Pollutants contaminant groups using

Persistent organic pollutants consist of a wide range of substances used in industrial applications, applied as pesticides, or generated inadvertently as byproducts of industrial processes. They are ubiquitous pollutants, distributed across the planet, even in regions where they have never been produced or used [32], Among others, the main groups of pollutants that have been studied in the Ebro river basin include PAHs, PPs, OCs and APs, considered as emerging compounds. Recently, the contamination by dioxin-like compounds has been considered. 

There are a wide range of bioremediation technologies either in use or proposed for use on oil/gasoline-contaminated land [301, 319], and these can be divided into two broad groups. In situ techniques treat the contamination at the site of the pollution event, whereas ex situ techniques remove the contamination from the ground and transfer it to another location for treatment. The use of in situ treatment is often preferable in terms of financial considerations, due to the cost of moving large quantities of soil [20]. Some novel approaches to the problem of hydrocarbon contamination of contaminated aqueous-solid phase environments is the use of (1) gas-liquid foams to enhance in situ bioremediation, and (2) biostimulation, as follows. 

The removal of dyes in industrial wastewaters is a major concern due to the high environmental impact caused by the presence of these pollutants [119]. Azo dyes represent a class of dyes extensively used in industry, and their complex structure presents several characteristics that can be extrapolated to many xenobiotics and contaminants, such as those with aromatic structure, azo linkage, and sulfonic group. 

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