45 research outputs found

    The role of mineral phases in the biogas production technology

    Get PDF
    In the field of electric power industry, renewable energy sources, fertilisers, reclamation, and waste management, biomass is widely studied and used. Minerals are present in every step of biogas transformation, but their forms, occurrence, and composition have not been studied yet. However, there is no comprehensive study research that would address the presence of mineral phases in the process of biogas production. This aim of the study is determination of the amount and composition of the mineral phases present in fermentation residues resulting from different production technologies. Digestate mineral composition was analysed using 46 samples from agricultural biogas plants and university testing biogas reactor. The majority of samples contained the amorphous phase. Minority phases consisted of quartz, albite, orthoclase, muscovite, and amphibole. Opal-CT was found in eleven samples (1.26 to 12.1% wt.). The elements present in gas-liquid fluids or in liquids, gases and aerosols within the biogas technology system may create mineral phases, namely the amorphous phase or the crystalline phase under certain conditions. Opal-CT may enter the fermenter as part of plant tissues referred to as phytoliths, or as an unwanted admixture of different origin. It may also originate from the present amorphous SiO2.Web of Science251595

    Temporal and Seasonal Variations of Silicate Svratka River and Sediment Characterization, Czech Republic: Geochemical and Stable Isotopic Approach

    Get PDF
    This study investigated weathering and hydrobiogeochemical processes in a silicate dominated watershed (Svratka river) in the Czech Republic in comparison with nearby carbonate dominated catchments. Elemental and isotopic analysis of river waters, particulates and sediments provided a more holistic view of weathering contributions, anthropogenic contamination, biological activity and evasion or sinks of CO2 to the atmosphere. In water samples, we determined total alkalinity after Gran 1974, and cations and anions were determined with inductively coupled plasma-optical emission spectrometer and ion chromatograph. δ13CDIC in water samples was determined with isotope ratio mass spectrometer. pCO2 and saturation indexes of calcite and dolomite were calculated with PHREEQC speciation program. Evasion fuxes were calculated after Broecker, 1974. Isotopic composition of carbon and nitrogen in particulate matter and sediments were determined with isotope ratio mass spectrometer. Mineral composition of sediments was determined with XRD method and elements with XRF method. Further enrichment factors of elements were calculated. The Svratka river, which is the major tributary of the Dyje river, is dominated by Ca2+ > Na+ > Mg2+ > K+ and HCO3 MINUS SIGN (as total alkalinity). Partial pressure (pCO2) concentrations range from close to 0-572-fold of atmospheric pressure. Isotopic composition of carbon in dissolved inorganic carbon (δ13CDIC) value ranged fromMINUS SIGN 13.3 toMINUS SIGN 8.0%o refecting degradation of organic matter and exchange with the atmosphere. Bicarbonate weathering intensity for the Svratka river at its mouth is 11.8 mol/(lDOT OPERATOR  km2 DOT OPERATOR  s), more on par with silicate terrains and lower than nearby carbonate watersheds. Isotopic composition of carbon (δ13C) and isotopic composition of nitrogen (δ15N) values of river sediment refect soil and temperate plant (C3 plant) values, while higher δ15N values could be attributed to application of organic fertilizers in lower reaches. The river sediments, which came from weathering of crystalline rocks, are dominated by silt size, geochemically less mature quartz, feldspar and muscovite particles. All the stream sediments examined revealed slightly increased amounts of Zn, Cu and Pb. However, using Al as the normalization element to calculate enrichment factors, Zn, Cu and Pb are only elevated downstream, related to industrial contamination. This study is important for local and global level since it deals with contribution of weathering rates and contribution of CO2 to the atmosphere in silicate watershed.O

    Prilagodba uzgojne dagnje Mytilus galloprovincialis Lamarck, 1819 u sjevernom Jadranu na uvjete u uzgajalištu i translokaciju

    Get PDF
    The ability of mussels to cope with environmental conditions depends on the species’ capacity to acclimate or adapt within its morphometric and physiological parameters. In the present study,we investigated the effect of aquaculture site and translocation on different stocks of Mediterranean mussel, Mytilus galloprovincialis Lamarck, 1819. We used shell morphological ratios (width/length, height/length and height/width) and allometric relationships (volume-length and shell weight-length) in addition to condition index (wet meat weight/total weight) and mortality to compare cultivated and translocated mussels from the northern Adriatic Sea, Croatia. Mussels were collected from five cultivation areas (Lim, Pomer, Raša, Vabriga and Budava), and then moved for three months to experimental station at marine protected area in Lim Bay. Differences between cultivated mussels suggested morphological plasticity, although translocation weakly affected allometric relationships. Decrease in condition index was pronounced in translocated mussels, indicating adaptation to different local environmental conditions. High post translocation mortality was observed in mussels transferred to the experimental area. Our study shows plastic response of M. galloprovincialis, which can provide a useful information of mussel stocks selection in aquaculture.Sposobnost dagnji da se nose s uvjetima okoliša ovisi o sposobnosti vrste da se prilagodi svojim morfometrijskim i fiziološkim obilježjima. U ovom radu smo istražili prilagodljivost mediteranske dagnje Mytilus galloprovincialis Lamarck, 1819 u akvakulturi i tijekom premještanja na novu lokaciju. Pored morfoloških omjera: širina/dužina, visina/dužina i visina /širina i alometrijskih odnosa (volumen/dužina i masa školjkaša/dužina) koristili smo indeks kondicije (masa mokrog tkiva /ukupna masa) i mortalitet dagnje kako bi usporedili primjerke dagnje iz uzgajališta s onima koje su translocirane. Jedinke dagnje uzorkovane su u pet uzgojališta (Lim, Pomer, Raša, Vabriga i Budava), a zatim je dio premješten na tri mjeseca na eksperimentalnu postaju na zaštićenoj morskoj površini u Limskom zaljevu. Razlike između primjeraka dagnji iz uzgajališta sugeriraju morfološku prilagodljivost. Translokacija dagnji je slabo utjecala na alometrijske odnose. Smanjenje indeksa kondicije izraženo je u translociranim dagnjama, što ukazuje na prilagodbu različitim uvjetima okoline. Također, primijećen je i mortalitet dagnji koje su translocirane u Lim. Naše istraživanje pokazuje morfometrijski i fiziološki odgovor M. galloprovincialis, koji može pružiti korisne informacijeo odabiru stoka dagnje u akvakulturi

    Data on stable isotopic composition of δ18O and δ15N in nitrate in groundwater, and δ15N in solid matter in the Varaždin area, NW Croatia

    Get PDF
    The Varaždin aquifer is the only source of drinking water for inhabitants of the Varaždin County. In the last decades, groundwater contamination with nitrate has become an increasing problem. Therefore, there is a need to define the origin of nitrate as the first step in groundwater remediation. The data in this article consist of δ18O and δ15N values in nitrate in groundwater, and δ15N in solid matter. Groundwater was sampled in the period from April 2018 to December 2019 at 10 different sites by pumping the wells, and directly in the gravel pit in Šijanec. Representative solid samples of plants, soil, manure, and synthetic fertilizers were collected from arable land in two field campaigns (July and October 2019). The presented dataset can be used as a baseline for identification of nitrate sources in groundwater and possible nitrate attenuation processes. The data is related to the research article “Tracking the nitrogen cycle in a vulnerable alluvial system using a multi proxy approach: case study Varaždin alluvial aquifer, Croatia.” [1]

    Isoscape of amount-weighted annual mean precipitation tritium (3H) activity from 1976 to 2017 for the Adriatic–Pannonian region – AP3H_v1 database

    Get PDF
    Tritium (3H) as a constituent of the water molecule is an important natural tracer in hydrological sciences. The anthropogenic tritium introduced into the atmosphere unintentionally became an excellent tracer of processes on a time scale of up to 100 years. A prerequisite for tritium applications is to know the distribution of tritium activity in precipitation. Here we present a database of isoscapes derived from 41 stations for amount-weighted annual mean tritium activity in precipitation for the period 1976 to 2017 on spatially continuous interpolated 1 km × 1 km grids for the Adriatic–Pannonian region (called the AP3H_v1 database), with a special focus on post-2010 years, which are not represented by existing global models. Five stations were used for out-of-sample evaluation of the model performance, independently confirming its capability of reproducing the spatiotemporal tritium variability in the region. The AP3H database is capable of providing reliable spatiotemporal input for hydrogeological application at any place within Slovenia, Hungary, and their surroundings.Results also show a decrease in the average spatial representativity of the stations regarding tritium activity in precipitation from∼440 km in 1970s, when bomb tritium still prevailed in precipitation, to∼235 km in the2010s. The post-2010 isoscapes can serve as benchmarks for background tritium activity for the region, helping to determine potential future local increases in technogenic tritium from these backgrounds. The gridded tritium isoscape is available in NetCDF-4 at https://doi.org/10.1594/PANGAEA.896938 (Kern et al., 2019)

    Investigating the process of ethical approval in citizen science research: The case of Public Health

    Get PDF
    Undertaking citizen science research in Public Health involving human subjects poses significant challenges concerning the traditional process of ethical approval. It requires an extension of the ethics of protection of research subjects in order to include the empowerment of citizens as citizen scientists. This paper investigates these challenges and illustrates the ethical framework and the strategies developed within the CitieS-Health project. It also proposes first recommendations generated from the experiences of five citizen science pilot studies in environmental epidemiology within this project.publishedVersio

    NPAHs and OPAHs in the atmosphere of two central European cities: Seasonality, urban-to-background gradients, cancer risks and gas-to-particle partitioning

    Get PDF
    Derivatives of polycyclic aromatic hydrocarbons (PAHs) such as nitrated- and oxygenated-PAHs (NPAHs and OPAHs) could be even more toxic and harmful for the environment and humans than PAHs. We assessed the spatial and seasonal variations of NPAHs and OPAHs atmospheric levels, their cancer risks and their gas-to-particle partitioning. To this end, about 250 samples of fine particulate matter (PM2.5) and 50 gaseous samples were collected in 2017 in central Europe in the cities of Brno and Ljubljana (two traffic and two urban background sites) as well as one rural site. The average particulate concentrations were ranging from below limit of quantification to 593 pg m-3 for Σ9NPAHs and from 1.64 to 4330 pg m-3 for Σ11OPAHs, with significantly higher concentrations in winter compared to summer. In winter, the particulate levels of NPAHs and OPAHs were higher at the traffic site compared to the urban background site in Brno while the opposite was found in Ljubljana. NPAHs and OPAHs particulate levels were influenced by the meteorological parameters and co-varied with several air pollutants. The significance of secondary formation on the occurrence of some NPAHs and OPAHs is indicated. In winter, 27-47% of samples collected at all sites were above the acceptable lifetime carcinogenic risk. The gas-particle partitioning of NPAHs and OPAHs was influenced by their physico-chemical properties, the season and the site-specific aerosol composition. Three NPAHs and five OPAHs had higher particulate mass fractions at the traffic site, suggesting they could be primarily emitted as particles from vehicle traffic and subsequently partitioning to the gas phase along air transport. This study underlines the importance of inclusion of the gas phase in addition to the particulate phase when assessing the atmospheric fate of polycyclic aromatic compounds and also when assessing the related health risk.This project was supported by the European Union's H2020 Framework Programme (ICARUS project) under grant agreement No – 690105, by the Czech Science Foundation (#P503 20-07117S) and by the RECETOX (LM2018121) and ACTRIS-CZ (LM2018122) research infrastructures funded by the Czech Ministry of Education, Youth and Sports of the Czech Republic and the European Structural and Investment Funds (CZ.02.1.01/0.0/0.0/16_013/0001761 and CZ.02.1.01/0.0/0.0/16_013/0001315). Funding of the Slovenian Agency of research through a programme P1-0143 is acknowledged. H2020 ERA-PLANET (No. 689443) iGOSP project is also acknowledged.S
    corecore