Priority organic pollutants phenolic compounds

An on-line technique coupling preconcentration via a precolumn packed with PGC and LC with a PGC analytical column has been applied to the trace-level determination of some polar and water-soluble organic pollutants from environmental waters.As these analytes are much more retained by the graphite surface than by silica Cig, preconcentration on the PGC precolumn cannot be coupled on-line with a widely used and more efficient Cjg silica analytical columns. In this study, applications were presented for the trace-level determination of 2-chloro-4-aminophenol, chloroanilines, amino-phenols, and cyanuric acid these organic compounds are included in the EC environmental priority pollutant list. The influence of the sample matrix was investigated with drinking and river water samples. 

The adsorption of phenol and phenolic compounds is by far the most studied of aU liquid-phase applications of carbon adsorbents [1]. This is because phenol is used as a model aromatic molecule and has been declared a priority pollutant. Therefore, this chapter devotes more attention to the adsorption of phenol and substituted phenols than to the adsorption of other organic solutes. 

Phenolic compounds are ubiquitous in the environment coming from different sources such as manufacturing processes used in the plastic, dye, drug, antioxidant, and pesticide industries. Chloro- and nitrophenols are the main degradation products of many chlorinated phenoxy acid and organophosphorus pesticides, respectively [1,2]. These compounds are of particular interest and concern to the environment because they are toxic to most aquatic organisms [3,4]. Moreover, they affect the taste and odor of both water and fish even at very low concentrations of phenolic compoimds in water [5]. The US Environmental Protection Agency (EPA) has listed 11 phenols as priority pollutants [6]. 

Petrasek et al. (1983) spiked the influent of an activated sludge plant with 50 /tg/liter of 22 organic compounds from the EPA list of priority pollutants. Polychlorinated phenols and biphenyls, phenols, phthalates, and PAHs were tested, with average removal rates of 97%. However, higher concentrations can destabilize an activated sludge system. The presence of cyanide, pentachlorophenol, 1,2-dichloropropane,acrylonitrile, phenolics, and ammonia can cause instability in the operation of activated sludge plants (Allsop et al., 1990). 

In this section, examples of laboratory studies concerning 03/UV/H202 advanced oxidations of some water pollutants are discussed. They have been chosen because of the high interest that their oxidation treatment has attracted among researchers in the field. Three different types of pollutants have been chosen phenols of different nature, s-triazine herbicides, and some volatile compounds, mainly chlorinated organics of low molecular weight (VOCs). Information is also given on the treatment of 1,4-dioxane, another important priority pollutant. These studies represent the scope and objectives to be reached in this type of laboratory research. 

In most laboratories today, PAHs are routinely monitored under EPA Method 8270 and comprise the majority of neutrals under the Base, Neutral, Adds (BNAs) designation of the method (2). This is a liquid-liquid extraction method with determination by gas chromatography-mass spectrometry (GC MS). Careful changes in pH of the aqueous phase enables a selective extraction of bases and neutrals from acidic compounds. Examples of priority pollutant organic bases include aniline and substituted anilines. Examples of priority pollutant organic acids include phenol and substituted phenols. The most popular method of recent years has been EPA Method 525, which incorporates SPE techniques and is applicable to PAHs in drinking water (3). 

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