城市污水处理厂甲烷排放研究——以芜湖市为例

Study on Methane Emission from Wastewater Treatment Plants—A Case Study of Wuhu City

人类活动造成的温室气体排放被认为是导致全球气候变暖的主要原因之一,甲烷(CH4)在其中的作用仅次于二氧化碳,而污水处理厂则是重要的甲烷排放源之一。为了解中小城市污水处理厂的CH4排放特征及其控制因素,对芜湖市污水处理厂CH4排放通量进行观测研究,并利用IPCC推荐的方法对其甲烷年排放通量进行了初步估算。结果表明:1) 芜湖市污水处理厂的CH4排放速率在517.28~1,075.26 mg/(m2•h)之间,具有一定的时空变异特征,具体表现为:时间上,CH4排放峰值出现在11月份;空间上,污水处理厂进水口的CH4排放速率显著高于其他构筑物。2) 污水处理厂甲烷排放速率的主要影响因素为水体pH、总磷和总氮含量。3) 根据实测法估算得出芜湖市污水处理厂甲烷年排放量为46,583.83 kg,比IPCC推荐方法的估算值高46.71%。

Greenhouse gas caused by human activities is considered to be one of the main causes of global warming. The influence of methane (CH4) is second only to that of carbon dioxide. Wastewater treatment plants are one of the important sources of methane emissions. In order to explore the features and influencing factors of CH4 emission from wastewater treatment plants in small-medium cities, the study observed and estimated the CH4 emission flux of Wuhu wastewater treatment plants. The annual methane emission flux of the wastewater treatment plant was estimated by the method recommended by IPCC. The results show that: 1) The CH4 emission rate of the wastewater treatment plants ranged from 517.28 to 1,075.26 mg/(m2∙h) with a certain temporal and spatial variation. In time, CH4 emission peak appeared in November;in space, the CH4 emission rate at the inlet of wastewater treatment plant was significantly higher than that of other structures. 2) The main influencing factors of methane emission rate in wastewater treatment plant were water quality factors, including pH, total phosphorus and total nitrogen in water. 3) The annual methane emission from wastewater treatment plants in Wuhu City estimated by the measured value was 46,583.83 kg, which was 46.71% higher than that estimated by IPCC algorithm.