Study On The Simulations Of Gas-liquid Flow And Starting Performance In Improved UASB

In this work, some problems in the Up-flow Anaerobic Sludge Blanket Reactor (UASB) were analyzed, and combined with Air-lift Loop Reactor (referred to as ALR) and Anaerobic Internal Circulation Reactor (IC) principles, improved the structure of the UASB, and researched the modified mechanism. The article took the continuous operation test of the hydrodynamic behavior and treatment of organic wastewater as major investigative carrier, and discussed the flow behavior of the reactor and operating characteristics. The new reactor could create self-circulation of the liquid, take high volumetric loading rate, and have high stability to resist the shock load.Taking the air-PAM solution system as the research object, this article carried out flow behavior in the reactor and discussed its theorization. The experimental results demonstrate that for the air-PAM solution system, the average gas holdup,local gas holdup and circulating fluid volume diameter liquid viscosity, but when the liquid PAM concentration reaches 0.009 percent, the average gas holdup began to decline and the increasing trend down; When the liquid PAM concentration is less than 0.007 percent, the local gas holdup increases relatively flat with the simulation gas, when the PAM concentration was increased to 0.009 percent, simulation gas is greater than 0.3L/min, the increasing tendency strengthen of the local gas holdup with the increase of simulation gas. The hydrodynamic model of reaction zone local gas holdup and liquid circulation velocity is established by the experimental result.In this study, glucose water was regarded as water in the start-up phase,75 days continuous operation, volumetric loading increased from 1.68±0.09kgCOD/m3·d gradually to 6.72±0.99kgCOD/m3·d, the reactor operation state is relatively stable, the average COD removal came to 81.06 percent during the operation. When the volumetric loading reached 5.16±0.47kgCOD/m3·d, a self-cyclical phenomenon could be seen in the reactor. When the reactor run 37 days, granular sludge formed at the bottom of the reactor, the vast majority of granular sludge is spherical, and have good settle ability, sludge granulation improved operating performance of anaerobic reactor. Besides, in this work, the stability of the reactor was investigated by impact test. Volumetric loading increased 6.72±0.99kgCOD/m3·d to 8.74±0.96kgCOD/m3·d (increase of 30 percent) in the load impact test, then COD removal rate decreased from 88.45% to 76.67%, however the reactor could keep operated normally; In the pH impact test, adjusting the influent pH=5 and pH=6, reactor effluent pH could quickly return to normal, and COD removal rate was only modestly lower. The result indicates that the testing equipment had a good operational stability.