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 ...

This study presents a rapid method on how to speed up aerobic granular sludge (AGS) cultivation and ensure excellent stable removal performance during bioreactor operation for domestic wastewater treatment. new strategy consists of start-up the using only anaerobic (AnGS) as seed feeding with crude sewage extracted from full-scale Extended Aeration Plant. experiment used 2.5 L lab-scale sequenc...

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...

Wastewater treatment is an energy-intensive process for treating liquid-phase pollutants in urban settlements. The aerobic processes of the biological involve a significant air demand. An optimal control strategy could be used to minimize amount excess entering system due safety factors applied design procedures. A plant-wide mechanistic modeling approach including activated sludge model and on...

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...

This study evaluated the effects of aeration (constant aeration, intermittent aeration and a lack of aeration) and hydraulic retention time (HRT) (2, 3 and 4 days) on a continuous process with cell recycling, using chitosan as a natural coagulant for the sedimentation of a C1 mixed culture. This culture was used for the biodegradation of hydrocarbons present in the effluent contaminated with di...

A model of the concentrations of suspended solids (SS) in the aeration tanks and in the effluent from these during Aeration tank settling (ATS) operation is established. The model is based on simple SS mass balances, a model of the sludge settling and a simple model of how the SS concentration in the effluent from the aeration tanks depends on the actual concentrations in the tanks and the slud...

A full scale swine (300 pigs) waste treatment system, including a solid/liquid separation unit (3 m) with a solids holding tank (1.2 m) and a liquid holding tank (20 m), two anaerobic reactors (10 m each) in series, an intermittent aeration unit (20 m), a sedimentation/polishing unit (20 m) and a sludge dewatering bed (17 m), was used to investigate the impact of integrating an intermittent aer...