Simulation of a biogas cleaning process using different amines

The use of biogas generated in landfills has gained importance in developing countries like Colombia. Taking into account that this biogas presents poor combustion properties that make interchangeability with other combustible gases difficult, the elimination of gases and vapors, such as CO2 and H2O, through a cleaning process, in which the biogas is converted to biomethane, improves the biogas properties as a fuel gas for general use. In this work, we simulated the generation of biogas at El Carrasco sanitary landfill in Bucaramanga, using the US EPA (United States Environmental Protection Agency) landfill gas emissions model. Additionally, we simulated the biogas cleaning process to extract the remaining moisture using the ProMax software; for this, we used three different amines (MDEA, MEA, and DEA), followed by a glycol dehydration process. The results showed that the amine MEA produced the largest increase in the concentration of CH4 (90.37 %) for the biogas generated in the landfill. Furthermore, dehydration with glycol was an efficient process to obtain a gas with a high percentage of methane (91.47 %) and low water presence (1.27 %); this would allow the use of biomethane in conventional industrial combustion processes and power generation.

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Geochemical Behavior of Uranium and Radon in Groundwater of Jurassic Granite Area, Icheon, Middle Korea

Water ◽

10.3390/w11061278 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1278 ◽

Cited By ~ 9

Author(s):

Byong Wook Cho ◽

Chang Oh Choo

Keyword(s):

Standard Deviation ◽

Environmental Protection Agency ◽

Maximum Contaminant Level ◽

Contaminant Level ◽

Low Concentrations ◽

Wide Range ◽

The Us ◽

Us Epa ◽

Independent Behavior ◽

Radon Concentrations

Uranium concentrations (a total of 82 samples) in groundwater in Icheon, middle Korea, showed a wide range from 0.02 to 1640 μg/L with a mean of 56.77 μg/L, a median of 3.03 μg/L, and a standard deviation of 228.63 μg/L. Most groundwater samples had quite low concentrations: 32.9% were below 1 μg/L, while 15.9% exceeded 30 μg/L, the maximum contaminant level (MCL) of the US EPA (Environmental Protection Agency). Radon concentrations also ranged widely from 1.48 to 865.8 Bq/L. Although the standard deviation of radon was large (151.8 Bq/L), the mean was 211.29 Bq/L and the median was 176.86 Bq/L. Overall, 64.6% of the samples exceeded the alternative maximum contaminant level (AMCL) of the US EPA (148 Bq/L). According to statistical analyses, there was no close correlations between uranium and radon, but there were correlations between uranium and redox potential (Eh) (−0.54), dissolved oxygen (DO) (−0.50), HCO3− (0.45), Sr (0.65), and SiO2 (−0.44). Radon showed independent behavior with respect to most components in groundwater. Uranium concentrations in groundwater increased with increasing water–rock interactions. Anomalously high uranium and radon concentrations in groundwater are preferentially localized in granite areas and spatial distributions are remarkably heterogeneous.

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Principles and techniques towards successful development of enzyme-linked immunosorbent assay (ELISA) for dioxin analysis

10.32920/ryerson.14648613.v1 ◽

2021 ◽

Author(s):

Wei Zhang

Keyword(s):

Immunosorbent Assay ◽

Environmental Protection Agency ◽

High Resolution Mass Spectrometry ◽

Enzyme Linked Immunosorbent Assay ◽

Environmental Matrices ◽

Successful Development ◽

Trace Level ◽

The Us ◽

Us Epa ◽

Technical Details

Dioxins are highly toxic, persistent and bio-accumulative compounds. Laboratory detection of dioxins in various environmental matrices is one of the most technically demanding and expensive tasks in analytical chemistry.The cost to analyze a soil sample by conventional gas chromatography-high resolution mass spectrometry (GC-HRMS) is approximately $1,900 USC accordign to the Unisted States Environmental Protection Agency (US EPA) (Billets, 2005). As an alternative, enzyme-linked immunosorbent assay (ELISA) for dioxin analysis has been commercially available for over a decade and recognized as the US EPA Method 3025. However, assay attributes need to be examined, especially at trace level detection. In this study, sources of error in ELISA, such as background contamination and dioxin-like polycholrinated biphenyl (dl-BCB) cross-reactions have been investigated. Quality assurance data on spikes have been reviewed and the recovery was estimated to be 70%. Technical details that are crucial for the performance of dioxin in ELISA were also identified and addressed.

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Sludge disposal: ethics and expediency

Water Science & Technology ◽

10.2166/wst.2000.0155 ◽

2000 ◽

Vol 42 (9) ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

P. A. Vesilind

Keyword(s):

Environmental Protection Agency ◽

Wastewater Treatment Plants ◽

Health Effect ◽

Health Protection ◽

Wastewater Sludge ◽

Worst Case ◽

Regulatory Decision ◽

Sludge Disposal ◽

The Us ◽

Us Epa

The United State Environmental Protection Agency (U.S. EPA) attempted to set health-based regulations for sludge disposal and used worst-case scenarios to estimate the detrimental health effect. In the absence of adequate information, this exercise led them to err so much on the conservative side that the regulations became unrealistic and would not have been accepted by the public. So the US EPA decided to do what was expedient – to establish regulations that allow most wastewater treatment plants to dispose of their sludges, knowing that these regulations are better than none at all. Such regulatory decision-making has ethical ramifications because it involves distributing costs and benefits between affected citizens. The principle of expediency as articulated by Earle Phelps calls for a regulator to optimize the benefits of health protection while minimizing costs within the constraints of technical feasibility. Phelps' expediency principle, proposed over fifty years ago, is still a useful application of ethics using scientific knowledge to set dynamic and yet enforceable environmental regulations. In the case of sludge disposal, the US EPA made an ethical decision based on the principle of expediency, weighing the moral good of human health protection versus the moral harm of taking wealth by requiring costly wastewater sludge treatment and disposal.

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Principles and techniques towards successful development of enzyme-linked immunosorbent assay (ELISA) for dioxin analysis

10.32920/ryerson.14648613 ◽

2021 ◽

Author(s):

Wei Zhang

Keyword(s):

Immunosorbent Assay ◽

Environmental Protection Agency ◽

High Resolution Mass Spectrometry ◽

Enzyme Linked Immunosorbent Assay ◽

Environmental Matrices ◽

Successful Development ◽

Trace Level ◽

The Us ◽

Us Epa ◽

Technical Details

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Geochemical Assessment of Trace Metal Distribution and Contamination in the Surface Sediments of the Coast of Okinawa Island, Japan

Environment and Pollution ◽

10.5539/ep.v6n1p1 ◽

2016 ◽

Vol 6 (1) ◽

pp. 1

Author(s):

Ibrahima M'Bemba Diallo ◽

Hiroaki Ishiga

Keyword(s):

Environmental Protection Agency ◽

Surface Sediments ◽

Sediment Quality ◽

Contamination Factor ◽

Sediment Quality Guideline ◽

Okinawa Island ◽

X Ray ◽

The Us ◽

Quality Guideline ◽

Us Epa

In this study, sediment samples were collected from the Awase tidal, the Minamigusuku, and Nakagusuku areas located in the Okinawa Island. The collected samples were analyzed using X-ray fluorescence to determine their geochemical compositions and distribution, and to assess the sediment quality in the study areas. Contamination factor (CF), geoaccumulation index (Igeo), and the United State Environmental Protection Agency Sediment Quality Guideline (US EPA SQG) were used to assess the sediment quality. The results show that the highest average concentrations of As (11mg/kg), Pb (8 mg/kg), Zn (19 mg/kg), Cu (6 mg/kg), and Cr (14mg/kg) occurred in the Minamigusuku area. The CF and Igeo values, and the US EPA SQG indicate that among the selected trace metals only As displays significant values in the study areas. The CF values of As in the Minamigusuku area show moderate enrichment, and in this same area, the Igeo values of As present significant values, ranging from moderate to considerable contaminations, implying a possible effect on the biota in this location. Compared to the US EPA SQG, the Awase tidal flat and Nakagusuku areas are moderately polluted, whereas Minamigusuku is heavily polluted, suggesting that As may possible impact the biota in these areas. Consequently, for a better sustainable development of the coast of Okinawa Island , a regular monitoring and assessment of study areas, particularly the Minamigusuku area, is necessary to determine over time the concentration of As.

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Evaluation of Alternative Annular Denuder Systems for the Collection of Fine Aerosol Particulate Matter

AgriEngineering ◽

10.3390/agriengineering2010007 ◽

2020 ◽

Vol 2 (1) ◽

pp. 96-110

Author(s):

Spencer ◽

Osborne ◽

Van Heyst

Keyword(s):

Particulate Matter ◽

Environmental Protection Agency ◽

Particle Deposition ◽

Inorganic Aerosols ◽

Filter Pack ◽

Fine Aerosol ◽

The Us ◽

In Series ◽

Us Epa ◽

Annular Denuder

Due to the complex manner in which secondary inorganic aerosols (SIAs) form, a need exists to develop a methodology to measure PM2.5 emissions from agricultural operations to better understand the contribution of SIAs to the PM2.5 fraction. When sampling particulate matter (PM), annular denuder systems (ADS) are a United States Environmental Protection Agency (US EPA) approved system used to measure both gaseous and particulate components of aerosols. While collecting basic gases, such as ammonia, using nine denuders was feasibly demonstrated in poultry housing units but the ability of additional denuders to accurately collect the SIAs on the filters is yet to be demonstrated. An experiment was designed to assess particle deposition behaviors throughout three different ADS configurations. It was determined that the nine denuder configuration resulted in particles being impacted and retained, mainly in the U-bend junctions, prior to reaching the filters with only 87.2% of PM2.5 reaching the filter pack. The US EPA-prescribed ADS configuration had 99.4% of PM2.5 reaching the filters, indicating that there is an impact due to the U-Bend addition to the system. It was further demonstrated that having additional denuders in series with no U-Bend had no significant impact on PM2.5 deposition on the filters with 98.9% of PM2.5 being collected.

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Potential Regulatory Problems Associated with Atrazine, Cyanazine, and Alachlor in Surface Water Source Drinking Water

Weed Technology ◽

10.1017/s0890037x00028815 ◽

1994 ◽

Vol 8 (4) ◽

pp. 852-861 ◽

Cited By ~ 14

Author(s):

Henry Nelson ◽

R. David Jones

Keyword(s):

Drinking Water ◽

Surface Waters ◽

Environmental Protection Agency ◽

Water Source ◽

The United States ◽

Corn Belt ◽

Annual Average ◽

The Us ◽

Us Epa ◽

Lakes And Reservoirs

Post-application seasonal (May-July) average concentrations of atrazine, cyanazine, and, to a lesser extent, alachlor sometimes exceed their Maximum Contaminant Levels (MCLs) (3 ug/L for atrazine and 2 ug/L for alachlor) or Maximum Contaminant Level Goal (MCLG) (1 ug/L for cyanazine) in surface waters of the Mississippi and Great Lakes Basins. These three chemicals are among the primary pre-emergent herbicides applied to corn. MCLs and MCLGs are compared to annual average concentrations for regulatory purposes. However, annual average concentrations are much less frequently reported than post-application seasonal averages. In most cases, both seasonal and annual average concentrations are substantially less than the MCLs or MCLG. However, actual and estimated annual mean concentrations occasionally exceed the MCLs or MCLG. Actual or estimated exceedences occur more frequently for atrazine and cyanazine than for alachlor, and may occur more frequently in lakes or reservoirs with long retention times than in streams and rivers. Additional year round data, and data for lakes and reservoirs, are needed to determine the extent to which such exceedences occur throughout the corn belt. The American Water Works Association (AWWA) believes that substantial numbers of Community Water Systems (CWSs) within the corn belt are currently, or will be, in violation of the revised Safe Drinking Water Act (SDWA) with respect to atrazine and cyanazine. They are concerned that such violations could result in numerous CWSs having to implement expensive tertiary treatment systems such as granular activated carbon to decrease herbicide concentrations. The United States Environmental Protection Agency, (US EPA) is continuing to review data on the pesticide concentrations in reservoirs and lakes that registrants have been submitting over the last 18 mo under the 6(a)(2) adverse impact provision of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The US EPA is also currently using computer modeling and other methods to evaluate potential alternative and/or supplemental herbicides to reduce atrazine use. In June 1992, the US EPA approved revised labeling that is designed to reduce indirect atrazine loadings to surface waters. Additional mitigation methods have been proposed and are being considered.

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Characterization of atmospheric aerosol in the US Southeast from ground- and space-based measurements over the past decade

Atmospheric Measurement Techniques ◽

10.5194/amt-5-1667-2012 ◽

2012 ◽

Vol 5 (7) ◽

pp. 1667-1682 ◽

Cited By ~ 23

Author(s):

E. J. Alston ◽

I. N. Sokolik ◽

O. V. Kalashnikova

Keyword(s):

Environmental Protection Agency ◽

Regional Scale ◽

Correlation Coefficients ◽

The State ◽

Study Region ◽

The Past ◽

The Us ◽

Us Epa ◽

Terra Satellite

Abstract. This study examines how aerosols measured from the ground and space over the US Southeast change temporally over a regional scale during the past decade. PM2.5 (particulate matter with aerodynamic diameter >2.5 micrometers) data consist of two datasets that represent the measurements that are used for regulatory purposes by the US EPA (Environmental Protection Agency) and continuous measurements used for quickly disseminating air quality information. AOD (aerosol optical depth) data come from three NASA sensors: the MODIS sensors onboard Terra and Aqua satellites and the MISR sensor onboard the Terra satellite. We analyze all available data over the state of Georgia from 2000–2009 of both types of aerosol data. The analysis reveals that during the summer the large metropolitan area of Atlanta has average PM2.5 concentrations that are 50% more than the remainder of the state. Strong seasonality is detected in both the AOD and PM2.5 datasets, as evidenced by a threefold increase of AOD from mean winter values to mean summer values, and the increase in PM2.5 concentrations is almost twofold over the same period. Additionally, there is agreement between MODIS and MISR onboard the Terra satellite during the spring and summer, having correlation coefficients of 0.64 and 0.71, respectively. Monthly anomalies were used to determine the presence of a trend in all considered aerosol datasets. We found negative linear trends for both the monthly AOD anomalies from MODIS onboard Terra and the PM2.5 datasets, which are statistically significant. Decreasing trends were also found for MISR onboard Terra and MODIS onboard Aqua, but those trends were not statistically significant. The observed decrease in AOD and PM2.5 concentrations may be indicative of the brightening over the study region during the past decade.

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Evaluation of Changes in Some Physico-Chemical Properties of Bottled Water Exposed to Sunlight in Bauchi, Nigeria

10.5194/dwes-2020-19 ◽

2020 ◽

Author(s):

Rose E. Daffi ◽

Fwangmun B. Wamyil

Keyword(s):

Drinking Water ◽

Bisphenol A ◽

Environmental Protection Agency ◽

Daily Intake ◽

Control Sample ◽

Bottled Water ◽

Guideline Values ◽

The Us ◽

Us Epa ◽

Control Samples

Abstract. It is common for bottled water and other assorted drinks to be seen displayed outside stores and in the sun in most parts of Nigeria. The country is mostly hot year-round and over the course of the year temperatures can rise to as high as 40 °C around March–April in the study area. The leaching effect of chemicals from polyethylene terephthalate (PET) bottled water was investigated for five (5) commercially available bottled water brands. Temperature, pH, Antimony, Bisphenol A and Nitrate levels were measured on day zero, 14 and 28 for control samples and samples exposed to direct sunlight, using destructive sampling technique. The study found that pH for brands B and D were lower than the Nigerian Standard for Drinking Water Quality (NSDWQ) and United States Environmental Protection Agency (US EPA) regulations at day zero. The control sample for Brand A maintained pH within the guideline values for 0–28 days while all Brands exposed to sunlight for 14 and 28 days had lower values than specified. Antimony was not detected in brands A, B and E in the baseline measurement at day zero while brands C and D had low values; after 28 days all the control samples still had Antimony levels within the US EPA standard. Meanwhile all the samples exposed to sunlight exceeded US EPA standard levels at 14 and 28days except brand A which was within limit at 14 days with value of 4.59 µg/L. All control and exposed samples were below the European Union Drinking Water Directive (EU DWD) total daily intake (TDI) of Bisphenol A (0.05 mg/kg body weight/day). Values obtained for Nitrate showed that all control samples did not exceed the US EPA guideline level for Nitrates in drinking water for 0, 14 ad 28 days while three (3) of the samples, Brands C, D and E, exceeded the guideline level at 28 days. Expose of bottled water to sunlight was seen to impair the quality of the water for consumption. It is recommended that regulators and practitioners drive implementation of proper storage/retailing of bottled water products and improve legislation on manufacture of plastics for food contact products.

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The case for integrating low dose, beneficial responses into US EPA risk assessments

Human & Experimental Toxicology ◽

10.1191/0960327106ht578oa ◽

2006 ◽

Vol 25 (1) ◽

pp. 7-10 ◽

Cited By ~ 3

Author(s):

J M DeSesso ◽

R E Watson

Keyword(s):

Environmental Protection Agency ◽

Low Dose ◽

Risk Assessments ◽

Protection Agency ◽

Beneficial Effects ◽

The Us ◽

Adverse Effect Level ◽

Us Epa ◽

Effect Level ◽

Epa Methods

When conducting risk assessments, the US Environmental Protection Agency (EPA) does not currently consider the beneficial effects from exposure to concentrations of agents below the no observed adverse effect level (NOAEL). If such benefits were observed, and if the beneficial and toxicological mechanisms of action were identical, this would probably be represented as a ‘j–shaped’ hormetic dose–response curve. If such data are available, they should be considered when assigning uncertainty factors for safe exposure calculations. However, when such data are not readily available, as is likely the case when the mechanism of action of the benefit differs from that of toxicity, current US EPA methods appear adequate.

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