Priority pollutants contaminants

Chromatographic and atomic spectral determinative techniques are mature and one should expect few, if any, breakthroughs. Priority pollutant contaminants, both organic and inorganic, are quantitated down to very low concentration levels in a variety of sample matrices. This author envisions the need to commercialize the hyphenated techniques as has been accom-... 

Initial field investigations of old, heterogeneous disposal sites where waste types are insufficiently documented, thus deferring expensive priority pollutant analysis until the fact and location of ground water contamination is established ... 

Polychlorinated biphenyls (PCBs), CFCs, petroleum products, and dioxin are major toxic contaminants in air (Section 3.3.2), soil (Section 3.5.3), and also in water. The readers are referred to Sections 3.3.2 and 3.5.3 for details about PCB characteristics, health effects, treatment technologies, and so on. For water quality management, they have been included in the list of the USEPA priority pollutants [86]. 

In addition to gasoline, CFC, and so on, various other organic and inorganic compounds such as heavy metals, sulfides, and cyanides on the USEPA Priority Pollutants List, and subject to various water quality criteria, guidelines, etc., when released can also contaminate the soil. The contaminated soil then becomes a hazardous solid waste which must be properly disposed of [63-86]. 

In 1984, the total worldwide production of PCP was 35 400 to 40 000 tons, 80% of which was used for wood preservation (Korte, 1987). CPs are widely distributed in the environment and many contaminated sites have been selected for cleanup in Europe and are on theNational Priorities List of the Superfund Program in theUS. (U.S.EPA, 1993). Some CPs are listed as priority pollutants by the U.S. EPA (Keith Telliard, 1979). 

Chlorinated aromatic compounds are commonly found as contaminants in environmental soil samples. For example, chlorobenzenes have been listed as priority pollutants and can be found in various matrixes such as water, soils, sediments and sewage sludges. Polychlorinated biphenyls are probable human carcinogens but have been applied in large doses in various industrial products. Analysis of these compounds in solid matrixes, such as soils and sediments, requires several steps. 

Chlorinated phenols are among the most important contaminants in the environment (aqueous systems and soils) due to their widespread use in industry and agriculture and for domestic purposes for over 50 years. It is well-known that chlorophenols are toxic at low levels. The more highly chlorinated phenols such as trichlorophenols and pentachlorophenol are also persistent. Five of the chlorophenols (2-chlorophenol, 2,4-dichlorophenol, 4-chloro-3-methylphenol, 2,4,6-trichlorophenol and pentachlorophenol) have been classified as priority pollutants by the US Environmental Protection Agency (EPA). 

Iannuzzi TJ, Huntley SL, Schmidt CW, et al. 1997. Combined sewer overflows (CSOs) as sources of sediment contamination in the lower Passaic river, New Jersey. I. Priority pollutants and inorganic chemicals. Chemosphere 34(2)213-231. 

The need for the application of these AOTs is based on different social, industrial, environmental, and even academic reasons. The increasing awareness of society for the quality of drinking water has led to the establishment of maximum contaminant levels of priority pollutants in drinking water [1,2], The preparation of ultrapure water is needed for some industrial activities such as those derived from the pharmaceutical and electronic processes. 

The widespread application of herbicides in agriculture has resulted in many polluted surface waters. As a result, numerous pesticides/herbicides have been treated in bench-scale laboratory studies with 03/UV/H202 processes during the last 10 years (see Table 10). Among them, many studies focused on the treatment of atrazine and other. v-triazine herbicides (simazine, prop-azine, etc.). Atrazine is a priority pollutant that similar to other individual pesticides has a very low maximum contaminant level (MCL) (0.1 pg L 1 for the European Environmental Commission according to Directive 80/778/ EEC). In some countries atrazine cannot be used but it is still found in many surface waters. In France, for example, atrazine was banned on September 28, 2001. From applied technologies, only carbon adsorption [180] and possibly advanced oxidations can be recommended to remove some of these... 

The photochemistry of polycyclic aromatic hydrocarbons (PAHs) and poly-chlorobiphenyls (PCBs) in water and on solids was reviewed in this series in 1999 [1]. The large interest in this field was due to the fact that many PAHs and mixtures of PCBs are on the United States Environmental Protection Agency s fist of priority pollutants (see [1] for the fist of compounds). Photochemists wanted to know what the fate of these materials in the environment is when exposed to sunlight and if one could use photochemistry to remediate contaminated sites. This interest has continued and will be the focus of the present review. The review covers the recent literature through the middle of 2003. 

Sixteen PAHs are on the lists of priority pollutants of the US Environmental Protection Agency and the European Union (Lehto et al., 2003) mixtures containing more than 50 individual PAHs have been found in sediments at hazardous waste sites (Brenner et al., 2002). Low-molecular-weight PAHs, with two or three rings, are the most volatile and usually the most abundant. High-molecular-weight PAHs, with four or more rings, are less volatile. The PAHs in contaminated soils and... 

Uncertainties in source characterization include imprecise source sampling, limitations of the analytical results, and selection of the contaminants used to calculate risk. For example, priority pollutant analyses are often used to screen... 

Phenol, a common priority pollutant, was extracted from two environmental matrices, soil and water, using near critical and supercritical carbon dioxide. The primary objective of this study was to determine the distribution of the contaminant between the soil or water and the supercritical phase, and the effect of soil moisture and co-solvents on the distribution coefficients. Static equilibrium extractions were performed on dry and wetted soil contaminated with 1 wt.% phenol and on water containing 6.8 wt.% phenol. Supercritical carbon dioxide (with and without en-trainers) was chosen as the solvent for the study. An appropriate entrainer for dry soil extractions (methanol) ffiffered from that found for aqueous extractions (benzene). However, soil moisture was found to have a significant impact on the effectiveness of en-trainers for soil extractions of phenol. Entrainers appropriate for extracting wetted soil were found to be the same as those advantageous for aqueous extractions. Benzene was also extracted from dry and wetted soil to investigate the extractability of a hydrophobic compound. 

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