2017年深圳市龙岗区和南山区大气环境空气PM_(2.5)中铵离子分布特征

Distribution characteristics of ammonium ion in ambient air PM_(2.5) of Longgang District and Nanshan District of Shenzhen City in 2017

目的了解深圳市龙岗区和南山区大气细颗粒物质量浓度与铵离子浓度特征。方法采集2017年1—12月间深圳市龙岗区和南山区的大气细颗粒物(PM_(2.5)),共171份,采用差重法测定PM_(2.5)浓度,采用超声提取-离子色谱仪法测定铵离子的浓度。结果 2017年深圳市龙岗区和南山区PM_(2.5)浓度范围在30.7～115.0μg/m^3,中位值是59.7μg/m^3,龙岗区PM_(2.5)平均浓度低于南山区,差异有统计学意义(t=3.06,P<0.01);所有PM_(2.5)样品中均检出了铵离子,含量在0.02～11.28μg/m^3之间,平均浓度为2.47μg/m^3。龙岗区和南山区两区PM_(2.5)中铵离子平均浓度比较差异有统计学意义(t=2.54,P<0.05),龙岗区高于南山区。结论 2017年深圳市龙岗区PM_(2.5)平均浓度低于南山区,但其PM_(2.5)中铵离子平均浓度高于南山区,提示两地空气雾霾的成分有所差别,导致空气污染的雾霾来源不同。铵离子浓度与空气雾霾严重程度并无相关关系;两区大气中PM_(2.5)浓度总体水平高于WHO及我国空气质量标准,提示政府应该采取有效措施来降低两区的PM_(2.5)水平。

[Objective]To study the mass concentration of fine particulate matter（PM2.5） and concentration characteristics of ammonium ion of Shenzhen City. [Methods] A total of 171 PM2.5 samples were collected in Longgang District and Nanshan District of Shenzhen City from January to December of 2017. The mass concentration of PM2.5 was analyzed by gravimetric method,and the concentration of ammonium ion was analyzed by ultrasonic extraction-ion chromatograph. [Results] The concentration range of PM2.5 in Shenzhen City in 2017 was 30.7-115.0 μg/m^3,with the median value of 59.7 μg/m^3. There was statistically significant difference in the average concentration of PM2.5 between two districts（t=3.06,P〈0.01）,and the average concentration of PM2.5 in Longgang District was lower than that in Nanshan District. Ammonium ions were detected in all the samples of PM2.5,the concentration range was 0.02-11.28 μg/m^3,with the average concentration of 2.47 μg/m^3. The difference in average concentration of ammonium ion in PM2.5 was statistically significant between Longgang District and Nanshan District（t=2.54,P〈0.01）,and the concentration in Longgang District was higher than that in Nanshan District. [Conclusion] The average concentration of PM2.5 in Longgang District is higher than that in Nanshan District in 2017,while the average concentration of ammonium ions in PM2.5 is higher than that in Nanshan District,which indicates the composition of air haze is different and source of haze resulting in air pollution is different. There is no correlation between the concentration of ammonium ion and haze severity.The general level of PM2.5 concentration in two districts is higher than those air quality standards in both WHO and China. It suggests that the government should take more effective measures to reduce PM2.5 level.