Pollutant transformation

In order to build new facilities or expand existing ones without harming the environment, it is desirable to assess the air pollution impact of a facility prior to its construction, rather than construct and monitor to determine the impact and whether it is necessary to retrofit additional controls. Potential air pollution impact is usually estimated through the use of air quality simulation models. A wide variety of models is available. They are usually distinguished by type of source, pollutant, transformations and removal, distance of transport, and averaging time. No attempt will be made here to list aU the models in existence at the time of this writing. 

What are the major limitations in modeling pollutant transformations in urban areas ... 

Almeida, M. (1999), Pollutant transformation processes in sewers under aerobic dry weather flow conditions, Ph.D. thesis, Department of Civil and Environmental Engineering, Imperial College of Science, Technology and Medicine, UK, p. 422. 

Bend, J. R., Foureman, G. L., and James, M. 0. Partially induced hepatic mixed-function oxidase systems in individual members of certain marine species from coastal Maine and Florida. In "Aquatic Pollutants Transformation and Biological Effects." Hutzinger, 0., Van Lelyveld, L. H., and Zoeteman, B. C. J. (eds.), pp. 483-486, Pergamon, Oxford,... 

Sasaki S. 1978. The scientific aspects of the chemical substances control law in Japan. In Hutzinger O, VonLetyveld LH, Zoetman BC eds. Aquatic Pollutants Transformation and biological effects Oxford Pergamon Press 283-298. 

Very significant photochemical processes can take place in various environmental compartments and account for the transformation of organic and inorganic compounds, including pollutants released by human activities. In many cases pollutant transformation is beneficial to the environment and to human health because it decreases the lifetime and hence the possible impact of harmful compounds. However, in some cases the environmental transformation of pollutants and of some otherwise harmless xenobiotics can yield compounds having much higher impact than the parent compounds (e.g., the case of carbamazepine transformation into acridine). It is therefore very important to assess the transformation pathways, including the photochemical ones, of compounds naturally present in the environment or released by human activities. 

Zepp, R.G., Baughman, G.L. (1978) Prediction of photochemical transformation of pollutants in aquatic environment. In Aquatic Pollutants Transformation and Biological Effects. Hutzinger, O., Van Lelyveld, I.H., Zoeteman, B.C.J., Editors, pp. 237-264, Pergamon Press, Oxford, England. 

B. Advantages and Limitations of Enzyme Applications for Pollutant Transformation... 

It was estimated that this could eliminate the need for the disposal of approximately 1000 tons of nonbiodegradable cleaning chemicals per year. These approaches demonstrate the application of enzymes as a means of pollution prevention, not just pollutant transformation. 

Zepp RG, Baughman GL (1978) In Hutzinger O, van Lelyveld IH, Zoeteman BCJ (eds) Aquatic pollutants transformation and biological effects. Pergamon, Oxford, UK, p 237... 

Faust, B. C. (1994a) Aqueous Phase Photochemical Reactions in Oxidant Formation, Pollutant Transformations and Atmospheric Geochemical Cycles, Environ. Sci. Technol. 28, 217A-222A. 

Zepp, R. G. Baughman, G. L. In "Aquatic Pollutants Transformation and Biological Effects" Hutzinger, 0. Van Lelyveld,... 

The purpose of this chapter is to give an overview of the chemical and biological processes that control the reactivity of Fe(II) in heterogeneous aqueous systems with respect to pollutant transformation. To this end, we will evaluate data collected in various laboratory systems as well as field studies. Two classes of model compounds with complementary properties will be used to monitor the reactivity of Fe(II) species in the various systems. Nitroaromatic compounds (NACs) primarily served to characterize the systems in terms of mass and electron balances. Reduction of NACs by Fe(II) species results in only a few major products (aromatic amines and hydroxy-lamines) which can be easily quantified by standard HPLC-UV methods in the low liM range. Polyhalogenated aliphatic compounds (PHAs) were used if little perturbation of the systems in terms of electron transfer to the organic substrates was crucial. Reduction of PHAs requires fewer electrons than nitro reduction and PHAs can be quantified by standard GC-ECD methods in the low ppb range. 

Catallo WJ, Junk T (2003) Effects of static vs. dynamic hydrology on pollutant transformations in wetland sediments. J Environ Qual 32 2421-2427... 

Waggott, A., and A.B. Wheatland. 1978. Contribution of different sources to contamination of surface waters with specific persistent organic pollutants. In O. Hutzinger, L.H. van Lelyveld, and B.C.J. Zoeteman (Eds.), Aquatic pollutants transformation and biological effects. Proceedings of the Second International Symposium on Aquatic Pollutants, Amsterdam, The Netherlands, September 26-28, 1977, pp. 141-168. 

Studies in the last decade show that iron sulfide minerals are very reactive in the reductive transformation of chlorinated aliphatic pollutants. These minerals, present in sulfate-reducing anaerobic environments, likely contribute to in-sUu transformation of chlorinated aliphatic pollutants and have potential application in remediation technologies. Solution pH, the presence of organic co-solutes with functional groups representative of natural organic matter, and the thermodynamic or molecular properties of the halogenated aliphatic pollutant all influence the rates and/or products of pollutant transformation. 

Empirical linear correlation analysis has also produced results that may be used in predicting the rates of FeS-mediated pollutant transformation based on pollutant thermodynamic or molecular properties. One study (77) performed linear correlation analysis of log kohs values for 8 halogenated aliphatic molecules with five molecular properties one-electron reduction potentials, lowest unoccupied molecular orbital (LUMO) energies, fi ee energies of formation of aqueous phase radicals formed upon one-electron reduction, gas-phase homo-[ytic bond dissociation enthalpies, and aqueous solubilities. Of these parameters, homolytic bond dissociation enthalpies (7)r.x values) were best correlated with log obs values for FeS reductive dechlorination (R =0.82). The correlation between log obs and 7)r x is illustrated in Figure 4. Another parameter shown... 

Gibson, D.T. Microbial transformation of aromatic pollutants. In Aquatic Pollutants - Transformation and Biological Effects, Pergamon 1, 187, 1977... 

Giger, W., Molnar-Kubica, E., Wakeham, S. Volatile chlorinated hydrocarbons in ground and lake waters. Aquatic Pollutants Transformation and Biological effects. Pergamon 1, 1977... 

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