The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

The Environmental Protection Agency (EPA) provides access to information on a variety of topics related to the environment and strives to inform citizens of health risks. The EPA also has an extensive library network that consists of 26 libraries throughout the United States, which provide access to a plethora of information to EPA employees, scientists, and researchers. The EPA implemented a reorganization project to digitize their materials so they would be more accessible to a wider range of users, but this plan was drastically accelerated when the EPA was threatened with a budget cut. It chose to close and reduce the hours and services of some of their libraries. As a result, the agency was accused of denying users the “right to know” by making information unavailable, not providing an adequate strategic plan, and discarding vital materials. This case study explores the background of the digitization project, the practices implemented, and the critiques of the project.

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The Environmental Protection Agency

Nanofiltration membranes review: Recent advances and future prospects

Heavy metals in agricultural soils of the European Union with implications for food safety

Selective adsorption of chromium(VI) in industrial wastewater using low-cost abundantly available adsorbents

Filamentous bulking sludge--a critical review.

Despite recognition of the possible role of biological nitrogen removal (BNR) processes in nitrous oxide (N2O) emission, a measured database of N2O emissions from these processes at the national scale does not currently exist. This study focused on the quantification of N2O emissions at 12 wastewater treatment plants (WWTPs) across the United States using a newly developed U.S. Environmental Protection Agency (USEPA) reviewed protocol. A high degree of variability in field-scale measurements of N2O was observed, both across the WWTPs sampled and within each WWTP. Additionally, aerobic zones, which have hitherto not been considered in the USEPA approach of estimating N2O emissions, generally contributed more to N2O fluxes than anoxic zones from BNR reactors. These results severely qualify the conventional use of a single emission factor to “estimate” N2O emissions from BNR processes, solely by virtue of denitrification. Upon subjecting the nationwide data set to multivariate regression data mining, high ni...

N2O emissions from activated sludge processes, 2008-2009: results of a national monitoring survey in the United States.

This paper presents a critical review of the literature on the application of genetically engineered microorganisms (GEMs) in bioremediation. The important aspects of using GEMs in bioremediation, such as development of novel strains with desirable properties through pathway construction and the modification of enzyme specificity and affinity, are discussed in detail. Particular attention is given to the genetic engineering of bacteria using bacterial hemoglobin (VHb) for the treatment of aromatic organic compounds under hypoxic conditions. The application of VHb technology may advance treatment of contaminated sites, where oxygen availability limits the growth of aerobic bioremediating bacteria, as well as the functioning of oxygenases required for mineralization of many organic pollutants. Despite the many advantages of GEMs, there are still concerns that their introduction into polluted sites to enhance bioremediation may have adverse environmental effects, such as gene transfer. The extent of horizontal gene transfer from GEMs in the environment, compared to that of native organisms including benefits regarding bacterial bioremediation that may occur as a result of such transfer, is discussed. Recent advances in tracking methods and containment strategies for GEMs, including several biological systems that have been developed to detect the fate of GEMs in the environment, are also summarized in this review. Critical research questions pertaining to the development and implementation of GEMs for enhanced bioremediation have been identified and posed for possible future research.

Use of Genetically Engineered Microorganisms (GEMs) for the Bioremediation of Contaminants

Soil washing processes and in-situ immobilization techniques have been often-suggested technologies for remediation of soils contaminated with heavy metals such as chromium. Laboratory batch extraction studies were conducted with synthetically contaminated soils [with Cr(VI)] to determine the ability of extractants such as 0.12 M Na4P2O7, 0.1 M NaF, and 1.0 M HCl to remove chromium from three types of soils with varying soil pH (5.8–8.1), organic matter (1.0–5.0%), and clay content (10–35%). Up to 73% of the total chromium present in the synthetically contaminated soil was removed by 0.12 M Na4P2O7. The synthetically contaminated soils were also treated with FeSO4 and NaOH solutions to immobilize chromium and investigated for leachability of Cr by Cr-free water. Up to 80% of the chromium could be retained in the soil following the immobilization process. The presence of soil organic matter and clay content enhanced the immobilization of chromium in both chromium flushing and immobilization experiments.

Krishna R. Pagilla

Papers

Filamentous bulking sludge--a critical review.

N2O emissions from activated sludge processes, 2008-2009: results of a national monitoring survey in the United States.

Use of Genetically Engineered Microorganisms (GEMs) for the Bioremediation of Contaminants

Laboratory Studies on Remediation of Chromium-Contaminated Soils

Treatment of malathion pesticide wastewater with nanofiltration and photo-Fenton oxidation