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Biomedical subjects

Yi-feng Jiang

Publications and source records attributed to Yi-feng Jiang.

3 recordsLinked to original sources

Determination of operational parameters of anaerobic phase for enhanced phosphorus removal in MBR.

Two runs of experiments were carried out to obtain an understanding of phosphorus release and uptake under the anaerobic condition and then the aerobic condition respectively. Under anaerobic condition, it was found that the extent of phosphorus release appeared to increase with the increase of the initial organic loading rate when the initial organic loading rate was up to 0.1 gSCOD/gMLSS. When the initial organic loading rate was higher than 0.1 gSCOD/gMLSS, the amount of phosphorus release per unit mass of MLSS reached nearly a same stationary value, and it seemed this is not affected by organic loading rate when there is external available substrate remained. In addition, the effect of NOx-N on the phosphorus release and uptake was also investigated, it was proved that the denitrifiers has an advantage over polyphosphate accumulating bacteria in competition for organic substrate under anoxic condition. Therefore, the existence of NOx-N is disadvantageous to the phosphorus release. Based upon the above investigations, the process configuration of membrane bioreactor(MBR) in combination with anaerobic phase was proposed to enhance the removal of phosphorus in treating domestic wastewater. During the experimental period of four months, average removals of 92.50%, 84.25%, 100%, 94.09% and 85.33% were achieved for COD, TP, SS, NH3-N and TN respectively.

Bacteria, Anaerobic↗

Treating both wastewater and excess sludge with an innovative process.

The innovative process consists of biological unit for wastewater treatment and ozonation unit for excess sludge treatment. An aerobic membrane bioreactor (MBR) was used to remove organics and nitrogen, and an anaerobic reactor was added to the biological unit for the release of phosphorus contained at aerobic sludge to enhance the removal of phosphorus. For the excess sludge produced in the MBR, which was fed to ozone contact column and reacted with ozone, then the ozonated sludge was returned to the MBR for further biological treatment. Experimental results showed that this process could remove organics, nitrogen and phosphorus efficiently, and the removals for COD, NH3-N, TN and TP were 93.17%, 97.57%, 82.77% and 79.5%, respectively. Batch test indicated that the specific nitrification rate and specific denitrification rate of the MBR were 1.03 mg NH3-N/(gMLSS x h) and 0.56 mg NOx-N/(gMLSS x h), and denitrification seems to be the rate-limiting step. Under the test conditions, the sludge concentration in the MBR was kept at 5000-6000 mg/L, and the wasted sludge was ozonated at an ozone dosage of 0.10 kgO3/kgSS. During the experimental period of two months, no excess sludge was wasted, and a zero withdrawal of excess sludge was implemented. Through economic analysis, it was found that an additional ozonation operating cost for treatment of both wastewater and excess sludge was only 0.045 RMB Yuan (USD 0.0054)/m3 wastewater.

Bioreactors↗

[The multi-resolution image registration algorithm for digital subtraction angiography].

The proposed registration algorithm based on wavelet transform is a multi-resolution block matching one, which exploits the hierarchical self-similarity of Digital Subtraction Angiography images. This method befittingly trades off between the estimation precision and computational complexity, because the registration precision is from coarse to fine, which reduces the searching complexity of motion vector. This technique has been proved that the convergence speed is exponential. The proposed method takes full advantage of the precise location both temporally and frequently which characterizes the wavelet transform. Both the matching speed and consistency are boosted without the loss of matching performance.

Algorithms↗