Enhanced anaerobic bioremediation of a TCE source at the Tarheel Army Missile Plant using EOS

EOS, or emulsified oil substrate, was used to stimulate anaerobic biodegradation of trichloroethene (TCE) and tetrachloroethene (PCE) at a former Army‐owned manufacturing facility located in the Piedmont area of North Carolina. Previous use of chlorinated solvents at the facility resulted in soil and groundwater impacts. Ten years of active remediation utilizing soil vacuum extraction and air sparging (SVE/AS) were largely ineffective in reducing the TCE/PCE plume. In 2002, the Army authorized preparation of an amended Remedial Action Plan (RAP) to evaluate in situ bioremediation methods to remediate TCE in groundwater. The RAP evaluated eight groundwater remediation technologies and recommended EOS as the preferred bioremediation alternative for the site. Eight wells were drilled within the 100 × 100 feet area believed to be the primary source area for the TCE plume. In a first injection phase, dilute EOS emulsion was injected into half of the wells. Distribution of the carbon substrate through the treatment zone was enhanced by pumping the four wells that were not injected and recirculating the extracted water through the injection wells. The process was repeated in a second phase that reversed the injection/extraction well pairs. Overall, 18,480 pounds of EOS were injected and 163,000 gallons of water were recirculated through the source area. Anaerobic groundwater conditions were observed shortly after injection with a corresponding decrease in both PCE and TCE concentrations. Dissolved oxygen, oxidation‐reduction potential, and sulfate concentrations also decreased after injection, while TCE‐degradation products, ferrous iron, and methane concentrations increased. The reduction in TCE allowed the Army to meet the groundwater remediation goals for the site. Approximately 18 months after injection, eight wells were innoculated with a commercially prepared dechlorinating culture (KB‐1) in an attempt to address lingering cis‐1,2‐dichloroethene (cis‐DCE) and vinyl chloride (VC) that continued to be observed in some wells. Dehalococcoides populations increased slightly post‐bioaugmentation. Both cis‐DCE and VC continue to slowly decrease. © 2007 Wiley Periodicals, Inc.     

Successfully applying sparging technologies

Air sparging is an innovative methodology for remediating organic compounds present in contaminated, saturated soil zones. In the application of the technology, sparging (injection) wells are used to inject a hydrocarbon-free gaseous medium (typically air) into the saturated zone below or within the areas of contamination. Two major mechanisms of remediation are engaged/enhanced due to the sparging process. First, volatile organic compounds are dissolved in the groundwater and sorbed on the soil partition into the advective air phase, effectively simulating an in-situ air stripping system. The stripped contaminants are transported in the air phase to the vadose zone, generally within the radius of influence of a standard vapor extraction and vapor treatment system. Second, with optimal environmental conditions, volatile and semivolatile organic compounds may be biodegraded by utilizing the sparging process to oxygenate the groundwater, thereby enhancing the growth and activity of the indigenous bacterial community. Air sparging is a complex multifluid phase process which has been applied successfully in Europe since the mid-1980s. Major design considerations include site geology, contaminant type, gas injection pressures and flow rates, injection interval (areal and vertical), and site-specific biofeasibility parameters. Site-specific geology and biofeasibility are the dominant design parameters. Pilot testing and full-scale design considerations should also be addressed. Mathematical models have been developed to simulate the air flow field during the sparging process and to examine the limitations imposed by site geology. Correct design and operation of this technology have been demonstrated to achieve groundwater cleanup to low part-per-billion contaminant levels. Incorrect design and operation can introduce significant pollution liability through undesirable contaminant migration in both the dissolved and vapor phases.     

Multiphase extraction radius of influence: Evaluation of design and operational parameters

A common remedial technology for properties with subsurface soil and groundwater contamination is multiphase extraction (MPE). MPE involves the extraction of contaminated groundwater, free‐floating product, and contaminated soil vapor from the subsurface. A network of recovery wells conveys fluids to a vacuum pump and to the treatment system for the contaminated groundwater and soil vapor. This article describes a study of MPE operational data from nine similar remediation projects to determine the most important design parameters. Design equations from guidance manuals were used to estimate the expected radius of influence (ROI) based on measured field data. ROIs were calculated for the vapor flow rate through the subsurface and for the groundwater drawdown caused by the MPE remediation activities. The calculated ROIs were compared to the measured ROIs to corroborate the assumptions made in the calculations. Once it was established that the calculated and field‐measured ROIs were comparable, a sensitivity analysis determined ranges of different design and operational parameters that most affected the ROIs. © 2012 Wiley Periodicals, Inc.     

高温分解及烟气净化处理电子垃圾的技术和设备

提出高温分解及烟气净化处理废弃电子垃圾的技术。通过喷水系统调节分解炉内气氛,控制有机物分解速度,使有机物裂解成二氧化碳和水蒸气,有害成份经净化系统再次处理后达到环保排放标准。金属部分可进一步进行提炼回收,实现有机物和金属的绿色分离。     

Pilot‐scale evaluation of in situ cometabolic bioremediation of TCE in groundwater using PHOSter® technology

A study was conducted to evaluate the efficacy of PHOSter® technology for treating groundwater contaminated with trichloroethene (TCE) at Edwards Air Force Base, California. The technology consists of injecting a gaseous mixture of air, methane, and nutrients into groundwater with the objective of stimulating the growth of methanotrophs, a naturally occurring microbial group that is capable of catalyzing the aerobic degradation of chlorinated solvents into nontoxic products. Injection operations were performed at one well for a period of three months. Six monitoring wells were utilized for groundwater and wellhead vapor monitoring and for groundwater and microbial sampling. In the five monitoring wells located within 44 feet of the injection well, the following results were observed: dissolved oxygen concentrations increased to a range between 6 and 8 milligrams per liter (μg/L); the biomass of target microbial groups increased by one to five orders of magnitude; and TCE concentrations decreased by an average of 92 percent, and to below the California primary maximum contaminant level (MCL; 5 micrograms per liter [µg/L]) in the well closest to the injection well. © 2008 Wiley Periodicals, Inc. *

1 This article is a U.S. Government work and, as such, is in the public domain of the United States of America.

     

Remediating TCE‐contaminated groundwater in low‐permeability media using hydraulic fracturing to emplace zero‐valent iron/organic carbon amendment

A field pilot test in which hydraulic fracturing was used to emplace granular remediation amendment (a mixture of zero‐valent iron [ZVI] and organic carbon) into fine‐grained sandstone to remediate dissolved trichloroethene (TCE)‐contaminated groundwater was performed at a former intercontinental ballistic missile site in Colorado. Hydraulic fracturing was used to enhance the permeability of the aquifer with concurrent emplacement of amendment that facilitates TCE degradation. Geophysical monitoring and inverse modeling show that the network of amendment‐filled fractures extends throughout the aquifer volume targeted in the pilot test zone. Two years of subsequent groundwater monitoring demonstrate that amendment addition resulted in development of geochemical conditions favorable to both abiotic and biological TCE degradation, that TCE concentrations were substantially reduced (i.e., greater than 90 percent reduction in TCE mass), and that the primary degradation processes are likely abiotic. The pilot‐test data aided in re‐evaluating the conceptual site model and in designing the full‐scale remedy to address a larger portion of the TCE‐contaminated groundwater plume. © 2012 Wiley Periodicals, Inc.     

Assessment of in situ thermal treatment for chlorinated organic source zones

The East Gate Disposal Yard (EGDY) at Fort Lewis is the source of a large trichloroethene (TCE) plume at this military installation. Source reduction using thermal treatment was applied using electrical resistance heating. A total of about 5,800 kg of TCE‐equivalent volatile organic compounds (VOCs; TCE and dichloroethene) was extracted during thermal treatment of the three zones selected for source reduction. Pretreatment groundwater TCE concentrations were measured up to 100 ppm. Posttreatment groundwater TCE concentrations within the treatment zones averaged less than 100 ppb. Posttreatment soil TCE concentrations decreased by over 96 percent compared to pretreatment soil concentrations. The overall contaminant flux from EGDY was reduced by an estimated 60 to 90 percent by the source reduction effort. The traditional and new techniques for site characterization and remediation performance monitoring applied at EGDY provide insight for installing, operating, monitoring, and assessing thermal treatment. © 2009 Wiley Periodicals, Inc.     

Matrix Diffusion Modeling Applied to Long‐Term Pump‐and‐Treat Data: 1. Method Development

Despite the installation in the 1980s and 1990s of hydraulic containment systems around known source zones (four slurry walls and ten pump‐and‐treat systems), trichloroethene (TCE) plumes persist in the three uppermost groundwater‐bearing units at the Middlefield‐Ellis‐Whisman (MEW) Superfund Study Area in Mountain View, California. In analyzing TCE data from 15 recovery wells, the observed TCE mass discharge decreased less than an order of magnitude over a 10‐year period despite the removal of an average of 11 pore volumes of affected groundwater. Two groundwater models were applied to long‐term groundwater pump‐and‐treat data from 15 recovery wells to determine if matrix diffusion could explain the long‐term persistence of a TCE plume. The first model assumed that TCE concentrations in the plume are controlled only by advection, dispersion, and retardation (ADR model). The second model used a one‐dimensional diffusion equation in contact with two low‐permeability zones (i.e., upper and lower aquitard) to estimate the potential effects of matrix diffusion of TCE into and out of low‐permeability media in the plume. In all 15 wells, the matrix diffusion model fit the data much better than the ADR model (normalized root mean square error of 0.17 vs. 0.29; r² of 0.99 vs. 0.19), indicating that matrix diffusion is a likely contributing factor to the persistence of the TCE plume in the non‐source‐capture zones of the MEW Study Area's groundwater‐extraction wells. © 2013 Wiley Periodicals, Inc.     

Aerobic Cometabolism of Halogenated Aliphatic Hydrocarbons: A Technology Overview

Bioremediation of chlorinated solvents has been moving from an innovative to mainstream technology for environmental applications. Cometablism of chlorinated solvents by monooxygenase has been demonstrated for trichloroethylene (TCE). Cl‐out microbes combine the dehalogenation of PCE with the monooxygenase destruction of TCE to complete the PCE breakdown pathway. Underthe right conditions, cometabolic bioremediation can be cost effective, fast, and complete. Aerobic bioremediation can augment mass transfer technologies such as pump and treat or sparging/vapor extraction to improve their efficiency.     

ART in‐well technology proves effective in treating 1,4‐dioxane contamination

A common industrial solvent additive is 1,4‐dioxane. Contamination of dissolved 1,4‐dioxane in groundwater has been found to be recalcitrant to removal by conventional, low‐cost remedial technologies. Only costly labor and energy‐intensive pump‐and‐treat remedial options have been shown to be effective remedies. However, the capital and extended operation and maintenance costs render pump‐and‐treat technologies economically unfeasible at many sites. Furthermore, pump‐and‐treat approaches at remediation sites have frequently been proven over time to merely achieve containment rather than site closure. A major manufacturer in North Carolina was faced with the challenge of cleaning up 1,4‐dioxane and volatile organic compound–impacted soil and groundwater at its site. Significant costs associated with the application of conventional approaches to treating 1,4‐dioxane in groundwater led to an alternative analysis of emerging technologies. As a result of the success of the Accelerated Remediation Technologies, LLC (ART) In‐Well Technology at other sites impacted with recalcitrant compounds such as methyl tertiarybutyl ether, and the demonstrated success of efficient mass removal, an ART pilot test was conducted. The ART Technology combines in situ air stripping, air sparging, soil vapor extraction, enhanced bioremediation/oxidation, and dynamic subsurface groundwater circulation. Monitoring results from the pilot test show that 1,4‐dioxane concentrations were reduced by up to 90 percent in monitoring wells within 90 days. The removal rate of chlorinated compounds from one ART well exceeded the removal achieved by the multipoint soil vapor extraction/air sparging system by more than 80 times. © 2005 Wiley Periodicals, Inc.     

Management of hazardous waste in Thailand: present situation and future prospects

 This paper deals with the present scenario of hazardous waste management practices in Thailand, and gives some insights into future prospects. Industrialization in Thailand has systematically increased the generation of hazardous waste. The total hazardous waste generated in 2001 was 1.65 million tons. It is estimated that over 300 million kg/year of hazardous waste is generated from nonindustrial, community sources (e.g., batteries, fluorescent lamps, cleansing chemicals, pesticides). No special facilities are available for handling these wastes. There are neither well-established systems for separation, storage, collection, and transportation, nor the effective enforcement of regulations related to hazardous wastes management generated from industrial or nonindustrial sectors. Therefore, because of a lack of treatment and disposal facilities, these wastes find their way into municipal wastewaters, public landfills, nearby dump sites, or waterways, raising serious environmental concern. Furthermore, Thailand does not have an integrated regulatory framework regarding the monitoring and management of hazardous materials and wastes. In addition to the absence of a national definition of hazardous wastes, limited funding has caused significant impediments to the effective management of hazardous waste. Thus, current waste management practices in Thailand present significant potential hazards to humans and the environment. The challenging issues of hazardous waste management in Thailand are not only related to a scarcity of financial resources (required for treatment and disposal facilities), but also to the fact that there has been no development of appropriate technology following the principles of waste minimization and sustainable development. A holistic approach to achieving effective hazardous waste management that integrates the efforts of all sectors, government, private, and community, is needed for the betterment of human health and the environment. Received: February 26, 2001 / Accepted: October 11, 2002     

The current situation of solid waste generation and its environmental contamination in China

In China, controlling environmental pollution resulting from solid waste (SW) and hazardous waste (HW) has become one of the most pressing tasks in the field of environmental engineering. It is reported that the annual generation of industrial solid waste (ISW) in China exceeded 0.6 billion tons in the 1990s, and is increasing every year. Although ISW management has been strengthened in recent years, about 40% of SW is put in uncontrolled landfill without appropriate treatment. According to statistics from the national Environmental Protection Agency, the cumulative ISW uncontrolled landfill in China had reached 6.6 billion tons by the end of 1995, occupying around 55 000 hectares of land. Although some major uncontrolled landfills were constructed, nonetheless groundwater contamination resulted from the use of low-standard liners and poor management. Furthermore, about 20 million tons of ISW was discharged into the environment illegally, and a third of this waste was discharged directly into water bodies, making ISW one of the greatest pollution sources for surface water and ground water. Environmental pollution accidents resulting from SW occur about 100 times a year in China, and environmental issues frequently arise because of ISW pollution. The practices of SW management, treatment, and disposal started relatively late in China, and for a long time the management of SW pollution has received little attention compared with water and air pollution management. China faces problems such as the insufficiency of management laws and regulations, insufficient investment, inadequate treatment and disposal technology, and a lack of qualified technicians. At present, most treatment and disposal technology cannot meet the requests for solid waste pollution control. In order to protect, restore, and improve environmental quality in China and to realize sustainable development, the safe management and disposal of solid and hazardous wastes is a pressing challenge. In recent years, much attention has been paid to SW management in China, and investment to develop management and treatment technologies has increased. In 1995, the Law for Solid Waste Pollution Protection was issued, and work on solid waste treatment and disposal began to be legally managed. SW treatment and disposal facilities have been constructed, and now operate in some large and medium-sized cities. In particular, rapid improvements have been seen in ISW recycling, collection, and disposal of municipal solid waste and regional HW management. All the figures in this paper are from 1995, and represent the situation in China in that year. Received: April 18, 2000 / Accepted: May 15, 2000     

ERD of Residual TCE DNAPL Achieving Nondetect from a Single Injection of Food‐Grade Waste

Residual dense nonaqueous phase liquid (DNAPL) composed of trichloroethene (TCE) was identified in a deeper interval of an overburden groundwater system at a manufacturing facility located in northern New England. Site hydrostratigraphy is characterized by two laterally continuous and transmissive zones consisting of fully‐saturated fine sand with silt and clay. The primary DNAPL source was identified as a former dry well with secondary contributions from a proximal aboveground TCE storage tank. A single additive‐injection mobilization in 2001 utilizing a food‐grade injectate formulated with waste dairy product and inactive yeast enhanced residual TCE DNAPL destruction in situ by stimulating biotic reductive dechlorination. The baseline TCE concentration was detected up to 97,400 μg/L in the deeper interval of the overburden groundwater system, and enhanced reductive dechlorination (ERD) achieved >99 percent reduction in TCE concentrations in groundwater over nine years with no evidence of sustained rebound. TCE concentrations have remained nondetect below 2.0 μg/L for the last five consecutive sampling rounds between 2013 and 2015. ERD utilizing a food‐grade injectate is a green remediation technology that has destroyed residual DNAPL at the site and achieved similar results at other residual DNAPL sites during both pilot‐ and full‐scale applications. ©2016 Wiley Periodicals, Inc.     

2020年危险废物市场分析

危险废物处理与政策、法规、标准、技术、市场等影响因素关系密切。对2019年以来我国出台的危险废物管理政策法规、管理措施和标准规范情况进行梳理,对危险废物产生和利用处置情况进行对比分析,对危险废物利用处置技术进展、价格变动和市场投资趋势等进行概述,对环境违法案件舆情及突发事件等因素对危险废物市场影响进行分析,综合运用类比、归纳和演绎等方法,对2020年危险废物市场进行预测分析。     

Improvements to TCE Microcosm Protocols for Biostimulation in Bedrock Aquifers

In this study, a factorial‐designed experiment of biostimulated trichloroethene (TCE) dechlorination in fractured bedrock aquifers using microcosms evaluated several potential biostimulants (i.e., nutrients, vitamins, and sterile groundwater). Substantial cost savings and resource efficiency can be provided by this approach because: factorial designs require relatively few microcosms per factor; the interpretation of the observations can proceed largely by common sense, simple arithmetic, and computer graphics; the observations can indicate promising directions for further experimentation and causative relationships; and designs can be suitably augmented when a more in‐depth exploration is needed. TCE degradation was evaluated using three methods of data analysis: (1) analysis of covariance (ANCOVA) between biotic and abiotic treatment trend‐line slopes; (2) calculation of biodegradation half‐life; and (3) effects screening by model fitting. Microcosm preparation with crushed rock in groundwater was found to more closely match the previously observed field rates than the preparation with only groundwater. Injection of nutrient and vitamin mixtures was made into microcosms that were previously aged to obtain consistent conditions, and the TCE concentration measured after incubating for 45 days. Comparison of results indicated that the nutrient mixture slows or inhibits the degradation of TCE compared to the sterile groundwater; however, the vitamin mixture offsets and nearly compensates for the inhibitory effect of the nutrient mixture. It is recommended that this factorial experiment be augmented with additional studies of individual or groups of compounds from the vitamin mixture using this methodology to isolate and identify the specific factor or interaction responsible for the inhibitory compensation. © 2013 Wiley Periodicals, Inc.     

Small-quantity-generator hazardous-waste production and management in Florida

Data are presented on the production and management of hazardous waste by approximately 20 000 small-quantity hazardous-waste generators (SQHWGs) in the state of Florida. SQHWGs are generators that produce less than 1000 kg of hazardous waste in a calendar month. There were approximately 117 000 metric tonnes of small-quantity-generator (SQG) hazardous waste produced annually. Included in this total are over 43 000 tonnes of waste oils even though they were not regulated as a hazardous waste at the time of the survey. Approximately half of this hazardous waste is managed using the following methods: recycling, treatment, and disposal in permitted hazardous-waste-management facilities. However, large quantities of this SQG hazardous waste are disposed of in sanitary landfills and discharged to public sewers and these facilities are typically not designed to handle hazardous waste. These data indicate that there are potential environmental and human-health problems associated with the management of SQG hazardous waste in Florida as well as throughout the U.S.A.     

油基钻屑处理处置研究新进展

油基钻屑是在勘探和开采油气资源的钻井过程中产生的一种典型危险废弃物。本文首先将现有各类繁杂技术划分为处置技术和处理技术,再通过进一步细化分类,系统综述了每项技术的原理、优缺点及应用潜力,总结出了“环保达标、经济可行”的处理处置基本原则,指出高值资源化是未来的研究方向之一。     

Chlorinated Solvent Treatment Wetland

A first‐of‐its‐kind wetland restoration project was completed in October 2000 to treat trichloroethene‐(TCE‐)impacted groundwater from a former manufacturing facility prior to discharge into a highly valued recreational surface water body in the upper Midwest. This article summarizes the design, construction, operation, and effectiveness of the restored wetland. The groundwater‐surface water discharge zone at the site was restored as a wetland to improve the natural degradation of TCE and subsequent degradation by‐products. For the past 11 years, the treatment wetland performance was evaluated by monitoring the wetland vegetation, wetland hydraulics, and water chemistry. Water quality data have been used to assess the wetland geochemistry, TCE and TCE‐degradation by‐product concentrations within the wetland, and the surface water quality immediately downgradient of the wetland. The treatment wetland has been performing according to design, with TCE and TCE‐degradation by‐products not exceeding surface water criteria. The monitoring results show that TCE and TCE‐degradation by‐products are entering the treatment wetland via natural hydraulic gradients and that the geochemistry of the wetland supports both reductive dechlorination (anaerobic degradation) and cometabolic degradation (aerobic degradation) of TCE and TCE‐degradation by‐products: cis‐ and trans‐1,2‐dichloroethene and vinyl chloride. © 2013 Wiley Periodicals, Inc.     

Optimization of regional hazardous waste management systems: an improved formulation

The planning and design of regional hazardous waste management system (RHWMS) involves selection of treatment and disposal facilities, allocation of hazardous wastes and waste residues from generator to the treatment and disposal sites and selection of the transportation routes. An improved formulation based upon multi-objective integer programming approach is presented to arrive at the optimal configuration of RHWMS components. This formulation addresses important practical issues like unique characteristics of the hazardous wastes reflecting on waste–waste and waste–technology compatibility. A utility function approach is presented to integrate both cost and risk related objectives. An illustrative case example is presented to demonstrate the usefulness of the improved formulation as a tool which can be used by environmental planning agencies in regional planning for hazardous waste management.     

SITE Demonstration of Enhanced In-Situ Bioremediation of Chlorinated and Nonchlorinated Organic Compounds in Fractured Bedrock

A field demonstration of an enhanced in-situ bioremediation technology was conducted between March 1998 and August 1999 at the ITT Industries Night Vision (ITTNV) Division plant in Roanoke, Virginia. The bioremediation process was evaluated for its effectiveness in treating both chlorinated and nonchlorinated volatile organic compounds (VOCs) in groundwater located in fractured bedrock. Chlorinated compounds, such as trichloroethene (TCE), in fractured bedrock pose a challenging remediation problem. Not only are chlorinated compounds resistant to normal biological degradation, but the fractured bedrock presents difficulties to traditional techniques used for recovery of contaminants and for delivery of amendments or reagents for in-situ remediation. The demonstration was conducted under the U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation (SITE) program. The SITE program was established to promote the development, demonstration, and use of innovative treatment technologies for the cleanup of Superfund and other hazardous waste sites. This article presents selected results of the demonstration and focuses on understanding the data in light of the fractured bedrock formation. © 2002 Wiley Periodicals, Inc.