Environmental Electrokinetics for a sustainable subsurface

International audienceSoil and groundwater are key components in the sustainable management of the subsurface environment. Source contamination is one of its main threats and is commonly addressed using established remediation techniques such as in-situ chemical oxidation (ISCO), in-situ chemical reduction (ISCR; most notably using zero-valent iron [ZVI]), enhanced in-situ bioremediation (EISB), phytoremediation, soil-washing, pump-and-treat, soil vapour extraction (SVE), thermal treatment, and excavation and disposal. Decades of field applications have shown that these techniques can successfully treat or control contaminants in higher permeability subsurface materials such as sands, but achieve only limited success at sites where low permeability soils, such as silts and clays, prevail. Electrokinetics (EK), a soil remediation technique mostly recognized in in-situ treatment of low permeability soils, has, for the last decade, been combined with more conventional techniques and can significantly enhance the performance of several of these remediation technologies, including ISCO, ISCR, EISB and phytoremediation. Herein, we discuss the use of emerging EK techniques in tandem with conventional remediation techniques, to achieve improved remediation performance. Furthermore, we highlight new EK applications that may come to play a role in the sustainable treatment of the contaminated subsurface

Evolutionary multi-objective environmental/economic dispatch: Stochastic versus deterministic approaches

Abstract. Due to the environmental concerns that arise from the emissions produced by fossil-fueled electric power plants, the classical economic dispatch, which operates electric power systems so as to minimize only the total fuel cost, can no longer be considered alone. Thus, by environmental dispatch, emissions can be reduced by dispatch of power generation to minimize emissions. The environmental/economic dispatch problem has been most commonly solved using a deterministic approach. However, power generated, system loads, fuel cost and emission coefficients are subjected to inaccuracies and uncertainties in real-world situations. In this paper, the problem is tackled using both deterministic and stochastic approaches of different complexities. The Nondominated Sorting Genetic Algorithm – II (NSGA-II), an elitist multiobjective evolutionary algorithm capable of finding multiple Pareto-optimal solutions with good diversity in one single run is used for solving the environmental/economic dispatch problem. Simulation results are presented for the standard IEEE 30-bus system.

State of nature 2016

The first State of Nature report that I helped to launch in 2013 revealed the severe loss of nature that has occurred in the UK since the 1960s. Three years on, I am pleased to see that the partnership of organisations behind that important report has grown. Thanks to the dedication and expertise of many thousands of volunteers working closely with the professionals, we are now able to document even more about the changing state of nature across our land and in our seas. The news, however, is mixed. Escalating pressures, such as climate change and modern land management, mean that we continue to lose the precious wildlife that enriches our lives and is essential to the health and well-being of those who live in the UK, and also in its Crown Dependencies and Overseas Territories. Our wonderful nature is in serious trouble and it needs our help as never before. But the State of Nature 2016 report gives us cause for hope too. The rallying call issued in 2013 has been met with a myriad of exciting and innovative conservation projects. Landscapes are being restored, special places defended, and struggling species are being saved and brought back. Such successes demonstrate that if conservationists, governments, businesses and individuals all pull together, we can provide a brighter future for nature and for people

An assessment of the state of nature in the United Kingdom: a review of findings, methods and impact

Clear, accessible, objective metrics of species status are critical to communicate the state of biodiversity and to measure progress towards biodiversity targets. However, the population data underpinning current species status metrics is often highly skewed towards particular taxonomic groups such as birds, butterflies and mammals, primarily due to the restricted availability of high quality population data. A synoptic overview of the state of biodiversity requires sampling from a broader range of taxonomic groups. Incorporating data from a wide range of monitoring and analysis methods and considering more than one measure of species status are possible ways to achieve this. Here, we utilise measures of species’ population change and extinction risk to develop three species status metrics, a Categorical Change metric, a Species Index and a Red List metric, and populate them with a wide range of data sources from the UK, covering thousands of species from across taxonomy. The species status metrics reiterate the commonly reported decline in freshwater and terrestrial species’ status in the UK in recent decades and give little evidence that this rate of decline has slowed. The utility of species status metrics is further improved if we can extrapolate beyond the species sampled to infer the status of the community. For the freshwater and terrestrial species status metrics presented here we can do this with some confidence. Nevertheless, despite the range and number of species contributing to the species metrics, significant taxonomic bias remained and we report weighting options that could help control for this. The three metrics developed were used in the State of Nature 2016 report and indications are they reached a large number of audience members. We suggest options to improve the design and communication of these and similar metrics in the future