Hazardous Waste Management

Hazardous waste management is a broad and evolving field. Applicable state and federal regulations comprising over 60,000 pages are continually being updated. Many of these regulations overlap and are subject to differences in interpretation that often lead to court rulings. Regulations, economic pressures and public perception are forcing companies to rapidly change the way they manufacture products in order to minimize hazardous waste generation. Over 200 million tons of solid hazardous waste are generated annually in the United States. Huge quantities of hazardous waste deposited in landfills, ponds, fields, and other locations require removal or in situ treatment. Common hazardous wastes include: Solvents, acids, bases, heavy metals, pesticides, plating and heat treating wastes. Six major effects of improper hazardous waste management are: groundwater contamination, contamination of surface runoff, air pollution, fire and explosion, adverse health effects via direct contact, and via the food chain. This chapter provides a general overview of federal regulations governing hazardous waste management, as well as a brief review of the types of hazardous waste, waste minimization, and treatment and disposal technologies. Four types of hazardous waste will be discussed here: chemical waste, radioactive waste, infectious waste, and mixed waste

Influence of a breakwater on nearby rocky intertidal community structure

Copyright © 2009 Elsevier Ltd. All rights reserved.It is widely recognised that coastal-defence structures generally affect the structure of the assemblages they support, yet their impact on adjacent systems has been largely ignored. Breakwaters modify the nearby physical environment (e.g. wave action) suggesting a local impact on biological parameters. In the present study, an ACI (After-Control-Impact) design was used to test the general hypothesis that the artificial sheltering of an exposed coast has a strong effect on the structure and functioning of adjacent systems. The effects of a reduction in hydrodynamics were clear for a number of taxa and included the replacement of barnacles, limpets and frondose algae by an increasing cover of ephemeral algae. These effects were evident both at early and late successional stages. Results suggest that the artificial sheltering of naturally exposed coasts can have a strong impact promoting a shift from consumer- to producer-dominated communities, which has important ecological and energetic consequences for the ecosystem

Physical Properties of 5,000 Cool LMC Supergiants with Gaia XP Spectra: A Detailed Portrait of the Upper HR Diagram Hints at Missing Supernova Progenitors

Characterizing the physical properties of cool supergiants allows us to probe the final stages of a massive star's evolution before it undergoes core collapse. Despite their importance, the fundamental properties for these stars -- $T_{\rm eff}$ and $\log L/L_\odot$ -- are only known for a limited number of objects. The third data release of the Gaia mission contains precise photometry and low-resolution spectroscopy of hundreds of cool supergiants in the LMC with well-constrained properties. Using these data, we train a simple and easily-interpretable machine learning model to regress effective temperatures and luminosities with high accuracy and precision comparable to the training data. We then apply our model to 5000 cool supergiants, many of which have no previously-published $T_{\rm eff}$ or $L$ estimates. The resulting Hertzprung-Russell diagram is well-populated, allowing us to study the distribution of cool supergiants in great detail. Examining the luminosity functions of our sample, we find a notable flattening in the luminosity function of yellow supergiants above $\log L/L_\odot=5$, and a corresponding steepening of the red supergiant luminosity function. We place this finding in context with previous results, and present its implications for the infamous red supergiant problem.Comment: Accepted to ApJ. 26 pages, 13 figures. Our catalog of temperatures and luminosities will be made publicly available onlin

Non-eruptive geological hazards of dormant volcanoes: Sao Miguel, Azores Perigos geologicos nao erurptivos en vulcoes adormecidos: Sao Miguel, Acores

São Miguel Island presents a diversity of geological hazards that are related to non-eruptive processes. Frequent seismic swarms and destructive earthquakes, of volcanic and tectonically related origin, have been recorded on the Island since it was settled in the 15th century. Large areas of volcanic edifices of Sete Cidades, Fogo and Furnas are unstable. Steep slopes, unconsolidated and poorly consolidated materials, such as volcaniclastic deposits occasionally weathered by hydrothermal activity, play an important role in landslide activity. Slope instability is mainly triggered by intense rainfall, but also by seismic activity, sea and fluvial erosion and/or anthropogenic activity. Volcano degassing represents a major risk during anomalous gas release and a continuous menace for the public health