Study of the sludge reduction in an oxic-settling-anaerobic activated sludge process based on UNITANK

An oxic-settling-anaerobic process (OSA) can effectively reduce sludge production, but most of the research studies on the OSA process have been either under laboratory test conditions or based on synthetic wastewater, which cannot fully reflect the performance and sludge reduction efficiency in existing OSA process. Thus, aiming at examining the sludge reduction efficiency and the stability of the OSA process, UNITANK and UNITANK-OSA processes were performed in a 120 m(3)/d pilot-scale system using actual sewage. The results indicate that UNITANK-OSA achieved a 48% reduction of the sludge compared to the reduction due to UNITANK, not considering the accumulation of the effluent-suspended solids. The effluent quality was not found to change significantly, except that the total phosphorus concentration increased slightly. The extracellular polymeric substances metal floc theory may, to some extent, explain this reduction in this study. The OSA process could be used to reform the classic wastewater treatment process to get lower sludge mass.

[Visual symptoms of sellar tumors: a report of 407 cases]

The common primary symptoms of sellar tumors are visual impairment and field defects associated with the anatomic relationship between the sella turcica and the visual route, and the patients often consult the oculist first. The authors reviewed 407 cases of sellar tumors at their hospital during the recent 10 years and analyzed the characteristics of these patients to present the general clinical patterns and main points for diagnosis of this disease.

Improved myocardial protection by antegrade perfusion in combination with coronary sinus occlusion in the presence of left anterior descending artery obstruction

The present study was undertaken to evaluate the improved protection of antegrade aortic root perfusion combined with intermittent coronary sinus occlusion (APCSO) for the 1-hour ischemic myocardium in the presence of left anterior descending artery occlusion, 12 dogs were divided into 2 groups: anteperfusion (AP) alone (n = 6) and APCSO (n = 6). The experimental results showed that APCSO provided a better cardioplegic distribution and a lower hypothermia (15.6 degrees C versus 17.2 degrees C) in the occluded LAD region, compared with AP. After ischemia, cardiac index and left ventricular stroke index recovered excellently in APCSO (128% to 141% and 115% to 158% of preischemic values, respectively), and much worse in AP (69% to 82% and 53% to 73% of preischemic values, respectively). Our study has confirmed that APCSO is superior to AP in myocardial protection in the presence of coronary artery occlusion.