城镇污水处理厂对周边大气中温室气体本底浓度的影响

Effect of municipal wastewater treatment plants on atmospheric background concentration of greenhouse gas

针对城镇污水处理厂温室气体排放检测需求,采用双检测器模式,构建了同时检测污水处理厂排放的甲烷(CH_(4))、二氧化碳(CO_(2))和氧化亚氮(N2O)浓度的气相色谱法监测技术,该方法采用HAYESEP Q色谱柱以及FID和μECD检测器对3种温室气体进行定量分析.结果表明:该色谱体系检测CH_(4)、CO_(2)和N_(2)O浓度的精密度相对标准偏差分别为0.217%、0.022%和0.545%,重复性相对标准偏差分别为0.147%、0.052%和0.981%,相关系数r>0.999,满足监测污水处理厂温室气体排放的要求.利用该色谱体系对某大型城镇污水处理厂周边大气进行监测,结果显示该污水处理厂CH_(4)、CO_(2)和N_(2)O的排放浓度均较高,且气体浓度的分布与其处理工艺相关联.

Aiming at the testing requirements of greenhouse gas emission from wastewater treatment plants,a gas chromatography monitoring method for the simultaneous analyses of CH_(4),CO_(2)and N_(2)O was established using dual detector mode.This method quantitatively detected the concentration of three greenhouse gas adopting HAYESEP Q chromatographic column and detector of FID andμECD.The results show that the relative standard deviation(RSD)values of accuracy of CH_(4),CO_(2)and N_(2)O concentration are 0.217%,0.022%and 0.545%respectively,and the relative standard deviation(RSD)values of repeatability are 0.147%,0.052%and 0.981%with correlation coefficient higher than 0.999.The system meets the greenhouse gas emission requirements of wastewater treatment plants.And the monitoring results of the surrounding atmosphere of one municipal wastewater treatment plant display higher emission concentrations of CH_(4),CO_(2)and N_(2)O from wastewater treatment plants and the distribution is closely associated with treatment process.