在冷解周期中形成的有机颗粒的大小,形状和稳定性:用酸进行模型实验
Stefan Dultz1, Myriam Speth2, Klaus Kaiser3
1Institute of Earth System Sciences, Section Soil Science, Leibniz Universität Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany.
Journal of colloid and interface science
|April 24, 2024
概括
结冰解周期 (FTC) 聚合物溶解的有机物. 低pH,电解质和更多的FTC循环促进了更大的颗粒的形成,影响了土壤有机物质的生物可用性.
科学领域:
- 土壤科学 土壤科学
- 环境化学环境化学
- 有机地化学 有机地化学
背景情况:
- 结冰解周期 (FTC) 是影响土壤特性的一个重要环境因素.
- FTC可以导致溶解有机物 (DOM) 的聚合,但根本的机制和控制因素尚未完全理解.
- 了解DOM聚合对于预测其在土壤中的命运和生物利用性至关重要.
研究的目的:
- 调查控制结解周期 (FTC) 下溶解有机物 (DOM) 聚合的因素.
- 检查酸 (TA) 度,pH值,电解质和FTC数量对颗粒形成和稳定性的影响.
- 阐明DOM由于FTC而发生的物理状态变化及其对生物可用性的影响.
主要方法:
- 实验中使用酸 (TA) 作为DOM的模型物质进行了实验.
- TA溶液在不同度 (0.005到10克L-1) 和pH水平 (3和6) 的1-20个FTC中进行了测试.
- 研究了电解质 (NaCl,CaCl2,AlCl3) 对粒子形成的影响. 使用共聚焦激光扫描显微镜分析了颗粒的大小和形状,并通过干燥状态等效圆径 (ECD) 和解溶液中的水力动力直径评估了稳定性.
主要成果:
- 形成的粒子类似于冰粒边界的形态,呈现为板块和静脉.
- 较低的pH值和电解质的存在促进了更大的TA颗粒的形成.
- 结度效应在低TA度时最明显,并且随着越来越多的FTC而加剧.
- 虽然干燥颗粒大小 (ECD) 在低TA度下较小,但由于冰结晶压力更高,它们的稳定性在解状态下增加.
结论:
- FTC显著改变了土壤中DOM的物理状态和聚合.
- 环境因素,如pH值和电解质度,在冷和解过程中对DOM聚合起着至关重要的作用.
- 观察到的DOM物理状态的变化对其在土壤环境中的生物可用性和生态功能有潜在的影响.
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