A flowsheet-based model approach to reduce water consumption and improve water networks management in the steel sector

Resource consumption is an important topic for steelmaking industry, which is spending significant efforts to reduce its environmental impact and improve its competitiveness. Water is largely exploited in steelworks for indirect and direct cooling, specific surface treatment, and fumes washing and cooling. It is already reused and recycled after restoring its quality through treatments for temperature and/or pollutant reduction. However, sometimes water networks are not optimized due to outdated water treatments, lack of continuous monitoring, and water network management strategies often based on experience without automation. In recent years, new water treatments, simulation, and optimization tools are becoming available, together with a stronger awareness of the importance of online parameters monitoring. Therefore, improvement of water cleaning, reuse, recycling, and consequent reduction of impact related to water exploitation are potentially achievable. The introduction of innovative treatments must be tested before their implementation in steel plants and the exploration of their behavior in different operating conditions is fundamental. The presented work addresses this topic through the application of several models of operational units, developed in OpenModelica environment and aggregated into a plant simulator. The simulator was used in different case studies related to an Italian plant to assess the impact of new filtering technology for reducing suspended solids on the analyzed water networks and test the effects of different operating configurations on the treatment efficiency. The introduction of new filtration technology leads to environmental and economic advantages due to freshwater intake reduction and water management improvemen

In vitro evaluation of the inhibitory activity of different selenium chemical forms on the growth of a fusarium proliferatum strain isolated from rice seedlings

In this study, the in vitro effects of different Se concentrations (5, 10, 15, 20, and 100 mg kg−1) from different Se forms (sodium selenite, sodium selenate, selenomethionine, and selenocystine) on the development of a Fusarium proliferatum strain isolated from rice were investigated. A concentration‐dependent effect was detected. Se reduced fungal growth starting from 10 mg kg−1 and increasing the concentration (15, 20, and 100 mg kg−1 ) enhanced the inhibitory effect. Se bioactivity was also chemical form dependent. Selenocystine was found to be the most effective at the lowest concentration (5 mg kg−1 ). Complete growth inhibition was observed at 20 mg kg−1 of Se from selenite, selenomethionine, and selenocystine. Se speciation analysis revealed that fungus was able to change the Se speciation when the lowest Se concentration was applied. Scanning Electron Microscopy showed an alteration of the fungal morphology induced by Se. Considering that the inorganic forms have a higher solubility in water and are cheaper than organic forms, 20 mg kg−1 of Se from selenite can be suggested as the best combination suitable to inhibit F. proliferatum strain. The addition of low concentrations of Se from selenite to conventional fungicides may be a promising alternative approach for the control of Fusarium species

Kit portatile per campionamenti di matrici ambientali imquinate Solide e liquide

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

Physiological Responses to Fe Deficiency in Split-Root Tomato Plants: Possible Roles of Auxin and Ethylene?

Iron (Fe) bioavailability in soils is often limited and can be further exacerbated by a non-homogeneous distribution in the soil profile, which has been demonstrated to vary both in space and time. Consequently, plants respond with morphological and physiological modifications at the root level involving a complex local and systemic signaling machinery. The present work unravels the role of two phytohormones (i.e., ethylene and auxin) and their integrated signaling in plant response to Fe deficiency. Inhibitors of auxin polar transport and of ethylene biosynthesis (N-1naphthylphthalamic acid - NPA and aminoethoxyvinylglycine - AVG, respectively) were applied on tomato (Solanum lycopersicum L.) plants grown by the split-root technique, which allows to simulate condition of Fe heterogeneous distribution. Results showed that plants, exposed to an uneven Fe supply, triggered a complex auxin-ethylene signaling. A systemic action of auxin on FERRIC REDUCTASE OXIDASE 1 (SlFRO1) expression was revealed, while ethylene signaling was effective both locally and systemically. In addition, the investigation of Fe concentration in tissues showed that when leaves overcame Fe deficiency a Fe “steady state” was maintained. Therefore, physiological adaptation to this heterogeneous Fe supply could be mediated by the integration of the complex signaling pathways prompted by both auxin and ethylene activities

DEMO radioactive wastes: Decarburization, recycling and reuse by additive manufacturing

Recycling is a real indicator of whether any nuclear industry is taking seriously about reducing its radioactive waste volume. Hence, manufacturing components starting from recycled activated material originated by DEMO reactor, with the relative manufacturing techniques, might be an important factor to support the environmental sustainability of fusion radioactive waste management. Accordingly, in this work the feasibility of recycling materials from decommissioned nuclear plants are presented. In the initial part, the powder production from activated steels AISI 316 L(N) and EUROFER and their use by Additive Manufacturing (AM) technologies is investigated as studied during EUROfusion Consortium funded activities. Chemical-physical parameters of this processed materials have been defined, together with the viability, of producing metal powders with an industrial VIGA (Vacuum Induction Gas Atomizer) facility. Experimental activities have been performed, aiming at powder production by VIGA and its characterization. A preliminary analysis of processing of these powders via selective laser melting (SLM) has been carried out. Additional results are presented for the experiments carried out on the decarburization of AISI 316 L(N) and EUROFER and experiments on the pollution of solid lithium orthosilicate breeder (Li4SiO4) coming from the refractory material, by simulating the thermal process of Li4SiO4 production or recycling, assessing the impact of platinum, zirconia, graphite and mullite on the quality of Li4SiO4 and on the feasibility of removing radioactive impurities

Root-shoot-root Fe translocation in cucumber plants grown in a heterogeneous Fe provision

Iron (Fe) is an essential micronutrient for plant life and development. However, in soil, Fe bioavailability is often limited and variable in space and time, thus different regions of the same root system might be exposed to different nutrient provisions. Few studies showed that the response to variable Fe provision is controlled at local and systemic levels, albeit the identity of the signals involved is still elusive. Iron itself was suggested as local mediator, whilst hormones were proposed for the long-distance signalling pathway. Therefore, the aim of this work was to assess whether Fe, when localized in a restricted area of the root system, might be involved in both local and systemic signaling. The combination of resupply experiments in a split-root system, the use of 57Fe isotope and chemical imaging techniques allowed tracing Fe movement within cucumber plants. Soon after the resupply, Fe is distributed to the whole plant, likely to overcome a minimum Fe concentration threshold aimed at repressing the deficiency response. Iron was then preferentially translocated to leaves and, only afterwards, the root system was completely resupplied. Collectively, these observations might thus highlight a root-to-shoot-to-root Fe translocation route in cucumber plants grown on a patchy nutrient substrate

Paving the way for the optimization of water consumption in the steelmaking processes: Barriers, analysis and KPIs definition

The efficient use of water resources is one of the main challenges of the steel sector, according to the European Union water policy. On this subject, monitoring and optimization systems, linked to the innovative water treatments, represent important tools to improve water management and the related energy use. The present paper describes a part of the work developed in the early stage of the project entitled "Water and related energy Hub Advanced Management system in steelworks - WHAM", which is co-funded by the Research Fund for Coal and Steel. The project aims at optimizing water consumption in the steelworks through a holistic combination of on-line monitoring and optimisation and innovative water treatment technologies. As different aspects affect water use in the steelmaking processes, in the first part of the paper, the main technical barriers and factors, that can impact on reuse and recirculation of wastewater and energy efficiency, are analysed. The main constraints on water management in the steel sector, such as fresh water availability, its quality and local legal requirements, were considered in order to maximise the water reuse and recycling. Furthermore, the main barriers, such as environmental issues and several costs, were investigated. In the second part of the paper, a set of Key Performance Indicators are listed. They aim at assessing and monitoring the water management sustainability in a holistic way, both in terms of environmental and economic performances, as well as of new water treatments efficiency and their economic viability. Key Performance Indicators will be used to monitor the efficiency of water management, aiming at achieving significant increase of performances. On the other hand, some of these indicators will be used as objective functions for problems optimization. The computation of the selected Key Performance Indicators will take into account both industrial data and results from simulations that will be carried out after the development of suitable tools in order to assess the feasibility of some relevant process modifications or the applications of new technologies

Modulation of Fe acquisition process by Azospirillum brasilense in cucumber plants

Despite being fairly abundant in soils, iron (Fe) represent one of the major constraints for plants growth and productivity, due to its low solubility. The possible contribution of Plant Growth-Promoting Rhizobacteria (PGPR) to the biogeochemical cycles of mineral elements aiming at increasing the metal bioavailable fraction as well as their ability to induce and/or regulate molecular and biochemical responses in plants is still under discussion. We had previously demonstrated that the presence of the PGPR Azospirillum brasilense in the rhizosphere of cucumber plants grown in calcareous soils could increase Fe nutrition alleviating Fe chlorosis symptoms. Within the present research, we showed that the inoculation of cucumber plants with the A. brasilense induced and anticipated the activation of Fe-deficiency mechanisms (i.e. Fe reduction and rhizosphere acidification) in both Fe-sufficient and Fe-deficient plants, thereby enhancing the capability of plants to cope with Fe stress. These biochemical mechanisms were supported by an increased expression of the genes encoding for Fe-chelate reductase (CsFRO) and PM H+-ATPase (CsHA1) and resulted in a higher Fe uptake rate. Our findings also highlighted that the molecular and physiological responses of cucumber plants to the inoculation are strictly related to the Fe nutritional status, suggesting the possible co-existence of multiple regulation mechanisms. These results further strengthen the capability of PGPRs, like Azospirillum, to modulate Fe acquisition in plants by differently triggering genes transcription