Larry W. Olson

Arsenate Removal by Iron (Hydr)Oxide Modified Granulated Activated Carbon: Modeling Arsenate Breakthrough with the Pore Surface Diffusion Model

Abstract This study focuses on evaluating the feasibility of using pore surface diffusion model (PSDM) to successfully predict arsenate breakthrough curves of continuous flow packed columns containing granulated activated carbon modified with iron (hydr)oxide. Two different treatment methods were used to synthesize modified granulated activated carbon media (M-GAC): (i) Fe(III)/alcohol treatment method (M-3–15), and (ii) KMnO4/Fe(II) treatment method (Mn-0.5–15). Adsorption capacities were obtained and fitted by Freundlich isotherm model ( ) for initial arsenate concentration of 120 µg As(V)/L at either pH = 7.3±0.1 for M-3–15 or pH = 8.3±0.1 for Mn-0.5–15 in 10 mM NaHCO3 buffered ultrapure water. Short bed adsorber (SBA) columns tests were conducted at the same water quality condition as the batch experiments and used to validate the PSDM.

HEALTH IMPACT AND CONTROL OF PARTICLE MATTER

Summary Particulate matter (PM), unlike other air pollutants such as carbon monoxide or ozone, is not a single compound. Particles can be either solids or liquids and can vary greatly in size, shape, and chemical composition. The effects of particulate aerosols on human health include damage to the cardiovascular system, aggravation of existing respiratory diseases, and increases in lung cancer mortality. Evidence of increased mortality from exposure to the types of particulate matter associated with traffic, including diesel exhaust, has been established. Children, the elderly, and those with pre-existing conditions such as asthma are particularly susceptible. Regulatory actions initially focused on larger particles, but increasingly they have targeted the smaller PM10 and PM2.5 fractions. Control strategies for particulate matter must be targeted to a given size fraction and take into account the various origins, both natural and man-made, for each type of particle.

Potential health implications of water resources depletion and sewage discharges in the Republic of Macedonia

Potential health implications of deficient sanitation infrastructure and reduced surface water flows due to climate change are examined in the case study of the Republic of Macedonia. Changes in surface water flows and wastewater discharges over the period 1955-2013 were analyzed to assess potential future surface water contamination trends. Simple model predictions indicated a decline in surface water hydrology over the last half century, which caused the surface waters in Macedonia to be frequently dominated by >50% of untreated sewage discharges. The surface water quality deterioration is further supported by an increasing trend in modeled biochemical oxygen demand trends, which correspond well with the scarce and intermittent water quality data that are available. Facilitated by the climate change trends, the increasing number of severe weather events is already triggering flooding of the sewage-dominated rivers into urban and non-urban areas. If efforts to develop a comprehensive sewage collection and treatment infrastructure are not implemented, such events have the potential to increase public health risks and cause epidemics, as in the 2015 case of a tularemia outbreak.

A µ-oxo mixed-metal complex of copper(II) and an iron(III)-porphyrin as a resting state model for the cytochrome c oxidase active site

The complex (TPP)FeIV : O (TPP = tetraphenylporphyrin) reacts in solution with an imidazole-bearing CuI complex to form a stable mixed-metal µ-oxo-species, [Fe3+–O–Cu2+]+, as a resting state model compound for the binuclear active site of cytochrome c oxidase.

Implications for Regulating Nanomaterial-Containing Wastes: Hazardous Waste or Not?

AbstractEngineered nanomaterials have been incorporated into thousands of commercial products that are widely used by consumers and industry. Studies show that nanomaterials can be leached from such products, providing a route of entry into the environment. Toxic effects from nanomaterials may differ significantly based on their structure, functional groups, characteristics of the environmental matrix at the time of exposure, and the transformation of the nanomaterials once released into the environment. Consequently, traditional risk assessment models for conventional chemicals may not apply. Currently, engineered nanomaterials are not regulated as hazardous wastes, but the potential for significant negative human or environmental effects should not be ignored. The authors suggest that existing Resources Conservation and Recovery Act (RCRA) regulations could be modified to include categories for engineered nanomaterials. Given the ubiquitous nature of nanoenabled products, some regulatory action is requi...

Comparative Analysis of Existing Water Resources Data in the Western Balkan States of Bosnia and Herzegovina, Macedonia, Montenegro, and Serbia

Abstract The vulnerability of water resources in Western Balkan States of Bosnia and Herzegovina, Macedonia, Montenegro, and Serbia is analyzed in this study. Due to absence of comprehensive data sets, the pool of available information was examined to define gaps and inconsistencies that hinder the initiation of in-depth water resource analyses. Comparative analysis of these four non-EU former Yugoslav republics indicated that lack of reliable data is a main issue that hinders estimation of existing and future states of water resources. Nevertheless, obtained results suggest high vulnerability of water resources. Defined circumstances, however, hindered any coordinated efforts to adequately manage the water management system and resist more frequent severe weather events predicted by climate changes.

Management of Chemicals for Sustainable Development

This chapter traces the growth of global actions related to the management of chemicals and hazardous wastes since the UN Conference on Environment and Development in 1992, through the World Summit on Sustainable Development in 2002, and projections into the future as far as 2020. It is important to understand this relationship, since the groundwork for essentially all of the recommendations found in the Article 23 of the Plan of Implementation from Johannesburg is found in Chapter 19 of Agenda 21.