A Methodology for the Evaluation of the Voc Abatement Capacity of Different Species of Potted Ornamental Plants in Phytoremediating Indoor Air

Since the end of the ’80s, it has been known that potted ornamental plants can remediate Volatile Organic Compounds (VOCs) from indoor air and, to date, a significant number of species have been tested in controlled environments to quantify their abatement capacity concerning specific VOCs. However, the experimental methodologies are not standardised yet, and different units and approaches are used to quantify the removal capacity of the species. Consequently, in most cases, the results obtained are not comparable and, most importantly, directly exploitable to set up phytoremediation interventions in real settings. This study proposes a new method for evaluating and comparing the VOC removal capacity of different plant species and a review, produced according to this methodology, of the results obtained in previous studies. Considering that the VOC abatement is related to the entire plant system and that the uptake cannot be considered neither a zero nor a first-order removal process but a hybrid of the two, the proposal consists in modelling the removal analogously to biological processes. In the first instance, this approach allows a simple but effective assessment of the results obtained in different tests, making possible an objective choice of the best performing species for phytoremediation applications in real settings. While applying this methodology to existing experimental studies, it was considered essential to rigorously review their protocols as the removal depends on many factors, inter alia the chamber dimensions, the environmental conditions, the initial pollutant concentrations and the metabolic characteristics of the tested species. This application has aimed to set the basis for an accurate and more complete comparison of the results obtained in controlled environment experimentations and, also, to prepare the way to a standardization of the methodologies. Plant-based remediation interventions could be a simple, green and innovative solution to address the complex indoor air pollution problem. The approach proposed in this paper is an essential step towards a rational design of these interventions, allowing, in particular, the assessment of the actual remediation capacity of different plant species tested in various conditions

Frequency evaluation for domino scenarios triggered by heat radiation exposure

Severe fires may damage process equipment or pipes, leading to accident escalation and domino effect. Several accidents that occurred in the chemical and petrochemical industry presented these features. In order to account for these accident scenarios in conventional Quantitative Risk Analysis (QRA) studies, the more critical step is the availability of reliable models to estimate the probability of escalation given the fire impact mode on industrial equipment. The present contribution was aimed at developing a methodological approach to the assessment of the damage probability of process and storage vessels, identified as escalation targets, with the final aim of quantifying the frequency of accidents triggered by domino effect and the implementation in QRA studies. Efforts were devoted to include in the analysis relevant site-specific factors and to consider the presence of eventual mitigation measures. The developed methodology was applied to a case study dealing with the escalation of a primary fire scenario

Cyber Threats in the Chemical and Process Industry

Presentatio

Quantitative Assessment of Safety Barrier Performance in the Prevention of Cascading Events

PresentationThe prevention of high-impact low-probability (HILP) events in industrial clusters or complex industrial areas where critical infrastructures are present critically depends on the presence and the performance of safety barriers that may have the potential to prevent escalation. In recent years a set of tools and models were developed for the quantitative assessment of risk due to cascading events and domino scenarios. The aim of the present study is the integration of tools for risk assessment with a specific approach allowing a detailed assessment of safety barrier performance. A LOPA (layer of protection analysis) based methodology, aimed at the definition and quantification of safety barrier performance in the prevention of escalation was developed. The method allowed the quantitative characterization of alternative mitigated and unmitigated escalation scenarios. Data were collected on the more common types of safety barriers aimed at the prevention of fire escalation. An example of application was developed, allowing the quantitative assessment of risk mitigation of cascading events triggered by fire escalation based on the assessment of safety barrier performance

NaTech scenarios caused by flooding: Evaluation of accident frequency by the use of fragility models

Natural events impacting on process plants may lead to severe technological accidents. These events are usually defined as NaTech events (Natural Hazard Triggering Technological Disasters). In order to derive the frequencies of accident scenarios associated to NaTech events for QRA (Quantitative Risk Assessment) implementation, a critical issue is the availability of equipment vulnerability models. The aim of the present study was to present a vulnerability model for the assessment of failure probability of atmospheric vessels involved in flooding events. The vulnerability model was based both on the severity of the natural event and on the construction features of the equipment. In order to explore the model features and its potentialities, the application to case-studies was carried out analysing an actual industrial layout. The results obtained confirmed that NaTech scenarios caused by floods may have an important influence on risk assessment and management of industrial facilities

Accident Scenarios Caused by Lightning Impact on Atmospheric Storage Tanks

In recent years, severe natural events raised the concern for the so-called NaTech (natural-technological) accident scenarios: technological accidents caused by the impact of a natural event on an industrial facility or infrastructure. Severe scenarios typical of the process industry, as fires, explosions, toxic releases, and water pollution were reported as the consequence of natural events in industrial areas. The historical analysis of accidental scenarios triggered by lightning shows that the impact of a lightning on an atmospheric storage tank might be the initiating event of a severe accident. The analysis of past accident evidences that several alternative damage mechanisms and accident scenarios may follow lightning impact. Although lightning hazard is well known and is usually considered in the risk analysis of chemical and process plants, well accepted quantitative procedures to assess the contribution of accidents triggered by lightning to industrial risk are still lacking. In particular, the approaches to the assessment of accident scenarios following lightning strike are mostly based on expert judgment. In the present study, a detailed methodology is presented for the assessment of quantified event trees following lightning impact on an atmospheric tank. Different damage mechanisms have been considered in order to assess the frequencies of loss of containment due to lightning strikes. The results were used in a case study to assess the overall risk due to lightning impact scenarios in typical lay-outs of tank farms of oil refineries.JRC.G.6-Security technology assessmen