Aeration method

Depending on the hole depth, the entire procedure requires 2 to 6 hr. Holes of over 11,000 ft have been successfully unloaded using the aeration method. A well can be dusted, mist-drilled, dried up and returned to dust drilling. To dry a hole properly, it is important that it be kept clean. Drying agents have been tried but without much success. The best drying agent available at the present lime is the formation itself. 

The tray aeration method is a simple, low-maintenance method of aeration that does not use forced air.19 Water is allowed to cascade through several layers of slat trays to increase the exposed surface area for contact with air (Figure 18.9). Tray aeration is capable of removing 10 to 90% of some VOCs, with a usual efficiency of between 40 and 60%.53 This method cannot be used where low effluent concentrations are required, but could be a cost-effective method for reducing a certain amount of VOC concentration prior to activated carbon treatment. 

The spray aeration method comprises a grid network of piping and nozzles over a pond or basin. Contaminated water is simply sprayed through the nozzles and into the air to form droplets. Mass transfer of the contaminant takes place across the air-water surface of the droplets. Mass transfer efficiency can be increased by multiple passing of the water through the nozzles. This method has three disadvantages ... 

Burgess, R.M., Pelletier, M.C., Ho, K.T., Serbst, J.R., Ryba, S.A., Kuhn, A., Perron, M.M., Raczelowski, P. and Cantwell, M.G. (2003) Removal of ammonia toxicity in marine sediment TIEs a comparison of Ulva lactuca, zeolite and aeration methods, Marine Pollution Bulletin 46, 607-618. 

Aeration. Among the first of the aeration methods was that of Folin (F4, F5), who devised a technique whereby body fluid, such as blood, was alkalinized and the ammonia aerated into an acid solution. 

Different aeration methods have been employed in animal cell culture ... 

The aeration method most widely used in animal cell cultures is bubble aeration, just as in microbial fermentations. This method is simple and consists of bubbling a gas stream directly into the culture medium, using a... 

Many other household products can be analysed in similar ways to those described above for chemicals. Household bleach is essentially an inorganic chemical. There has been concern expressed about mercury levels in hypochlorite bleach because of the way it is manufactured. The cold vapour reduction/aeration method referred to above is a good way of determining low mercury levels with minimal matrix problems [82]. In the past organo-mercurial compounds have been used (e.g. as bactericides) in some household products these may be selectively determined by extraction with an organic solvent (e.g. carbon tetrachloride or benzene), and then application of the cold-vapour method following the addition of cysteine acetate, or by coupled gas chromatography/atomic absorption [83],... 

Only mercury and the noble gases are commonly encountered as atoms in the gaseous state. This property of mercury is commonly exploited in the cold vapour, reduction-aeration method described elsewhere in this text. Monitors for mercury vapour are commercially available which consist... 

A modified reduction-aeration method to analyse mercury in environmental water samples is described. After aeration of the sample, the mercury is pre-concentrated on gold-coated sand which is then analysed by thermal desorption and cold vapour atomic absorption spectrometry (CVAAS). When applying reduction-cells of volumes up to 1 1, limits of detection as low as 1 ng.r are obtained. The method avoids matrix-effects caused by complexing agents such as Cl and 1, which interfere in the direct measurement of mercury by common CVAAS-techniques. The method was applied to dty drinking-water. Mercury levels ranging from less than 1 ng.l" to 10 ng.T were found. 

The sohd-state fermentation for cellulase production is an aerobic process therefore, aeration is necessary for cell growth and cellulase formation. In addition, aeration is important in order to maintain humidity, to remove gaseous metabolites, such as COj, as well as to remove the heat of metabolism [42,43]. In a large-scale solid-state fermentor, aeration is so important that it must be controlled carefully. The aeration method and the flow rate as well as the temperature and humidity of the air supply must be regulated to avoid sudden changes in temperature and water activity of the solid medium [29,31]. 

Kimura, Y, and Miller. V.L (1962) Mercury determination at the microgram level by reduction-aeration method of concentration. Anal. Chim. Acta 27. 325-331. 

Moreira JL, Cmz PE, Santana PC, Feliciano AS, Lehmann J, Carrondo MJT. (1995) Influence of power input and aeration method on mass transfer in a laboratory animal cell culture vessel. J. Chem. Technol. Biotechnol., 62 118-131. 

Oxygen-based MBfRs can be used for removal of xenobiotic compounds. They are especially suitable for oxidation of VOCs that would otherwise be stripped to the air using conventional aeration methods. The use of MBfRs for degradation of xenobiotics is discussed in Section 20.5 of this chapter. 

---