Activity and Use Limitations applied to Risk‐Based Corrective Action—A checklist for efficacy

Activity and Use Limitations (AULs) comprise both institutional controls and engineering controls. AULs, when properly implemented, are valuable tools in the risk‐based corrective action arsenal. However, the proponent of AULs must evaluate their life‐cycle costs and the short‐term and long‐term effectiveness of the AULs to protect human health and the environment. This article describes the various types of AULS and provides a checklist for evaluating the efficacy of the proposed AULs. © 2002 Wiley Periodicals, Inc.     

Assessing the potential of using phytoremediation for pyrene‐contaminated soils

Forage crop species representing two biologically distinct families (legumes and grasses) were evaluated on soil spiked with 100 mg/kg of pyrene to determine the potential effectiveness of the rhizospheres of these plants for phytoremediation. In this experiment, pyrene dissipation could not be attributed to the presence of plants. Pyrene dissipation was also not related to rhizosphere biological activity, such as microbial counts and enzyme activity. Planting with reed canarygrass and switchgrass significantly increased the microbial counts in soil; however, the differences in the microbial counts were not correlated to the levels of pyrene dissipation. Reed canarygrass rhizosphere had significantly higher dehydrogenase activity compared to the switchgrass rhizosphere, but this difference in soil dehydrogenase activity was not related to pyrene dissipation. In general, the use of plants was not effective in causing pyrene transformation; however, the presence of vegetation on polycyclic aromatic hydrocarbon–contaminated soils could play a significant role in limiting the spread of contaminants (erosion, leaching) and enhancing ecosystem restoration. © 2004 Wiley Periodicals, Inc.     

Phytoremediation of arsenic in mining‐contaminated areas: The future of transgenic technology

A considerable number of contaminated mining sites in Europe and other parts of the world pose environmental hazards. Given the multifaceted benefits of phytoremediation, screening of plant communities grown in contaminated areas is being conducted to identify hyperaccumulating plant species. A few arsenic (As) hyperaccumulating plants are found in tropical countries; however, generally, they are not grown in contaminated mining sites of cold and temperate countries (Europe and other parts of the world). The transgenic plants identified to date are not believed to be suitable for commercial use of phytoremediation. A few tolerant plant species in mining sites that are found to have elevated As levels primarily concentrate As in their roots. The remediation potential of many of these tolerant plants is limited because of their slow growth and low biomass. Therefore, phytostabilization of contaminated mining sites using tolerant plant species with high biomass and a more extensive root system is the only solution to date in Europe and some other parts of the world. © 2010 Wiley Periodicals, Inc.     

600 MW机组除尘器升级改造及效益评价

元宝山发电有限责任公司2号600 MW机组配套电除尘器由于设计效率低、燃烧煤种变化、设备老化等多方面原因,除尘效率下降,除尘器出口烟尘排放浓度超标严重。为了满足新的《火电厂大气污染物排放标准》的要求,对元宝山发电有限责任公司2号机组配套电除尘器进行升级改造,将原有的4台四电场静电除尘器增效改造为4台电袋复合式除尘器。通过电除尘器的改造,降低了除尘器出口粉尘排放浓度,提高了除尘效率,保证了2号机组电除尘器的安全稳定运行。     

Life cycle environmental benefit and waste-to-energy potential of municipal solid waste management scenarios in Indonesia

Journal of Material Cycles and Waste Management - Appropriate municipal solid waste management transition should be promoted for developing Asian countries. Thus, we established a life-cycle...     

Study of the future land use of a contaminated site: Preferences versus potential use

Worldwide, agencies with high levels of contamination are faced with decisions about remediation and restoration. These decisions should be informed by future land use and long‐term stewardship goals. In the United States, the Department of Energy has lands in some 34 states that require cleanup. They are involved in massive remediation and restoration efforts on lands from the Cold War legacy and wish to reduce their overall footprint. Understanding future land use preferences is essential for determining the nature and degree of remediation and restoration. The objective of this study was to examine future land use preferences for the Department of Energy's Los Alamos National Laboratory as a function of ethnicity for attendees at the Los Alamos Gun Show in New Mexico (1999), and to determine whether their own activity influences future land use preferences. The highest preferred future land uses for Los Alamos National Laboratory were hiking, camping, National Environmental Research Park, and birdwatching, followed by hunting and fishing. Increased nuclear waste storage and building homes and factories were rated the lowest. Further, hiking and camping were rated higher than at two other DOE sites. There were few ethnic differences, although American Indians rated camping, hiking, building houses, and returning the land to American Indians higher than did others, and Hispanics rated using it for a preserve as a higher preferred land use than all others. The differences, however, were not great. Relative ratings for using the land for hunting and fishing were directly related to individual frequency of hunting and fishing for both whites and Hispanics, indicating that people perceive the importance of land use by how they want to use it. Ratings for hiking and camping were not related to the number of days people hiked and camped, suggesting these are general preferences overall. © 2004 Wiley Periodicals, Inc.     

Passive to active tie‐in for soil gas surveys: Improved technique for source‐area,spatial variability,remediation‐monitoring,and vapor‐intrusion assessment

The mass‐to‐concentration tie‐in (MtoC Tie‐In) correlates passive soil gas (PSG) data in mass to active soil gas data in concentration determined by the US EPA Method TO‐17 or TO‐15. Passive soil gas surveys consist of rapid deployment of hydrophobic sorbents (dozens to several hundred locations typically installed in one day) to a depth of six inches to three feet in a grid pattern with exposure in the field from three days to two weeks to target a wide variety of organic compounds. A power function is used on a compound‐to‐compound basis to correlate spatially varying mass (nanograms) from selected locations within a passive soil gas survey to concentration (µg/m³) at those same locations. The correlation from selected PSG locations is applied to the remainder of the PSG grid. The MtoC Tie‐In correlations provide added value to a PSG survey, with the PSG data then used to estimate risk throughout the limits of the investigation for quantitative assessment. The results from a site in northern California show the MtoC Tie‐In correlations for both benzene and total petroleum hydrocarbons (TPH). The correlations are applied on a compound‐to‐compound basis to the remaining locations in the PSG grid to provide an estimate of concentration that can be used for comparison to risk/screening levels or fate‐and‐transport diagnostic tools (partitioning equations, solubility laws, etc.). An example of how the correlations are applied is presented in tabular form. The results from a chlorinated solvent survey show the MtoC Tie‐In correlation from a site in Maryland for tetrachloroethene (PCE). In this instance, there was a near‐perfect relationship between the PSG mass and the active soil gas concentration (R² value of 1). The concentration estimated throughout a PSG grid enables a vast new realm of interpretive power at sites. Several other sites are discussed, including an example application for groundwater. © 2009 Wiley Periodicals, Inc.     

Editor's perspective‐‐‐Shale gas development: Environmental issues and opportunities

Many professionals in the environmental industry have questioned whether the rapid expansion in shale gas development, particularly in the Marcellus Shale Play, is providing business opportunities. While gas production is a routine practice, the development of shale gas requires a process (fracturing, or, more commonly, “fracing'') that uses chemicals and is far more intrusive to the subsurface environment than traditional gas production. In this Editor's Perspective, we evaluate the environmental issues surrounding shale gas development, with a specific focus on the Marcellus Shale Play because it is currently the most active play in the United States, from both the drilling and political perspectives. In addition, we examine where the business opportunities are likely to be for environmental professionals relative to shale gas development. © 2011 Wiley Periodicals, Inc.     

Surfactant‐Oxidant Co‐Application for Soil and Groundwater Remediation

In situ chemical oxidation (ISCO) typically delivers oxidant solutions into the subsurface for contaminant destruction. Contaminants available to the oxidants, however, are limited by the mass transfer of hydrophobic contaminants into the aqueous phase. ISCO treatments therefore often leave sites with temporarily clean groundwater which is subject to contaminant rebound when sorbed and free phase contaminants leach back into the aqueous phase. Surfactant Enhanced In situ Chemical Oxidation (S‐ISCO^®) uses a combined oxidant‐surfactant solution to provide optimized contaminant delivery to the oxidants for destruction via desorption and emulsification of the contaminants by the surfactants. This article provides an overview of S‐ISCO technology, followed by an implementation case study at a coal tar contaminated site in Queens, New York. Included are data points from the site which demonstrate how S‐ISCO delivers desorbed contaminants without uncontrolled contaminant mobilization, as desorbed and emulsified contaminants are immediately available to the simultaneously injected oxidant for reaction. ©2016 Wiley Periodicals, Inc.     

A chemox treatment for urea‐ and ammonium‐contaminated groundwater

In a pilot project performed at a fertilizer manufacturing facility, a one‐step chemical oxidation technique successfully treated urea‐ and ammonium‐contaminated groundwater. The oxidation reaction occurred in an 1,100‐gallon batch reactor. The contaminated inflow was buffered by the metered addition of sodium bicarbonate solution and subsequently treated with sodium hypochlorite in an 8:1 weight ratio of Cl₂:N. In an instantaneous reaction, the urea and ammo‐nium‐N were completely oxidized to nitrogen gas that was vented to the atmosphere during mixing. The pH of the reactor discharge was ?6.5. Sodium sulfite was used to reduce residual hypochlorite in the reactor effluent to chloride to provide process water with characteristics suitable for discharge. Oxidation rates were similar with different strengths of hypochlorite; however, a 5 to 6 percent sodium hypochlorite (as Cl₂) solution was the most stable. © 2005 Wiley Periodicals, Inc.     

Preliminary studies on potential remediation of acid mine drainage‐impacted soils by amendment with drinking‐water treatment residuals

Mining operations result in a wide range of environmental impacts: acid mine drainage (AMD) and acid sulfate soils being among the most common. Due to their acidic pH and high soluble metal concentrations, both AMD and acid sulfate soils can severely damage the local ecosystems. Proper post‐mining management practices are necessary to control AMD‐related environmental issues. Current AMD‐impacted soil treatment technologies are rather expensive and typically not environmentally sustainable. We conducted a 60‐day bench‐scale study to evaluate the potential of a cost‐effective and environment‐friendly technology in treating AMD‐impacted soils. The metal binding and acid‐neutralizing capacity of an industrial by‐product, drinking water treatment residuals (WTRs) were used for AMD remediation. Two types of locally generated WTRs, an aluminum‐based WTR (Al‐WTR) and a lime‐based WTR (Ca‐WTR) were used. Highly acidic AMD‐impacted soil containing very high concentrations of metals and metalloids, such as iron, nickel, and arsenic, was collected from the Tab‐Simco coal mine in Carbondale, Illinois. Soil amendment using a 1:1 Al‐ and Ca‐WTR mix, applied at 5 and 10 percent rates significantly lowered the soluble and exchangeable fractions of metals in the AMD‐impacted soil, thus lowering potential metal toxicity. Soil pH increased from an extremely acidic 2.69 to a near‐neutral 6.86 standard units over the 60‐day study period. Results from this preliminary study suggest the possibility of a successful scale‐up of this innovative, cost‐effective, and environmentally sustainable technology for remediating AMD‐impacted acid sulfate soils.     

粉煤灰综合利用现状及发展方向

介绍了电厂粉煤灰的物化特性及综合利用情况，总结了影响粉煤灰大规模应用的不利因素，并提出信后粉煤灰综合利用的发展方向。     

Re‐evaluation of treatment approach for a site contaminated with Freon‐113 and 1,1,1‐trichloroethane

This study demonstrates a remedial approach for completing the remediation of an aquifer contaminated with 1,1,2‐trichlorotrifluoroethane (Freon‐113) and 1,1,1‐trichloroethane (TCA). In 1987, approximately 13,000 pounds of Freon‐113 were spilled from a tank at an industrial facility located in the state of New York. The groundwater remediation program consisted of an extraction system coupled with airstripping followed by natural attenuation of residual contaminants. In the first phase, five recovery wells and an airstripping tower were operational from April 1993 to August 1999. During this time period over 10,000 pounds of CFC‐13 and 200 pounds of TCA were removed from the groundwater and the contaminant concentrations decreased by several orders of magnitude. However, the efficiency of the remediation system to recover residual Freon and/or TCA reduced significantly. This was evidenced by: (1) low levels (< 10 ppb) of Freon and TCA captured in the extraction wells and (2) a slight increase of Freon and/or TCA in off‐site monitoring wells. A detailed study was conducted to evaluate the alternative for the second‐phase remediation. Results of a two‐year groundwater monitoring program indicated the contaminant plume to be stable with no significant increase or decrease in contaminant concentrations. Monitored geochemical parameters suggest that biodegradation does not influence the fate and transport of these contaminants, but other mechanisms of natural attenuation (primarily sorption and dilution) appear to control the fate and transport of these contaminants. The contaminants appear to be bound to the soil matrix (silty and clay units) with limited desorption as indicated by the solid phase analyses of contaminant concentrations. Results of fate and transport modeling indicated that contaminant concentrations would not exceed the action levels in the wells that showed a slight increase in contaminant concentrations and in the downgradient wells (sentinel) during the modeled timeframe of 30 years. This feasibility study for natural attenuation led to the termination of the extraction system and a transaction of the property, resulting in a significant financial benefit for the original site owner. © 2003 Wiley Periodicals, Inc.     

Full‐scale in‐situ biobarrier demonstration for containment and treatment of MTBE

The Naval Facilities Engineering Service Center (NFESC), Arizona State University, and Equilon Enterprises LLC are partners in an innovative Environmental Security Technology Certification Program cleanup technology demonstration designed to contain dissolved MTBE groundwater plumes. This full‐scale demonstration is being performed to test the use of an oxygenated biobarrier at Naval Base Ventura County, in Port Hueneme, California. Surprisingly, few cost‐effective in‐situ remedies are known for the cleanup of MTBE‐impacted aquifers, and remediation by engineered in‐situ biodegradation was thought to be an unlikely candidate just a few years ago. This project demonstrates that MTBE‐impacted groundwater can be remediated in‐situ through engineered aerobic biodegradation under natural‐flow conditions. With respect to economics, the installation and operation costs associated with this innovative biobarrier system are at least 50 percent lower than those of a conventional pump and treat system. Furthermore, although it has been suggested that aerobic MTBE biodegradation will not occur in mixed MTBE‐BTEX dissolved plumes, this project demonstrates otherwise. The biobarrier system discussed in this article is the largest of its kind ever implemented, spanning a dissolved MTBE plume that is over 500 feet wide. This biobarrier system has achieved an in‐situ treatment efficiency of greater than 99.9 percent for dissolved MTBE and BTEX concentrations. Perhaps of greater importance is the fact that extensive performance data has been collected, which is being used to generate best‐practice design and cost information for this biobarrier technology. © 2001 John Wiley & Sons, Inc.     

Bench‐ and pilot‐scale applications of electrochemical peroxidation: A new remedial concept

Electrochemical peroxidation (ECP) is a proprietary process that utilizes sacrificial iron electrodes and stochiometrically balanced applications of hydrogen peroxide to efficiently destroy aqueous phase contaminants. In laboratory trials it has been successful in reducing, often to non‐detectable levels, BTEX, fuel additives, chlorinated solvents, and polychlorinated biphenyls in ground waters. The process has also been found effective in reducing the chemical and biological oxygen demand of industrial waste water. Agency‐approved pilot tests will be conducted at two gasoline spill sites during 2000 where traditional pump and treat methods have proven ineffectual because of ground water chemistry or subsurface hydrologic conditions. The ECP process utilizes a tripartite treatment strategy consisting of 1) ex situ chemical oxidation; 2) in situ oxidation by reinjection of treated water with residual oxidants at the head of the plume; and 3) reestablishment of aerobic biodegradation by alteration of subsurface redox conditions. In contrast to other in situ oxidation treatment methods, dissolved iron is derived electrochemically, negating the need for ferrous salt addition. Dilute hydrogen peroxide (3 percent) is incrementally added to maximize oxidation efficiency and eliminate safety and environmental concerns accompanying the use of highly concentrated solutions. Results of laboratory trials and the geological and geochemical considerations of upcoming pilot‐scale applications are presented. Other potential applications currently under investigation include combination with other remedial processes (e.g. permeable barriers and hydrogen release compounds) to insure complete and rapid contaminant mineralization.     

Treatment technologies for 1,4‐Dioxane: Fundamentals and field applications

1,4‐Dioxane is a synthetic industrial chemical frequently found at contaminated sites where 1,1,1‐trichloroethane was used for degreasing. It is a probable human carcinogen and has been found in groundwater at sites throughout the United States. The physical and chemical properties and behavior of 1,4‐dioxane create challenges for its characterization and treatment. It is highly mobile and has not been shown to readily biodegrade in the environment. In December 2006, the U.S. Environmental Protection Agency's Office of Superfund Remediation and Technology Innovation (OSRTI) prepared a report titled “Treatment Technologies for 1,4‐Dioxane: Fundamentals and Field Applications.” The report provides information about the chemistry of dioxane, cleanup goals, analytical methods, available treatment technologies, and site‐specific treatment performance data. The information may be useful to project managers, technology providers, consulting engineers, and members of academia faced with addressing dioxane at cleanup sites or in drinking water supplies. This article provides a synopsis of the US EPA report, which is available at http://cluin.org/542R06009 . © 2007 Wiley Periodicals, Inc.     

Remediation of PCB‐Contaminated Soil Using Extraction and Destruction: Bench‐Scale Test

Polychlorinated biphenyls (PCBs) are a persistent environmental issue worldwide. This study summarizes the results obtained from a bench‐scale test of remediating PCB‐impacted soil. The research aimed to evaluate the effectiveness of extracting the PCB Aroclor 1260 from soil, transferring it to a liquid matrix, and then treating the PCB‐containing liquid using an Activated Metal Treatment System, a technology developed by NASA based on zero valent magnesium (ZVMg). The soil was from a former electrical plant area impacted by PCBs. The initial concentration of untreated soil contained an average of 4.7 ± 0.15 mg/kg of Aroclor 1260. The results showed that the mass transfer phenomena is possible using ethanol as a liquid matrix, reaching transfer results up to 93 percent. The ZVMg enabled the destruction of the Aroclor 1260, which reached 20 percent without any buildup of undesirable by‐products, such as less chlorinated PCBs.  ©2016 Wiley Periodicals, Inc.     

Borehole‐scale testing of matrix diffusion for contaminated‐rock aquifers

A new method was developed to assess the effect of matrix diffusion on contaminant transport and remediation of groundwater in fractured rock. This method utilizes monitoring wells constructed of open boreholes in the fractured rock to conduct backward diffusion experiments on chlorinated volatile organic compounds (CVOCs) in groundwater. The experiments are performed on relatively unfractured zones (called test zones) of the open boreholes over short intervals (approximately 1 meter) by physical isolation using straddle packers. The test zones were identified with a combination of borehole geophysical logging and chemical profiling of CVOCs with passive samplers in the open boreholes. To confirm the test zones are within inactive flow zones, they are subjected to a series of hydraulic tests. Afterward, the test zones are air sparged with argon to volatilize the CVOCs from aqueous to air phase. Backward diffusion is then measured by periodic passive‐sampling of water in the test zone to identify rebound. The passive (nonhydraulically stressed) sampling negates the need to extract water and potentially dewater the test zone. The authors also monitor active flowing zones of the borehole to assess trends in concentrations in other parts of the fractured rock by purge and passive sampling methods. The testing was performed at the former Pease Air Force Base (PAFB) in Portsmouth, New Hampshire. Bedrock at the former PAFB consists of fractured metasedimentary rocks where the authors investigated back diffusion of cis‐1,2‐dichloroethylene (cis‐1,2‐DCE), a CVOC. Postsparging concentrations of cis‐1,2‐DCE showed initial rebounding followed by declines, excluding an episodic spike in concentrations from a groundwater recharge event. The authors theorize that there are three processes that controlled concentration responses in the test zones postsparging. First, the limited back diffusion of CVOCs from a halo or thin zone of rock around the borehole contributes to the initial rebounding. Second, aerobic degradation of cis‐1,2‐DCE occurred causing declines in concentrations in the test zone. Third, microflow from microfractures contributed to the episodic spike in concentrations following the groundwater recharge event. In active flow zones, the latter two processes are not measurable due to equilibration from groundwater transport between the borehole and active flowing fractures.