Department of Environmental Science and Engineering, Anhui University of Technology, Ma'an Shan 243002, China.
Engineering Research Center of Biofilm Water Purification and Utilization Technology, Ministry of Education, Anhui University of Technology, Ma'an Shan 243002, China.
Environ Sci Process Impacts. 2022 Jun 22;24(6):960-972. doi: 10.1039/d2em00071g.
To better understand the impacts of non-carbonic acid (NCAs, including sulfuric, nitric and organic acids) stress on DIC generation during chemical weathering, this study investigated the water chemistry and stable isotope composition (C) from a granitic-hosted watershed at Huangshan UNESCO Global Geopark, China. The results show that the dissolved loads of the watershed are dominated by both silicate and carbonate weathering. As a region with greatly distributed acid soil and high occurrence of acid rain, the evolution of the dissolved loads and C show that DIC generation in carbonate dissolution is promoted by HSO, reduced by HNO and little disturbed by organic acids. The reduction is due to CO release in carbonate weathering by strong nitric acid formed by nitrification in acid soil. New participating proportions of NCAs in rock weathering yielded by the multiple linear regressions between major ions, DIC and C are introduced into calculations of DIC yields. The overestimated DIC yields by silicate and carbonate weathering by NCAs account for about 34% of total DIC yields calculated with the assumption that all carbonates and silicates are dissolved by HCO alone during a year. The results imply that the modifications of DIC generation by NCAs, especially HNO formed in acidic silicate soil, could consequently partly counterbalance the natural CO sink in the granitic-host region.
为了更好地了解非碳酸（包括硫酸、硝酸和有机酸）胁迫对化学风化过程中 DIC 生成的影响，本研究调查了中国黄山世界地质公园一处花岗岩流域的水化学和稳定同位素组成（C）。结果表明，流域的溶解负荷主要由硅酸盐和碳酸盐风化作用所控制。由于酸土分布广泛，酸雨频发，溶解负荷和 C 的演化表明，DIC 的生成受到 HSO 的促进、HNO 的抑制，而有机酸的影响较小。这种抑制作用是由于酸土中硝化作用形成的强硝酸导致碳酸盐风化过程中 CO 的释放所致。通过主要离子、DIC 和 C 之间的多元线性回归，引入了新的 NCAs 在岩石风化中参与比例，以计算 DIC 的产量。非碳酸对硅酸盐和碳酸盐风化产生的 DIC 产量的高估约占假设一年内所有碳酸盐和硅酸盐仅由 HCO 溶解所计算的总 DIC 产量的 34%。这些结果表明，非碳酸对 DIC 生成的影响，特别是酸性硅酸盐土壤中形成的 HNO，可能会部分抵消花岗岩地区的自然 CO 汇。
