Experimental research of oily sawdust air gasification

This article shows oily sawdust gasification research on countercurrent installation. Experimental research was on a laboratory scale. The main purpose of the experiment was combustible gas production with higher CH₄ concentration. Gas concentrations like CO, CO₂, CH₄, H₂, and C_nH_m determine syngas composition. The technological parameter’s value defines experimental conditions. Value of this was fuel to air ratio. With fuel to air ratio change, syngas composition was a differential phenomenon where it depended on the process parameters like temperature. Additionally, evaluation of methane formation from CO, H₂, and CO₂ was done. Methanization coefficients were based on CO and CO₂ hydrogenation reactions. Component’s activity was in analogs way to syngas components changed.

     

Comparative life cycle analysis of municipal waste management systems: Kırklareli/Turkey case study

Environmental Science and Pollution Research - Waste-to-energy approaches are becoming increasingly important around the world, and municipal solid waste (MSW) as a renewable and sustainable energy...     

Removal efficiency of emerging micropollutants in biofilter wastewater treatment plants in tropical areas

Environmental Science and Pollution Research - We studied the removal of 61 emerging micropollutants, including illicit drugs, in a biofilter wastewater treatment plant located in the French Indies...     

Contribution of precursor compounds to the release of per- and polyfluoroalkyl substances (PFASs) from waste water treatment plants (WWTPs)

Per-and polyfluoroalkyl substances(PFASs) are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs,precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as well.Levels of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids(PFCAs and PFSAs), in 2015 the sum of polyfluoroalkyl phosphoric acid esters(PAPs) were 15–20 ng/g dry weight, the sum of fluorotelomer sulfonic acids(FTSAs) was 0.8–1.3 ng/g,and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2 ng/g. Persistent PFSAs and PFCAs were detected at 1.9–3.9 ng/g and 2.4–7.3 ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid(PFHxA), perfluorooctanoic acid(PFOA), perfluorohexane sulfonic acid(PFHxS), and perfluorooctane sulfonic acid(PFOS)had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%,respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment.     

Identification of structural breaks in the forest product markets: how sensitive are to changes in the Nordic region?

Forests play a fundamental role in the global carbon cycle and can be managed to mitigate greenhouse gas emissions and conserve or sequester carbon. Global policy and environmental changes can affect regional consumption of forest products, as well as inter-regional trade of forest goods and services. This study analyzes global and regional change impacts on the production, consumption and trade of forest products in two Nordic countries, Finland and Sweden. Annual data on removal and trade (1964–2012) for roundwood and sawnwood is used to identify structural breaks based on Chow tests. According to the analysis, the time period is divided into two periods: t1 (1964–1980) and t2 (1981–2012). In the first period, breaks occurred in 1975 and 1976 in the Finnish model and no break is found in the Swedish model. In the second period, we identify breaks in 1991 and 1992 for the Finnish model and in 2004, 2005 and 2006 for the Swedish model. Although our findings have broad empirical support, we do not identify any specific incident as a direct cause of the changes in the consumption and trade patterns of the two types of wood in these countries. The models and analysis presented here can serve as methodological tools for policymakers to better understand the effects of structural changes in the production of forest goods and services in the Nordic region and globally.     

Surface lipids of queen-laid eggs do not regulate queen production in a fission-performing ant

In animal societies, most collective and individual decision making depends on the presence of reproductive individuals. The efficient transmission of information among reproductive and non-reproductive individuals is therefore a determinant of colony organization. In social insects, the presence of a queen modulates multiple colonial activities. In many species, it negatively affects worker reproduction and the development of diploid larvae into future queens. The queen mostly signals her presence through pheromone emission, but the means by which these chemicals are distributed in the colony are still unclear. In several ant species, queen-laid eggs are the vehicle of the queen signal. The aim of this study was to investigate whether queen-laid eggs of the ant Aphaenogaster senilis possess queen-specific cuticular hydrocarbons and/or Dufour or poison gland compounds, and whether the presence of eggs inhibited larval development into queens. Our results show that the queen- and worker-laid eggs shared cuticular and Dufour hydrocarbons with the adults; however, their poison gland compounds were not similar. Queen-laid eggs had more dimethylalkanes and possessed a queen-specific mixture of cuticular hydrocarbons composed of 3,11?+?3,9?+?3,7-dimethylnonacosane, in higher proportions than did worker-laid eggs. Even though the queen-laid eggs were biochemically similar to the queen, their addition to experimentally queenless groups did not prevent the development of new queens. More studies are needed on the means by which queen ant pheromones are transmitted in the colony, and how these mechanisms correlates with life history traits.     

Detection of Viruses in Coastal Seawater Using <Emphasis Type="Italic">Mytilus Galloprovincialis</Emphasis> as an Accumulation Matrix

The purpose of this study was to demonstrate that shellfish can be used to detect enteric viruses in marine waters where they are present at very low concentrations. Aqua-cultured mussels were placed in the sea just off the mouth of a drainage channel affected by human and animal faecal contamination. Samples were taken from the channel, the sea and the mussels at intervals over two 4-week periods. The samples were tested to verify the presence of both rotaviruses and E. coli. Rotaviruses were detected by Real Time-PCR, typed by multiplex PCR and subsequently sequenced. E. coli was enumerated in water matrices by a filtering method and in mussels by the MPN method. The presence of E. coli in the examined matrices demonstrates contamination of faecal origin throughout the studied environments. Rotaviruses were recorded in channel waters, but not in sea water. In both experiments, rotaviruses were detected in mussels 21 and 28 days after being placed in the sea water off the channel mouth. The use of mussels thus enabled the detection of rotaviruses in waters where the high dilution rendered direct investigation impossible. This study indicates that mussels can be used in marine virological surveillance programs.     

Greenhouse gas mitigation and offset options for suckler cow farms: an economic comparison for the Swiss case

We assessed the economic suitability of 4 greenhouse gas (GHG) mitigation options and one GHG offset option for an improvement of the GHG balance of a representative Swiss suckler cow farm housing 35 Livestock units and cultivating 25 ha grassland. GHG emissions per kilogram meat in the economic optimum differ between the production systems and range from 18 to 21.9 kg CO₂-eq./kg meat. Only GHG offset by agroforestry systems showed the potential to significantly reduce these emissions. Depending on the production system agroforestry systems could reduce net GHG emissions by 66% to 7.3 kg CO₂-eq./kg meat in the most intensive system and by 100% in the most extensive system. In this calculation a carbon sequestration rate of 8 t CO₂/ha/year was assumed. The potential of a combination of the addition of lipids to the diet, a cover of the slurry tank and the application of nitrification inhibitors only had the potential to reduce GHG emissions by 12% thereby marginal abatement costs are increasing much faster than for agroforestry systems. A reduction of the GHG emissions to 7.5 kg CO₂-eq./kg meat—possible with agroforestry only—raised costs between 0.03 CHF/kg meat and 0.38 CHF/kg meat depending on the production system and the state of the system before the reduction. If GHG emissions were reduced maximally average costs ranged between 0.37 CHF/kg meat, if agroforestry had the potential to reduce net GHG emissions to 0 kg CO₂-eq., to 1.17 CHF/kg meat if also other options had to be applied.     

Population dynamics and regulation in the cave salamander <Emphasis Type="Italic">Speleomantes strinatii</Emphasis>

Time series analysis has been used to evaluate the mechanisms regulating population dynamics of mammals and insects, but has been rarely applied to amphibian populations. In this study, the influence of endogenous (density-dependent) and exogenous (density-independent) factors regulating population dynamics of the terrestrial plethodontid salamander Speleomantes strinatii was analysed by means of time series and multiple regression analyses. During the period 1993–2005, S. strinatii population abundance, estimated by a standardised temporary removal method, displayed relatively low fluctuations, and the autocorrelation function (ACF) analysis showed that the time series had a noncyclic structure. The partial rate correlation function (PRCF) indicated that a strong first-order negative feedback dominated the endogenous dynamics. Stepwise multiple regression analysis showed that the only climatic factor influencing population growth rate was the minimum winter temperature. Thus, at least during the study period, endogenous, density-dependent negative feedback was the main factor affecting the growth rate of the salamander population, whereas stochastic environmental variables, such as temperature and rainfall, seemed to play a minor role in regulation. These results stress the importance of considering both exogenous and endogenous factors when analysing amphibian long-term population dynamics.     

Direct evidence of hybodont shark predation on Late Jurassic ammonites

Sharks are known to have been ammonoid predators, as indicated by analysis of bite marks or coprolite contents. However, body fossil associations attesting to this predator–prey relationship have never been described so far. Here, I report a unique finding from the Late Jurassic of western France: a complete specimen of the Kimmeridgian ammonite Orthaspidoceras bearing one tooth of the hybodont shark Planohybodus. Some possible tooth puncture marks are also observed. This is the first direct evidence of such a trophic link between these two major Mesozoic groups, allowing an accurate identification of both organisms. Although Planohybodus displays a tearing-type dentition generally assumed to have been especially adapted for large unshelled prey, our discovery clearly shows that this shark was also able to attack robust ammonites such as aspidoceratids. The direct evidence presented here provides new insights into the Mesozoic marine ecosystem food webs.