This article reports studies on the coagulation of kaolin(from Wuxian, Jiangsu, China) on various red tide organisms, and the observation for the first time that the coagulation of kaolin is much greater than that of ...This article reports studies on the coagulation of kaolin(from Wuxian, Jiangsu, China) on various red tide organisms, and the observation for the first time that the coagulation of kaolin is much greater than that of montmorillonite so that kaolin is a more effective clay for removing red tide organisms. The authors' theoretical explanation and analysis by a mathematical-physical model prove that compared to montmorillonite. kaolin has greater attraction for organism cells and therefore greater coagulation capabil-ity. This project's studies on the effects of pH and acid-treatment show that the acid-treatment does not have much influence on the kaolin system; whereas the effect of pH on the kaolin system is the same as that on the montmorillonite system.展开更多
Study on the coagulation of four species of red tide organisms (Nitzschia pungens, Skeletonema costatum, Prorocentrum minimum and Noctiluca scintillans) with montmorillonite, and the effect of montmorillonite pretrea...Study on the coagulation of four species of red tide organisms (Nitzschia pungens, Skeletonema costatum, Prorocentrum minimum and Noctiluca scintillans) with montmorillonite, and the effect of montmorillonite pretreatment on the coagulation shows that the capability for montmorillonite to coagulate with them is in the order: N. pungens > S. costatum > P. minimum > N. scintillans. The coagulation is discussed from the aspects of the structure, shape, size, movement, habit, etc. of different species and the results are explained theoretically. The experimental results also indicate that the treatment of montmorillonite with acid can enhance its coagulating capability. This is due to the fact that A1(OH2)6+3, exchanged from the clay lattice by hydrogen ion H+, forms hydroxy-aluminum polymers on the surface of the montmorillonite. The hydroxy-aluminum polymers positively charge and increase the positive characteristic of the clay surface, and also serves as a bridge between adjacent surfaces of particles. These two functions enhance the montmorillonite's capability for coagulating with the organism cells.展开更多
Coagulation of red tide organism cells with clays is discussed in theory and the effects of some factors on it are studied. A quantitative model is presented which describes how the coagulation varies with pH in solut...Coagulation of red tide organism cells with clays is discussed in theory and the effects of some factors on it are studied. A quantitative model is presented which describes how the coagulation varies with pH in solution. According to the model, within the pH-range between pHzpcb, and pHzpcb, VR is negative and the coagulation is strong and strongest at pH = (pHzpca + pHzpcb)/2. It is also demonstrated that when the diameter of clay particles is close to that of cells, the collision probability is low, resulting in weaker coagulation. The model results have been corroborated by experiments and so are scientific and theoretical bases for application.展开更多
Surface modification of montmorillonite by means of Mg<sup>2+</sup> insertion reaction has been studied and a positively charged montmorillonite has been prepared. The effects of preparation temperature an...Surface modification of montmorillonite by means of Mg<sup>2+</sup> insertion reaction has been studied and a positively charged montmorillonite has been prepared. The effects of preparation temperature and Mg<sup>2+</sup> concentration on the positive charge property of the clay and on the clay coagulating Heterosigma akashiwo have been studied. The results showed that the modified clay enhanced the coagulation and the used amount decreased to 1/5—1/10 of the original. The removal rates of Heterosigma akashiwo were correlated positively with positive charge on the clay in accordance with theoretical model.展开更多
基金Project supported by Chinese Possteoctoral Fund Shandong Natural Science Fund No.93E0175
文摘This article reports studies on the coagulation of kaolin(from Wuxian, Jiangsu, China) on various red tide organisms, and the observation for the first time that the coagulation of kaolin is much greater than that of montmorillonite so that kaolin is a more effective clay for removing red tide organisms. The authors' theoretical explanation and analysis by a mathematical-physical model prove that compared to montmorillonite. kaolin has greater attraction for organism cells and therefore greater coagulation capabil-ity. This project's studies on the effects of pH and acid-treatment show that the acid-treatment does not have much influence on the kaolin system; whereas the effect of pH on the kaolin system is the same as that on the montmorillonite system.
基金the Chinese postdoctoral fund Natural Science fund of Shandong province No 93E0157 and State Major Besearch project (PD-B6-7-2)
文摘Study on the coagulation of four species of red tide organisms (Nitzschia pungens, Skeletonema costatum, Prorocentrum minimum and Noctiluca scintillans) with montmorillonite, and the effect of montmorillonite pretreatment on the coagulation shows that the capability for montmorillonite to coagulate with them is in the order: N. pungens > S. costatum > P. minimum > N. scintillans. The coagulation is discussed from the aspects of the structure, shape, size, movement, habit, etc. of different species and the results are explained theoretically. The experimental results also indicate that the treatment of montmorillonite with acid can enhance its coagulating capability. This is due to the fact that A1(OH2)6+3, exchanged from the clay lattice by hydrogen ion H+, forms hydroxy-aluminum polymers on the surface of the montmorillonite. The hydroxy-aluminum polymers positively charge and increase the positive characteristic of the clay surface, and also serves as a bridge between adjacent surfaces of particles. These two functions enhance the montmorillonite's capability for coagulating with the organism cells.
基金Chinese Postdoctoral Fund and Natural Scienced Found of Shandong Province(No.93E0157)
文摘Coagulation of red tide organism cells with clays is discussed in theory and the effects of some factors on it are studied. A quantitative model is presented which describes how the coagulation varies with pH in solution. According to the model, within the pH-range between pHzpcb, and pHzpcb, VR is negative and the coagulation is strong and strongest at pH = (pHzpca + pHzpcb)/2. It is also demonstrated that when the diameter of clay particles is close to that of cells, the collision probability is low, resulting in weaker coagulation. The model results have been corroborated by experiments and so are scientific and theoretical bases for application.
文摘Surface modification of montmorillonite by means of Mg<sup>2+</sup> insertion reaction has been studied and a positively charged montmorillonite has been prepared. The effects of preparation temperature and Mg<sup>2+</sup> concentration on the positive charge property of the clay and on the clay coagulating Heterosigma akashiwo have been studied. The results showed that the modified clay enhanced the coagulation and the used amount decreased to 1/5—1/10 of the original. The removal rates of Heterosigma akashiwo were correlated positively with positive charge on the clay in accordance with theoretical model.
