scholarly journals Radon as a Natural Tracer for Monitoring NAPL Groundwater Contamination

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3327
Author(s):  
Martina Mattia ◽  
Paola Tuccimei ◽  
Michele Soligo ◽  
Claudio Carusi
Keyword(s):  
Noble Gas ◽  
Water Soluble ◽  
Source Zone ◽  
Contaminated Site ◽  
Butyl Ether ◽  
Good Correspondence ◽  
Tertiary Butyl ◽  
Local Reduction ◽  
Close Proximity ◽  
Natural Tracer

In this research, the radioactive noble gas radon was used as a tracer for Non-Aqueous Phase Liquids (NAPLs) contamination, since it is much more soluble in these substances than in air or water. Soil radon remains trapped within the NAPLs, resulting in a local reduction in the radon concentration within close proximity to the contaminated area. This technique was applied to a contaminated site in Roma (Italy). The main residual NAPLs are total hydrocarbons and methyl-tertiary-butyl ether (MTBE), a water-soluble additive. The monitoring activities included two sampling campaigns of groundwater from 18 wells in February and May 2020. Concentration maps were produced using radon data. The results show that the radon deficit traces the location of NAPLs in the fuelling station very well, with a residual source zone extending in a NNW-SSE direction. A good correspondence between a low amount of radon and a higher concentration of NAPLs was found. A reduction in the average amount of radon in the May 2020 survey indicated a stronger remobilization of NAPLs compared to that of the February 2020 monitoring campaign. The peaks of Volatile Organic Compounds (VOCs) detected between 8–9 and 11–12 m depths indicate the presence of residual blobs of NAPLs in the vadose zone of the aquifer.

Finding the Information of the Unknown DNAPL Residual Source using various tracer data, Wonju, Korea

2020 ◽  
Author(s):  
Seong-Sun Lee ◽  
Il-Ryoung Cho ◽  
Yeojin Ju ◽  
Kang-Kun Lee
Keyword(s):  
Analytical Solution ◽  
Noble Gas ◽  
Quantitative Information ◽  
Gas Analysis ◽  
Monitoring Data ◽  
Source Zone ◽  
Contaminated Site ◽  
Remedial Action ◽  
Rayleigh Fractionation ◽  
Source Mass

<p>In this study, analytical solution method which can evaluate and quantify the impacts of partial mass reduction by remedial action performed in study site is applied to estimate the unknown DNAPL source mass and dissolved concentration using long-term monitoring data collected from 2009 to 2019. Also, noble gas tracer method was applied to identify the partitioning processes which can be happened in TCE contaminated site. By using the source zone monitoring data during about 10 years and analytical solution, initial dissolved concentration and residual mass of TCE in spilled period at the main source zone were roughly estimated 150 mg/L and 1000 kg, respectively. These values decreased to 0.45 mg/L and 33.07 kg direct after an intensive remedial action performed in 2013 and then it expected to be continuously decreased to 0.29 mg/L and 25.41 kg from the end of remedial actions to 2020. From results of quantitative evaluation using analytical solution, it can be evaluated that the intensive remedial action had effectively performed with removal efficiency of 70% for the residual source mass during the remediation period. From the results of noble gas analysis, the distance from TCE source zone was divided into three groups from Zone 1 to 3. Zone 1 includes samples that are the closest from the TCE main source, and are highly partitioned to TCE compared to other zones. Zone 3 samples show least accordance with either of the fractionation lines, showing that sampling points are influenced highly by other mechanism rather than partitioning to TCE. Also, it is identified that seasonal variation of groundwater level can be affected to the distribution of noble gas at around TCE source zone. Samples from only “High TCE” zone are plotted along with ideal batch equilibrium and Rayleigh fractionation line again and divided into two groups according to their sampling date. From August 2018 to October, 2018, samples shift from right to left in the figure, getting closer to Rayleigh fractionation line. In August, noble gas was relatively in equilibrium between groundwater and TCE. However, as water table rises, noble gas became touch with residual TCE locating above the previous water-level, which is a receiving fluid in water-TCE system. Results of this study was support that it was able to estimate the unknown quantitative information for TCE contamination and noble gas as the indicator of DNAPL contamination could be applied in allocating the DNAPL source which is relatively hard to estimate.</p>

APPLICATION OF IR SPECTROSCOPY IN THE STUDY OF MINERAL OIL

2017 ◽  
pp. 91-95
Author(s):  
E. I. Grushova ◽  
A. .. Al Razuqi ◽  
E. S. Chaiko ◽  
O. A. Miloserdova
Keyword(s):  
Ir Spectroscopy ◽  
Group Composition ◽  
Mineral Oil ◽  
Vacuum Distillate ◽  
Methyl Tertiary Butyl Ether ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Mineral Oils ◽  
Modifying Additive

IR spectroscopy investigated structural and group composition of base mineral oils isolated from the vacuum distillate by selective purification of N-methylpyrrolidone and the low temperature dewaxing in the presence of a solvent. The role of the latter was carried out by the systems acetone - toluene, acetone - methyl tertiary butyl ether, methyl ethyl ketone - toluene, acetone - toluene - modifying additive. It was shown that the chemical composition of the group of base oils and slack waxes is defined as the nature of the solvent to the dewaxing, and oils sequence of purification steps.

The Effect of Adding Oxygenated Compounds to Gasoline on Automotive Exhaust Emissions

2002 ◽  
Vol 125 (1) ◽  
pp. 344-350 ◽  
Author(s):  
S. G. Poulopoulos ◽  
C. J. Philippopoulos
Keyword(s):  
Octane Number ◽  
Combustion Engine ◽  
Methyl Tertiary Butyl Ether ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Research Octane Number ◽  
Oxygenated Compounds ◽  
Reid Vapor Pressure ◽  
Three Way Catalyst ◽  
Unregulated Emissions

In the present work, the effect of adding ethanol or methyl tertiary butyl ether (MTBE) to gasoline on the regulated and unregulated emissions from an internal combustion engine with a typical three-way catalyst was studied. The addition of ethanol to fuel (10% w/w) increased both the research octane number and the Reid vapor pressure of the fuel, whereas adding 11% w/w MTBE caused an increase only in the research octane number of the fuel. When the fuel contained MTBE, less hydrocarbons, carbon monoxide, and acetaldehyde were emitted in the tailpipe. The increased emissions of acetaldehyde and ethanol were the main disadvantages of using ethanol.

scholarly journals Can We Protect Everybody from Drinking Water Contaminants?

2002 ◽  
Vol 21 (5) ◽  
pp. 389-395 ◽  
Author(s):  
Robert A. Howd
Keyword(s):  
Drinking Water ◽  
The Elderly ◽  
Butyl Ether ◽  
Water Contaminants ◽  
Tertiary Butyl ◽  
Health Goals ◽  
Fuel Tanks ◽  
Beneficial Uses ◽  
Alkyl Benzenes

Dozens of chemicals, both natural and manmade, are often found in drinking water. Some, such as the natural contaminants uranium and arsenic, are well-known toxicants with a large toxicology database. Other chemicals, such as methyl tertiary-butyl ether (MTBE) from leaking fuel tanks, we learn about as we go along. For still others, such as the alkyl benzenes, there are very little available data, and few prospects of obtaining more. In some cases, chemicals are purposely added to drinking water for beneficial purposes (e.g., chlorine, fluoride, alum), which may cause a countervailing hazard. Removing all potentially toxic chemicals from the water is virtually impossible and is precluded for beneficial uses and for economic reasons. Determination of safe levels of chemicals in drinking water merges the available toxicity data with exposure and human effect assumptions into detailed hazard assessments. This process should incorporate as much conservatism as is needed to allow for uncertainty in the toxicity and exposure estimates. Possible sensitive subpopulations such as unborn children, infants, the elderly, and those with common diseases such as impaired kidney function must also be considered. However, the range of sensitivity and the variability of toxicity and exposure parameters can never be fully documented. In addition, the validity of the low-dose extrapolations, and whether the toxic effect found in animals occurs at all in humans, is never clear. This publication discusses how these competing needs and uncertainties intersect in the development of Public Health Goals for uranium, fluoride, arsenic, perchlorate, and other highly debated chemicals.

Remediation of MTBE-contaminated groundwater by integrated circulation wells and advanced oxidation technologies

2017 ◽  
Vol 18 (2) ◽  
pp. 399-407 ◽  
Author(s):  
Bassam Tawabini ◽  
Mohammed Makkawi
Keyword(s):  
Groundwater Remediation ◽  
Treatment Time ◽  
Shallow Groundwater ◽  
Advanced Oxidation ◽  
Shallow Aquifer ◽  
Contaminated Groundwater ◽  
Butyl Ether ◽  
Tertiary Butyl ◽  
Industrial Facilities ◽  
Environmental Threats

Abstract The proximity of shallow groundwater systems to sources of contamination usually exposes them to severe environmental threats. Hazardous pollutants that leak from gas stations, landfills, and industrial facilities may eventually reach the underneath shallow groundwater aquifers, posing risks to human health and the environment. Cleaning contaminated groundwater sources has always been a challenge to the local authorities. This is even more challenging when dealing with difficult pollutants such as methyl tertiary butyl ether (MTBE) due its high solubility in water, poor biodegradability, and poor adsorption onto solids. This study aims to assess the efficiency of a pilot groundwater remediation system to treat a shallow aquifer contaminated with MTBE. The in-house designed and fabricated pilot system combines the technology of circulation wells and UV-based advanced oxidation technology for the breakdown and removal of MTBE from water. An ultraviolet/hydrogen peroxide (UV/H2O2) process was used in this study to remove MTBE from water. The concentration of MTBE was reduced from approximately 1,400 μg/L to as low as 34 μg/L within 30 minutes, with a treatment efficiency of about 98%. The study also assesses the effects of the UV intensity and the treatment time needed to remove the target pollutant.

Methyl tertiary-butyl ether mode of action for cancer endpoints in rodents

2007 ◽  
Vol 47 (2) ◽  
pp. 156-165 ◽  
Author(s):  
George Cruzan ◽  
Susan J. Borghoff ◽  
Ann de Peyster ◽  
Gordon C. Hard ◽  
Michael McClain ◽  
...  
Keyword(s):  
Mode Of Action ◽  
Methyl Tertiary Butyl Ether ◽  
Butyl Ether ◽  
Tertiary Butyl
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