ABR成熟颗粒污泥的分形特征与尺度效应

建立了基于SEM照片研究ABR成熟颗粒污泥分形特征的操作程序,采用Photoshop、Newscan和Fips程序对该图形进行处理和分形维数计算.颗粒污泥的计盒维数值处于1.85以上,第3格室和第5格室形成的颗粒污泥较为致密.不同格室颗粒污泥边界的计盒维数的值在1.10左右,表明它们的边界或表面是不规则的,而且第1格室和第5格室形成的颗粒污泥的表面不规则程度高一些.颗粒污泥边界的圆规维数计算结果也表明其表面是不规则的,而且每一个颗粒污泥都存在2个分形维数的尺度区间,有的区间跨度达一个数量级.另外,不同的计算维数的方法会导致结果的差异.建立不同尺度域下的分形维数与颗粒污泥的组成、结构及物化特征的关系将具有重要意义.

Fractal Characteristics and Scale Dependence of Mature Granular Sludge in Anaerobic Baffled Reactor (ABR)

Based on the SEM-images of mature granular sludge in ABR, the research process on fractal characteristics of these granules was built. The treatment and fractal dimensions calculation of the images were carried on through Photoshop, Newscan and Fips programs. The results showed that the boxing-counting dimensions of the mature granular sludge were more than 1.85, and the granules formed in the third and fifth compartments were more compact. The boundaries of the same granular sludge were fractal with the fractal dimensions of approximate 1.10, demonstrating the irregularity of the boundaries or surfaces, furthermore the surface of these granules formed in the first and fifth compartments was more irregular. It seemed that the compass dimensions of the granules boundary were a proof of irregularity of their surface. Moreover, there existed two scale scopes in calculating the compass dimensions of each granule, especially some of them with a range of one order of magnitude. A little discrepancy was appeared between box-counting and compass ways to calculating fractal dimensions. It will be important to build relationship between fractal dimensions with different scales and composition, structure, physico-chemical characteristics of granular sludge.