The Operating Characteristics of Partial Nitrification by Controlling pH and Alkalinity

In many experiments, a partial nitrification device is initiated with the use of highly active nitrating sludge because large number nitrifying bacteria. Ammonia-oxidizing bacteria (AOB) are more adaptable to low-dissolved oxygen environments than nitrite-oxidizing (NOB). NOB activity was inhibited when dissolved (DO) levels were decreased, causing nitrate-nitrogen concentration gradually decrease in effluent and nitrite-nitrogen increase, achieving accumulation nitrous nitrogen. this experiment, sequencing batch reactor (SBR) used suppress at given pH while maintaining DO very low level so that ammonia–water reaction mainly occurred device, then mud water separated. Compared other approach can occur 25 days, it runs stably for two months until closes ammonia-nitrogen about 170 mg/L. This experiment also compared difference between change beginning operation after stable. order increase efficiency bacterial appreciation, supplementing NaHCO3 increased HCO3? by 300 mg/L on 25th day. It found some reactions still occurred, but they not enough destabilize device. The nitrosate increased, average nitrite 87.25% supplementation.