[Cultivation of aerobic granular sludge with municipal wastewater and studies on its characteristics under the continuous flow].

The aerobic granular sludge was cultivated successfully in a continuous-flow airlift aerobic granular sludge fluidized bed (CAFB), with low-concentration municipal sewage as the influent and flocculent activated sludge as the seeding sludge. The formation, characteristics and the biological diversity of the aerobic granules in the CAFB were investigated and analyzed. Experimental results showed that many dense and compact granules with diameter of 800-1 000 microm were formed as early as the 6th days operation. At the start-up stage, sludge volume index (SVI) decreased to 35 mL x g(-1), the mixed liquor suspended solid (MLSS) concentration increased to 6000 mg x L(-1), and the mass fraction of extracellular polymeric substances increased significantly. The granules presented a good biological diversity and high biomass contents at the steady running stage. The aerobic granules were basically composed of coccid and bacillus as observed by the scanning electron microscope. A large number of voids and channels were found to be located on the surface of the granules. The removal rate of COD maintained at 70% -75% at the steady stage of CAFB running, and the effluent COD concentrations were 70 mg x L(-1). At the 32nd day of operation, filamentous bacteria grew apparently and sludge bulking happened. Above results showed the CAFB aerobic granules formed rapidly, and performed a good ability on the pollutant removal. However, more work is necessary on the steady running of this novel bioreactor in the future.

[Acoustic analysis of the voice restored by using a tracheoesophageal slit-like fistula].

OBJECTIVE: To evaluate the quality of voice restored by using a tracheoesophageal slit-like fistula objectively through acoustic analysis. METHODS: Seven objective voice parameters (fundamental frequency, intensity, duration, formant F1, F2, F3 and their energy, jitter, and shimmer) of esophageal speech, Blom-Singer prosthesis voice, tracheoesophageal slit-like fistula voice, primary or modified surgical restored, and normal voice were analyzed and compared. RESULTS: T test was used for statistical analysis. The maximum phonation time of slit-like fistula voice was shorter than that of normal voice, longer than that of esophageal voice, no significant difference compared with that of Blom-Singer prosthesis voice. Its sound intensity of it was similar to that of normal voice and Blom-Singer voice, better than that of esophageal voice. Its fundamental frequency was lower than that of normal voice. Its shimmer and jitter was more than that of normal voice, less than that of esophageal voice, and similar to that of Blom-singer one. Compared with esophageal voice, all formants but F1 of it were not statistically different. No statistical difference between the 2 groups of slit-like fistula patients, i.e., the instant slit-like fistula construction after total laryngectomy and the second stage slit-like fistula construction. CONCLUSION: The voice quality of the patients with tracheoesophageal slit-like fistula is similar to that of the normal and could meet the needs of daily life.