Environmental Sciences Europe最新文献

Background

This study examines seasonal and regional trends in chlorophyll-a concentrations and the dynamics of nitrogen (N) and phosphorus (P) in 32 fishponds (resulting in 150 pond-year cases) employed for fish production. Fishponds have a poor ecological state, requiring further insights for pond management. To gain those insights, monthly data on the pond environment were collected over the growing seasons from April to September (up to 14 years) across lowland to highland regions in Czechia. We used a ratio of dissolved inorganic nitrogen to total phosphorus (DIN:TP) to investigate seasonal patterns of N and P limitations.

Results

Fishponds in the lowland region (below 199 m above sea level, a.s.l.) were predominantly N-limited (80%), while ponds in the midland region (200–449 m a.s.l.) exhibited P limitation at the beginning of the growing season (April–May) and N limitation by the end of the season (August–September; 90% of fishponds). Highland fishponds (above 450 m a.s.l.) showed frequent P limitations, especially during the beginning of the season. Chlorophyll-a concentrations varied on both regional and seasonal scales, with the overall phytoplankton biomass peak at 31 ha of pond surface area. Chlorophyll-a remained stable at the beginning of the season regardless of the DIN:TP ratio but increased with a lower DIN:TP ratio by its end. The chlorophyll-a concentrations were lowest at the beginning and highest at the end of the season and decreased with altitude.

Conclusions

Seasonal and regional variations in nutrient limitations and chlorophyll-a occur in fishponds. Our study suggests that targeted seasonal nutrient input and enhanced monitoring can significantly improve fishpond management practices and ecosystem stability.

In summer 2021, the Dutch Province of Limburg faced an acute high-water event caused by two days of heavy rainfall, resulting in €383 million worth of damage. Afterwards, various policy actors organised a number of evaluations. This study analyses these evaluations and the long-term lessons drawn from this flood event. Dealing with climate change requires insights into how lessons from acute shocks such as floods can stimulate the anticipation of climate change and solutions that can cope with future extremes. This study therefore applies policy learning theory—single, double and triple loop learning—to different layers of flood safety to analyse the extent to which governments prepare for future events and how.

The results show that pre-2021 water and flood risk management policies—our point of comparison to derive what lessons emerge after the 2021 flood—focused mostly on flood prevention (layer 1) and from 1996 onwards with the start of the Room for the River programme also on spatial planning (layer 2), without paying much attention to crisis management (layer 3). Based on the 2021 flood, the official evaluation committee recommends adding two more layers to the multilayer flood safety approach: increasing water awareness (layer 0 as a base layer for the other layers) and focusing on climate-robust recovery after floods (layer 4) to improve long-term robustness. Based on our research, triple-loop learning as the deepest type of learning appeared in the form of applying the Room for the River approach to the tributary brooks systems. To prepare for the future, policy evaluations recommend improving stress tests to better deal with climate change. Futures scenarios and visions for the future are also recommended. Creating future visions can help to steer changes in existing land use and re-think areas to build or to use for water retention, for example. Governments are advised to strengthen their anticipatory capacities as part of their crisis management response and recovery systems. Furthermore, governments will need to apply the different layers for multilayer safety in an integrated way to ensure that regions are able to prepare for future floods.

Background

The Huangpu River serves as a vital water source for around 24 million individuals residing in the metropolitan area of Shanghai. Despite this, elevated levels of heavy metals persist in the sediments of the river, with their chemical fractionation and sources remaining inadequately understood.

Results

To improve the management of heavy metal contamination, sequential extractions and zinc (Zn) isotopic compositions were utilized to evaluate pollution levels in the Huangpu River. The findings reveal that the majority of heavy metals in the river sediments are present in residual fractions, constituting an average of 67.5% for Cd, 57.6% for Cu, 60.6% for Ni, 56.2% for Pb, and 74.4% for Cr, with the exception of Zn (33.8%). Furthermore, a substantial portion of Zn, exceeding 66%, was found in acid-exchangeable, reducible, and oxidizable fractions, indicating a high potential for Zn release into aquatic ecosystems.

Conclusion

Further analysis of Zn isotopes pinpointed traffic emissions, including exhaust fumes and tire wear particles (account for ~ 34.0%), along with anthropogenic emissions and fertilizer (~ 31.7%), as the major culprits behind this contamination. These findings highlight the critical need for stricter regulations to control heavy metal contamination from traffic and domestic sources within the Huangpu River basin.

Background

Understanding the release characteristics of soil colloids is a prerequisite for studying the co-transport of colloids and pollutants in subsurface environment. As a crucial agricultural management measure, fertilization not only alters the material composition of farmland soil, but also significantly regulates the properties and release patterns of soil colloids. This study systematically investigated the regulatory mechanism of short-term cattle manure fertilization on the macroscopic release and microscopic properties of soil colloids with different particle sizes, providing a theoretical foundation for subsequent research on the fate and transport of agricultural non-point source pollutants.

Results

The colloids in natural agricultural soil primarily consist of inorganic components. Graded extraction of the colloids has revealed that the combined proportion of colloids with particle sizes of 1–2 μm and 0.45–1 μm accounts for approximately 80.5%. Applying cattle manure inhibits the release of soil colloids, and the content of large particle size (1–2 μm) components increases. The content of organic colloids is increased due to the high total organic carbon (TOC) in cattle manure, particularly those with a particle size less than 1 μm. The characterization of organic colloid components revealed a significant increase in aromatic carbon and oxygen-containing functional groups, while the aliphatic content decreased. The response sequence regarding changes in functional groups within organic colloids induced by fertilization was as follows: –CH₃, –CH₂ > C–O > –OH > C=C. Fertilization promotes the release of 1:1-type inorganic mineral colloids, increasing the content of poorly crystalline minerals. The retention of aromatic carbon and oxygen-containing functional groups by poorly crystalline mineral colloids served as the primary mechanism leading to their increased content levels. Changes in environmental factors significantly impacted the release and properties of soil colloids. Conditions such as low cationic valence, high ionic strength, and high pH promoted the release of soil colloids.

Conclusions

The short-term fertilization resulted in a reduction in the release of soil colloids and brought about significant alterations in their particle size composition and properties. The findings of this study provide valuable insights into understanding the impact of fertilization-induced colloid release on the environmental behavior of agricultural non-point source pollutants.

Climate change, caused by both natural and human activities, poses significant threats to global health, including rising temperatures, extreme weather events, and environmental disruptions. The One Health concept, emphasizing the interconnectedness of human, animal, and environmental health, is crucial in addressing these challenges. Climate change is linked to the emergence and resurgence of infectious diseases, resulting in substantial economic losses worldwide due to outbreaks, floods, and disrupted trade, among other factors. Therefore, it is crucial to adapt to this changing climate to safeguard One Health. By implementing a One Health approach, we can effectively address the consequences of climate change and make substantial contributions to health and food safety. This approach also holds the potential to mitigate economic losses, particularly in low and middle-income countries. Additionally, in the future, research interventions based on the One Health framework may offer sustainable solutions to combat climate change.

This study evaluated the source apportionment and level of contamination with potential toxic elements (PTEs)—As, Cd, Cr, Cu, Ni, Pb and Zn—in a riparian zone of the Sava River by calculating the Enrichment Factor (EF) and the Geo-Accumulation Index (Igeo). The study analysed the non-carcinogenic and carcinogenic health risks to both adults and children in the local population. Soil and sediment samples collected during high and low water events from 12 sites along 945 km of the river were screened. Elevated soil contents of As, Cr, Cu, Ni, and Zn were observed along the middle and lower stretches from Županja (ZUP) to Belgrade (BEO), and an elevated Cu content was detected in the upper stretch Čatež (CAT), highlighting these elements as a potential risk for the human population. Elevated As, Cd Cr, Ni, and Zn levels in the sediment were also detected, with the Ni content three times higher than the Permissible Exposure Limit (PEL) values, indicating high contamination. The study established that As, Cr, and Ni primarily originate from geological sources; Cu, Pb, and Zn are predominantly from anthropogenic sources; and Cd originates from both geological and anthropogenic sources. Although the EF and Igeo varied along the entire river stretch, they were significantly higher for most elements in the lower stretch, indicating intensive anthropogenic contamination and potential health risks. The carcinogenic and non-carcinogenic risks associated with soils and sediments during high and low water events did not imply a potential risk for adults. However, As, Cd, Cr, and Pb potentially pose the greatest non-carcinogenic risk for children in both high and low water events, with ingestion as the main route of exposure. According to our findings, the elevated concentrations of As, Cd, Cr, and Pb in the Sava River basin (SRB) pose a significant potential health risk to the local population based on several factors: the high levels of these elements, their potential contamination risk as determined by the EF and Igeo, and their bioavailability and solubility. Although the cumulative Total Hazard Index (THI) and Total Carcinogenic Risk (TCR) values are low, particularly in the lower stretch of the Sava River, these elements still present a high potential health threat.

Background

Irrigation with low-quality water without considering the acceptable levels negatively impacts not only humans, but also extends to the whole surrounding ecosystem. The current research is a comprehensive-integrated appraisal of the irrigation water quality gathered from El-Batts drain in Fayoum Governorate, from September 2021 to June 2022, together with the drain sediments and the soils adjacent to it. The characteristics (physical, chemical and biological), and the risk fate of some heavy metals (As, B, Cr, Cu, Zn, Cd, Pb, Ni, Fe and Mn) were measured. Moreover, the risks of the studied pollutants were assessed using many indices: irrigation water quality index (IWQI), contamination factor (Cf), degree of contamination (Cd), Salinity indices and Zn equivalent (ZE). Additionally, kinetic studies of the inorganic pollutants were evaluated to determine their availability and impact on the surrounding environment.

Results

Data from IQWI showed that water in all five sites was assumed to be very bad and unsuitable for usage with a general average (14.62 and 25.35) in all four seasons. ZE exceeds the critical level of 250, which means there is a risk of soil contamination.

Conclusions

The elevated levels of heavy metals, microbial enzymes, pathogenic fecal coliform and Salmonella reflect bad and direct risk of dealing with such water in irrigation and its effect on the soil ecosystem and the growing crops. Most of the tested parameters exceeded the acceptable levels of the Egyptian Governmental Law Guidelines, WHO and FAO, which may threaten aquatic life. Best managements practices and remediation techniques should be applied to minimize the hazards in such waters.

Background

Discharge of large amounts of untreated industrial effluent into water bodies pose significant environmental challenges worldwide. This is due to the limitations of traditional wastewater treatment methods in the treatment of recalcitrant organic pollutants. Fenton processes involves the generation of hydroxyl radicals that are well suited to degrade organics in effluent water. This study focuses on reducing slag generation during Fenton processes and enhancing the reuse of nano-zero-valent iron (NZVI) through the immobilization of NZVI on activated carbon cloth (ACC) through a chitosan (CH) linker with phenol as a model pollutant.

Results

Microstructural and spectroscopic techniques were employed to study the materials prepared and 37.5 wt% iron loading was achieved. Phenol degradation of 96.3% at 40 °C at pH of 3.0 with 50 mM H₂O₂ was achieved using ACC-CH-NZVI. Adsorption and degradation studies carried out using ACC-CH-NZVI catalyst revealed that phenol adsorption onto ACC-CH-NZVI fits the Langmuir isotherm model, following the pseudo-second-order kinetic model and first-order reaction kinetics. Thermodynamic studies indicate the non-spontaneous, endothermic and irreversible nature of the removal process. Comparing ACC-CH-NZVI with ACC and ACC-CH, phenol removal using ACC drops from 87.8 to 39%, while using ACC-CH, the removal efficiency drops from 73 to 20.9% and using ACC-CH-NZVI, phenol removal drops from 96.3 to about 70% and total organic carbon removal drops from 79 to about 60% with minimal iron leaching, highlighting the superior performance of ACC-CH-ZVI and the role of NZVI in enhancing phenol removal.

Conclusions

The catalyst demonstrated good stability for phenol degradation to about 70% phenol removal from simulated wastewater and 60% TOC removal from industrial wastewater after five treatment cycles with minimal Fe leaching.

Graphical abstract

Background

African countries are among the most vulnerable and affected by climate change. Comprehending climate change poses a major hurdle for the African population, politicians, and the African Union alike, presenting a substantial challenge for all involved. It is generally accepted that universities and other higher education institutions must play a leading role as drivers of change. Therefore, it is very important that African universities educate students about both mitigation and adaptation measures, develop the necessary initiatives to foster research in climate change-related topics and promote cooperation and alliances with key stakeholders.

Results

This research reports on a study aimed at identifying the extent to which higher education institutions in Africa are engaging in efforts to deal with the challenges posed by climate change. The objectives were accomplished through a mixed method approach, incorporating a review of literature, an international survey, and the inclusion of selected case studies from African universities that have developed successful initiatives. The research has brought to light significant disparities, such as varying perceptions regarding the potential outcomes of climate change and its associated extreme events in African countries. In addition, the study highlighted areas where there is a notable consensus on specific issues. It also offers a comprehensive view of the different strategies that universities are implementing to contribute to climate change mitigation and adaptation in several areas. Although there is a growing interest in the need to contribute to the joint task of mitigating the effects of climate change and adapting to its consequences, HEIs need to increase their efforts to enhance the work of their professors and researchers. To this end, the involvement of public authorities and other private sector actors is essential.

Conclusions

This article outlines some actions that need to be undertaken so that universities may play a more active role in global efforts to handle the problems associated with a changing climate. There is a notable focus from academic actors on addressing climate change challenges in Africa. In addition, there is a proactive emphasis on utilizing science and research to comprehend climate change issues and offer widely applicable tools for adaptation and mitigation to safeguard both people and the environment. Consequently, it is crucial and time-sensitive for African universities to enhance their expertise in the field of climate change, fostering the capacity to conduct innovative research that addresses the various challenges linked to the evolving climate. This study offers several useful lessons for African universities to replicate experiences that have generated results in different countries and contexts.