Cho Youngil, Driscoll Charles T, Blum Joel D
Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY 13244, USA.
Sci Total Environ. 2009 Oct 1;407(20):5392-401. doi: 10.1016/j.scitotenv.2009.06.030. Epub 2009 Jul 28.
Patterns of storm runoff chemistry from a wollastonite (calcium-silicate mineral, CaSiO(3)) treated watershed (W1) were compared with a reference watershed (W6) at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire (NH), USA to investigate the role of Ca(2+) supply in the acid-base status of stream chemistry. In the summer of 2003, six storm events were studied in W1 and W6 to evaluate the effects of the wollastonite treatment on the episodic acidification of stream waters. Although mean values of Ca(2+) concentrations decreased slightly from 33.8 to 31.7 mumol/L with increasing stream discharge in W1 during the events, the mean value of acid neutralizing capacity (ANC) was positive (1.2 mueq/L) during storm events, compared to negative values (-0.2 mueq/L) in W6. This pattern is presumably due to enhanced Ca(2+) supply in W1 (20.7 to 29.0% of dissolved Ca(2+) derived from the added wollastonite) to stream water as a result of interflow along shallow flowpaths. In addition, the application of wollastonite increased pH and dissolved silica (H(4)SiO(4)) concentrations, and decreased the concentration of inorganic monomeric Al (Al(i)) in W1 in comparison with W6 during storm events. Despite an increase in SO(4)(2-) concentration, likely due to desorption of sulfate from soil after the treatment, the watershed showed an increase in ANC compared to the reference watershed, serving to mitigate episodic acidification.
在美国新罕布什尔州（NH）哈伯德布鲁克实验森林（HBEF），将硅灰石（硅酸钙矿物，CaSiO₃）处理流域（W1）的暴雨径流化学模式与参考流域（W6）进行比较，以研究Ca²⁺供应在溪流化学酸碱状况中的作用。2003年夏季，在W1和W6研究了6次暴雨事件，以评估硅灰石处理对溪流水体突发性酸化的影响。尽管在这些事件期间，W1中Ca²⁺浓度的平均值随着溪流流量增加从33.8微摩尔/升略有下降至31.7微摩尔/升，但暴雨事件期间酸中和能力（ANC）的平均值为正值（1.2微当量/升），而W6中的值为负值（-0.2微当量/升）。这种模式可能是由于W1中Ca²⁺供应增加（溶解的Ca²⁺中有20.7%至29.0%来自添加的硅灰石），这是浅层流路中壤中流导致的。此外，与W6相比，暴雨事件期间硅灰石的施用提高了W1的pH值和溶解二氧化硅（H₄SiO₄）浓度，并降低了无机单体铝（Al(i)）的浓度。尽管SO₄²⁻浓度有所增加，可能是由于处理后土壤中硫酸盐的解吸，但与参考流域相比，该流域的ANC有所增加，有助于减轻突发性酸化。
