Ionic Composition in Aqueous Extracts from PM2.5 in Ambient Air at the City of Cuernavaca,Mexico  

作　　者：Hugo Saldarriaga-Norena Leonel Hernandez-Mena Enrique Sanchez-Salinas Fernando Ramos-Quintana Laura Ortiz-Hernandez Rodrigo Morales-Cueto Vanesa Alarcon-Gonzalez Sandra Ramirez-Jimenez 

机构地区：[1]Chemical Research Center,Autonomous University of the Morelos State,Cuernavaca,Mexico [2]Center for Research and Assistance in Technology and Design of the State of Jalisco,Guadalajara,Mexico [3]Biotechnology Research Center,Autonomous University of the Morelos State,Cuernavaca,Mexico

出　　处：《Journal of Environmental Protection》2014年第13期1305-1315,共11页环境保护（英文）

基　　金：National Council for Science and Technology(CONACyT,for its acronym in English)for the financial support in this project.

摘　　要：The present study was carried out between May and June 2012 in the city of Cuernavaca, Mexico. During this time the average ambient temperatures were about 25°C, suggesting the formation of secondary aerosols, consisting mainly of ammonium and sulfate. The average PM2.5 concentration was 37 μg·m-3 for the entire urban area and there were only two days which exceeded the limit established by the official standards for periods of 24 h. The most abundant ionic species associated with PM2.5 were sulfates (3634.82 ng·m-3, average) and ammonium (1709.53 ng·m-3, average). The ratio estimated between total anions and total cations indicated that the concentration of total anions was 1.94 times total cations. The contribution percentage of the ionic species associated with PM2.5 revealed that 76% of the PM2.5 is sulfates and ammonium. The ion balance made for the urban area of Cuernavaca indicated that during the study period, the aerosols showed alkaline characteristics;that is to say the concentration of anions was not sufficient to neutralize the cations, specifically ammonia (m = 0.060). Finally, wind fields showed that during the study the winds came in 50% from the south west, followed by 25% from east and 12.5% of the south east, which in part allowed transport of contaminants into the portion of the city, where the AUSM campus site was located.The present study was carried out between May and June 2012 in the city of Cuernavaca, Mexico. During this time the average ambient temperatures were about 25°C, suggesting the formation of secondary aerosols, consisting mainly of ammonium and sulfate. The average PM2.5 concentration was 37 μg·m-3 for the entire urban area and there were only two days which exceeded the limit established by the official standards for periods of 24 h. The most abundant ionic species associated with PM2.5 were sulfates (3634.82 ng·m-3, average) and ammonium (1709.53 ng·m-3, average). The ratio estimated between total anions and total cations indicated that the concentration of total anions was 1.94 times total cations. The contribution percentage of the ionic species associated with PM2.5 revealed that 76% of the PM2.5 is sulfates and ammonium. The ion balance made for the urban area of Cuernavaca indicated that during the study period, the aerosols showed alkaline characteristics;that is to say the concentration of anions was not sufficient to neutralize the cations, specifically ammonia (m = 0.060). Finally, wind fields showed that during the study the winds came in 50% from the south west, followed by 25% from east and 12.5% of the south east, which in part allowed transport of contaminants into the portion of the city, where the AUSM campus site was located.

关 键 词：Ionic species Cuernavaca Ion Balance 

分 类 号：R73[医药卫生—肿瘤]