Safety analysis approach based on thermodynamic and chemical reactions modelling

Safety analysis of nuclear and chemical/petrochemical facilities is the systematic process that is carried out throughout the design process to ensure that all the relevant safety requirements are met by the proposed design of the plant. Safety analysis should incorporate both deterministic and probabilistic approaches. These approaches have been shown to complement each other and both should be used in the decision making process on the safety and ability of the plant to be licensed.This paper deals with the deterministic safety approach in order to distill the experience of nuclear and chemical/petrochemical protection engineering through a safety analysis approach aiming at analysis of chemically reacting processes including thermodynamic and chemical reactions modelling that are present in both industries. For instance, there are some similarities between the Bhopal disaster and Three Mile Island-Fukushima-like H₂ deflagration-detonation scenarios in nuclear containments. The phenomenology is similar in that the temperature and the pressure caused by exothermic reactions had increased dramatically leading to a loss of containment.The study aims to translate and adapt to general chemically reacting modelling, major features of the equivalent analysis inside the nuclear containments. Compartment containment for H₂ deflagrations has been translated and adapted, with fixed tools, to the methyl-isocyanate storage tank 610 of the Bhopal plant.     

Effect of some heavy metals and soil humic substances on the phytochelatin production in wild plants from silver mine areas of Guanajuato, Mexico

Phytochelatins (PCs) were determined in the wild plants, focusing on their relationship with the levels of heavy metals and humic substances (HS) in soil. Ricinus communis and Tithonia diversifolia were collected from several sites in Guanajuato city (Mexico), which had long been the silver and gold mining center. The analysis of PCs in root extracts was carried out by liquid chromatography (derivatization with monobromobimane). Total Ag, Cd, Cu and Pb in plant roots and in soil samples, as well as soil HS were determined. The association of metals with HS in soils was evaluated by size exclusion chromatography (SEC) with UV and ICP-MS detection. The results obtained revealed the induction of PCs in R. communis but not in T. diversifolia. The levels of Cd and Pb in plant roots presented strong positive correlation with PC-2 (r = 0.9395, p = 0.005; r = 0.9573, p = 0.003, respectively), indicating that these two metals promote PCs induction in R. communis. On the other hand, the inverse correlation was found between soil HS and metal levels in roots of R. communis (Cu > Pb > Cd > Ag), in agreement with the decreasing affinity of these metals to HS. Importantly, the inverse correlation between soil HS and plant PC-2 was observed (r = −0.7825, p = 0.066). These results suggest that metals strongly bound to HS could be less bioavailable to plants, which in turn would limit their role in the induction of PCs. Indeed, the SEC elution profiles showed Pb but not Cd association with HS and the correlation between metal in soil and PC-2 in plant was statistically significant only for Cd (r = 0.7857, p = 0.064). Based on these results it is proposed that the role of heavy metals in PCs induction would depend on their uptake by R. communis, which apparently is controlled by the association of metals with soil HS. This work provides further evidence on the role of environmental conditions in the accumulation of heavy metals and phytochelatin production in plants.     

A new simple methodology for evaluation of explosion risk in underground coal mines

The key objective of this paper is the presentation of a new risk assessment tool for underground coal mines based on a simplified semi-quantitative estimation and assessment method.In order to determine the risk of explosion of any work process or activity in underground coal mines it is necessary to assess the risk. The proposed method is based on a Risk Index obtained as a product of three factors: frequency of each individual scenario P_ucm, associated severity consequences C_ucm and exposure time to explosive atmospheres E_ucm. The influence of exposure time is usually not taken into account up to now. Moreover, the exposure to explosive atmospheres may affect factors of hazardous event probability as much as its consequences. There are many definitions of exposure to explosive atmospheres but in the case of underground coal mines the exposure is defined as frequency risk of firedamp and coal dust. The risk estimation and risk assessment are based on the developed of a risk matrix.The proposed methodology allows not only the estimation of the explosion risk but also gives an approach to decide if the proposal investment is well-justified or not in order to improve safety.     

Official control of plant protection products in Poland: detection of illegal products

Market presence of illegal and counterfeit pesticides is now a global problem. According to data published in 2012 by the European Crop Protection Association (ECPA), illegal products represent over 10% of the global market of plant protection products. Financial benefits are the main reason for the prevalence of this practice. Counterfeit and illegal pesticides may contain substances that may pose a threat to the environment, crops, animals, and humans, inconsistent with the label and registration dossier. In Poland, action against illegal and counterfeit plant protection products is undertaken by the Main Inspectorate of Plant Health and Seed Inspection (PIORiN), the police, the prosecution, and the pesticide producers. Results of chemical analyses carried out by the Institute of Plant Protection - National Research Institute So?nicowice Branch, Pesticide Quality Testing Laboratory (PQTL IPP-NRI Sosnicowice Branch) indicate that a majority of illegal pesticides in Poland are detected in the group of herbicides. Products from parallel trade tend to have the most irregularities. This article describes the official quality control system of plant protection products in Poland and presents the analytical methods for testing pesticides suspected of adulteration and recent test results.     

Modeling land use/land cover change using remote sensing and geographic information systems: case study of the Seyhan Basin,Turkey

Land use and land cover (LULC) changes affect several natural environmental factors, including soil erosion, hydrological balance, biodiversity, and the climate, which ultimately impact societal well-being. Therefore, LULC changes are an important aspect of land management. One method used to analyze LULC changes is the mathematical modeling approach. In this study, Cellular Automata and Markov Chain (CA-MC) models were used to predict the LULC changes in the Seyhan Basin in Turkey that are likely to occur by 2036. Satellite multispectral imagery acquired in the years 1995, 2006, and 2016 were classified using the object-based classification method and used as the input data for the CA-MC model. Subsequently, the post-classification comparison technique was used to determine the parameters of the model to be simulated. The Markov Chain analyses and the multi-criteria evaluation (MCE) method were used to produce a transition probability matrix and land suitability maps, respectively. The model was validated using the Kappa index, which reached an overall level of 77%. Finally, the LULC changes were mapped for the year 2036 based on transition rules and a transition area matrix. The LULC prediction for the year 2036 showed a 50% increase in the built-up area class and a 7% decrease in the open spaces class compared to the LULC status of the reference year 2016. About an 8% increase in agricultural land is also likely to occur in 2036. About a 4% increase in shrub land and a 5% decrease in forest areas are also predicted.     

Historical deforestation as a cause of alluviation in small valleys, subcarpathian loess plateau, Poland

The undulating loess Kanczuga Plateau, 250–270 m a.s.l., is located in the temperate climatic zone of Central Europe, within the northern foreland of the Carpathians. It is dissected by a network of valleys 30–60 m deep, infilled with several metres of complex minerogenic and organic deposits which started to accumulate during the early Holocene. The southern side of one of these valleys is dissected by several dry valleys. The mouth sections of these valleys have buried surface comprising peat and/or organic silts, overlain by sandy–silty alluvium. ¹⁴C dates indicate that the alluviation of these valley floors, which proceeded from the headwaters to the mouth sections, began in the 1100 ad. The gradual intensification of soil erosion in the upper part of the catchment and associated sedimentation probably encompassed only a few centuries, with greatest alluviation during the Little Ice Age. This plateau, which is under the influence of more continental climatic conditions than the low-mountain and upland regions of Western Europe, features more climatic contrasts. Here environmental changes triggered by land use were superimposed on climatic change. The most intensive processes of soil erosion and sediment transfer as well as alluviation, coincided with the first phase of cooling during the Little Ice Age. It was the final stage of the intensification of these processes, probably more intensive than its initial phase in the eleventh century, caused primarily by deforestation resulting from the development of agriculture.     

SEC-ICP-MS studies for elements binding to different molecular weight fractions of humic substances in compost extract obtained from urban solid waste

In this work, the speciation of elements in compost was studied with emphasis on their binding to humic substances. In order to assess the distribution of As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, U, Th and Zn among molecular weight fractions of humic substances, the compost extract (extracted by 0.1 mol l(-1) sodium pyrophosphate) was analyzed by size exclusion chromatography coupled on-line with UV-Vis spectrophotometric and ICP-MS detection. Similar chromatograms were obtained for standard humic acid (Fluka) and for compost extract (254 nm, 400 nm) and three size fractions were operationally defined that corresponded to the apparent molecular weight ranges > 15 kDa, 1-15 kDa and < 1 kDa. The percentage of total element content in compost that was leached to the extract ranged from 30% up to 100% for different elements. The elution profiles of Co, Cr, Cu, Ni and Pb (ICP-MS) followed that of humic substances, while for other elements the bulk elution peak matched the retention time observed for the element in the absence of compost extract. Spiking experiments were carried out to confirm elements' binding and to estimate the affinity of individual elements for humic substances derived from compost. The results obtained indicated the following order of decreasing affinity: Cu > Ni > Co > Pb > Cd > (Cr, U, Th) > (As, Mn, Mo, Zn). After standard addition, further binding of Cu, Ni and Co with the two molecular weight fractions of humic substances was observed, indicating that humic substances derived from compost were not saturated with these elements.     

Evaluation of zeolite-sand mixtures as reactive materials protecting groundwater at waste disposal sites

To recognize properties of a mixture of Vistula sand (medium sand acc. to USCS) with Slovak zeolite as reactive materials suitable for permeable reactive barriers proposed for protection of groundwater environment in vicinity of old landfills comprehensive laboratory investigations were performed. The present study investigates the removal of contaminants specific for landfill leachates onto zeolite-sand mixtures containing 20%, 50% and 80% of zeolite (ZS20, ZS50 and ZS80). Taking into account the results of batch tests it was concluded that the Langmuir isotherm best fitted the data. It was observed that the presence of ammonium, calcium and magnesium decreases the removal efficiency of copper by 32%. Column tests of contaminant migration through the attenuation zone of the reactive materials were interpreted using the software package CXTFIT, which solves a one-dimensional advection-dispersion equation. Column test results also indicate the strong influence of the presence of interfering substances on copper immobilisation; dynamic sorption capacities decrees twofold. Throughout the landfill leachate flow through ZS80 sample, a constant reduction of NH+4 (at 100%), K+ (at 93%) and Fe total (at an average of 86%) were observed. There was no reduction in chemical oxygen demand and biochemical oxygen demand.     

Social-ecological drivers and dynamics of seagrass gleaning fisheries

Invertebrate gleaning (walking) fisheries are common within intertidal seagrass meadows globally, contributing to the food supply of hundreds of millions of people, but understanding of these fisheries and their ecological drivers are extremely limited. The present study provides a unique analysis of these fisheries using a combined social and ecological approach. Catches contained 34 species and were dominated by Bivalves, Urchins and Gastropods. CPUE in all sites varied from 0.05 to 3 kg gleaner−1 hr−1, respectively, with the majority of fishers being women and children. Landings were of major significance for local food supply and livelihoods at all sites. Local ecological knowledge suggests seagrass meadows are declining in line with other regional trends. Increasing seagrass density significantly and positively correlated with CPUE of the invertebrate gleaning (r = 0.830) highlighting the importance of conserving these threatened habitats. Understanding the complexities of these fisheries, their supporting habitats and their sustainability is important for the support of sustainable coastal livelihoods.