DYNAMICS OF CILIATED PROTOZOA COMMUNITIES IN ACTIVATED-SLUDGE PROCESS

The purpose of this research is to describe and examine the importance of ciliated protozoan communities in the activated-sludge process. During this study a total number of 21 species of ciliates was recorded and 19 physico-chemical variables measured in the wastewater. The presence of the most common species of ciliates was related to plant operational parameters using multivariate statistical procedures. Principal Component Analysis with Varimax rotation performed on the total biological and non-biological set of data showed that six component factors explained 73% of the variability of the process. The first factor has a significant biological importance; it groups together the species of ciliates and explains 25% of the variability of the sewage plant. This study helps to understand the ecology of these organisms and the operational and control methods of the activated-sludge process.