Vieira M J, Pacheco A P, Pinho I A, Melo L F
Centro de Engenharia Biológica-IBQF, Universidade do Minho, Campus de Gualtar 4710-057 Braga, Portugal.
Environ Technol. 2001 Feb;22(2):123-35. doi: 10.1080/09593332208618298.
Clay minerals have some properties, namely a high surface area and the ability of ion exchange that may exert some effects on microbial systems. It is often difficult to know the way the clay is exerting its influence and whether its presence improves a given metabolic process. The present work concerns the study of the effect of the addition of powdered kaolin to autotrophic nitrification systems, and includes the study of the effects of the particles on the activity of a suspended nitrifying bacteria consortium and on the performance of an air-lift biofilm reactor used for tertiary nitrification. Concerning the suspended culture, kaolin particles produced stimulation on the specific endogenous and exogenous respiration rates of the bacteria, probably due to a nutritional effect supplied by the clay. This effect was more pronounced for the ammonia oxidation rates, although nitrite oxidation was also enhanced but to a lesser extent. In respect to the presence of kaolin particles in the air-lift reactor, the results obtained indicate that the clay particles become incorporated in the biofilm pellets, but do not change significantly their thickness or their shape. However, nitrate production decreased when the concentration of particles increased. The low adsorption of ammonia by the kaolin indicated that the clay particles embedded in the biofilm did not probably retain the ions. Although it was not proved, precipitation of salts may have occurred.
黏土矿物具有一些特性，即高比表面积和离子交换能力，这可能会对微生物系统产生一些影响。通常很难了解黏土发挥其影响的方式以及它的存在是否会改善特定的代谢过程。目前的工作涉及研究向自养硝化系统中添加高岭土粉末的效果，包括研究这些颗粒对悬浮硝化细菌聚生体活性以及用于三级硝化的气升式生物膜反应器性能的影响。关于悬浮培养，高岭土颗粒对细菌的特定内源和外源呼吸速率产生了刺激作用，这可能是由于黏土提供的营养效应。这种效应在氨氧化速率方面更为明显，尽管亚硝酸盐氧化也有所增强，但程度较小。关于气升式反应器中高岭土颗粒的存在情况，所获得的结果表明黏土颗粒融入了生物膜颗粒中，但并未显著改变其厚度或形状。然而，当颗粒浓度增加时，硝酸盐产量下降。高岭土对氨的低吸附表明嵌入生物膜中的黏土颗粒可能不会保留离子。尽管未得到证实，但可能发生了盐的沉淀。
