Gal J Y, Bollinger J C, Tolosa H, Gache N
Laboratoire de Chimie Analytique, Université de Montpellier-II, Sciences & Techniques du Languedoc, 34095 Montpellier, France.
Talanta. 1996 Sep;43(9):1497-509. doi: 10.1016/0039-9140(96)01925-X.
Considerable disparity exists in the published thermodynamic data for selected species in the Ca(2+) /CO(2)/H(2)O system near 25 degrees C and 1 atm pressure. Some authors doubt the significance of CaCO(3)(0)aq) complexes although there is experimental evidence of their occurrence. Evaluation of all the published experimental and estimated data for aqueous calcium carbonate species confirms that the consistent set of constants given by Plummer and Busenberg in 1982 is the best available, and suggests a formation constant log beta = 3.22 for CaCO(3)(0)(aq). This value was confirmed by additional experimental data and calculations using a specially developed computer program. The solubility s and solubility product K(s) are critically evaluated for each solid polymorph (amorphous CaCO(3), ikaite, vaterite, aragonite and calcite) using a hydrated ion pair model and we give coherent explanations for the calcium carbonate precipitation/dissolution process and the existence of supersaturated waters. The practical cases of scale formation and its inhibition by phosphonate-type compounds are discussed and explained with the same model, taking into account the CaCO(3)(0)(aq) species.
在25摄氏度和1个大气压附近的Ca(2+) /CO(2)/H(2)O系统中，特定物种已发表的热力学数据存在相当大的差异。尽管有实验证据表明CaCO(3)(0)aq)络合物的存在，但一些作者怀疑其重要性。对所有已发表的碳酸钙水合物种的实验和估算数据进行评估后证实，Plummer和Busenberg在1982年给出的一组一致常数是目前可用的最佳数据，并表明CaCO(3)(0)(aq)的生成常数logβ = 3.22。这个值通过额外的实验数据和使用专门开发的计算机程序进行的计算得到了证实。使用水合离子对模型对每种固体多晶型物（无定形碳酸钙、六水碳酸钙、球霰石、文石和方解石）的溶解度s和溶度积K(s)进行了严格评估，并且我们对碳酸钙的沉淀/溶解过程以及过饱和水的存在给出了连贯的解释。考虑到CaCO(3)(0)(aq)物种，用同一模型讨论并解释了结垢的实际案例及其被膦酸盐类化合物抑制的情况。
