Influence of peat fires on the rainwater chemistry in intra-mountain basins with specific atmospheric circulations (Eastern Carpathians, Romania)

Róbert Szép; Zsolt Bodor; Ildikó Miklóssy; Ion-Andrei Niță; Oana A Oprea; Ágnes Keresztesi

doi:10.1016/j.scitotenv.2018.07.462

Influence of peat fires on the rainwater chemistry in intra-mountain basins with specific atmospheric circulations (Eastern Carpathians, Romania)

Sci Total Environ. 2019 Jan 10:647:275-289. doi: 10.1016/j.scitotenv.2018.07.462. Epub 2018 Aug 2.

Authors

Róbert Szép¹, Zsolt Bodor², Ildikó Miklóssy², Ion-Andrei Niță³, Oana A Oprea³, Ágnes Keresztesi⁴

Affiliations

¹ Sapientia Hungarian University of Transylvania, Faculty of Economics, Socio - Human Science and Engineering, Department of Bioengineering, Piaţa Libertăţii 1, ZIP 530104 Miercurea Ciuc, Romania; University of Pécs, Faculty of Natural Sciences, Doctoral School of Chemistry, Ifjúság 6, ZIP 7624 Pécs, Hungary.
² Sapientia Hungarian University of Transylvania, Faculty of Economics, Socio - Human Science and Engineering, Department of Bioengineering, Piaţa Libertăţii 1, ZIP 530104 Miercurea Ciuc, Romania.
³ National Meteorology Administration, Soseaua București-Ploiești 97, District 1, ZIP 013686 Bucharest, Romania.
⁴ Sapientia Hungarian University of Transylvania, Faculty of Economics, Socio - Human Science and Engineering, Department of Bioengineering, Piaţa Libertăţii 1, ZIP 530104 Miercurea Ciuc, Romania; University of Pécs, Faculty of Natural Sciences, Doctoral School of Chemistry, Ifjúság 6, ZIP 7624 Pécs, Hungary. Electronic address: keresztesiagnes@uni.sapientia.ro.

PMID: 30081365
DOI: 10.1016/j.scitotenv.2018.07.462

Abstract

A comprehensive study on the chemical composition of precipitation, the influence of peat fires and their relations with atmospheric circulation was conducted in the year of 2012, in two intra-mountain basins, the Ciuc basin (CB) and the Giurgeu basin (GB), Eastern Carpathians, Romania. Atmospheric circulation types showed the presence of a westerly anticyclonic circulation, characterized by a strong development of the Azores High to the northern Atlantic, contributing to the appearance of peat-fires. Using ROCADA daily gridded climatic datasets, the maximum and minimum daily temperatures were extracted, showing deviation from 2 °C to 6 °C in the studied year against the multiannual mean for the 1981-2016 period. Rainwater samples were analyzed for pH, major anions and cations; HCO₃^- concentrations were calculated based on the empirical relationship between pH and HCO₃^-. The results showed that 45.16% and 54.55% of precipitation had pH > 7.0 at CB and GB, respectively. NH₃, NH₄⁺ and Ca²⁺ are the main neutralizing agents. The significant correlation between SO₄^2- and NH₄⁺ (r = 0.711 - CB; r = 0.736 - GB) indicated neutralization by NH₃ in the forms of (NH4)₂SO₄ and NH₄HSO₄. Positive regression coefficient between the sum of (H⁺ + [NH₄⁺] + [Ca²⁺]) and the sum of ([nss - SO₄^2-] + [NO₃^-]) (r = 0.855 - CB; r = 0.796 - GB), showed that acid neutralization was primarily brought by NH₄⁺ and/or CaCO₃. Using Na as an indicator of marine origin, the proportions of sea salt and non-sea-salt were estimated from elemental ratios. According to correlation analysis and PCA, main acidic ions (SO₄^2- and NO₃^-) and NH₄⁺ were mainly derived from anthropogenic activities (biomass burning, peat fires, fertilization), while Ca²⁺ and Mg²⁺ originated from terrestrial sources. The behavior of gaseous pollutants and smoke distribution resulted from peat fires were deciphered using the HYSPLIT model in a case study.

Keywords: Atmospheric circulation; Long-range transport; Peat fire; Rainwater chemistry; Varimax rotated factor analysis; Wet and dry deposition.