Aerobic oxidation, effluents

Purification of effluents with high organic content takes place in two main steps anaerobic reduction and aerobic oxidation causing mineralization of the organic products. Azo... 

Clearly catalytic systems operating under neutral conditions and moderate temperatures and pressures are desirable both from an environmental and economic viewpoint. A new generation of supported reagents that will efficiently promote aerobic oxidation has been developed [26]. They can be used on an industrial scale in place of traditional oxidants, without the production of effluent or byproducts, and have the great advantage of being genuinely catalytic. An example where these catalysts may be effectively utilised is in the production of benzophenones. The... 

The changes in DO concentration can be clearly seen from the data in Figure 5. The DO concentrations in the influent wastewater were about 0.3mg/L. DO concentrations in the effluents were, however, more than ten times higher than the corresponding values in the influent. This result indicates that the natural air draft system supplies in the aerobic tank with sufficient oxygen for the biochemical oxidation. 

Many wastewater flows in industry can not be treated by standard aerobic or anaerobic treatment methods due to the presence of relatively low concentration of toxic pollutants. Ozone can be used as a pretreatment step for the selective oxidation of these toxic pollutants. Due to the high costs of ozone it is important to minimise the loss of ozone due to reaction of ozone with non-toxic easily biodegradable compounds, ozone decay and discharge of ozone with the effluent from the ozone reactor. By means of a mathematical model, set up for a plug flow reactor and a continuos flow stirred tank reactor, it is possible to calculate more quantitatively the efficiency of the ozone use, independent of reaction kinetics, mass transfer rates of ozone and reactor type. The model predicts that the oxidation process is most efficiently realised by application of a plug flow reactor instead of a continuous flow stirred tank reactor. 

This paper reports on a laboratory study to evaluate the capability of bio-contact oxidation to treat oil field wastewater. Aerobic, up flow, submerged biofilm are used to degrade oil with low N and P compoimds imder low COD load and high salinity condition. The influent and effluent streams were sampled, and then analyzed to indicate the percentage removed of oil and COD concentration. The effeets of three hio-eontact oxidation systems with different microorganisms were compared. Finally, a prototype hio-treatment is proposed for oil field wastewater pre-treatment to meet the standards required hy desalination membrane equipment. 

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