Bio-oxidation

An alternative route increasingly investigated is bio-oxidation using bacteria to oxidize pyrite or arsenopyrites at 45°C. 

Laboratory tests of ethylene glycol containing formulations have shown a complete bio-oxidation within 20 days. The rate of bio-oxidation is stationary over the full period. On the other hand, propylene glycol initially degrades more rapidly during the first 5 days of the test to an extent of 62%, slowing to 79% conversion after 20 days. 

Vance, D.B., Lupo M., and McHugh, N., Anaerobic bio-oxidation of MTBE and 1,2-DCA, Proceedings of the 10th Annual International Petroleum Environmental Conference, Houston, TX, November... 

A process, which considered the bio-oxidation of naphthalene compounds using naphthalenes-oxidizing bacteria, was applied for the treatment of gas oil. The quality of the product not only exhibited a sulfur content closed to specifications but also a high lubricity. Description on the used microbial strain was not provided [432],... 

Sulfidic matrices often require an oxidative pre-treatment prior to leaching the gold (see above). Bio-oxidative processes to achieve this usually generate acidic aqueous phases which must be neutralized prior to cyanidation. To avoid this neutralization step, lixiviants such as thiourea have been considered, which can be used in acidic media.57-67 The thiourea-based processes have a... 

Bio-oxidation of bromobenzene 11 catalyzed by Pseudomonas putidae leads to diol 12. Protection of diol 12, followed by the addition of an acyl nitroso dienophile and subsequent reduction gives compound 14. This compound can be used as the key intermediate in the preparation of (+)-l-deoxy-galacto-nojirimycin (16) and related indolizidine compounds (15) (Scheme 8-5).12... 

As for demethoxylation, it is known that 1,4-dimethoxybenzene is oxidized to the corresponding benzoqninone. The reaction takes place under conditions of bio-oxidation and proceeds through intermediacy of an ESR-detectable cation-radical (Kersten et al. 1985) (Scheme 8.21). 

As for (i-0-4 ethereal bond cleavage, reaction of the primary cation-radical with solvent water under the same conditions of bio-oxidation was shown to form an arylglycerol and the corresponding phenoxy radical (Kirk et al. 1986, Fabbri et al. 2005) (Scheme 8.22). Since the p-0-4 ethereal bond is the most abundant type of interunit linkage in the lignin polymer, this ethereal bond cleavage represents an important depolymerization reaction. 

The trickling filter process, including conventional rate filters, multiple-stage, high-rate systems, and bio-oxidation roughing towers. 

Surfactant concentrations also exert a negative influence on the bio-oxidation of certain substances, as evidenced in studies with even readily biodegradable substances [7]. It should be noted that this protection of substances from bio-oxidation is only temporary and it slowly reduces until its virtual disappearance in about a week for most substances. This phenomenon serves to retard the self-purification process in organically polluted rivers, even in the presence of high concentrations of dissolved oxygen. 

Sharma, M.A. Treatment of cotton textile mills effluent - a case study. Colourage 1989, 36, 15-21. Schulze-Rettmer, R. Treatment of textile dyeing wastewater by adsorption/bio-oxidation process. Text. Chem. Color. 1998, 30, 19-23. 

Mills, R.E. Progress report on the bio-oxidation of phenolic and 2,4-D waste waters. In Proceedings of 4th Ontario Industrial Waste Conference, June 1957 30. 

Reductive biotransformation of a contaminant can occur when the contaminant serves as the terminal electron acceptor. Many contaminants that are recalcitrant to bio-oxidation will undergo reductive biotransformations. These biotransformations can lead to detoxification, mineralization, or changes in the mobility of the targeted contaminant. Hexavalent chromium and tetra-chloroethene (PCE) have been investigated as candidates for reductive biotransformation. This technology may be most applicable for in situ remediation for the following scenarios PCE contamination, low-yield aquifers, areas contaminated by both alkylbenzenes and chlorinated ethenes, and deep aquifer contamination. 

The bio-oxidants that are formed are highly suited to attacking organic molecules by attracting the most readily available electrons in the substrates structures (Table 17.4). Often these are -electrons of aromatic rings and carbon-carbon double bonds ... 

It must be noted that during WWII nearly all US expl and ammo plants used bio-oxidation for disposal of some of their organic wastes. This did not include TNT and some other expls for which no effective bacteria was found(See also under Waste Disposal)... 

CA 45, 2885(195lXHydrogenati°n of nitrocompds with Raney Ni treated with chloroplatinic acid and with alkali) p)J.A.Grand R.Miller, USP 2555333(1951) CA 45, 7337(1951XUse of Cu chromite as combustion catalyst in solid compressed fuel, such as mixt of NGu 75 GuN 25%) r)Anon, ChemEngrg 1951, June, p 183 (Catalytic process for waste disposal developed by D.V.Moses and put into operation at DuPont s Belle Plant, West Virginia, consists of vapor -phase catalytic destruction of organic wastes by oxidation to C02 H20. It was claimed that the method is more convenient than bio-oxidation... 

A report that hydroxytamoxifen can form quinone methides (QM) as a result of bio-oxidation [151] inspired an electrochemical study of some of the compounds discussed in the structure-activity relationship study ([128, 129], reviewed in [152]). In MeOH medium alone (these compounds are only sparingly soluble in water), the cyclic voltammograms (CV) of most of the compounds exhibited the expected reversible Fc/Fc+ redox couple, often followed by that of the phenolic moiety (where appropriate). However, when an organic base such as pyridine was added, two distinct types of electrochemical behaviour were observed. In the cases of the compounds which showed low or no cytotoxic effects in vitro, very little change in the CV was observed upon the addition of base. However, for the most... 

A managed process that controls the biological decomposition of biodegradable materials into a humus-like substance called compost The aerobic and mesophilic and thermophilic degradation of organic matter to make compost the transformation of biologically decomposable materials through a controlled process of bio-oxidation... 

Mulheim, West Germany [lO] Surface water Ruhr River Ozonation (1) Flocculation Sedimentation Ozonation (2) Filtration GAC filtration Safety chlorination Adsorption of toxic organics A site for bio-oxidation of organics Carbon application 2nd stage of dual stage filter Particle size 0.5—2.5 mm Filter velocity 11—22 m/hr Bed depth 4 m... 

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