Abstract
In a wastewater treatment process using attached microorganisms, microbial carriers such as plastic resins, porous ceramics, sands etc. have conventionally been employed. Since the performance of the biological wastewater treatment has been regarded as a function of the concentration of microorganisms in a reactor, microbial carriers have been focused on to increase the specific surface area. The fluidized bed process using small particles is one example of the application.
Nonwoven fabrics made of plastic resin are considered highly effective microbial carriers because of the attachment of microorganisms on each thread as well as microbial growth in three dimensional intertwisted spaces. However, there have been few reports on the application of nonwoven fabrics as aerobic microbial carriers.
Experimental studies have been conducted to clarify the features of attachment of microorganisms to nonwoven fabrics by the initial phase filtration test, the intial phase bioattachment test in a reactor and the continuons biofilm growth test.
The highest concentration of attached microbes has been found to be attainable in a specific range of the opening length rather than over a specific surface area. The composition difference of the attached microbes compared with the suspended microbes had a great effect on the kinetic constants.
