Within the limits of this study, it was found that 5 ppm of cobalt was adequate to give good levels of vitamin B(12). The vitamin B(12) precursor 5,6-dimethylbenzimidazole was found to be adequate at 10 ppm in the absence of aeration. In the presence of aeration, a zero level of precursor was found to be most desirable. The analysis of variance showed aeration to be highly significant, and the ...

A laboratory scale aeration treatment system was built to study the fate of nitrogen during aeration of pig slurry. For each run evaluated, the nitrogen mass balance was determined including measurement of the nitrous oxide gas emissions. Intermittent aeration led to a nitrogen removal of about 53% of the total nitrogen content of the raw slurry. About 18% of the total nitrogen content of the r...

Surface transfer and bubble transfer both contribute significantly to oxygen transfer in a diffused aeration system. In the present study, liquid-film-forming apparatus is successfully developed on a laboratory scale to improve considerably the surface transfer via the unique liquid film transfer technique. The experimental results show that the volumetric mass transfer coefficient for liquid-f...

Quantitative analysis of computed tomography (CT) is essential to the study of acute lung injury. However, quantitative CT is made difficult by poor lung aeration, which complicates the critical step of image segmentation. To overcome this obstacle, this study sought to develop and validate a semiautomated, multilandmark, registration-based scheme for lung segmentation that is effective in cond...

with its well-known biological toxicity, the excessive concentrations of sulfide in tannery wastewaters may upset the biological treatment processes, thus leading to a substantial decrease in the efficiency of treatment plants. the presence of sulfide in wastewaters may dramatically interfere with microbial activities and consequently disturb the function of the system as a whole. in this study...

The ability of Aureobasidium pullulans NCYC 4012 to produce gluconic acid (GA) was firstly studied in flask batch cultures and it found that GA productivity not affected by initial glucose concentration, but highest substrate uptake rate observed at concentration 80 g L−1. effect oxygen mass transfer, varied changing agitation aeration rates or total air pressure, evaluated A. stirred tank bior...

−A packed bed external loop airlift bioreactor (PBELAB) was proposed as an alternative treatment system for wastewater containing ammonia and nitrate compounds. The 60L PBELAB consisted of aeration and non-aeration zones, both of which were packed with plastic bioballs to enhance the surface area for the attachment of bacteria. The system was able to achieve complete removal of all nitrogen com...

Aerated, slow-release oxidants are a relatively new technology for treating contaminated aquifers. A critical need advancing this is developing reliable method predicting the radius of influence (ROI) around each drive point. In work, we report series laboratory flow tank experiments and numerical modeling efforts designed to predict release spreading permanganate from aerated oxidant candles (...

Aerated treatment wetlands have become an increasingly recognized technology for treating wastewaters from domestic and various industrial origins. To date, treatment wetland aeration is provided by air pumps which require access to the energy grid. The requirement for electricity increases the ecological footprint of an aerated wetland and limits the application of this technology to areas wit...