Organic and metal pollutants

Organic and Metal Pollutants of Importance to Environmental Restoration... 

Radiation treatment To remove organics and metallic pollutants from waste water and SO and NO from flue gases emitted from coal power stations and industrial plants have been studied in great detail. The cleaning of flue gases has been developed to the pilot plant stage. 

The goal of setting operating requirements for hazardous waste combustion units is to ensure that the unit will operate in a way that meets the performance standards for organics, chlorine, particulate matter, and metal pollutants. The unit s permit will specify the operating conditions that have been shown to meet the performance standards for organics, chlorine gas, particulate matter, and metals. 

This chapter presents the theory and application of zero-valent iron and includes the relevant in situ chemical/physical processes. To illustrate these in situ technologies, the basic mechanisms of adsorption reduction and oxidation processes are discussed for in situ treatment of (1) organic pollutants, (2) heavy metals, and (3) mixtures of organic and inorganic pollutants. The history of zero-valent iron, current applications, mechanisms and kinetics of the system, system improvements, and advantages and disadvantages for zero-valent iron are also discussed. 

Although removal of organic and microbiological pollutants from waters has been thoroughly studied, less attention has been paid to the transformation of metal or metalloid ions in species of lower toxicity or more easily isolated. Metals in their various oxidation states have infinite lifetimes, and chemical or biological treatments present severe restrictions or are economically prohibitive. Removal of these species is carried out, generally, by precipitation, electrolysis, chemical oxidation, adsorption, or chelation, all of them presenting drawbacks. 

One of the most relevant environmental consequences of the existence of colloids derives from their ability to adsorb different species and to exchange ions. Examples include radionuclides, organics, and metal derivatives that may be toxic pollutants. Colloids that retain these species may participate in transforming them into catalysts, after which they transport them into aqueous systems located far from their original discharge points. 

This book is a guidance manual for source Identification and detection of heavy metals, toxic organics, and other pollutants that can have negative impacts on the operation of POTWS. 

In the technical literature, this approach was considered, in only a few studies. For instance, Ag, Au, Cd, Cr, Hg, Ni and Pt dissolved as metal cations in water media were successfully photoreduced in the presence of methanol, formic acid, salicylic acid, EDTA, phenol and nitrobenzenes (Burns et al., 1999 Prairie et al., 1993). Furthermore, the reduction of these inorganic species can be enhanced in the presence of the described organic molecules (hole scavengers) (Buttler and Davis, 1993 Chen and Ray, 2001 R airie et al., 1993). Thus, there is evidence of the importance of the combined organic and inorganic pollutant photoconversion and this topic deserves continued attention in order to take full advantage of enhancement effects. 

Maturi K, Reddy KR. (2008). Cosolvent-enhanced desorption and transport of organic and metal contaminants in soils during electrokinetic remediation. Water, Air, and Soil Pollution 189(1-4) 199-211. 

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