【作者】 蒋皎梅；

【导师】 陈国松；

【作者基本信息】 南京工业大学 ， 应用化学， 2004， 硕士

【摘要】 为了从理论上研究循环冷却水中碳酸钙的结垢与阻垢问题,本文在自制的结晶器内,不同温度下同时测定了含有不同浓度Ca²⁺和HCO₃^-的溶液及其在添加了不同浓度的各类阻垢剂后的结晶过程中pH值、吸光度和Ca²⁺浓度的变化情况。所考察的阻垢剂为ATMP、HEDP和PBTCA。1、自行设计制作了结晶观察装置。2、用临界pH法测定了一定条件下碳酸钙结晶介稳区的宽度,实验表明添加阻垢剂后介稳区的宽度明显比未添加阻垢剂时加宽。Ca²⁺较低(3.192mmol·L^-1 、6.000mmol·L^-1 )时,HEDP效果较好;而Ca²⁺浓度较高(12.01mmol·L^-1和20.01mmol·L^-1),ATMP效果较好。3、向不同浓度的Ca²⁺溶液中添加一系列不同浓度的ATMP,得到Ca²⁺浓度、阻垢剂与pH的关系。理论上只要知道实际水样中Ca²⁺浓度,就可以估算出在要求达到的pH值下运行需要添加的阻垢剂浓度,对今后建立水处理专家系统有一定的参考价值。4、用分光光度计测定碳酸钙结晶过程中体系吸光度的变化。选择测量波长为450nm,添加阻垢剂前后,吸光度的变化明显,其突跃范围与pH值下降区域同步,可以作为观察结晶过程的一种较好的方法。 5、未加阻垢剂的同一体系中同时测定的pH、Ca²⁺浓度和吸光度三者的变化几乎同步, 而添加阻垢剂后,Ca²⁺浓度减少速度缓慢,并不与pH和吸光度突变同步。更多还原

【Abstract】 In order to study the calcium carbonate scale and scale inhibition of the circulating cooling water, the variety of the pH value, absorbency and the Ca²⁺ concentration of the different concentration Ca²⁺ and HCO₃^- solution in different temperature are determined in the self-made crystal ware, which is in the absorbency process adding three different categories and different concentration scale inhibition agents. Different concentration of Ca²⁺; 3.192mmol·L^-1 6.000mmol·L^-1 、12.01mmol·L^-1 and 20.01mmol·L^-1 are contained in the experimental solution. ATMP、HEDP and PBTC are used as the adding scale inhibition agents. 1 A device was self-made for observing the crystal pocess.2 The width of calcium carbonate crystal metastable region is determined by using the critical pH method. The width of metastable region with adding scale inhibition agent is more wide than it without the scale inhibition agent. The same concentration ATMP、HEDP and PBTC are added to the solution of Ca²⁺: 3.192mmol·L^-1 、6.000mmol·L^-1 . Through the experiment, the effection of adding HEDP is good. While these three scale inhibition agents are added the solution of Ca²⁺: 12.01mmol·L^-1 、20.01mmol·L^-1 , the effection of adding ATMP is good.。3 A series of solution of Ca²⁺: 6.000mmol·L^-1、12.01mmol·L^-1 and 20.01mmol·L^-1 are added the different concentration ATMP in 45℃, the connection of the Ca²⁺ concentration and the scale inhibition agent concentration is gained in the end. If knowing the Ca²⁺ concentration of the fact water in theory, the adding scale inhibition agent concentration which can made the solution reach the desired pH value can be figured out. <WP=5>4. The diversification of the absorbency value of the calcium carbonate crystal process is determined by the spectrophotometer. The wavelength of 450nm is selected. Both after and before adding the scale inhibition regent, the change of the absorbency value is obviously, the extension of the sudden change and the descend trend of the pH value are same. This method can be as a good way to observe the crystal process. 5. The pH value and the Ca²⁺ concentration determined at the same time are made on the same chart. The changes are almost synchronous in the experimental solution without inhibition agent. But in the experimental solution contained inhibition agent, the change of Ca²⁺ concentration is not synchronous as the other two.更多还原