An innovative experimental device to assess the behavior of a chemical under controlled environmental parameters

Abstract (ID 2017-381) Knowledge of the behavior of HNS (Hazardous and Noxious Substances) spilled into the aquatic environment is essential to define appropriate response actions; e.g. deployment of efficient equipment and activation of appropriate procedures. As a first approach, the Standard European Behaviour Classification (SEBC) may be used to acquire global knowledge of the short-term behavior of the chemical spilled, taking into account its basic physical and chemical properties (density, solubility and vapor pressure). However, the SEBC presents several limitations. Indeed, the competition between mass transfer processes (evaporation, dissolution, etc.) is not considered when the behavior of the chemical is theoretically determined from its physical chemical properties alone. Moreover, these measurements are made in standardized conditions (e.g. temperature of 20°C, freshwater) while, depending on its nature, the behavior of a chemical can greatly vary with temperature (e.g. palm oil may be solid under about 25°C) and other environmental parameters (velocity of wind, salinity and suspended matter in the water, etc.). To tackle these issues, Cedre has developed an experimental device able to rapidly determine the behavior of a chemical under some specific environmental conditions. It is composed of a 80 L tank, specially equipped with a wind generator and a lamp, in order to reproduce some critical environmental parameters: water temperature, velocity of wind and solar radiation. After pouring the chemical onto the surface of the fresh or salt water, under the fixed controlled parameters mentioned above, the concentration of the studied chemical is monitored over time, in both the air and water compartments. These measurements can be used to characterize the short-term behavior of a chemical in specific controlled conditions and thus to compare it to the behavior estimated from the SEBC. Such a tool could be of a considerable interest for responders. In the framework of the preparation of contingency plans, the response to a specific chemical can be optimized by performing experimentations covering a wide range of environmental conditions. In the event of a spill, specific conditions can be immediately reproduced to support responders and authorities who may have to take strategic decisions. The whole experimental device will be presented, including the tools and procedures to reproduce the environmental conditions. Then, initial results obtained with different chemicals will be presented.

Download Full-text

Assessment of the Reliability of the Moorings of a Floating Structure Against the Extreme Cyclone Hazard

Volume 3: Structures, Safety, and Reliability ◽

10.1115/omae2019-96032 ◽

2019 ◽

Author(s):

Mark Manzocchi ◽

Vikas Kejriwal ◽

Eric Hoo

Keyword(s):

Environmental Conditions ◽

Joint Distribution ◽

Environmental Parameters ◽

Exceedance Probability ◽

Surface Model ◽

Short Term ◽

Floating Structure ◽

Time Histories ◽

Vessel Response

Abstract This paper describes the methodology adopted for an analysis performed to assess the reliability of the moorings of a free weathervaning FPSO against the cyclone hazard. A joint distribution characterizing the long-term cyclone metocean conditions was fitted to a database of environmental conditions at the site of interest. A series of archetype cyclone histories were selected from the cyclone database to capture the evolving relationships between key environmental parameters during a cyclone. A response-surface model for extreme tension in the vessel moorings was developed for the short-term extreme vessel response as a function of environmental conditions by fitting the surface to an extensive series of time-domain vessel response analyses. The reliability of the mooring system was evaluated using Monte Carlo simulation by sampling from the fitted joint distribution of long-term cyclone characteristic and generating simulated cyclone time histories by scaling the archetype cyclones. The response model for short-term exceedance probability is used to develop the probability of exceedance within each simulated cyclone, and the probability of exceeding a given response is derived from the simulation.

Download Full-text

Platinum Group Elements in Geosphere and Anthroposphere: Interplay among the Global Reserves, Urban Ores, Markets and Circular Economy

Minerals ◽

10.3390/min10060558 ◽

2020 ◽

Vol 10 (6) ◽

pp. 558 ◽

Cited By ~ 1

Author(s):

Juris Burlakovs ◽

Zane Vincevica-Gaile ◽

Maris Krievans ◽

Yahya Jani ◽

Mika Horttanainen ◽

...

Keyword(s):

Waste Management ◽

Chemical Properties ◽

Platinum Group Elements ◽

Global Market ◽

Commodity Markets ◽

Short Term ◽

Specific Chemical ◽

Recycling Potential ◽

Platinum Group

Industrial and strategic significance of platinum group elements (PGEs)—Os, Ir, Ru, Rh, Pd, Pt—makes them irreplaceable; furthermore, some PGEs are used by investors as “safe heaven” assets traded in the commodity markets. This review analyzes PGEs from various aspects: their place in the geosphere, destiny in the anthroposphere, and opportunity in the economy considering interactions among the exploration, recycling of urban ores, trade markets, speculative rhetoric, and changes required for successful technological progress towards the implementation of sustainability. The global market of PGEs is driven by several concerns: costs for extraction/recycling; logistics; the demand of industries; policies of waste management. Diversity of application and specific chemical properties, as well as improper waste management, make the recycling of PGEs complicated. The processing approach depends on composition and the amount of available waste material, and so therefore urban ores are a significant source of PGEs, especially when the supply of elements is limited by geopolitical or market tensions. Recycling potential of urban ores is particularly important in a long-term view disregarding short-term economic fluctuations, and it should influence investment flows in the advancement of innovation.

Download Full-text

Relationship between Environmental Conditions and Structure of Macroinvertebrate Community in a Hydromorphologically Altered Pre-Alpine River

Water ◽

10.3390/w12112987 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2987

Author(s):

Igor Zelnik ◽

Tjaša Muc

Keyword(s):

Plant Species ◽

Environmental Conditions ◽

Riparian Zone ◽

Abiotic Factors ◽

Environmental Parameters ◽

Macroinvertebrate Community ◽

Alien Plant Species ◽

Alien Plant ◽

Invasive Alien Plant ◽

Wide Range

Hydromorphological alterations influence a wide range of environmental conditions as well as riparian vegetation and the structure of the macroinvertebrate community. We studied relationships between the structure and diversity of the macroinvertebrate community and hydromorphological and other environmental conditions in the river Gradaščica (central Slovenia). The Gradaščica river is a pre-Alpine torrential river that has been morphologically altered by humans. A selection of abiotic factors was measured, the ecomorphological status of the river was assessed, vegetation in the riparian zone was surveyed and benthic macroinvertebrates were sampled. Correlations between diversity and the structure of the macroinvertebrate community, environmental parameters and occurrence of invasive alien plant species in the riparian zone were identified. The significance of the influence of environmental parameters on the structure of the macroinvertebrate community was examined. We found that hydromorphological alterations in the river have had a significant influence on the diversity and composition of the macroinvertebrate community because of changes of flow velocity and the spread of invasive alien plant species that has followed those changes. Factors that also significantly influence the composition of macroinvertebrate community are distance from the source and conductivity. Our findings suggest minimization of further human hydromorphological changes of watercourses could prevent the loss of biodiversity of riverine ecosystems.

Download Full-text

Biodegradable Hydrogels: Evaluation of Degradation as a Function of Synthesis Parameters and Environmental Conditions

Soil Systems ◽

10.3390/soilsystems5030047 ◽

2021 ◽

Vol 5 (3) ◽

pp. 47

Author(s):

Chiara Turioni ◽

Giacomo Guerrini ◽

Andrea Squartini ◽

Francesco Morari ◽

Michele Maggini ◽

...

Keyword(s):

Environmental Conditions ◽

Three Dimensional ◽

Chemical Properties ◽

Decisive Role ◽

Environmental Parameters ◽

Functional Materials ◽

Crosslinking Degree ◽

Swelling Degree ◽

Biodegradable Hydrogels ◽

Synthesis Parameters

The development of functional materials that promote the infiltration and retention of water and the controlled release of fertilizers and nutrients in soil is of interest in agriculture. In this context, hydrogels, three-dimensional polymeric structures able to absorb high amounts of water in their swelling process, play an important role. The swelling ability of hydrogels depends on their crosslinking: the higher the crosslinking degree, the higher the number of interactions in the structure, the lower the swelling response. In this work, we describe biodegradable hydrogels composed of natural feedstocks: cellulose, clay minerals, and humic acids, designed to (i) protect, hydrate, and help germinating seedlings to root even in unfavorable conditions; (ii) sustainably contribute to soil fertility in terms of moisture and nutrients; and (iii) act as a nutritive and protective coating for the seeds. Upon assessing the correlations between curing process and swelling degree (SW), we evaluated the degradation of new biodegradable hydrogels as a function of the synthesis parameters (swelling degree and composition) and environmental conditions (type of soil and water amount for the hydration of the hydrogels). The term curing is hereafter referred to the operation of baking the ingredients at given combinations of time and temperature to obtain a dry hydrogel. The results show that the environmental parameters considered, i.e., amount of hydration water and physical and chemical properties of the soil, play a more decisive role in determining the stability of these hydrogels in soil than their synthesis parameters, such as the composition and the swelling degree.

Download Full-text