36 research outputs found
Cadmium contamination of sediments in the water reservoirs in Silesian Upland (southern Poland)
Purpose Cadmium (Cd) is considered a toxic element and its concentrations are relevant to human health and the environment. Therefore, the purpose of the study was to determine the extent to which the bottom sediments of water bodies (artificial lakes and ponds) in the Silesian Upland in southern Poland are contaminated with Cd; an attempt was also made to determine the factors that condition spatial differences in the concentration of this element between individual water bodies in the region.
Materials and methods Measurements of the Cd content in bottom sediments were carried out in 35 water bodies in southern Poland in 2011 and 2012. Depending on the surface area and morphometric characteristics, from two to nine samples representative in terms of sediment thickness were collected in each water body. Cadmium concentrations were determined for 92 0.25 g aliquots using the TD-ICP method.
Results and discussion Cadmium content in all samples (0.7â580.0 mg kgâ1) was higher than the natural range of concentrations for this element in the Earthâs crust (0.1â0.3 mg kgâ1) and the geochemical background for Poland (0.5 mg kgâ1) and, with a few exceptions, was also higher than the preindustrial concentration (1.0 mg kgâ1) and the regional geochemical background (2.5 mg kgâ1). Adopting natural Cd concentrations in the Earthâs crust (0.1â0.3 mg kgâ1) as the baseline for the geoaccumulation index (Igeo), the sediments examined can be classified as extremely and heavily contaminated (and moderately contaminated in a small number of cases). The assessment of sediment quality based on Igeo, with the regional geochemical background (2.5 mg kgâ1) adopted as the baseline, results in non-contaminated and moderately contaminated sediments being dominant with a far smaller number of heavily and extremely contaminated ones.
Conclusions In the case of several water bodies, Cd concentrations were at record levels that have not been found anywhere else in the world. On the basis of the Igeo, sediments of varying quality were foundâfrom virtually uncontaminated to extremely contaminated. The Igeo index as an indicator of the quality of bottom sediments is a measure that requires careful interpretation, especially when different concentration levels regarded as natural are used for determining its value
Impacts of the eastern route of the South-to-North Water Diversion Project emergency operation on flooding and drainage in water-receiving areas: an empirical case in China
The water levels of lakes along the eastern route of the
South-to-North Water Diversion Project (ER-SNWDP) are expected to rise
significantly and subsequently affect the processes of flood control and
drainage in corresponding lake basins. However, few studies have focused on
the impacts of inter-basin water diversion on the flood control and drainage
of water-receiving areas at the lake basin scale. Using MIKE software, this
paper builds a coupled hydrodynamic model to address the existing literature
gap regarding the impacts of inter-basin water diversion on the processes of
flood control and drainage in a water-receiving lake basin, and it considers
the many types of hydraulic structures in the model. First, a flood
simulation model was constructed to simulate the complex movement of water
transferred by the ER-SNWDP, by waterlogging in the lakeside area around
Nansi Lake (NL), and water in NL and its tributaries. The ER-SNWDP was also
considered in the model. Second, the model was calibrated and verified with
measurement data, and the results showed that the model was efficient and
presented a NashâSutcliffe efficiency coefficient (NSE) between 0.65 and
0.99. Third, the processes of flooding and draining in the lakeside area of
NL were simulated under different water diversion and precipitation values.
Finally, the impacts of the emergency operations of the ER-SNWDP on flood
control and waterlogging drainage in the lakeside area of NL were analysed
based on the results from the proposed model, and some implications are
presented for the integrated management of inter-basin water diversion and
affected lakes.</p
Advances in Industrial and Environmental Microbiology
The development of civilization entails the need to find new technological solutions leading to products with new properties. Allies in these efforts are microorganisms that have developed skills to synthesize products with properties of interest to the industry, environmental remediation or water treatment. The evolution of the omics approaches brought new tools to explore the microbial diversity and microorganismsâ potential. These new methodological approaches are readily used in both industrial and environmental microbiology. This Special Issue collects research papers as well as review articles addressing recent advances on applied and environmental microbiology. The review articles critically discuss the importance of biopolymers, specifically xanthan gum, to improve soil properties and the importance that microorganisms of poorly explored environments, such as caves, may have in the production of new bioactive compounds. The microbiological aspects of wastewater treatment and occurrence of antibiotic resistance genes in wastewater and sludge are studied in two research papers. These works demonstrate the effect that treatment conditions may have in the modulation of the water bacterial communities and how treated wastewater may impact the receiving environment in terms of pollution with antibiotic resistance genes. Additionally, the influence that an invasive species (alligator weed) may have on wetlands organic matter accumulation and bacterial communities was studied, being demonstrated that the presence of the invasive weed affects the wetland microhabitat both in terms of organic matter content and bacterial communities structure
Patterns and drivers of evapotranspiration in South American wetlands
Evapotranspiration (ET) is a key process linking surface and atmospheric energy budgets, yet its drivers and patterns across wetlandscapes are poorly understood worldwide. Here we assess the ET dynamics in 12 wetland complexes across South America, revealing major differences under temperate, tropical, and equatorial climates. While net radiation is a dominant driver of ET seasonality in most environments, flooding also contributes strongly to ET in tropical and equatorial wetlands, especially in meeting the evaporative demand. Moreover, significant water losses through wetlands and ET differences between wetlands and uplands occur in temperate, more water-limited environments and in highly flooded areas such as the Pantanal, where slow river flood propagation drives the ET dynamics. Finally, floodplain forests produce the greatest ET in all environments except the Amazon River floodplains, where upland forests sustain high rates year round. Our findings highlight the unique hydrological functioning and ecosystem services provided by wetlands on a continental scale
Advances in ecotechnological methods for diffuse nutrient pollution control: wicked issues in agricultural and urban watersheds
Considerable time and funding have been committed to tackling nonpoint source (NPS) pollution in agricultural and urban watersheds . Notwithstanding all these efforts, the water quality in many AUWs has not significantly improved. Diffuse nutrient pollution involves the movement of these pollutants between soil and water. Excessive diffuse pollution has been accepted as one of the main causes of failure to attain favorable environmental conditions in freshwater systems. Recently, several technologies and practices have been implemented to manage diffuse pollution, namely: a) source reduction, b) pollutant retention over the movement process; c) nutrient recycling, and d) purification and restoration of the eutrophic water bodies. This paper synthesized the existing knowledge of key methods to tackle diffuse pollution from AUWs. Furthermore, the predominant purification mechanisms and impacting factors are explored, allowing a comprehensive and critical understanding of different control strategies to improve the management of diffuse pollution. Therefore, potential approaches for strengthening the performance of control technologies for diffuse pollution treatment and remediation are discussed. Although adopting source reduction strategies (e.g., the â4Râ approach: right rate, right time, right source, and right placement of nutrients) could efficiently decrease surface runoff and pollutant levels, they may not stop runoff from entering nearby streams. Consequently, comprehensive treatment of agricultural runoff still requires extra process retention strategies. Overall, the findings of this paper showed that treatment system design and operational and environmental factors played crucial but variable roles in diffuse pollution treatment. Moreover, the results showed that combining or integrating constructed wetlands with other control technologies could enhance the comprehensive purification of diffuse pollution compared to using a single method. This review proposes a systematic approach for diffuse pollution control based on three components (water, soil and microbiota) and maximizing the regulating services of agroecosystems via land use/cover types. The current review contributes to the documentation of existing research trends. It sheds light on diffuse pollution control approaches in AUWs, and further encourages the development of this vital field
Dynamics of the seasonal floodplain fishery of the Okavango Delta, Botswana
Inland fisheries provide vital proteins, jobs and income, for some of the most marginalized communities of the world. The role of inland fisheries in household food security is particularly important in Africa, where most of the worldâ poorest are found. Therefore, there is a compelling need to enhance our understanding of the dynamics of floodplain fisheries because of their intrinsic value to riparian communities. Understanding their impotance will lead to their sustainable utilisation, which will contribute to the attainment of some of the 2030 Sustainable Development Goals. Therefore, this thesis examines the relationship between fish dynamics and environmental variability in flood-pulsed systems, by using the Okavango Delta as a case study. Establishing this relationship is important towards identifying the key drivers of change, restoration and persistence in floodplain fish communities. The thesis also highlights the dynamic interactions between seasonal hydrology and nutrient dynamics in floodplain systems. These dynamic processes, coupled with a heterogeneous system, sustain a diverse fish community that is a key source of livelihoods for the deltaâs riparian community. Dynamic processes within the fish community, such as distribution, feeding and growth are driven by the seasonal flood pulse. Currently, the Okavango Delta fishery is managed through a series of classical management approaches which are incompatible with the dynamic nature of floodpulsed systems. The best management approach is through balanced harvesting, which has been inadvertently implemented by traditional exploitation practices. Management interventions in floodplain fisheries should be adaptive, practical, realistic and implementable, which in particular means acceptable to the stakeholders. Most developing countries have limited resources, and these should be spent on achievable and practical activities. Informed management also necessitates continuous long-term monitoring of exploited fisheries to follow changes and to gradually improve our understanding fishing patterns and their impact on the fish communities. This involves the collection of fisheries related data across a broad spectrum of activities (e.g. fish consumption, employment creation, various kinds of biological data on species exploited, gear use and efficiencies, etc.) and associated factors/ variables (e.g. environmental factors, various land-use activities, etc.). Once these have been documented and understood, they can be integrated into a flexible management system, which will allow for more adaptive management of these resources. Such integration is currently lacking in the Okavango Delta and also in floodplain fisheries in general.Doktorgradsavhandlin
Energy and Water Cycles in the Third Pole
As the most prominent and complicated terrain on the globe, the Tibetan Plateau (TP) is often called the âRoof of the Worldâ, âThird Poleâ or âAsian Water Towerâ. The energy and water cycles in the Third Pole have great impacts on the atmospheric circulation, Asian monsoon system and global climate change. On the other hand, the TP and the surrounding higher elevation area are also experiencing evident and rapid environmental changes under the background of global warming. As the headwater area of major rivers in Asia, the TPâs environmental changesâsuch as glacial retreat, snow melting, lake expanding and permafrost degradationâpose potential long-term threats to water resources of the local and surrounding regions. To promote quantitative understanding of energy and water cycles of the TP, several field campaigns, including GAME/Tibet, CAMP/Tibet and TORP, have been carried out. A large amount of data have been collected to gain a better understanding of the atmospheric boundary layer structure, turbulent heat fluxes and their coupling with atmospheric circulation and hydrological processes. The focus of this reprint is to present recent advances in quantifying landâatmosphere interactions, the water cycle and its components, energy balance components, climate change and hydrological feedbacks by in situ measurements, remote sensing or numerical modelling approaches in the âThird Poleâ region
Anthropogenic point-source and non-point-source nitrogen inputs into Huai River basin and their impacts on riverine ammoniaânitrogen flux
This study provides a new approach to estimate both anthropogenic non-point-source and point-source nitrogen (N) inputs to the landscape, and determines their impacts on riverine ammonia-nitrogen (AN) flux, providing a foundation for further exploration of anthropogenic effects on N pollution. Our study site is Huai River basin of China, a waterâshed with one of the highest levels of N input in the world. Multi-year average (2003-2010) inputs of N to the watershed are 27 200 ± 1100 kg N km-2 yr-1. Non-point sources comprised about 98 % of total N input, and only 2 % of inputs are directly added to the aquatic ecosystem as point sources. Fertilizer application was the largest non-point source of new N to the Huai River basin (69 % of net anthropogenic N inputs), followed by atmospheric deposition (20 %), N fixation in croplands (7 %), and N content of imported food and feed (2 %). High N inputs showed impacts on riverine AN flux: fertilizer application, point-source N input, and atmospheric N deposition were proved as more direct sources to riverine AN flux. Modes of N delivery and losses associated with biological denitrification in rivers, water consumption, interception by dams may influence the extent of export of riverine AN flux from N sources. Our findings highlight the importance of anthropogenic N inputs from both point sources and non-point sources in heavily polluted watersheds, and provide some implications for AN prediction and management.This study was financially supported by the Key Research Program of the Chinese Academy of Sciences (no. KZZD-EW-10-02-3), the 13th Five-Year Plan of Chinese Academy of Sciences (no. YSW2013B02) and State Key Laboratory of Urban and Regional Ecology scientific project (no. SKLURE2013-1-05). The authors wish to express their gratitude to the China Scholarship Council (201408110138) for funding the visiting venture that generated this paper, and to Huai River Basin Water Resources Protection Bureau and Hydrologic Information Center of Huai River Commission for providing water quality and hydrological data
Remote Sensing of Surface Water Dynamics in the Context of Global Change - A Review
Inland surface water is often the most accessible freshwater source. As opposed to groundwater, surface water is replenished in a comparatively quick cycle, which makes this vital resourceâif not overexploitedâsustainable. From a global perspective, freshwater is plentiful. Still, depending on the region, surface water availability is severely limited. Additionally, climate change and human interventions act as large-scale drivers and cause dramatic changes in established surface water dynamics. Actions have to be taken to secure sustainable water availability and usage. This requires informed decision making based on reliable environmental data. Monitoring inland surface water dynamics is therefore more important than ever. Remote sensing is able to delineate surface water in a number of ways by using optical as well as active and passive microwave sensors. In this review, we look at the proceedings within this discipline by reviewing 233 scientific works. We provide an extensive overview of used sensors, the spatial and temporal resolution of studies, their thematic foci, and their spatial distribution. We observe that a wide array of available sensors and datasets, along with increasing computing capacities, have shaped the field over the last years. Multiple global analysis-ready products are available for investigating surface water area dynamics, but so far none offer high spatial and temporal resolution