[Non-CO Greenhouse Gas Release from Different Biological Wastewater Treatment Processes].

Methane (CH) and nitrous oxide (NO) are two of the most important non-CO greenhouse gases. And municipal sewage treatment plant is an important anthropogenic source of CH and NO. Therefore, it is essential to measure the production and emission of CH and NO during biological wastewater treatment process. The surface emission flux isolation chamber was employed to collect the gas sample from the Xi'an No.3 WWTP (the Orbal oxidation ditch process) and Xi'an NO.4 WWTP (A/A/O process) to determine the contents of methane and nitrous oxide. And the effects of temperature and dissolved oxygen concentration on non-CO greenhouse gases emission from Xi'an NO.4 WWTP were discussed. The results showed that methane and nitrous oxide emission factors from No.3 WWTP were 1181 mg CH per m influent and 36.20 mg NO per m influent, respectively while those from the No.4 WWTP were 209 mg CH per m influent and 54.64 mg NO per m influent. In addition, the important influencing factors which affected methane and nitrous oxide emission were temperature, aeration strategy, DO, nitrite oxidation rate and specific methanogenic activity.