Fire and risk analysis during loading and unloading operation in liquefied petroleum gas (LPG) bottling plant

The article focuses on analyzing risks associated with the gas transfer operation in a liquified petroleum gas (LPG) bottling plant in India. The transfer operations involve transferring liquified gas from the transport tanker to the underground storage tank. Due to the rapid expansion of the cities, many LPG bottling plants in India got surrounded by residential areas and business centers. Moreover, to maintain the supply chain, the frequency of the transfer operations at the bottling plant also increased. In this scenario, an accidental release of LPG during the transfer operation may lead to various consequences such as a pool fire, a fireball, and even a catastrophic rupture of the tank with a successive explosion of its contents. In the study, the operations involved in bottling plants are classified into different hazard zones and analyzed. The probability of occurrence of events leading to an accident is modeled using modeling tools such as ALOHA and PHAST. The consequences of an accident following various events, such as jet fire, fireball, etc., are modeled, and the simulation results are compared. The thermal radiation has been estimated as 4–40 kW/m², which could adversely affect the nearby population and could result in damaging plant machinery and equipment.     

外加营养源作用下微生物黏结剂对土壤团聚体的影响

通过室内培养实验研究了外加营养源条件下微生物黏结剂(真菌菌丝和微生物胞外多糖)对土壤稳定性的影响以及微生物在不同粒径团聚体中的分布.所加营养源分别为葡萄糖(以C计)和硝酸铵(以N计),实验周期为30 d.实验设计包括对照(0.5 mg.g-1)、CN5(0.5 mg.g-1,0.1 mg.g-1,C/N=5)、CN10(0.5 mg.g-1,0.05 mg.g-1,C/N=10)3个水平.结果表明,3个处理的土壤呼吸速率十分接近,最大值都在3.10 mg.(h.kg)-1左右,说明无机氮肥的施加短期内对葡萄糖的矿化作用不明显.除培养第5 d CK的大团聚体形成量(15.67%)显著低于CN5(25.32%)和CN10(24.63%)外,其余培养期间3个处理的团聚体含量总体无显著性差异,表明本实验中葡萄糖对微生物的影响较大,覆盖了施加无机氮的影响,从而导致团聚体含量之间差异不显著.     

Variations in the elemental compositions of plants,and computer‐aided sampling in ecosystems∗

To obtain comparable results of multi‐element analysis of plant materials by different laboratories, a harmonized sampling procedure for terrestrial and marine ecosystems is essential. The heterogeneous distribution of chemical elements in living organisms is influenced by different biological parameters. These parameters are mainly characterized by genetic predetermination, seasonal changes, edaphic and climatic conditions, and delocalization processes of chemical substances by metabolic activities.

The biological variations of the element content in plants were divided into 5 systematic levels, which are: 1. the plant species; 2. the population; 3. the stand (within an ecosystem); 4. the individual; and 5. the plant compartment. Each of these systematic levels can be related to: 1. genetic variabilities; 2. different climatic, edaphic and anthropogenic influences; 3. microclimatic or microedaphic conditions; 4. age of plants (stage of development), exposure to environmental influences (light, wind, pollution etc.), seasonal changes; and 5. transport and deposition of substances within the different plant compartments (organs, tissues, cells, organelles).

An expert system for random and systematic sampling for multi‐element analysis of environmental materials, such as plants, soils and precipitation is presented. After statistical division of the research area, the program provides advice for contamination‐free collection of environmental samples.     

Seasonal and tidal impact on the organic compounds and nutrients distribution in tropical mangroves,Kerala, India

Seasonal changes in the concentration of nutrients and various organic compounds were studied in the waters surrounding mangroves and in the marshy areas of mangroves. Higher amounts of nutrients and organic compounds were observed during low tide. This is due to the remineralisation of plant detritus in this area. High concentration of carbohydrates, proteins, chlorophyll and phosphate were observed during monsoon, which can be attributed to the leaching of plant detritus as well as the land run-off. During pre-monsoon and post-monsoon high tannin and lignin concentration was noted. A 24-hour sampling was also done to study the tidal impact on the concentrations of various organic compounds and nutrients in this ecosystem. Even though a tidal impact was observed, a clear picture was not reported in this study.     

Definition and calculation of uncertainty in ecological process models

We present a method of multi-criteria assessment for the analysis of process model uncertainty that combines analysis of model structure, parameters and data requirements. There are three components in calculation and definition of uncertainty.

(1)

Assessment criteria: Uncertainty in a process model is reduced as the model can simultaneously simulate an increased number of assessment criteria selected to test specific aspects of the theory being investigated, and within acceptable limits set for those criteria. This reduces incomplete specification of the model—the characteristic that a model may explain some, but not all, of the observed features of a phenomenon. The calculation required is computation of the Pareto set which provides the list of simultaneously achieved criteria within specified ranges.     

The dynamics of heavy metals in plant-soil interactions

The effects of soil contamination by heavy metals are studied by a mathematical interaction model, validated by experimental results. The model relates the dynamics of uptake of heavy metals from soil to plants. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality. Data are taken from soil with Cd, Cu and Zn treatments for alfalfa, lettuce, radish and Thlaspi caerulescens, measuring the concentrations in the aboveground biomass of plants. At low concentrations, the effects of heavy metals are moderate, and the dynamics seem to be linear. However, increasing concentrations exhibit nonlinear behaviors.     

Stress response to nanoplastics with different charges in Brassica napus L. during seed germination and seedling growth stages

● Higher concentrations of PS, PS-NH₂ and PS-SO₃H inhibited seed germination. ● PS, PS-NH₂ and PS-SO₃H influenced seedling growth in a dose-dependent manner. ● PS, PS-NH₂ and PS-SO₃H reduced essential nutrients uptake and plant quality. ● PS, PS-NH₂ and PS-SO₃H increased antioxidant enzyme activities and MDA content. ● Nanoplastic toxicity was related to surface charges. Nanoplastic pollution has become a significant problem in farmland systems worldwide. However, research on the effects of nanoplastics (NPs) with different charges on field crops is still limited. In our study, NPs with different charges, including unmodified polystyrene nanoplastics (PS), positively charged polystyrene nanoplastics (PS-NH₂), and negatively charged polystyrene nanoplastics (PS-SO₃H), were investigated for their impacts on seed germination and seedling growth of rape. The results showed that seed water uptake (after 12 h), seed germination, seed vigour, and relative root elongation were all significantly reduced under exposure to NPs (200 mg/L). Similarly, remarkable decreases in plant biomass (root weight, shoot weight), growth (root length, plant height), photosynthesis ability (chlorophyll a, chlorophyll b, carotenoids), essential nutrient uptake (Fe, Mn, Zn, Cu), and plant quality (soluble protein, soluble sugar, crude fibre content) of rape seedlings were also observed after exposure to NPs. Among the three kinds of NPs, PS-NH₂ showed stronger effects. Moreover, superoxide dismutase, peroxidase, and catalase activities of rape seedlings were changed, and the content of malondialdehyde was significantly increased under exposure to NPs. Furthermore, positively charged PS-NH₂ showed stronger effects on the phenotype, physiology, biochemistry, nutrient uptake, and plant quality of rape. Notably, a comprehensive toxicity evaluation revealed that PS-NH₂ had the strongest toxicity to rape. The present study provides important implications for the interaction and risk assessment of NPs and crops in soil-plant systems.     

Uptake of uranium and thorium by native and cultivated plants

Large part of available literature on biogeochemistry of uranium and thorium refers to the studies performed either in highly contaminated areas or in nutrient solutions that have been artificially ‘spiked’ with radionuclides. Effects of background levels of natural radioactivity on soil-grown plants have not been studied to the same extent. In this paper, we summarised results of greenhouse and field experiments performed by the author from 2000 to 2006. We examined some of the factors affecting transfer of U and Th from soil to plants, differences in uptake of these radionuclides by different plants, relationships between U and Th in soil and in plants, and temporal variations of U and Th in different plant species. Concentrations of radionuclides (critical point for experimental studies on biogeochemistry of U and Th - rare trace elements in non-contaminated regions) and essential plant nutrients and trace elements were determined by instrumental neutron activation analysis.     

Differences in U root-to-shoot translocation between plant species explained by U distribution in roots

Accumulation and distribution of uranium in roots and shoots of four plants species differing in their cation exchange capacity of roots (CECR) was investigated. After exposure in hydroponics for seven days to 100 μmol U L⁻¹, distribution of uranium in roots was investigated through chemical extraction of roots. Higher U concentrations were measured in roots of dicots which showed a higher CECR than monocot species. Chemical extractions indicated that uranium is mostly located in the apoplasm of roots of monocots but that it is predominantly located in the symplasm of roots of dicots. Translocation of U to shoot was not significantly affected by the CECR or distribution of U between symplasm and apoplasm. Distribution of uranium in roots was investigated through chemical extraction of roots for all species. Additionally, longitudinal and radial distribution of U in roots of maize and Indian mustard, respectively showing the lowest and the highest translocation, was studied following X-ray fluorescence (XRF) analysis of specific root sections. Chemical analysis and XRF analysis of roots of maize and Indian mustard clearly indicated a higher longitudinal and radial transport of uranium in roots of Indian mustard than in roots of maize, where uranium mostly accumulated in root tips. These results showed that even if CECR could partly explain U accumulation in roots, other mechanisms like radial and longitudinal transport are implied in the translocation of U to the shoot.     

Nitrogen mediates above-ground effects of ozone but not below-ground effects in a rhizomatous sedge

Ozone and atmospheric nitrogen are co-occurring pollutants with adverse effects on natural grassland vegetation. Plants of the rhizomatous sedge Carex arenaria were exposed to four ozone regimes representing increasing background concentrations (background-peak): 10-30, 35-55, 60-80 and 85-105 ppb ozone at two nitrogen levels: 12 and 100 kg N ha⁻¹ yr⁻¹. Ozone increased the number and proportion of senesced leaves, but not overall leaf number. There was a clear nitrogen × ozone interaction with high nitrogen reducing proportional senescence in each treatment and increasing the ozone dose (AOT40) at which enhanced senescence occurred. Ozone reduced total biomass due to significant effects on root biomass. There were no interactive effects on shoot:root ratio. Rhizome tissue N content was increased by both nitrogen and ozone. Results suggest that nitrogen mediates above-ground impacts of ozone but not impacts on below-ground resource translocation. This may lead to complex interactive effects between the two pollutants on natural vegetation.