Removal of environmentally harmful agent and multi-functionalization of water treatment using Microbubbles

在人们生活方式和价值观念日益多元化的当代社会，随着生活的丰富性和便利性的增加，各种有害物质暴露在我们周围的环境中。尤其是水环境恶化非常迅速，呈现出区域或行业要求不同的复杂污染特征，这就带来了严重的问题。因此，迫切需要开发适用于各种废水的水处理技术。在这项研究中，我们研究了有效的方法去除泡沫中的微小颗粒的可能性，这些微小颗粒在利用微泡(微泡)净化废水的气浮过程中是重要的。在浮选过程中，有害物质被吸附在气泡表面，并在泡沫的上升和破裂过程中凝聚在泡沫层中。在这里，我们研究了小颗粒在泡沫层中的行为。假设这些小颗粒的行为类似于去除物质，并随着泡沫的上升运动而被抬起。为了阐明泡沫中颗粒行为的细节，我们进行了一系列实验。我们使用了两种表面活性剂。一种是酪蛋白，具有硬泡特性；另一种是皂素，具有软泡特性。在实验中，使用了一个薄的水箱，并从水箱的侧面暴露了一张激光薄片。然后，利用高速摄像机跟踪微小荧光粒子的运动轨迹。结果表明，皂素泡沫等软、干泡沫对污染水中细小颗粒物的去除效果较好。

In the contemporary society where people's life style and concept of values are getting more multifaceted with the increase of richness and convenience of life, various kinds of harmful substances are exposed to the environment surrounding us. Especially, water environment is getting worse very rapidly, showing the complicated pollution features depending on the regional or industrial requirements, and this causes serious problems. Hence, the development of the water treatment technology applicable for various kinds of waste water is strongly required. In this study, we investigated the possibility of efficient methods to remove the tiny particles from the foam, which are important in the floatation process to purify the waste water using tiny bubbles (microbubbles). In the floatation process, harmful substances are adsorbed on the bubble surface and they are condensed in the foam layer during the rise and collapse of the foam. Here, we investigated small particle behaviors in the foam layer. These small particles are assumed to behave like the removal substances and they are lifted up with the rising motion of foams. To elucidate the detail particle behaviors in the foam, we conducted series of experiments. We used two kinds of surfactant. One is Casein which has a rigid foam characteristic and the other is Saponin which has the soft one. In the experiments, a thin tank was used and a laser sheet was exposed from the side of the tank. Then, the trajectories of small fluorescent particles were tracked by using the high speed video camera. Aa a results, it was shown that soft and dry foams such as Saponin foam gives the better performance to remove the small particles from the polluted water.