Effect of ferrate on green algae removal

Green algae Cladophora aegagropila, present in cooling water of thermal power plants, causes many problems and complications, especially during summer. However, algae and its metabolites are rarely eliminated by common removal methods. In this work, the elimination efficiency of electrochemically prepared potassium ferrate(VI) on algae from cooling water was investigated. The influence of experimental parameters, such as Fe(VI) dosage, application time, pH of the system, temperature and hydrodynamics of the solution on removal efficiency, was optimized. This study demonstrates that algae C. aegagropila can be effectively removed from cooling water by ferrate. Application of ferrate(VI) at the optimized dosage and under the suitable conditions (temperature, pH) leads to 100% removal of green algae Cladophora from the system. Environmentally friendly reduction products (Fe(III)) and coagulation properties favour the application of ferrate for the treatment of water contaminated with studied microorganisms compared to other methods such as chlorination and use of permanganate, where harmful products are produced.

     

Sediments as a sink for UV filters and benzotriazoles: the case study of Upper Iguaçu watershed,Curitiba (Brazil)

Ingredients in home and personal care products, including UV filters and benzotriazoles, are high production volume chemicals extensively used in our daily life, despite several studies revealed their potential eco-toxicity and endocrine-disrupting capacity. Due to some features, such as high lipophilicity, low degradability, and persistence of many of these compounds, sediments can be considered a sink for them in the aquatic environment. In the present study, nine organic UV filters and three benzotriazoles were investigated for the first time in sediments from four urban rivers in Brazil. The contaminants were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results revealed that octocrylene (OC), etylhexyl-methoxycinnamate (EHMC), benzophenone-3 (oxybenzone, BP3), and benzotriazole (BZT) were the predominant compounds adsorbed on the sediments, with concentrations ranging from 5.6 to 322.2 ng g⁻¹ dry weight. The results reported in this work constitute the first data on the accumulation of polar benzotriazoles and lipophilic organic UV filters in sediments from Brazil.

     

Vegetation cover and rainfall seasonality impact nutrient loss via runoff and erosion in the Colombian Andes

Regional Environmental Change - Mountain ecosystems provide key services to a large portion of the population in the tropics. However, they are particularly vulnerable to regional environmental...     

Sustainable forest management in a mountain region in the Central Western Carpathians,northeastern Slovakia: the role of climate change

European forestry is facing many challenges, including the need to adapt to climate change and an unprecedented increase in forest damage. We investigated these challenges in a Norway spruce-dominated mountain region in Central Europe. We used the model Sibyla to explore forest biomass production to the year 2100 under climate change and under two alternative management systems: the currently applied management (CM), which strives to actively improve the forest’s adaptive capacity, and no management (NM) as a reference. Because biodiversity is thought to have mostly positive effects on the adaptive capacity of forests and on the quality of ecosystem services, we explored how climate change and management affect indicators of biodiversity. We found a differential response across the elevation-climatic gradient, including a drought-induced decrease in biomass production over large areas. With CM, the support of non-spruce species and the projected improvement of their growth increased tree species diversity. The promotion of species with higher survival rates led to a decrease in forest damage relative to both the present conditions and NM. NM preserved the high density of over-matured spruce trees, which caused forest damage to increase. An abundance of dead wood and large standing trees, which can increase biodiversity, increased with NM. Our results suggest that commercial spruce forests, which are not actively adapted to climate change, tend to preserve their monospecific composition at a cost of increased forest damage. The persisting high rates of damage along with the adverse effects of climate change make the prospects of such forests uncertain.     

Renewable energy sources: conflicts and opportunities in a changing landscape

Regional Environmental Change - Replacement of conventional energy sources with renewables such as solar panels and wind turbines requires adequate land. Impact assessments should be conducted to...     

Projected twenty-first-century changes in the Central American mid-summer drought using statistically downscaled climate projections

Regional Environmental Change - In addition to periodic long-term drought, much of Central America experiences a rainy season with two peaks separated by a dry period of weeks to over a month in...     

Greening flood protection through knowledge processes: lessons from the Markermeer dikes project in the Netherlands

Greening flood protection (GFP) is increasingly recognized as an adaptive and flexible approach to water management that is well suited to addressing uncertain futures associated with climate change. In the last decade, GFP knowledge and policies have developed rapidly, but implementation has been less successful and has run into numerous barriers. In this paper, we address the challenge of realizing green flood protection goals by specifically considering knowledge in the decision-making of a Dutch flood protection project in Lake Markermeer. In this project, an ecological knowledge arrangement and a traditional flood protection knowledge arrangement are compared and their interactions analysed. The analysis provides insight into the specific difficulties of implementing GFP measures and identifies ways to realize GFP goals. The primary challenge is twofold: First, a self-reinforcing cycle of knowledge production and decision-making in the flood protection domain inhibits the introduction of innovative and multifunctional approaches such as GFP; second, the distribution of power is severely unbalanced in terms of ecological enhancement and flood protection, favouring the latter. Implementation of GFP requires structural change and the integration of ecological and flood protection knowledge and policy. Potentially rewarding routes towards this integration are the exploration of shared interests in GFP and the creation of mutual dependency between knowledge arrangements. The case study and the insights it provides show that GFP is far from mainstream practice and that implementation requires serious effort and courage to break with historical practices.     

Synergistic vulnerabilities: climate variability and fire management policy increase farming challenges in southeastern Mexico

Agricultural fire for land preparation is central in the livelihoods of subsistence farmers practicing shifting cultivation. Achieving a good agricultural burn, one in which the biomass is thoroughly consumed within the chosen area, depends on specific weather conditions. Fire use decisions are also shaped by institutions that define the timing and rules for fire use but also constrain the alternatives and shape adaptive capacities. Global and regional climate changes interact with the institutional framing of fire management affecting local fire use and burn outcomes. These effects are documented and analyzed to suggest adaptations to existing governance systems. We examined subsistence farmers’ socio-ecological vulnerability in the Calakmul municipality, located in southeastern Mexico. Using interviews with farmers and government agents, as well as participatory mapping and observation of agricultural burns, we studied fire management knowledge, practices and burn outcomes. Our results describe a continuum of burn outcomes covering good agricultural burns, uncontrolled burns leading to wildfires and “malquemados” literally poorly burned areas. Malquemados represent unsuccessful combustion associated with excess moisture that results in scorched vegetation. We discuss how unexpected early rains trigger effects that cascade through space and the ecological, economic and cultural domains. We argue that fire management has been historically approached from a conservation standpoint yet agricultural fire use and wildfire prevention should also be addressed from a rural development perspective. This shift in fire management would lead to the proper inclusion of the entire array of burn outcomes in studies and policies addressing farmers’ vulnerability amplified by synergistic effects between climate variability and institutional change.     

Overview of surface measurements and spatial characterization of submicrometer particulate matter during the DISCOVER-AQ 2013 campaign in Houston,TX

The sources of submicrometer particulate matter (PM₁) remain poorly characterized in the industrialized city of Houston, TX. A mobile sampling approach was used to characterize PM₁ composition and concentration across Houston based on high-time-resolution measurements of nonrefractory PM₁ and trace gases during the DISCOVER-AQ Texas 2013 campaign. Two pollution zones with marked differences in PM₁ levels, character, and dynamics were established based on cluster analysis of organic aerosol mass loadings sampled at 16 sites. The highest PM₁ mass concentrations (average 11.6 ± 5.7 µg/m³) were observed to the northwest of Houston (zone 1), dominated by secondary organic aerosol (SOA) mass likely driven by nighttime biogenic organonitrate formation. Zone 2, an industrial/urban area south/east of Houston, exhibited lower concentrations of PM₁ (average 4.4 ± 3.3 µg/m³), significant organic aerosol (OA) aging, and evidence of primary sulfate emissions. Diurnal patterns and backward-trajectory analyses enable the classification of airmass clusters characterized by distinct PM sources: biogenic SOA, photochemical aged SOA, and primary sulfate emissions from the Houston Ship Channel. Principal component analysis (PCA) indicates that secondary biogenic organonitrates primarily related with monoterpenes are predominant in zone 1 (accounting for 34% of the variability in the data set). The relevance of photochemical processes and industrial and traffic emission sources in zone 2 also is highlighted by PCA, which identifies three factors related with these processes/sources (~50% of the aerosol/trace gas concentration variability). PCA reveals a relatively minor contribution of isoprene to SOA formation in zone 1 and the absence of isoprene-derived aerosol in zone 2. The relevance of industrial amine emissions and the likely contribution of chloride-displaced sea salt aerosol to the observed variability in pollution levels in zone 2 also are captured by PCA.

Implications: This article describes an urban-scale mobile study to characterize spatial variations in submicrometer particulate matter (PM₁) in greater Houston. The data set indicates substantial spatial variations in PM₁ sources/chemistry and elucidates the importance of photochemistry and nighttime oxidant chemistry in producing secondary PM₁. These results emphasize the potential benefits of effective control strategies throughout the region, not only to reduce primary emissions of PM₁ from automobiles and industry but also to reduce the emissions of important secondary PM₁ precursors, including sulfur oxides, nitrogen oxides, ammonia, and volatile organic compounds. Such efforts also could aid in efforts to reduce mixing ratios of ozone.     

Physicochemical fingerprinting of thermal waters of Beira Interior region of Portugal

Mineral natural waters and spas have been used for therapeutic purposes for centuries, with Portugal being a very rich country in thermal waters and spas that are mainly distributed by northern and central regions where Beira Interior region is located. The use of thermal waters for therapeutic purposes has always been aroused a continuous interest, being dependent on physicochemical fingerprinting of this type of waters the indication for a treatment in a specific pathological condition. In the present work, besides a literature review about the physicochemical composition of the thermal waters of the Beira Interior region and its therapeutic indications, it was carried out an exhaustive multivariate analysis—principal component analysis and cluster analysis—to assess the correlation between different physicochemical parameters and the therapeutic indications claims described for these spas and thermal waters. These statistical methods used for data analysis enables classification of thermal waters compositions into different groups, regarding to the different variable selected, making possible an interpretation of variables affecting water compositions. Actually, Monfortinho and Longroiva are clearly quite different of the others, and Cró and Fonte Santa de Almeida appear together in all analysis, suggesting a strong resemblance between these waters. Thereafter, the results obtained allow us to demonstrate the role of major components of the studied thermal waters on a particular therapeutic purpose/indication and hence based on compositional and physicochemical properties partially explain their therapeutic qualities and beneficial effects on human health. This classification agreed with the results obtained for the therapeutic indications approved by the Portuguese National Health Authority and proved to be a valuable tool for the regional typology of mineral medicinal waters, constituting an important guide of the therapeutic armamentarium for well and specific-oriented pathological disturbs.