Ca^(2+)含量对微粒释放的影响

Influence of Ca^(2+) contents on the particle release

通过批量试验和水平砂柱试验,以NaCl与CaCl2的混合溶液为研究对象,对Ca2+含量影响微粒释放的过程进行了研究,并提出了在不同浓度Ca2+存在情况下,混合溶液引起微粒释放的临界离子强度。研究结果表明:Ca2+不但不能引起微粒释放,而且对微粒释放过程具有明显而强烈的抑制作用,导致混合溶液引起微粒释放的浓度值急剧下降;Ca2+摩尔百分数为5%时,对应微粒释放的临界离子强度为0.02mol/L;Ca2+摩尔百分数为10%与20%时,对应微粒释放的临界离子强度分别为0.007mol/L与0.0005mol/L;Ca2+摩尔百分数为100%时,无微粒释放现象发生。上述临界离子强度值都远低于单一NaCl溶液引起微粒释放的临界盐浓度值0.06±0.005mol/L,且混合溶液中Ca2+含量越高,发生微粒释放的临界离子强度值越低,这一现象进一步验证了Ca2+对微粒释放的抑制作用。

With the batch and level sand column experiments, and with the study object of NaCl and CaCl2 mixed solution, the particle release process influenced by Ca^2＋ contents was examined in this paper. The critical total ionic strength （CTIS） values were brought forward under different Ca^2＋ contents. The research results indicate that the Ca^2＋ not only cannot result in particle release, but also restrain the release process obviously and intensively, and the existence of the Ca^2＋ will result in the descending of the concentration values which induces particle release. When the Ca^2＋ contents were 5%, 10% and 20%, the corresponding CTISs were 0.02, 0.007 and 0.0005tool/L, respectively. There was not particle release when the content of Ca^2＋ was 100%. All the above CTISs were much lower than that of the single NaCI solution of 0.06 ± 0.005mol/L. The CTISs become lower with the increasing Ca^2＋ content, which validates the restraining effect of the Ca^2＋ on the particle release.