rss_2.0Chemistry FeedSciendo RSS Feed for Chemistry Feed and Active Biomonitoring of Atmospheric Aerosol with the Use of Mosses<abstract> <title style='display:none'>Abstract</title> <p>The aim of the carried out research was passive and active biomonitoring of woodlands in the Opole province. <italic>Pleurozium schreberi</italic> mosses were used during the research, in which the following heavy metals concentrations were determined: Mn, Fe, Ni, Cu, Zn, Cd and Pb. Concentrations were determined with absorption atomic spectrometry (AAS). On the basis of the carried out research, concentrations of heavy metals in moss samples used in the passive and active biomonitoring methods were compared. The obtained results indicate that <italic>Pleurozium schreberi</italic> mosses can be successfully used in both passive and active biomonitoring, however, these methods should not be used interchangeably in a defined study area. On the basis of carried out research it was determined that the applied biomonitoring methods can be supplementary.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Removal of Lead(II) and Zinc(II) from Aqueous Solutions Applying Fibber Hemp ( L.)<abstract> <title style='display:none'>Abstract</title> <p>Lead and zinc are heavy metals with toxic properties. These chemical elements are found in wastewater. The article deals with the removal of lead(II) and zinc(II) ions from polluted water using adsorption. As object of researches was selected natural polymer - fibber hemp (<italic>Cannabis sativa</italic> L.). Big quantities of fibber hemp are produced as waste in textile, agricultural industry, and therefore their usage could help to solve two problems -reducing quantity of fibber hemp as waste and reducing of water pollution by heavy metals. Pb(II) and Zn(II) ions adsorption with fibber hemp was investigated for contact time, pH, and heavy metal ions concentration impact. Pb(II) and Zn(II) ions biosorption rate was highest within the first hour, with optimal their biosorption recorded at pH = 5.0. Highest lead and zinc ions removal efficiency was recorded after 240-480 min and reached 60.5 and 61.7 % respectively. This study demonstrated the applicability and effectiveness of fibber hemp in lead and zinc ions removal, which could be applied for the sewage treatment plant in small scale.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00The Issue of Shading Photovoltaic Installation Caused by Dust Accumulation on the Glass Surface<abstract> <title style='display:none'>Abstract</title> <p>The issue of accumulation of dust and other pollutants on the surface of photovoltaic modules was thoroughly analysed over the years. One of the first surveys in this field of knowledge linked pollutant accumulation on the module surface with transmittance loss of its glass covering, which leads to lessened amount of solar radiation reaching solar cells. First stage of this accumulation process is linear transparency loss, and second stage - molecule agglomeration and settlement some grains on the already existing layer of dust. Additionally, the pace of working parameters reduction for photovoltaic installation is influenced by the type of dust itself. Molecules with smaller grains cover the surface much more densely, therefore limiting the amount of light passing though the top glass layer far more than molecules with bigger grains. The aim of the carried out study was to find the relationship between dust surface density and change in electrical parameters. Such approach makes it possible to compare electrical and physical parameters of different photovoltaic modules. Additionally, glass coverage itself was noted to have a significant impact on the overall decrease in working parameters of PV modules.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Mycoremediation of Soil Contaminated with Cadmium and Lead by sp.<abstract> <title style='display:none'>Abstract</title> <p>Conducted research determined the effect of the <italic>Trichoderma</italic> fungi on the presence of cadmium and lead ions in the soil contaminated by mentioned elements. The aim of the study was to demonstrate whether the fungi of this kind can contribute to remediation of soil by the immobilization of heavy metals. Experiments were conducted in laboratory conditions. The vaccine containing spores of <italic>Trichoderma asperellum</italic> was introduced into the soil contaminated with cadmium and lead by direct injection. Analyses of the soluble fraction of selected heavy metals were performed after 3 and 15 days of cultivation using atomic absorption spectrometry (AAS). Statistical significant positive effects on the immobilization of lead ions and no statistical differences in inhibition of cadmium translocation were observed. The results showed that <italic>Trichoderma</italic> fungi are suited to support the process of environment remediation by removal of lead. This suggests possible application of <italic>Trichoderma asperellum</italic> in mycoremediation and supporting role in phytoremediation of soil.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Compost Produced with Addition of Sewage Sludge as a Source of Fe and Mn for Plants<abstract> <title style='display:none'>Abstract</title> <p>Direct application of sewage sludge to soil is controversial due to, among others, its highly variable composition, odour, and risks for health. The obtained composts with the addition of sewage sludge were tested for the contents and availability of manganese and iron. Once composts were applied to the soil, their effect on the content and availability of Mn and Fe in soil and bioaccumulation in the plant were determined. The addition of sewage sludge enriched composts with manganese and iron, but did not increase the content of water-extracted forms of Mn and Fe. The compost with addition of biochar had more organic matter-bound forms of Mn and Fe. Composts amended with sewage sludge had lower effect on the amount of <italic>Poa pratensis</italic> L. biomass than maize straw compost. The content of Mn and Fe in <italic>Poa pratensis</italic> L. was in the range permissible for biomass used as fodder. Smaller addition of all composts to the soil significantly increased the content of mobile manganese forms; however, neither the type nor the dose had effect on the content of iron mobile forms. There was no significant differences in the content of organic matter-bound forms of Mn and Fe in soil after the application of composts.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Volumes Ratio Optimization in a Cascade Anaerobic Digestion System Producing Hydrogen and Methane<abstract> <title style='display:none'>Abstract</title> <p>As focus of humans has turned to renewable energy, the role of anaerobic digestion has started to become economically viable. Reducing the volume of agro-wastes for the generation of gaseous and liquid fractions with energy carriers and valuable products is an enormous challenge. A two-stage anaerobic digestion process consisting of hydrogenic stage followed by methanogenic stage was studied in a laboratory scale. Five simple nonlinear models of this continuous cascade process were studied in order to determine the optimal ratio of working volumes of bioreactors, in view of maximising energy production. This ratio was reported for all adopted models. The optimal ratio (maximal energy production criterion) depends of the adopted mathematical model. Static characteristics of both bioreactors were obtained using <italic>Symbolyc</italic> toolbox of <italic>Matlab.</italic> Numerical experiments concerning dynamics of the main variables of both bioreactors for these models using <italic>Simulink</italic> of <italic>Matlab</italic> are performed for different step changes of the dilution rate of the first bioreactor, together with the influence of the substrate (acetate) inhibition for one of the models. The value of the constant of inhibition plays an important role on the admissible interval of the dilution rate. The developed idea could serve for optimally designed experiments of anaerobic digestion for production of hydrogen and methane from lignocelluloses wastes (wheat straw) in two phase process.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Heat Recovery of Compost Reactors: Field Study of Operational Behaviour, Heating Power and Influence Factors<abstract> <title style='display:none'>Abstract</title> <p>This study evaluates the common process and set-up design of a static compost bioreactor for heat recovery. A technology, which fits the goal of a sustainable, growing bioeconomy which combines the utilization of compost heat and compost material. Interest on this technology has been growing the last years but precise data of pilot scale reactors is rare. Data is required to adjust the process for custom needs and further technical development. Therefore, lignin-cellulose based biomass was composted in unaerated cylindrical compost reactors size 20 to 70 m<sup>3</sup> for 140 days. The biomass comes with C:N ratio of about 25:1, water content of 43-48 %, organic matter content of 40.6 % d.m. and calorific value of 8.3 MJ/kg d.m. Spatial distribution of temperature and gas concentration (oxygen, carbon dioxide, methane) within the reactor shows methane production of the anaerobic core area. Maximum thermal power of 5.2 kW from a 63 m<sup>3</sup> reactor with average temperature of heating flow about 40 °C was reached. Maximum recovered heating power of 4.8 MJ/kg d.m. was calculated for an operation of 6 month. This corresponds to 50 % of the measured calorific value. Biggest influence factors detected on the recovered heating power of the pilot scale reactor has been the size of reactor, the set up quality and the control of heat exchanger. The spatial correlation between heat production and aerobic digestion suggests a technical development in terms of aeration.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Effects of Human Activities in the Coastal Zone of Laizhou Bay<abstract> <title style='display:none'>Abstract</title> <p>The serious destruction of resources and environment in Laizhou Bay has attracted extensive attention of researchers. This study mainly analysed the changes of fish structure and environment in the coastal zone of Laizhou Bay caused by human activities. By consulting literatures and field measurements, the changes of dominant fish species, coastline and sea water intrusion were analysed. The results showed that dominant fish species in Laizhou Bay change from high-economic species to low-economic species under the influence of human activities, and the coastline erosion was serious, and the area of sea water intrusion was also increasing year by year. It is concluded from the research results that human activities had a significant impact on the structure of fish school and the environment. It is necessary to arrange human activities in an appropriate amount to reduce the overexploitation of resources in order to restore the fishery resources and environment in Laizhou Bay.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Mobility of Potentially Toxic Elements from the Abandoned Uranium Mine’s Spoil Bank<abstract> <title style='display:none'>Abstract</title> <p>This study is part of the ongoing environmental monitoring program of the abandoned Mecsek uranium mine during the remediation period. During this program on the recultivated No.1 spoil bank, the radioactivity and the potentially toxic element (PTE) contents in the covering soil had shown some anomalies which refers to possible migration alongside the slope. Therefore, in a previous study, soil and plant samples were collected from top to bottom position of the slope and the total element content was determined by multi-elemental inductively coupled plasma-optical emission spectrometry. The results have indicated that there was a high possibility for PTEs to be mobile and available for uptake by plants. To confirm this indication in the present study for the soil samples the BCR sequential extraction procedure was applied to characterise the environmental mobility of PTEs, and it was compared with soil pH and cation exchange capacity (CEC). The results indicated that the ratio of Cd, Co, Mn, Pb, and U in the non-residual fractions ranged between 36.8 to 100 % and increased from top to bottom direction. The comparison showed that the samples with the lowest pH and CEC had the most mobility of the PTEs. The distribution of U, Cd, Mn, Co, and Pb in fractions indicated that some parts of the spoil deposit require additional steps to hinder the migration through the covering soil layer, and the BCR sequential extraction procedure has proven to be useful in providing information for the planning and management of remediation operations.</p> </abstract>ARTICLE2021-07-23T00:00:00.000+00:00Research on dose correction method of vehicle-borne environmental radiation measurement equipment<abstract> <title style='display:none'>Abstract</title> <p>This study establishes a near-ground reference radiation field based on typical radionuclides of the Fukushima accident in response to the need for vehicle-borne environmental radiation measurement equipment that can accurately evaluate the environmental dose of nuclear accidents. The Monte Carlo code FLUKA is used to study the environmental dose of such equipment in the early and mid-late reference radiation fields of nuclear accidents. Results of the air dose rate at 1 m above the ground were corrected to eliminate data difference between diverse measurement platforms. Simulation results show that t he dose correction factor (CF) fluctuates at approximately 0.8813 in the early reference radiation field and at approximately 0.6711 in the mid-late reference radiation field. This deviation of the dose CF in the early and mid-late reference radiation fields is within 2% and is not affected by the change in detector position. This research can be applied to obtain more accurate measurement of an ambient dose in the near-ground radiation field and support the vehicle-borne environmental radiation measurement technology.</p> </abstract>ARTICLE2021-09-17T00:00:00.000+00:00European inter-comparison studies as a tool for perfecting irradiated food detection methods<abstract> <title style='display:none'>Abstract</title> <p>In this paper, we present the results of inter-comparison studies on identification of irradiated food carried out by the leading European laboratories from 1991 to 2018. In 1990s, the Federal Institute for Health Protection of Consumers and Veterinary Medicine in Germany played the leading role in the organization of the inter-laboratory tests on this subject. At the beginning of the present century, the Spanish Agency for Food Safety and Nutrition and Food National Spanish Centre took over this role. In total, 47 international tests were carried out in which nearly 500 samples of alimentary products were analysed in 37 laboratories from 14 European countries. The tests were aimed at proving the reliability of analytical methods – thermoluminescence (TL), photostimulated luminescence (PSL), and electron paramagnetic resonance (EPR) spectroscopy – for identification of specific irradiated food products and to control the analytical skills and experience of participating laboratories. The results made possible a discussion on why some irradiated food samples are more difficult for identification. In general, the tests showed that TL measurements of products such as herbs, nuts, peppers, and raisins, and EPR studies of fish and chicken bones, fresh strawberries, and dried fruits could be used as reliable control methods. The challenge that control laboratories are facing now, is related to the identification of complex food products such as diet supplements or biopharmaceuticals, in which only some additives are irradiated.</p> </abstract>ARTICLE2021-09-17T00:00:00.000+00:00Gamma radiation calculations and gamma blocker design for the high-energy beam transport region of the European Spallation Source<abstract> <title style='display:none'>Abstract</title> <p>The purpose of this paper is to present the Monte-Carlo calculations performed to design a special element called gamma blocker (GB), necessary to stop the gamma radiation in the Accelerator-to-Target (A2T) section of European Spallation Source (ESS) linac. Very high levels of gamma radiation emitted backward from the activated target through the beam pipe could effectively block any human intervention close to the beam transport system. The residual dose rate in the linac tunnel was calculated without and with different GBs as a function of time. The final GB material and dimensions are proposed.</p> </abstract>ARTICLE2021-09-17T00:00:00.000+00:00The use of gamma irradiation to stimulate bioactive compound synthesis in submerged cultures<abstract> <title style='display:none'>Abstract</title> <p><italic>Inonotus obliquus</italic> is a parasite on the birch and other trees and is also a well-known medicinal mushroom. Its sterile conk is highly sought for its bioactive compounds such as phenols, polysaccharides, triterpenoids, and steroids. It was traditionally used to treat various gastrointestinal diseases, viral and parasitic infections, to counteract the progression of cancers, and to stimulate the immune system. We used acute gamma irradiation, followed by short-term submerged cultivation, as an oxidative stress inducer to enhance the synthesis of mycelial metabolites. The 300 Gy and 400 Gy doses showed the best results across the whole experimental design. Each assayed criterion had a different corresponding optimal stimulation dose. In one experiment, sublethal doses of irradiation triggered the dry weight of the cultured mycelium to increase by 19.764%. The free radical scavenging potential of the mycelium extracts increased by 79.83%. The total phenolic content of mycelium extracts and culture broth increased by 55.7% and 62.987%, respectively. The total flavonoid and sinapinic acid content of the broth increased by 934.678% and 590.395%, respectively. As such, gamma irradiation pre-treatment of the mycelial inoculum proved an interesting, economically and environmentally effective tool for stimulating secondary metabolite synthesis in submerged mycelium cultures.</p> </abstract>ARTICLE2021-09-17T00:00:00.000+00:00Nodulation and biological nitrogen fixation in soybean ( L.) as influenced by phosphorus fertilization and arbuscular mycorrhizal inoculation<abstract><title style='display:none'>Abstract</title><p>Arbuscular mycorrhizal fungi (AMF) can be used to promote the productivity of legumes on phosphorus- (P) deficient soils. The present study investigates the inoculation effects of three AMF species (<italic>Funneliformis mosseae</italic>, <italic>Rhizophagus intraradices</italic>, and <italic>Claroideoglomus etunicatum</italic>) and the control (uninoculated) on nitrogen fixation efficiency and growth performance of tropical soybean cultivar (TGx1448-2E) under varying P fertilizer rates (0, 20, and 40 kg P<sub>2</sub>O<sub>5</sub> ha<sup>−1</sup>) in a derived savannah of Nigeria. The results showed that shoot and root dry matter, number of nodules, relative ureide abundance (RUA), nitrogen derived from atmosphere (Ndfa), total N fixed, shoot P uptake, grain, and biomass yield significantly increased with AMF inoculation, with better performance observed in plants inoculated with <italic>Rhizophagus intraradices</italic> and <italic>Funneliformis mosseae</italic> compared to <italic>Claroideoglomus etunicatum</italic>. Similarly, the soybean growth variables, P uptake, and nitrogen fixation activities increased with increasing P application rates. Conversely, AMF root colonization significantly reduced with increasing P rate. Interaction of AMF inoculation and P rates significantly influenced soybean growth and nitrogen fixation. <italic>R. intraradices</italic> inoculation with 20 kg P<sub>2</sub>O<sub>5</sub> ha<sup>−1</sup> resulted in the highest amount of RUA, Ndfa, N fixed, and grain yield. It could be concluded from this study that <italic>R. intraradices</italic> with moderate P rate could be used to enhance nodulation, nitrogen fixation, and soybean yield in P-deficient soils.</p></abstract>ARTICLE2020-12-28T00:00:00.000+00:00The analytical assessment of the weaknesses of the agriculture of Szabolcs-Szatmár-Bereg County based on empirical research results<abstract><title style='display:none'>Abstract</title><p>In our empirical research, we examined the agriculture of Szabolcs-Szatmár-Bereg County. We surveyed the situation of agriculture through farmers using certain criteria to rank the situation within the framework of a SWOT analysis. The responses received from farmers in the county were quantified and evaluated on the basis of what these farmers have considered to be true. The interdisciplinary study of agriculture is a timely and important task. It can be enforced on the basis of systemic contexts studying not only food production but also environmental issues, preservation of rural habitats, employment, and regional development.</p></abstract>ARTICLE2020-12-28T00:00:00.000+00:00Seedling and adult plant resistance to in Ethiopian rice cultivars<abstract><title style='display:none'>Abstract</title><p>Two separate experiments were done for seedling and adult resistance in rice varieties against blast. Each experiment consists of 20 varieties and is evaluated under artificial inoculation with blast. The result of the study confirmed that NERICA varieties have shown low disease infection at the seedling stage whereas the varieties Chewaka and Edget have shown adult plant resistance. Severe yield reduction and highly diseased grain were obtained from Superica-1, which is highly susceptible at adult plant stage. In contrast, the maximum grain yield was obtained from the Chewaka and Edget varieties, these having a high level of adult resistance. Therefore, Chewaka and Edget are promising candidates for utilization in yield and blast resistance in rice improvement.</p></abstract>ARTICLE2020-12-28T00:00:00.000+00:00PM concentration reduction due to the wet scavenging in the Ciuc Basin, Romania<abstract><title style='display:none'>Abstract</title><p>The PM<sub>10</sub> concentration reduction caused by large-scale precipitation in the Ciuc Basin was studied under no-wind conditions. The PM<sub>10</sub> concentration changing before, during, and after the rainfall was followed up from 2008 to 2019. After the rainfall episode, the PM<sub>10</sub> concentrations were lower in the cold and warm periods with 2.8 μg/m<sup>3,</sup> and 2 μg/m<sup>3</sup> respectively. The highest PM<sub>10</sub> concentration reduction was detected in the cold season, by the moderate and light rain intensity, after 6 hrs of continuous rain (35.61%, 32.46%), and the average PM<sub>10</sub> concentration reduction in the cold and warm periods was 22.3% and 16.1% respectively.</p></abstract>ARTICLE2020-12-28T00:00:00.000+00:00Comparative analysis of relevant climate change, landscape and regional development strategies regarding the areas pertaining to Debrecen (Hajdú-Bihar County)<abstract><title style='display:none'>Abstract</title><p>Today, the countries of the world have to face several global challenges with regard to the plans they have developed together. The protection of the natural values of our country and their sustainable use is receiving more and more attention in today’s society. In order to achieve the above, a change of perspective in social strategy built on knowledge and professional training is inevitable. An environmental strategy paradigm shift emphasizing the protection of biodiversity, resources, and landscape cultivation is also necessary. The need for documents providing a basis for the paradigm shift is indubitable; however, more efforts are needed to induce fundamental changes by plans detailed in the documents.</p><p>The aim of this study is to review the current environmental protection initiatives in Hajdú-Bihar County and to assess the degree to which the relevant plans are harmonized and that the objectives outlined in the documents overlap.</p></abstract>ARTICLE2020-12-28T00:00:00.000+00:00The influence of slope aspect on soil moisture<abstract><title style='display:none'>Abstract</title><p>In this research, we investigated the variability of soil moisture on two slopes of opposite aspect (a northern slope and a southern slope) but with the same soil type. To identify the spatial disposal of the soil type on both slopes, we georeferenced the paper-based soil map of Sfântu Gheorghe, using the QGIS platform. In order to use the correct slope aspect, we used a numerical model of the terrain (relief). The research plot was soil sampled at the depth of 10 cm on two different dates: on 7 November 2019 and on 3 March 2020, using a Buerkle soil sampler.</p><p>Gravimetric method was used to determine the soil moisture values that proved to be the most accurate for our purpose.</p><p>The soil moisture values, obtained in weight percentage, were assigned to the coordinates of the sampling points, and soil moisture maps were generated in QGIS for both slopes and for both sampling dates. These maps gave us the opportunity to evaluate the variability in time of the soil moisture distribution on the sample plots.</p><p>The water holding capacity of the soils is mostly influenced by their organic C content. So, the total organic carbon content of the soil from the sampling plots was measured using the Tyurin method.</p></abstract>ARTICLE2020-12-28T00:00:00.000+00:00Genetic variation in common bean ( L.) using seed protein markers<abstract><title style='display:none'>Abstract</title><p>The genetic diversity of common bean accessions were assessed using seed storage protein markers. At regional level, accessions from the two major growing regions showed the highest level of gene diversity (H = 0.322, I = 0.485, and H = 0.312, I = 0.473), which can be exploited for the future improvement of the crop. Based on phaseolin, the major storage protein in common bean, the majority of the accessions (86%) were grouped under Mesoamerican gene pool. Seed proteins were also used to differentiate various Phaseolus species, indicating the usefulness of seed storage proteins in species identification in this genus.</p></abstract>ARTICLE2020-12-28T00:00:00.000+00:00en-us-1