1,720,988 research outputs found
Arabian Journal of Geosciences
No full textThe official journal of the Saudi Society for Geosciences, the Arabian Journal of Geosciences examines the entire range of earth science topics focused on, but not limited, to those that have regional significance to the Middle East and the Euro-Mediterranean Zone.
The journal features peer-reviewed original and review articles on such topics as: geology, hydrogeology, earth system science, petroleum sciences, geophysics, seismology and crustal structures, tectonics, sedimentology, palaeontology, metamorphic and igneous petrology, natural hazards, environmental sciences and sustainable development, geoarchaeology, geomorphology, paleo-environment studies, oceanography, atmospheric sciences, GIS and remote sensing, geodesy, mineralogy, volcanology, geochemistry and metallogenesis
Modelling soil carbon sequestration with biochar using RothC
Full text linkThe aim of this work was to assess and predict how biochar influences the soil C dynamics, by modifying the RothC model to simulate the findings of a long-term field experiment on biochar application to a short coppice rotation in Italy. We first modified the model to include two stocks of C input into the soil: the labile and the recalcitrant biochar pools. We also included a parametrized function to account for the priming effect on SOC dynamics in the soil. Secondly, we calibrated the model parameters with the data obtained from the field experiment. Finally, we validated the model results by estimating the remaining biochar amount in the site after 10 years from application, using an isotopic mass balance.
The results confirm that biochar degradation can be faster in field conditions in comparison to laboratory experiments; nevertheless, it can contribute to substantially increase the C stock in the long-term. Moreover, the modified RothC model allowed to assess the SCS potential of biochar application in soils, at least in the specific conditions examined, and could represent a flexible tool to assess the effect biochar as a SCS strategy in the long-term. We are exploring the possibility to use data from other long-term field experiment to move in that direction. The results of this study could be added to the Italian biochar database, providing new knowledge about a topic that needs to be explored
Exploitable fish waste and stranded beach debris in the Emilia-Romagna Region (Italy)
No full textAbstract Within Circular Economy principles, this paper analyses and estimates exploitable marine residues, such as fish waste and stranded debris in beaches and their potential valorisation scenarios. The Emilia-Romagna Region (Italy) has been chosen as a case study. Based on the sold fish, about 200 Mg/year of fish waste are produced at the five major fish markets of the Region. Including all regional fish processing plants and retail trade, the estimated availability of fish waste increases up to 30,000 Mg/year. Stranded beach debris collected by mechanical cleaning operations are currently deposited in landfill. About 63,000 Mg/year of sieved debris are collected each year, out of which the recoverable fractions consist of 19,000 Mg/year of organic material, 8,000 Mg/year of shells and 5,200 Mg/year of stones. Classification and valorisation routes for these residual biomasses are proposed and their applicability to other regions discussed. In order to investigate the possible use in anaerobic digestion plants and the effects on biogas production, Biochemical Methane Potential (BMP) assays have been carried out with fish waste samples and with organic material found in marine debris. Salt content in driftwood has been quantified to assess its potential use in Combined Heat and Power (CHP) plants. Proposed valorisation routes for shells and stones include the production of calcium carbonate (cement industry, wastewater treatment and mulching) and the application in building industry, respectively
Impact of Population Growth and Climate Change on the Freshwater Resources of Lamu Island, Kenya
No full textDemand for freshwater is rising with factors, such as population growth, land
use change and climate variations, rendering water availability in the future uncertain.
Groundwater resources are being increasingly exploited to meet this growing demand.
The aim of this study is to identify the influence of population growth induced by land use
change and climate change on the future state of freshwater resources of Lamu Island in
Kenya where a major port facility is under construction. The results of this study show that
the “no industrial development” population scenario (assuming the port was not constructed)
would be expected to reach ~50,000 people by 2050, while the projected population upon
completion is expected to reach 1.25 million in the same year when the Lamu Port-South
Sudan-Ethiopia Transport Corridor Program (LAPSSET) port reaches its full cargo-handling
capacity. The groundwater abstraction in 2009 was 0.06 m3 daily per capita, while the demand
is expected to raise to 0.1 m3 by 2050 according to the “LAPSSET development” projection.
The modelling results show that the Shela aquifer in Lamu, which is the main source of water
on the island, will not experience stress by 2065 for the “no industrial development”population scenario, whereas for the “LAPSSET development projection” population
scenario, it will occur sooner (between 2020 and 2028). The modelling results show that the
Representative Concentration Pathways (RCP) climate change scenarios will have a smaller
impact on the effective water volume reserves than Special Report on Emissions Scenarios
(SRES) for the “no industrial development”, while the impact is expected to be similar for the
“LAPSSET development”, suggesting that population growth exacerbated by land use change
will be a more significant driving force than climate change in affecting freshwater availabilit
"Bare soil" detection addressing agricultural production optimization throughout the year: case study in Emilia Romagna using Sentinel-2 images
No full textChanges in soil practices and management policies are fundamental in order to satisfy future growing food and energy demand, limiting risks of soil depletion. To this purpose remote sensed data are proving crucial for precision farming and for soil characterization and monitoring. In regions where agronomic rotations are adopted, soils experience unproductive periods between two main crops ("bare soil"), causing nutrient leaching, erosion and acceleration of organic matter consumption. Although the presence of "bare soil" period is evident and well known, there are no studies able to provide a dedicated regional framework to draw attention to this issue.
This study aims at mapping soils cultivated but unproductive during certain times of the year ("bare soil") using satellite images. Once detected, "bare soils" are deeply investigated to define their surface and the time duration of the bare soil status. Thereafter, valorization scenarios for these "bare soil" are proposed considering an optimized mix of energy and cover crops.
The applied methodology includes Sentinel-2, 5-days-return-time optical images, with 20 m ground spatial resolution acquired during 2017. The images were pre-processed using the Satellite Image Automatic MapperTM (SIAMTM) and outputs subsequently processed on the QGIS platform and validated with ground truths provided by the regional agriculture authority.
Of the total Utilised Agricultural Area (UAA), results show that up to 20% is "bare soil" from July to October and about 10% is unproductive from November to April. The size of most plots varies from 0.5-2 ha, however, about 30% of the "bare soil" fields have surface size from 3 to 50 ha, sufficient to justify their agronomic exploitation. In a basic scenario where biomass sorghum is cultivated from July to October, 50% of the bioenergy demand can be met through anaerobic digestion.
This study proposes a digital soil mapping methodology able to answer several questions: if yields can be improved, in what period of the year, in which area, how large are the plots. Therefore, the potential of "bare soils" for increasing food or energy crops and to store more carbon in soils is highlighted
Long Term Experiment Platform ({LTEP}) to establish the effectiveness of biochar applications: a case study in vineyards at Tebano, Ravenna, Italy
No full textLTEP-Biochar
No full textThe dataset inventories and compares experiments regarding on field application of biochar for agronomic purposes and its environmental effects (e.g. carbon sequestration) over a significative timeframe. Remediation of polluted soils is not in scope. The field experiments shall take place under dynamically, meteorologically and biologically complex conditions. We are mapping activities across Europe, North Africa and the Middle East (see the Highlights box here below). The LTEP project is an ICHAR initiative implemented and managed by the EMRG group of the University of Bologna
PO4 recovery using mixtures of biochar and carbonate materials
Full text linkThe recovery of PO4 from wastewaters by using biochar proves not to be completely satisfactory.
The surface of the biochar is typically negatively charged, which prevents the adsorption of PO4.
For this reason, mixtures of biochar and natural carbonate materials have been tested as a novel
sorbent material for PO4 recovery from both synthetic-and waste- water. The goal of the research
is to obtain a PO4 based complex starting from natural second-generation materials such as food
industry byproducts, plants and other residues to prepare fertilisers compliant to the component
material category CMC 6 defined in the Regulation (EU) 2019/1009/EU It has to be noted that
natural carbonate materials are not pure CaCO3, but present small impurities that contribute to
modify their properties. Therefore, the use of carbonate materials obtained from different sources
can lead to different performances when it comes to PO4 removal from wastewaters.
In this work we present results of PO4 removal obtained from a mixture of biomass and different
carbonate materials. The mixture has been treated through a specific thermal protocol to obtain
two different calcium-oxide rich charcoals here named composites C1 and C2. Initially, each
composite was added to synthetic waters with different PO4 concentration, with a composite:water
ratio of 1:1000. The initial concentrations of PO4 were 10, 100 and 1000 mg/l. After treatment with
the composite, regardless of whether C1 or C2 was used, the PO4 concentration in the waters with
initial concentration of 10 and 100 mg/L was nearly zero, with pH values at equilibrium around
11.9. The treatment of the water with initial PO4 concentration of 1000 mg/l shows a reduction of
20% and 40% with C1 and C2, respectively, with final pH values around 7.8.
After addition of the composites to the water, the solutions present very high pH values except for
the water with the highest concentration. Although this is an optimal situation for the removal of
PO4, it leads to two problems. First, the filtered water is not suitable for direct disposition in
sewers, since the pH is higher than the limit established by the wastewater legislation (9.5).
Second, a pH value larger than 9 determines the precipitation of PO4 regardless of the presence of
the composite, which suggests that the PO4 is not adsorbed by the composites, thus not leading to
the desired comple
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
