Departamento de Engenharia Ambiental (DAM), Universidade Federal de Lavras (UFLA), Av. Sylvio Menicucci 1001, Campus da UFLA, Lavras, Minas Gerais, 37200-000, Brazil.
Departamento de Ciências Atmosféricas, Instituto de Astronomia, Geofísica e Ciências (IAG), Atmosféricas da Universidade de São Paulo (USP), Rua do Matão, 1226, Cidade, Universitária, São Paulo, SP, 05508-090, Brazil.
Environ Sci Pollut Res Int. 2021 May;28(18):23448-23458. doi: 10.1007/s11356-020-12317-3. Epub 2021 Jan 14.
Since 2000s, several studies have been reporting an increase of alkaline species in atmospheric deposition worldwide. This study aims to evaluate and give a better understanding about atmospheric deposition chemistry collected in Lavras, a Brazilian city with rural background. Bulk atmospheric deposition samples were collected from March 2018 to February 2019 and major ionic species were quantified. The pH values ranged from 5.52 to 8.29, with an average of 5.92 and most deposition samples (~ 94%) were alkaline (pH > 5.60). For the whole sampling campaign, the ions profile in volume weighted mean (VWM) was described as follows: Ca (35.02) > NH (11.26) > Cl (11.19) > Mg (9.04) > NO (8.57) > Na (5.65) > K (2.61) > SO (2.43) > H (0.94) μmol L. We identified Ca and NH as the most predominant species accounting for 53% of the total ionic species distribution. In addition, all samples showed neutralization factor (NF) index greater than 1, with mean value of 6.4. Regarding regression analysis, acidity neutralization precursors such as calcium and ammonia accounted for 50% and 4%, respectively. In addition, samples alkaline pattern was mainly due to agricultural sources, including fertilizer production and application, and cement manufacturing inside the county air basin.
自 21 世纪初以来，已有多项研究报告称，全球大气沉积中的碱性物质有所增加。本研究旨在评估并更好地了解巴西拉瓦拉斯市大气沉积化学物质，该市具有农村背景。从 2018 年 3 月到 2019 年 2 月，采集了大量的大气沉积样本，并对主要的离子物质进行了定量分析。pH 值范围为 5.52 到 8.29，平均值为 5.92，且大部分（约 94%）的沉积样本呈碱性（pH>5.60）。在整个采样期间，按体积加权平均值（VWM）得出的离子特征如下：Ca（35.02）>NH（11.26）>Cl（11.19）>Mg（9.04）>NO（8.57）>Na（5.65）>K（2.61）>SO（2.43）>H（0.94）μmol/L。我们确定 Ca 和 NH 是最主要的两种物质，占总离子物质分布的 53%。此外，所有样本的中和因子（NF）指数均大于 1，平均值为 6.4。就回归分析而言，钙和氨等酸度中和前体分别占 50%和 4%。此外，样本的碱性模式主要归因于农业来源，包括县空气盆地内的肥料生产和应用以及水泥制造。
