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1.
Abstract

After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford Tank 241-AN-107 waste simulant was spiked with 14 target volatile, semi-volatile, and pesticide compounds and evaporated under vacuum in a bench-scale natural circulation evaporator fitted with an industrial stack off-gas sampler at the Savannah River National Laboratory. An evaporator material balance for the target organics was calculated by combining liquid stream mass and analytical data with off-gas emissions estimates obtained using U.S. Environmental Protection Agency (EPA) SW-846 Methods. Volatile and light semi-volatile organic compounds (<220 °C BP, >1 mm Hg vapor pressure) in the waste simulant were found to largely exit through the condenser vent, while heavier semi-volatiles and pesticides generally remain in the evaporator concentrate. An OLI Environmental Simulation Program (licensed by OLI Systems, Inc.) evaporator model successfully predicted operating conditions and the experimental distribution of the fed target organics exiting in the concentrate, condensate, and off-gas streams, with the exception of a few semi-volatile and pesticide compounds. Comparison with Henry's Law predictions suggests the OLI Environmental Simulation Program model is constrained by available literature data.  相似文献   

2.
长江口区域饮用水源地有机污染特性研究   总被引:1,自引:0,他引:1  
以南通市为例,对长江口区域饮用水源地53种挥发性有机物( VOCs)、64种半挥发性有机物(SVOCs)、33种农药、20种多氯联苯等有机污染物进行定性、定量检测,选取汇龙镇水厂、如皋水厂、海门长江水厂3个水厂水源地进行r枯水期、平水期、丰水期3个水期的监测.结果表明:(1)VOCs中仅在枯水期有四氯化碳检出,33种农...  相似文献   

3.
The Hazardous and Solid Waste Amendments to the Resource Conservation and Recovery Act direct the Environmental Protection Agency to determine the available treatment technologies for a number of hazardous waste streams, including halogenated organics. If it is determined that existing technology and capacity is sufficient for the safe management of the designated halogenated organic wastes, these wastes will be prohibited from land disposal, effective July 8,1987. This article summarizes the general characteristics and treatment alternatives for this waste category.  相似文献   

4.
The Superfund Innovative Technology Evaluation (SITE) Program is now in its sixth year of demonstrating technologies applicable to Superfund sites. The SITE Program, conducted by the U.S. Environmental Protection Agency's Risk Reduction Engineering Laboratory, is intended to accelerate the use of new and innovative treatment processes as well as evaluate innovative measurement and monitoring techniques. Within the SITE Program, the Demonstration Program and the Emerging Technologies Program are responsible for innovative/alternative waste treatment technology development. Separate and parallel activities are progressing for development and evaluation of measuring and monitoring technologies as well as technology transfer operations.  相似文献   

5.
An ambient air sampling study was conducted around a municipal waste combustor; a primary goal was to develop procedures and methods to evaluate the emissions of organic mutagens resulting from incomplete combustion of municipal waste. The products of Incomplete combustion from incineration include complex mixtures of organics, particularly polycycllc aromatic compounds, which are present after atmospheric dilution and cooling In emissions as semi-volatile or particle bound organic compounds. Combustion emissions are generally recognized as a potential cancer risk since they contain many carcinogenic and mutagenlc polycyclic aromatic hydrocarbons. Analyzing such a complex mixture for the presence of even a few selected chemicals is difficult and provides risk information on only a fraction of the chemicals present. Bioassay methods, however, may be directly applied to evaluate the mutagenic and potential carcinogenic activity of the complex organics from combustion emissions. The Salmonella (Ames) assay was used to determine the mutagenicity associated with particles from ambient air collected near a municipal waste combustor. Dose-response data was generated, and mutagenicity concentrations were calculated to demonstrate the utility of bioassay In assessing the potential Impact of emissions from municipal waste combustion. This phase of study quantified mutagenicity concentrations In ambient air but did not detect organic mutagens that could be attributed to Incinerator emissions.  相似文献   

6.
The Assessment and Remediation of Contaminated Sediments (ARCS) Program within the U.S. Environmental Protection Agency's Great Lakes National Program Office (GLNPO) contained a component for demonstrating and evaluating sediment remediation technologies. Toward this end, bench-scale tests of solvent extraction, thermal desorption, and wet air oxidation technologies were conducted. Contaminated sediments were tested from the Grand Calumet River, Indiana; Buffalo River, New York; Saginaw River, Michigan; and Ashtabula River, Ohio. The primary contaminants of concern in these sediments were polychlorinated biphenyls (PCBs) and polynuclear aromatic hydrocarbons (PAHs). The solvent extraction tests were conducted with sediments from the Grand Calumet, Buffalo, and Saginaw rivers. The thermal desorption studies were conducted with sediments from the Grand Calumet, Buffalo, and Ashtabula rivers. The wet air oxidation testing was performed with the Grand Calumet River sediment. Raw sediment contaminant concentrations ranged from 0.32-21.9 mg/kg dry mass for PCBs and 2.70-266 mg/kg dry mass for PAHs. PCB removal or destruction efficiencies ranged from approximately 6-99%. PAH removal or destruction efficiencies ranged from 65-99%. Mass balance closures ranged from 40-99% for solids; 59-139% for water; 29-3500% for oil; 16-129% for PCBs; and 69-3170% for PAHs.  相似文献   

7.
The Superfund Innovative Technology Evaluation (SITE) Program is now in its sixth year of demonstrating technologies applicable to Superfund sites. The SITE Program, conducted by the U.S. Environmental Protection Agency’s Risk Reduction Engineering Laboratory, is intended to accelerate the use of new and innovative treatment processes as well as evaluate innovative measurement and monitoring techniques. Within the SITE Program, the Demonstration Program and the Emerging Technologies Program are responsible for innovative/ alternative waste treatment technology development. Separate and parallel activities are progressing for development and evaluation of measuring and monitoring technologies as well as technology transfer operations.  相似文献   

8.
Hoddinott KB  Lee AP 《Chemosphere》2000,41(1-2):77-84
The authors of this paper chose several target compounds that have been found in average US homes, applied the current United States Environmental Protection Agency (USEPA) Superfund risk assessment methodologies to indoor air quality, and produced risk numbers for hazard quotients and predicted increases in incidence of cancer which would be unacceptable at US hazardous waste sites. The calculations were made for the average child and adult with USEPA default exposure values. Calculations were also made for a worst case scenario using maximum concentrations and exposure estimates defined by the USEPA as describing the reasonable exposure (RME). Significant cancer risks and non-cancer hazard quotients were predicted.  相似文献   

9.
饮用水中微量有机物的污染是关系饮用水生态安全的重要问题。以饮用水中微量的内分泌干扰类除草剂阿特拉津为研究对象,分别采用微生物降解技术和光催化氧化技术对其进行降解,考察温度对阿特拉津降解效果的影响。研究结果表明:阿特拉津浓度为1 mg/L时,3种温度条件下,除锰功能菌MB4对阿特拉津均有明显的去除效果,降解时间为7 d时,阿特拉津的去除率达到65%。底物浓度为200 μg/L,3种温度条件下,活性炭负载二氧化钛(TiO2/PAC)催化剂光降解阿特拉津30 min时,其去除率均达到90%。光催化氧化技术协同微生物降解技术在饮用水中微量的内分泌干扰物的去除中有广阔的应用前景。  相似文献   

10.
ABSTRACT

Terpene-based cleaners are being widely used in industrial cleaning formulations because of their ability to replace suspected ozone-depleting chemicals such as 1,1,1-trichloroethane and 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). Substitution of chlorinated solvents with ter-pene-based cleaners, however, is expected to result in increased discharges to wastewater from industrial operations. A pilot-scale study was conducted at the U.S. Environmental Protection Agency's (EPA) Test & Evaluation Facility in Cincinnati, OH, to quantify the fate of specific terpene compounds in the activated sludge wastewater treatment process. Biodegradation rates of terpenes were estimated from the difference between the influent terpene mass flow rates and the amounts volatilized to air, partitioned to waste sludge, and passed through the treatment process unchanged. Any chemical transformation of the terpene compounds studied was attributed to biodegradation.

Analytical methods were developed to determine ter-pene concentrations in aqueous and gaseous media. The fate of two common terpene compounds (d-limonene and terpinolene) were evaluated in three identical pilot-scale systems: (1) a system with a high target spike range (2–10 mg/L), (2) a system with a low target spike range (0.5–2 mg/L), and (3) a control system (no spike).

The study showed that the primary removal mechanism for the terpene compounds in the activated sludge process is biodegradation. Typically, greater than 90% of the mass of terpenes entering the aeration basin of the activated sludge process biodegrades to other compounds; volatilization from the reaction basin accounts for less than 10%, while loss to waste activated sludge and the secondary clarifier effluent accounts for less than 1%.  相似文献   

11.
In recent years, scientific discussion has included the influence of thermodynamic conditions (e.g., temperature, relative humidity, and filter face velocity) on PM retention efficiency of filter-based samplers and monitors. Method-associated thermodynamic conditions can, in some instances, dramatically influence the presence of particle-bound water and other light-molecular-weight chemical components such as particulate nitrates and certain organic compounds. The measurement of fine particle mass presents a new challenge for all PM measurement methods, since a relatively greater fraction of the mass is semi-volatile. The tapered element oscillating microbalance (TEOM) continuous PM monitor is a U.S. Environmental Protection Agency (EPA) PM10 equivalent method (EQPM-1090079). Several hundred of these monitors are deployed throughout the United States. The TEOM monitor has the unique characteristic of providing direct PM mass measurement without the calibration uncertainty inherent in mass surrogate methods. In addition, it provides high-precision, near-real-time continuous data automatically. Much attention has been given to semi-volatile species retention of the TEOM method.  相似文献   

12.
On December 20, 1989, the Environmental Protection Agency (EPA) proposed revised new source performance standards for new municipal waste combustion (MWC) units and guidelines for existing sources. The proposed national regulations require tighter particulate matter control and address pre-combustion, combustion, and post-combustion controls, the latter two depending on capacity and age of the facility.

The air pollutants of concern when municipal solid waste (MSW) is burned will be discussed. Generally, particulate control is an inherent part of the systems used to limit the emissions of these air pollutants. The relationships between MWC air emissions (acid gases, trace organics, and trace heavy metals) control and particulate control will be discussed. Test results to quantify air pollutant emissions from MWC units and their control will be presented and compared with the proposed regulations.  相似文献   

13.
TOXI模型是美国环保局的WASP(水质分析模拟程序)中的一部分。由于该模型考虑了污染物质在河流中溶解态,颗粒态和底泥态的分布关系,对于模拟重金属在河流中的浓度变化效果较好。为保证计算结果的可靠性,首先应对重金属浓度的衰减变化特性进行研究,本文重点讨论的是重金属在河流中迁移转化的过程,并如何将这一过程用数学公式来进行模拟。  相似文献   

14.
This paper provides a summary of the results of an 18-month study conducted by Clean Sites, Inc. of Alexandria, Virginia. The study was designed to take a critical look at the way remedies are selected for abandoned hazardous waste sites that are cleaned up under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) and to develop recommendations for improving that process. The recommendations were released in an October 1990 report entitled “Improving Remedy Selection: An Explicit and Interactive Process for the Superfund Program.” Through a cooperative agreement with the U.S. Environmental Protection Agency, Clean Sites is working to test these recommendations. At two actual Superfund sites, Clean Sites will assist EPA in performing the remedy selection in accordance with the process Clean Sites has developed.  相似文献   

15.
This paper provides a summary of the results of an 18-month study conducted by Clean Sites, Inc. of Alexandria, Virginia. The study was designed to take a critical look at the way remedies are selected for abandoned hazardous waste sites that are cleaned up under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) and to develop recommendations for improving that process. The recommendations were released in an October 1990 report entitled "Improving Remedy Selection: An Explicit and Interactive Process for the Superfund Program." Through a cooperative agreement with the U.S. Environmental Protection Agency, Clean Sites is working to test these recommendations. At two actual Superfund sites, Clean Sites will assist EPA in performing the remedy selection in accordance with the process Clean Sites has developed.  相似文献   

16.
The FATE and treatibility estimator (FATE) model, developed by the United States Environmental Protection Agency was used for the prediction of the FATE of 26 persistent organic pollutants (POPs), i.e. 7 PCBs and 19 organochlorine compounds (OCs), during the conventional activated sludge treatment process applied in the waste water treatment plant (WWTP) of Thessaloniki, Greece. The removal rates predicted by the model for the primary and the secondary treatment stages were found to differ substantially from those experimentally measured. When the overall treatment was considered, the differences between measured and model predicted removals were within acceptable limits of confidence. Possible reasons that might cause deviations from experimental values were suggested to be the wastewater content in dissolved organic carbon (DOC), and/or the low concentrations of POPs in untreated wastewater.  相似文献   

17.
A repository of 14 gaseous organic compounds at parts-per-billion levels (7-430 ppb) in compressed gas cylinders has been established by the Environmental Protection Agency. This repository was established to provide audit materials for use in conducting performance audits to assess the accuracy and precision of principal organic hazardous constituent (POHC) measurements, especially those performed during hazardous waste trial burn tests. Five- and nine-component mixtures In a balance gas of nitrogen were prepared in aluminum cylinders for use in the performance audit program. The five-component mixtures contain carbon tetrachloride, chloroform, perchloroethylene, vinyl chloride, and benzene. The ninecomponent mixtures contain trichloroethylene, 1,2-dichloroethane, 1,2-dibromoethane, acetonitrile, trichlorofjuoromethane, dichlorodifluoromethane, bromomethane, methyl ethyl ketone and 1,1,1-trichloroethane.

Studies of all 14 gaseous organic compounds were performed to determine the stability of the compounds and the feasibility of using them in performance audits. Results indicate that ail of the 14 compounds were adequately stable to be used as reliable audit materials. Also, the estimation of specific uncertainties associated with the analysis of these audit materials and how those uncertainties are used to assign a total uncertainty to the final analyte concentration for 14 organics Is described.

Subsequent to completion of the stability studies, several performance audits were conducted using the repository gases to assess the accuracy and precision of the volatile organic sampling train (VOST) and bag measurement methods. The audit results indicate that laboratories can use these methods to analyze POHC with accuracy usually to within ± 50 percent of the audit concentrations.  相似文献   

18.
The Particle Concentrator-Brigham Young University Organic Sampling System (PC-BOSS) has been previously verified as being capable of measuring total fine particulate matter (PM2.5), including semi-volatile species. The present study was conducted to determine if the simple modification of a commercial speciation sampler with a charcoal denuder followed by a filter pack containing a quartz filter and a charcoal-impregnated glass (CIG) fiber filter would allow for the measurement of total PM2.5, including semi-volatile organic material. Data were collected using an R&P (Rupprecht and Pastasnik Co., Inc.) Partisol Model 2300 speciation sampler; an R&P Partisol speciation sampler modified with a BOSS denuder, followed by a filter pack with a quartz and a CIG filter; a Met One spiral aerosol speciation sampler (SASS); and the PC-BOSS from November 2001 to March 2002 at a U.S. Environmental Protection Agency (EPA) Science to Achieve Results (STAR) sampling site in Lindon, UT. Total PM2.5 mass, ammonium nitrate (both nonvolatile and semi-volatile), ammonium sulfate, organic carbon (both non-volatile and semi-volatile), and elemental carbon were determined on a 24-hr basis. Results obtained with the individual samplers were compared to determine the capability of the modified R&P speciation sampler for measuring total PM2.5, including semi-volatile components. Data obtained with the modified speciation sampler agreed with the PC-BOSS results. Data obtained with the two unmodified speciation samplers were low by an average of 26% because of the loss of semi-volatile organic material from the quartz filter during sample collection.  相似文献   

19.
Solvent extraction and tandem dechlorination for decontamination of soil   总被引:1,自引:0,他引:1  
The United States Environmental Protection Agency (US EPA) guidelines allow removal of polychlorinated biphenyls (PCBs) from soils via solvent extraction. This option holds promise for removal of other recalcitrant organic contaminants as well. A study was undertaken to evaluate the effectiveness of solvent extraction with two tandem degradation techniques. The degradation techniques were chemical dehalogenation with immobilized reagents and gamma-ray irradiation. The integrated approach was evaluated with contaminated soils from wood treatment and electric power substation sites. Evaluations were carried out on a bench scale in the laboratory and on a semi-pilot scale at a contaminated site. Binary solvent mixture of alkanes and alcohols yielded the highest extraction efficiencies. Extraction efficiencies in excess of 90% were obtained for PCBs, polychlorinated dibenzo-p-dioxins (PCDDs) and polynuclear aromatic hydrocarbons (PAHs). Extracted PCBs were rapidly degraded through chemical dehalogenation or with high doses of the gamma-ray irradiation. The residual organics in the solvent mixture were removed with activated carbon, and the solvent was recycled for subsequent soil extractions. Contaminants adsorbed on the activated carbon were destroyed with a counter flow oxidation process.  相似文献   

20.
Abstract

Over the last few decades, the use of chemical pesticides has increased dramatically in the U.S. This relatively sudden increase greatly concerns the U.S. Environmental Protection Agency (EPA), since it has the responsibility for ensuring the safety of all pesticides used in the U.S. In response to this concern, EPA has established a review program, the Rebuttable Presumption Against Registration (RPAR), for periodically reassessing the mutagenic and carcinogenic potential of pesticide compounds.

This paper presents a review and evaluation of the data reported in the literature on six chemical pesticides suspect for mutagenic potential. The pesticide chemicals discussed are maleic hydrazide; rotenone; monuron; diallate; triallate, and benomyl.  相似文献   

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