Oxidation numbers, chemical conventions

Convention 1 is fundamental because it guarantees charge conservation The total number of electrons must remain constant in chemical reactions. This rule also makes the oxidation numbers of the neutral atoms of all elements zero. Conventions 2 to 5 are based on the principle that in ionic compounds the oxidation number should equal the charge on the ion. Note that fractional oxidation numbers, although uncommon, are allowed and, in fact, are necessary to be consistent with this set of conventions. 

Bubble columns are also used for a number of conventional processes such as oxidation, hydrogenation, chlorination, chemical gas cleaning and also various bio-technological applications [28, 109, 132, 133, 126]. 

Because every chemical reaction involves charge transfer (or at least partial electron shifts), the distinction between an acid-base reaction and an oxidation-reduction reaction becomes meaningless unless defined in terms of changes in conventionally assigned oxidation number.21 This point of view also has been expressed before, but still is not discussed in contemporary textbooks of general, organic, and inorganic chemistry. 

There are several chemical compounds found in the waste waters of a wide variety of industries that must be removed because of the danger they represent to human health. Among the major classes of contaminants, several aromatic molecules, including phenols and aromatic amines, have been reported. Enzymatic treatment has been proposed by many researchers as an alternative to conventional methods. In this respect, PX has the ability to coprecipitate certain difficult-to-remove contaminants by inducing the formation of mixed polymers that behave similarly to the polymeric products of easily removable contaminants. Thus, several types of PX, including HRP C, LiP, and a number of other PXs from different sources, have been used for treatment of aqueous aromatic contaminants and decolorization of dyes. Thus, LiP was shown to mineralize a variety of recalcitrant aromatic compounds and to oxidize a number of polycyclic aromatic and phenolic compounds. Furthermore, MnP and a microbial PX from Coprinus macrorhizus have also been observed to catalyze the oxidation of several monoaromatic phenols and aromatic dyes (Hamid and Khalil-ur-Rehman 2009). 

One good example of noncovalent functionalization for subsequent hybridization is the use of benzyl alcohol (BA) [118]. n-n interactions between the aromatic ring of BA and the CNT sidewalls result in a good dispersibility in ethanol. Furthermore, BA offers a well-ordered and well-distributed functionalization [119] of hydroxyl groups on the sidewalls of the CNTs that can be used to hybridize the material with a large number of metal oxides using conventional chemical methods [60]. 

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