PBTCA对硫酸钡结晶动力学的影响  

Effect of PBTCA on Kinetics of Formation of BaSO_4 Crystal

作　　者：尹晓爽[1] 杨文忠[1] 唐永明[1] 刘瑛[1] 

机构地区：[1]南京工业大学水处理技术研究所,南京210009

出　　处：《应用化学》2008年第3期356-360,共5页Chinese Journal of Applied Chemistry

摘　　要：通过电导率法研究了PBTCA对硫酸钡结晶过程动力学的影响。运用经典的晶体生长理论推算出硫酸钡结晶时的表面自由能为61.1 mJ/m2。加入PBTCA后,硫酸钡结晶时表面自由能随着PBTCA浓度的增加而增加(12 mg/L PBTCA存在时,硫酸钡结晶时表面自由能增加到73.7 mJ/m2)。4种硫酸钡过饱和溶液的诱导时间随着PBTCA浓度的增加而延长,无PBTCA存在时,诱导时间为61.6、39.9、6.5、3.1 s,加入12 mg/LPBTCA后分别增加到18 000.4、7 204.2、800.8、60.3 s。硫酸钡晶体生长的速率可以用一级反应方程来表示,生长速率随PBTCA浓度的增加而下降,尤其在过饱和度较低的溶液中,加入PBTCA后硫酸钡晶体的生长速率下降了2个数量级。PBTCA对于硫酸钡晶体生长的抑制主要是由于其对活性生长点等特殊位置的吸附作用,而这种吸附作用符合Langmuir等温吸附特征。Effects of 2-phosphonobutane-1,2,4-tricarboxylic acid （PBTCA） on the nucleation kinetics of BaSO4 were studied by means of solution conductivity measurement. According to the classic homogeneous nucleation theory, the surface free energy between BaSO4 and supersaturated solutions was estimated to be 61.1 mJ/m^2 in the absence of PBTCA. It increases with increasing the concentration of PBTCA （to be 73.7 mJ/m^2 in the presence of 12 mg/L PBTCA）. The induction periods of BaSO4 of four supersaturated solutions can be prolonged in the presence of PBTCA, which increase from 61.6, 39. 9, 6.5, 3.1 s in the absence PBTCA to 18 000.4, 7 204. 2, 800. 8, 60. 3 s at a concentration of 12 mg/L of PBTCA. BaSO4 crystal growth can be expressed as a first order reaction. The growth rate is decreased with the increase of the concentration of PBTCA. Especially at the lower supersaturation index, the growth rate constant is decreased by a factor of two orders of magnitude. PBTCA is adsorbed at active sites on the BaSO4 crystal surface. The adsorption follows a Langmuir adsorption model .

关 键 词：硫酸钡 电导率 动力学 PBTCA 阻垢 

分 类 号：O647[理学—物理化学]