水系统中微生物与碳酸钙混合垢的形成过程

MIXED FOULING GROWTH PROCESS-MICROBIAL AND CaCO_3 FOULING IN WATER SYSTEMS

对模拟工业水系统中荧光假单胞菌与碳酸钙在固体壁面上形成混合垢的过程进行了实验研究,考察了在不同碳酸钙饱和程度及主体流速下混合垢在不同材料表面上的结垢行为,获得了不同材料表面上混合垢随时间的生长曲线。结果表明:平均混合垢量少于平均生物垢量;在碳酸钙不饱和水体中,平均混合垢量极少;在碳酸钙饱和水体中,随碳酸钙过饱和程度及主体流速的增大,平均混合垢量减少,混合垢生长的诱导期缩短;非金属表面上的平均混合垢量多于金属表面上的;碳酸钙颗粒首先吸附到材料表面上,然后是微生物的黏附生长;碳酸钙的存在抑制微生物与材料表面的结合,而微生物的生长繁殖又抑制了碳酸钙的沉积。

The initial formation process of mixed fouling of Pseudomonas fluorescent and CaCO3 on the different solid surfaces in a simulated cooling water system was investigated. The mixed fouling behavior on different solid surfaces under the conditions of different CaCO3 saturation levels and bulk velocities was examined, and the growth curves of mixed fouling were obtained. The results show that the average mass of mixed fouling is less than that of biofouling. In the unsaturated CaCO3 solution, the average mixed fouling mass was little; but in the saturated CaCO3 solution, with the increase of the saturation level of CaCO3 and bulk velocity, the average mass and induction period of the mixed fouling decrease. The mixed fouling mass on non-metallic material surfaces is more than that on metal material surfaces. It is also found that CaCO3 particles are adsorbed to the surfaces firstly, then microbes are adsorbed. The existence of CaCO3 inhibits the combination of microbes with surfaces, on the other hand, the adsorption and growth of microbes suppress CaCO3 fouling development.