duration which, for a chosen return period, will result in the largest required storage volume of a detention pond. A graphical solution has been provided and its use has been described by application to an example.     

ADAPTATION OF FLOOD PEAKS AND DESIGN HYDROGRAPHS FROM GAGED TO NEARBY UNGAGED WATERSHEDS1

ABSTRACT: Equations were developed to transform peak flows and to adapt design hydrographs and unit hydrographs from gaged watersheds to ungaged watersheds with similar hydrologic characteristics. Dimensional analysis was used to develop adjustment equations for peak flow and time base, and these equations were reinforced with results from regional flood frequency research. The authors believe that the use of these transformation equations should yield more reliable flood peak values and hydrogrphs than the common use of empirical flood estimating curves or equations.     

Do male "long-distance calls" function in mate defense? A comparative study of long-distance calls in primates

Long-distance calls produced by males are common among vertebrate species. Several hypotheses have been proposed to explain features of male long-distance calls and their phylogenetic distribution in primates, but the putative functions of male long-distance calls have yet to be tested comprehensively. We used phylogenetic comparative methods to investigate hypotheses for the function of male long-distance calls. We focused on the mate defense hypothesis, which states that male long-distance calls function in intra-sexual competition for mates, but we also examined factors involving resource defense, mate attraction, and habitat. Phylogenetic reconstruction of male long-distance calls in 158 primate species indicates that the presence of male long-distance calls is the ancestral state. The carrying distance of male long-distance calls is correlated with the size of the home range, which is consistent with the role of male long-distance calls in defending mates, attracting mates, and defending resources. However, measures of male intra-sexual competition were not associated with the evolution of male long-distance calls. Evolutionary transitions were only partly correlated with factors related to mate attraction. Instead, the strongest correlates of male long-distance calls were activity period, body mass, home range, habitat and some measures of resource defense. Our results are consistent with long-distance call production as a costly signal, but detailed study within species is required to assess these costs and the functions of long-distance calls in individual cases. Electronic Supplementary Material is available if you access this article at http://dx.doi.org/10.1007/.