Improved speciation of dissolved organic nitrogen in natural waters: amide hydrolysis with fluorescence derivatization

The objective of this study was to improve primary-amine nitrogen (1°-N) quantification in dissolved organic matter (DOM) originating from natural waters where inorganic forms of N, which may cause analytical interference, are commonly encountered. Efforts were targeted at elucidating organic-N structural criteria influencing the response of organic amines to known colorimetric and fluorescent reagents and exploring the use of divalent metal-assisted amide hydrolysis in combination with fluorescence analyse...     

CO2 embodied in trade: trends and fossil fuel drivers

Environmental Science and Pollution Research - The amount of CO2 embodied in trade has substantially increased over the last decades. We contribute to understanding the reasons for this evolution...     

Why telecoupling research needs to account for environmental justice

ABSTRACT

Engaging with normative questions in land system science is a key challenge. This debate paper highlights the potential of incorporating elements of environmental justice scholarship into the evolving telecoupling framework that focuses on distant interactions in land systems. We first expose the reasons why environmental justice matters in understanding telecoupled systems, and the relevant approaches suited to mainstream environmental justice into telecoupled contexts. We then explore which specific elements of environmental justice need to be incorporated into telecoupling research. We focus on 1) the distribution of social-ecological burdens and benefits across distances, 2) power and justice issues in governing distantly tied systems, and 3) recognition issues in information flows, framings and discourses across distances. We conclude our paper highlighting key mechanisms to address injustices in telecoupled land systems.     

Sink–float density separation of post-consumer plastics for feedstock recycling

The paper focuses on current mechanical waste processing technologies and out-of-the-box processes linked to the processing of coal and mineral resources, to ensure high-quality feedstock recycling of polyolefin-rich post-consumer plastic fractions. Moreover, the study aims to provide the basis for the technical and economic feasibility of the chemical recycling route of this plastic fraction. When evaluating common mechanical processes, either dry or wet ones, sink–float separation in a cylindrical centrifugal force separator achieves the best results. It combines the advantages of a simple, robust apparatus of low complexity and high capacity with selective separation through the accelerated settling of particles in the centrifugal field. Furthermore, the disconnection of the separation medium feed from the solid input increases residence times. Based on the above findings, a pilot-scale plant was constructed which consists of a centrifugal force separator and a hydro jig for the pre-separation of heavy waste components. Several test campaigns were conducted to separate polyolefins from various waste fractions. Two-stage processing in the centrifugal force separator rendered almost 90 wt% of polyolefin content in the produced lightweight fraction and of polyolefin recovery. One-stage processing, on the other hand, resulted in reduced polyolefin content in the lightweight fraction.

     

Conservation resource allocation,small population resiliency,and the fallacy of conservation triage

Some conservation prioritization methods are based on the assumption that conservation needs overwhelm current resources and not all species can be conserved; therefore, a conservation triage scheme (i.e., when the system is overwhelmed, species should be divided into three groups based on likelihood of survival, and efforts should be focused on those species in the group with the best survival prospects and reduced or denied to those in the group with no survival prospects and to those in the group not needing special efforts for their conservation) is necessary to guide resource allocation. We argue that this decision-making strategy is not appropriate because resources are not as limited as often assumed, and it is not evident that there are species that cannot be conserved. Small population size alone, for example, does not doom a species to extinction; plants, reptiles, birds, and mammals offer examples. Although resources dedicated to conserving all threatened species are insufficient at present, the world's economic resources are vast, and greater resources could be dedicated toward species conservation. The political framework for species conservation has improved, with initiatives such as the UN Sustainable Development Goals and other international agreements, funding mechanisms such as The Global Environment Facility, and the rise of many nongovernmental organizations with nimble, rapid-response small grants programs. For a prioritization system to allow no extinctions, zero extinctions must be an explicit goal of the system. Extinction is not inevitable, and should not be acceptable. A goal of no human-induced extinctions is imperative given the irreversibility of species loss.     

MACROPHYTE STANDING CROP AND PRIMARY PRODUCTWITY IN SOME FLORIDA SPRING-RUNS1

ABSTRACT: A survey of 31 Florida spring-runs was conducted to estimate their submerged macrophyte standing crop and primary productivity. The standing crops of submerged vegetation were not significantly (p > 0.05) correlated to either total nitrogen (r = 0) or total phosphorus (r =?0.20) concentrations, but standing crops were significantly (p < 0.01) correlated to the percentage of the spring-run's water surface shaded by marginal vegetation (r =?0.76). Maximum daily rates of primary productivity were positively correlated with average submerged macrophyte standing crops (r = 0.81; p < 0.001) and inversely correlated with the degree of shading by marginal vegetation (r =? 0.43; p < 0.05).     

Metallothioneins and cadmium uptake by the liver in Bufo arenarum

Bufo arenarum females were treated daily with 0.5 mg Cd kg(-1) during 10 days to evaluate the uptake of this heavy metal and the induction of metallothionein synthesis in the liver. The liver incorporated 26% of the Cd administered, about 6.5 times higher than the average uptake of the other tissues of B. arenarum. Three protein fractions from the B. arenarum liver bound Cd, and were induced by this xenobiotic up to approx. 24 times above the basal level of these proteins.