Found 14 results
Article
12 December 2024Adsorption of Bisphenol A and 2,6-Dichlorophenol in Water Using Magnetic Phosphogypsum Composite Materials
Phenolic pollutants in water bodies pose a huge threat to human health and environmental safety. In this paper, a hydrophobicity-enhanced magnetic C-SiO2/MPG composite was prepared by a two-step method to remove bisphenol A (BPA)and 2,6-dichlorophenol (2,6-DCP), typical phenolic trace pollutants in livestock wastewater and natural water bodies. The results of pH gradient experiments showed that C-SiO2/MPG showed a stable removal effect on BPA in the pH range of 2–11. The adsorption of 2,6-DCP by C-SiO2/MPG peaked at pH = 2, while the adsorption of 2,6-DCP by C-SiO2/MPG was severely inhibited under alkaline conditions. The PSO kinetic model and the Langmuir isotherm model can better describe the adsorption process of BPA and 2,6-DCP on C-SiO2/MPG, indicating that the monolayer chemical adsorption has a rate-controlling step. With the Langmuir equation fitting, the maximum adsorption capacity of C-SiO2/MPG for BPA and 2,6-DCP at 298 K was calculated to be 561.79 mg/g and 531.91 mg/g, respectively. The results of adsorption thermodynamics indicated that the adsorption of BPA and 2,6-DCP on C-SiO2/MPG was spontaneous, accompanied by a process of entropy decrease. C-SiO2/MPG showed good environmental resistance and repeated use stability for BPA and 2,6-DCP in electrolyte ion interference, actual water samples and cycle experiments. Mechanism analysis showed that the adsorption of BPA and 2,6-DCP on C-SiO2/MPG was mainly controlled by hydrogen bonding and hydrophobic interactions. This study designed an efficient adsorbent for phenolic pollutants that can be used in actual wastewater and broadened the resource utilization of industrial waste phosphogypsm.
Article
15 November 2024Long-Term Change in Human Impact and Environmental Perceptions: A 40-Year Case Study of an Environment-Focused Non-Governmental Organization
Non-governmental environmental organizations are diverse in scope, goals and doctrine, ranging from natural history societies to green parties. It was from the 1960s that they became widespread worldwide. To characterize a French NGO and assess the changing trends in its objectives over time, we have qualitatively and quantitatively analyzed the journal it has published without interruption for 40 years: 140 issues, 4500 pages, and almost 250 keywords. The initial scope of the NGO was focused on ‘humans and nature’: we do not protect the environment against humans but with humans, i.e., at the same time as humans, which is the very definition of sustainable development, with its three-fold focus: nature, economy and social justice. The primary issues included recognizing water as a shared resource for all people, promoting sustainable agriculture and transportation (such as railways), advancing peace efforts, and protecting nature. This approach emphasizes a rigorous, evolving scientific perspective that goes beyond a focus on a few charismatic species (‘deluxe biodiversity’), embracing biodiversity in its entirety. Over time, the discourse has kept track of the shifting priorities of most Green parties: less and less focused on nature (e.g., forests, ecosystems) and more and more on social issues (e.g., health, housing, transport). However, it differs in not focusing on the idées fixes of the Greens (e.g., rejection of civil nuclear power, GMOs).
Article
25 September 2024Evolution in the Dinarids: Phylogeography, Diversity and Evolutionary History of the Endemic Genus Delminichthys (Actinopteri; Leuciscidae)
The origin of exceptionally rich fish communities harboured within the freshwater systems of southern Europe is usually explained by allopatric speciation due to a long isolation of water basins. On the other hand, hybridization events have been recorded in several fish species, but they role in the speciation of freshwater fishes in the Southern Europe has not received significant attention. Contrary to most species within the Leuciscidae family, the genus Delminichthys inhabits a geographically restricted area (middle and southern Dinarides) and consists of only four endemic species. This study analysed the population genetic structure and demographic history of each Delminichthys species as a contribution to the understanding of the evolutionary peculiarities in Dinaric water systems. The obtained results revealed pronounced mito-nuclear and nuclear-nuclear discordance, likely the result of incomplete lineage sorting, as well as nuclear introgression observed in the Ombla River population in southernmost Croatia. In addition to allopatric speciation, ancient hybridization might have played an important role in the evolutionary history of this genus. The origin of the genus Delminichthys can be dated back to the Oligocene/Miocene boundary, to a period of significant tectonic activity in the Mediterranean region, and its ancestor likely inhabited the region of the central Dinarides. Intrageneric divergences occurred in the lower Miocene and Pliocene. Similarly, as previously proposed for Delminichthys adspersus, traces of underground migrations were found among Delminichthys ghetaldii populations, implying adaptations to underground life to be characteristic for the genus. All Delminichthys species express high levels of genetic diversity, likely as a consequence of their old origin. Size of D. adspersus is currently decreasing, while the remaining three species appear stable.
Article
19 August 2024Differences in Flood Quantiles Estimate of Disturbed and Undisturbed Watersheds in the United States
Nonstationarity due to climate variation and anthropogenic disturbances has altered high flow regimes. However, the extent of change has not been evaluated for undisturbed versus disturbed watersheds. This article aimed to determine how partitioning watersheds into undisturbed and disturbed categories can improve the performance of probability distributions for flood analysis throughout the United States. We utilized peak flow information for 26 reference (undisturbed) and 78 nonreference (disturbed) watersheds with drainage areas ranging from 135 to 42,367 km2 and record lengths of 100 to 140 years. Results indicated that flood quantile estimates of the Log Pearson Type III (LP3) distribution were likely being overestimated for return periods of 2 to 10 years, while flood estimates of 50 years and higher might be underestimated. In contrast, the Generalized Extreme Value (GEV) distribution outperformed LP3 in estimating floods with return periods of 50 years or more. These findings enhance flood frequency analysis and forecasting under nonstationary conditions.
Article
06 August 2024Evaluation of a Present-Day Thermal Activity on the Constitutive Minerals of a Granite and of Its Impact on the Whole-Rock Sealing Potentials
Mineralogical and chemical analyses of the major constitutive minerals from granite des Crêtes collected near the thermal site of Plombières-les-Bains (Vosges Mountains, eastern France) clearly show that recently circulating thermal waters up to 90 °C do not impact them. Even the constitutive minerals smaller than 2 microns are not affected. As a result, all minerals reflect the entire complex tectonic-thermal history of the granitic massif rather than just the recent thermal impact. Only the open faults and natural drains contain calcite from recent thermal waters. This is confirmed by similar calcite deposits with the same elemental contents sampled in the pipes of thermal installations. As a complementary conclusion, storage of containers of nuclear waste that diffuse an overall temperature up to 100 °C will not alter the potential sealing properties of a plutonic host massif, of course, without any recent thermal drainage that could potentially spread radioactive waste. This conclusion was already obtained on a moderately faulted sedimentary environment after a one-year in-situ heating experiment at about 100 °C. Calcium is a key indicator of low thermal impact. After an initial decrease, its levels rose significantly in the most "altered" granite samples, inducing calcite precipitation, even in the water pipes at the thermal site. The negligible impact of a hydro-thermal activity at a maximum of about 100 °C in a granitic material represents, indeed, a piece of useful information, as deep sites for nuclear waste in plutonic host rocks appear to act, also, as potential isolated host systems.
Opinion
26 June 2024Prospective Approaches for Ecosystem Sustainability Including Climate Mitigation
A summary, based upon foresight, futures, ideation and frontier technology studies of prospective approaches to foster ecosystem sustainability including climate mitigation at the technology and societal levels which are at scale and profitable. Approaches summarized include halophytes/salt plants grown on deserts/wastelands using saline/seawater, to address land, water, food, energy and climate, frontier energetics, nascent climate mitigation concepts, cellular agriculture, materials optimization, the virtual age, efficiency and redesigning the ecosystem for the Anthropocene. Solution/mitigation approaches are targeted at deforestation, desertification, pollution writ large (land, sea, air, space), and extensive urbanization along with soil salination, ocean acidification, mining, and water scarcity.
Article
11 April 2024Exploring Bi4V2O11 as Photoanode for Water Splitting with a Wide Range of Solar Light Capture and Suitable Band Potential
Bi4V2O11 possesses a bandgap of ~1.9 eV, and the band positions of minimum conduction band and maximum valence band straddle the redox potentials of H+/H2 and O2/H2O. In the current work, photoanode made of particulate Bi4V2O11 film displays a wide range of light adsorption. However, when the anode was fabricated by drop-casting and examined for photoelectrochemical water splitting, the photocurrent density of the pristine Bi4V2O11 was low. Improvement has then been carried out by Mo-doping. The Mo-doped Bi4V2O11 photoanode achieves a maximum photocurrent density of 0.3 mA/cm2 after a post deposition necking treatment to improve the connectivity of the drop-cast particles in the film. This material also shows a stability with maintaining 80% photocurrent after 2 h test. Discussion has been made on the displayed performance in PEC water splitting of the Bi4V2O11 materials. Potential solutions have been proposed for this type of promising photoanode material for water splitting.
Review
02 April 2024Mapping the (in)Effective Enforcement of EU Environmental Law in Greece: Lessons from the EU and Domestic Courts
The effective implementation and enforcement of EU environmental law at national level constitutes a thorny issue with both legal and practical aspects. Greece is among the EU Member States which has historically faced difficulties in complying with the EU environmental acquis due to the poor functioning of the Greek administration, the limited manpower, expertise and resources (especially during the recent period of the economic crisis) for the competent authorities, the lack of political will, the low awareness of environmental problems. In this context, this paper aspires to unpack these enforcement challenges at the national level based on the case law of both the Greek Council of State and the Court of Justice of the European Union. Considering that waste management, nature protection, and water and air quality sectors are recognized as areas with the most significant deficiencies in implementation at the domestic level, the analysis will focus on these four key sectors. To this end, by reviewing the relevant EU and Greek jurisprudence, this paper aspires to identify the disparities between the formal requirements and the practical application of EU environmental regulations in Greece in light of the national political, economic, social, and cultural dynamics.
Article
13 March 2024The Potential of Salinity Gradient Energy Using Reverse Electrodialysis to Generate Electricity for Seawater Desalination Plants, an Example from Western Australia
Seawater desalination plays a vital role in addressing the increasing global demand for freshwater. However, the energy-intensive nature of desalination processes and the generation of brine by-products pose environmental challenges. In Western Australia (WA), approximately 48% of freshwater is supplied by two seawater desalination plants employing the energy-intensive seawater reverse osmosis (SWRO) method. These plants are powered by a combination of renewable and conventional energy sources. Typically, the most efficient approach for desalination plants involves a blend of renewable energy sources. Salinity gradient energy (SGE) harnessed through the reverse electrodialysis (RED) system, which derives energy from mixing waters with varying salinities, has emerged as a potential solution. RED utilizes ion-exchange membranes to convert the chemical potential difference between two solutions into electric power. The net specific energy of SGE, calculated based on the Gibbs free energy associated with mixing seawater and wastewater, is estimated at approximately 0.14 kWh per cubic metre of brine for SWRO desalination plants. The combined SGE potential of WA’s two desalination facilities theoretically amounts to approximately 87.4 MWh of energy. However, due to the inherent limitations of the RED system’s current energy efficiency, only about 2.5% of the desalination plant’s energy requirements can be met through this technique. This paper addresses a significant gap in the literature by analyzing the technical and economic constraints of utilizing salinity gradient energy (SGE) through the reverse electrodialysis (RED) system for seawater desalination plants. This marks the first examination of its kind, shedding light on both the technical feasibility and economic challenges of SGE-RED application in this context. The scientific contribution lies in its innovative approach, integrating technical and economic perspectives to provide an understanding of SGE-RED technology’s potential drawbacks and opportunities. By identifying and tackling these challenges, this paper aims to pave the way for optimizing SGE-RED systems for practical implementation in seawater desalination plants.
Article
19 September 2023Advancing Green Hydrogen Production in Saudi Arabia: Harnessing Solar Energy and Seawater Electrolysis
The transition to clean and sustainable energy sources is crucial for combating the challenges posed by climate change. Green hydrogen, produced through renewable energy-driven electrolysis, holds significant promise as a viable clean energy carrier. The study introduces a system that leverages abundant solar energy and utilizes seawater as the feedstock for electrolysis, potentially offering a cost-effective solution. A comprehensive mathematical model, implemented in MATLAB, is employed to simulate the design and operational efficiency of the proposed green hydrogen production system. The system’s core components include solar panels as a clean energy source, an advanced MPPT charge controller ensuring optimal power delivery to the electrolyzer, and a seawater tank serving as the electrolyte source. The model combines these elements, allowing for continuous operation and efficient hydrogen production, addressing concerns about energy losses and cost-effectiveness. Results demonstrate the influence of solar irradiance on the system’s performance, revealing the need to account for seasonal variations when designing green hydrogen production facilities. Theoretical experiments are conducted to evaluate the behavior of a lithium battery, essential for stabilizing the system’s output and ensuring continuous operation during periods of low solar radiation.
