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We examine the possibility of making useful climate extrapolations in inner basins. Stressing the role of the local geographic features, for a practical example we focus our attention on the Red Sea. We observe that in spite of being an enclosed and relatively small Sea, its climate conditions are heavily affected by those of the larger neighboring regions, in particular the Mediterranean and the Arabian Seas. Using existing high-resolution information of the recent decades, we use both reasoned extrapolation and knowledge of, past and future, longer term general climatic information to frame what is presently possible to assess for the Red Sea. Specifically, the northern part, influenced by the Mediterranean Sea, shows a clear decreasing trend of both the meteorological and wave conditions in the recent decades. However, within a longer span record of 100 years, this decrease appears to be part of a 70-year cycle, which may be overturning, partly at least, in the coming decades. These trends are consistent with the expectations inferred from regional climatic indices, such as North Atlantic Oscillation and Atlantic Multidecadal Oscillation. No similar long term trend has been found for wave, hence implicitly the wind, conditions in the southern part of the basin. As expected, some correlation exists with the typical patterns of the Indian Ocean, but without any specific indication of a future trend. We suggest that, suitably adapted for the specific local conditions and dominant patterns, similar correlation and physical patterns may exist in several of the enclosed areas of the world, opening the possibility of exploring their possible trends in the future decades.

The chemical and biological properties of the water column at a Tyrrhenian site (Isola del Giglio) were studied during a 3-year period. The results highlighted the oligotrophic features of the site, characterised by quite low concentrations of organic carbon (on average DOC 102 micromol/L and POC 9 micromol/L). Relevant bacterial biomass (on average 42.1 microg C/L) and a notable activity (in terms of frequency of dividing cells, on average more than 5%) were observed. However, remarkable changes for these parameters were seasonally recorded. The cyclic occurrence, generally during the late spring-summer period, of benthic mucilage indicated that localised distrophic processes may occur. In particular, the benthic mucilage events of 2000 and 2001 were investigated, although some comparative information was available also for 1999 and 2002. The mucilage aggregates generally showed high bacterial colonisation, which have remarkable effects on the organic matter cycle both inside the aggregates and in the surrounding seawater. During the benthic mucilage development, an increase of DOC and POC concentrations was observed (up to 129 and 18 micromol/L, respectively, in June 2000 and up to 145 and 10 micromol/L, respectively, in May and June 2001) in the water column adjacent to the bottom. However, a general decrease of the trophic value of particulate matter (in terms of C/N ratio) was also observed, especially in 2000 after the disappearance of the mucilage. The available energy and organic matter during the mucilage events led to an increased presence of bacteria in the bottom waters of the Isola del Giglio, with maximum biomass values in 2001. Similarly, the replicative activity of bacteria was higher in 2001 (frequency of dividing cells about 5% vs. 3% of 2000). The lower activity of 2000, in addition to the lower trophic value of organic matter and different environmental conditions (namely lower temperature), might be involved in the persistence of mucilage in 2000 with respect to the rapid disappearance observed in 2001.

Abstract Orange Peel Waste (OPW) is a widely produced residue whose management is complicated by its physical and chemical properties. Anaerobic digestion (AD), which is commonly used for the treatment and exploitation of many biodegradable wastes, is inefficient on OPW due to the presence of essential oils (mainly d -Limonene) as well as the low pH, which cause the process to be unstable. Here we explore the effect of alkaline pre-treatment of OPW and of the addition of granular activated carbon (GAC) and Zero Valent Iron (ZVI) in improving AD in two semi-continuous reactors at a laboratory scale. The addition and pre-treatment of ZVI/GAC were shown to help process stability up to a loading of 3 kgVS·m−3·d−1 and to increase methane production even at a sub-optimal pH. The investigation of the bacterial community, by high-throughput sequencing, has also increased our insight on their involvement in AD in the presence of ZVI, including its biotic oxidation. In addition, direct interspecies electron transfer was shown to play a role in the reactor supplemented with ZVI.

The agro-livestock sector produces about one third of global greenhouse gas (GHG) emissions. Since more energy is needed to meet the growing demand for food and the industrial revolution in agriculture, renewable energy sources could improve access to energy resources and energy security, reduce dependence on fossil fuels, and reduce GHG emissions. Hydrogen production is a promising energy technology, but its deployment in the global energy system is lagging. Here, we analyzed the theoretical and practical application of green hydrogen generated by electrolysis of water, powered by renewable energy sources, in the agro-livestock sector. Green hydrogen is at an early stage of development in most applications, and barriers to its large-scale deployment remain. Appropriate policies and financial incentives could make it a profitable technology for the future.

AbstractHydrothermal carbonization (HTC) is an emerging path to give a new life to organic waste and residual biomass. Fulfilling the principles of the circular economy, through HTC “unpleasant” organics can be transformed into useful materials and possibly energy carriers. The potential applications of HTC are tremendous and the recent literature is full of investigations. In this context, models capable to predict, simulate and optimize the HTC process, reactors, and plants are engineering tools that can significantly shift HTC research towards innovation by boosting the development of novel enterprises based on HTC technology. This review paper addresses such key-issue: where do we stand regarding the development of these tools? The literature presents many and simplified models to describe the reaction kinetics, some dealing with the process simulation, while few focused on the heart of an HTC system, the reactor. Statistical investigations and some life cycle assessment analyses also appear in the current state of the art. This work examines and analyzes these predicting tools, highlighting their potentialities and limits. Overall, the current models suffer from many aspects, from the lack of data to the intrinsic complexity of HTC reactions and HTC systems. Therefore, the emphasis is given to what is still necessary to make the HTC process duly simulated and therefore implementable on an industrial scale with sufficient predictive margins.Graphic Abstract

Research to date has suggested that both individual marine species and ecological processes are expected to exhibit diverse responses to the environmental effects of climate change. Evolutionary responses can occur on rapid (ecological) timescales, and yet studies typically do not consider the role that adaptive evolution will play in modulating biological responses to climate change. Investigations into such responses have typically been focused at particular biological levels (e.g., cellular, population, community), often lacking interactions among levels. Since all levels of biological organisation are sensitive to global climate change, there is a need to elucidate how different processes and hierarchical interactions will influence species fitness. Therefore, predicting the responses of communities and populations to global change will require multidisciplinary efforts across multiple levels of hierarchy, from the genetic and cellular to communities and ecosystems. Eventually, this may allow us to establish the role that acclimatisation and adaptation will play in determining marine community structures in future scenarios.