再生水管道碳酸钙沉积机理研究

Research on the mechanisms of calcium carbonate deposition in reclaimed water pipelines

针对再生水管道结垢问题,以碳酸钙为研究对象,基于碳酸钙沉积静态模拟实验,对碳酸钙沉积发生的临界条件和沉积速率影响因素进行系统研究。结果表明:再生水中碳酸钙沉积的临界过饱和度随pH的增大而显著下降,pH>8.5时临界过饱和度处于较低水平,较易发生沉积结垢;再生水中碳酸钙的沉积过程分为晶核生成和晶粒长大2个阶段,pH和溶液组成对晶核的生成速率有显著影响,pH越大,碳酸根比例越高,晶核生成速率常数越大。

:Calcium carbonate is set as the research object in this study,aiming at scaling problems in reclaimed water pipelines.Systematical research has been accomplished on the critical conditions and the influencing factors of deposition rate that cause the occurrence of calcium carbonate deposition,based on the static simulated experiments of calcium carbonate deposition.The results show that the degree of critical supersaturation decreases significantly with the increase of pH,and when pH is greater than 8.5 and the degree of critical supersaturation is at a low level,it is easy for the deposition and scaling to occur.Calcium carbonate deposition process in reclaimed water can be divided into two stages:crystal nucleus formation and crystal grain growth.pH and solution composition have significant impacts on crystal nucleus formation rates.The higher the pH,the higher the carbonate proportion,and the faster the constant of crystal nucleus formation rate.