Biology Centre CAS, Institute of Hydrobiology, Na Sádkách 7, 37005 České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic.
Biology Centre CAS, Institute of Hydrobiology, Na Sádkách 7, 37005 České Budějovice, Czech Republic.
Water Res. 2016 Oct 15;103:30-37. doi: 10.1016/j.watres.2016.07.017. Epub 2016 Jul 11.
Using statistical relationships between the composition of precipitation at eight long-term monitoring stations and emission rates of sulphur (S) and nitrogen (N) compounds, as well as industrial dust in the Czech Republic and Slovakia (Central Europe), we modelled historic pH and concentrations of sulphate (SO4(2-)), nitrate (NO3(-)), ammonium (NH4(+)), chloride (Cl(-)), base cations (BC), and bicarbonate (HCO3(-)) in bulk precipitation from 1850 to 2013. Our model suggests that concentrations of SO4(2-), NO3(-), and HCO3(-) were similar (11-16 μeq l(-1)) in 1850. Cations were dominated by NH4(+) and BC (24-27 μeq l(-1)) and precipitation pH was >5.6. The carbonate buffering system was depleted around 1920 and precipitation further acidified at an exponential rate until the 1980s, when concentrations of SO4(2-), NO3(-), Cl(-), NH4(+) and BC reached maxima of 126, 55, 16, 76, and 57 μeq l(-1), respectively, and pH decreased to 4.2. Dust emissions from industrial sources were an important source of BC. Without their contribution, pH would have decreased to 4.0 in the 1980s, and the carbonate buffering system would have been depleted already in the 1870s. Since the late 1980s, concentrations of strong acid anions and BC have decreased by 46-81% (i.e. more than in Europe on average) due to a 53-93% reduction in regional emissions of S and N compounds and dust from industrial and agricultural sources. The present composition of precipitation is similar to the late 19th century, except for NO3(-) concentrations, which are similar to those during 1926-1950. Precipitation pH now exceeds 5.0, the carbonate buffering system has been re-established, and HCO3(-) has again become (after almost a century) a significant component of precipitation chemistry.
利用在捷克共和国和斯洛伐克（中欧）的 8 个长期监测站的降水成分与硫（S）和氮（N）化合物以及工业粉尘排放量之间的统计关系，我们模拟了从 1850 年到 2013 年期间降水中 pH 值和硫酸盐（SO4(2-)）、硝酸盐（NO3(-)）、铵（NH4(+)）、氯（Cl(-)）、碱基阳离子（BC）和重碳酸盐（HCO3(-)）浓度的历史变化。我们的模型表明，1850 年时 SO4(2-)、NO3(-) 和 HCO3(-) 的浓度相似（11-16 μeq l(-1)）。阳离子主要由 NH4(+) 和 BC（24-27 μeq l(-1)）组成，降水 pH 值大于 5.6。大约在 1920 年，碳酸盐缓冲系统被耗尽，降水进一步以指数速率酸化，直到 20 世纪 80 年代，SO4(2-)、NO3(-)、Cl(-)、NH4(+) 和 BC 的浓度分别达到 126、55、16、76 和 57 μeq l(-1)的最大值，pH 值降至 4.2。来自工业源的粉尘排放是 BC 的重要来源。如果没有它们的贡献，降水的 pH 值在 20 世纪 80 年代就会降至 4.0，而且碳酸盐缓冲系统在 19 世纪 70 年代就已经耗尽。自 20 世纪 80 年代末以来，由于 S 和 N 化合物以及工业和农业源粉尘的区域排放量减少了 53-93%，强酸性阴离子和 BC 的浓度下降了 46-81%（即超过了欧洲的平均水平）。目前的降水成分与 19 世纪后期相似，只是 NO3(-)浓度与 1926-1950 年期间相似。降水 pH 值现在超过 5.0，碳酸盐缓冲系统已经重建，HCO3(-)在近一个世纪后再次成为降水化学的重要组成部分。
