[1]金筱英,聂小保,蒋昌波,等.饮用水钙硬度去除中C/Ca值对CaCO3结晶的影响[J].中国给水排水,2020,36(7):37-41.
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饮用水钙硬度去除中C/Ca值对CaCO3结晶的影响

中国给水排水[ISSN:1000-4062/CN:12-1073/TU] 卷: 第36卷 期数: 2020年第7期 页码: 37-41 栏目: 出版日期: 2020-04-01
Title:
Effect of C/Ca Ratio on Crystallization of CaCO3 during Calcium Hardness Removal in Drinking Water
作者:
金筱英1,2,3，聂小保1,2,3，蒋昌波1,2,3，隆院男1,2,3，余志1,2,3，胡明睿1,2,3，唐韵子1,2,3，周梨1,2,3
关键词:
钙硬度; CaCO3结晶; C/Ca值; 过饱和度; pH值
Keywords:
calcium hardness; crystallization of CaCO3; C/Ca ratio; supersaturation; pH
摘要:
饮用水中钙硬度去除效能主要受CaCO3结晶过程影响。通过改变C/Ca值模拟饮用水钙硬度去除，考察不同C/Ca值条件下，溶液体系pH值和Ca2+浓度变化、上清液浊度变化以及结晶产物颗粒粒径分布、晶型和形态，以阐明钙硬度去除过程中CaCO3结晶行为。结果表明：试验条件下结晶产物均为方解石；溶液体系中加入的CO2-3首先发生质子化，提高体系pH值，然后与Ca2+结晶反应降低体系pH值；C/Ca值的增大提高了pH值，有助于Ca2+的去除，但同时也会提高结晶产物颗粒数量、密度和减小结晶产物颗粒粒径，导致上清液浊度增大。饮用水钙硬度去除中要综合考虑残余Ca2+浓度、出水pH值和浊度以及混凝剂用量等来优化确定C/Ca值。
Abstract:
The removal efficiency of calcium hardness in drinking water is mainly affected by CaCO3 crystallization process. The removal of calcium hardness in drinking water was simulated by changing the C/Ca ratio. Variations in pH value and Ca2+ concentration of the solution system and turbidity of the supernatant, and particle size distribution, polymorph and crystal shape of the crystallized products were investigated under different C/Ca ratios, so as to clarify the crystallization behavior of CaCO3 during the removal of calcium hardness. Calcite was the only crystallized product in the present experimental conditions. The addition of CO2-3 to the solution first protonized and increased the pH value of the system, and then it crystallized with Ca2+ and reduced the pH value of the system. The increase of C/Ca ratio increased the pH value and was conducive to the removal of Ca2+. However, it also increased the particle number and density of the crystallized products and reduced the particle size of the crystallized products, resulting in the increase of the turbidity of the supernatant. Therefore, factors such as residual Ca2+ concentration, pH value and turbidity of the supernatant, and the dosage of coagulant should be comprehensively considered to determine the optimal C/Ca ratio during calcium hardness removal in drinking water.
更新日期/Last Update: 2020-04-01