TY - JOUR ID - TI - Characteristics of microfauna and their relationships with the performance of an activated sludge plant in China AU - ZHOU Kexin AU - XU Muqi AU - LIU Biao and CAO Hong VL - 20 IS - 4 PB - SP - 482 EP - 486 PY - JF - Journal of Environmental Sciences JA - J. Environ. Sci. UR - http://www.jesc.ac.cn/jesc_en/ch/reader/view_abstract.aspx?file_no=2008200416&flag=1 KW - microfauna; activated sludge; indicators; sludge biotic index (SBI) AB - The occurrence and abundance of the microfauna groups were compared with the physico-chemical and operational parameters of the Baoding Lugang Sewage Treatment Plant in China. Attached and crawling ciliates were the dominant groups of ciliates. Crawling ciliates and testate amoebae showed a strong association with e uent BOD5 (biochemical oxygen demand). Therefore, these two groups are likely to be useful bioindicators since their number decreased as the process produced poor quality e uent. Testate amoebae also had significant negative correlations with e uent TN (total nitrogen), NH4 +-N, SS (suspended solids) and SVI (sludge volumetric index), which means that this group of ciliates may be indicators of good performance of the activated sludge system. Carnivorous ciliates and flagellates had significant positive correlations with SVI, suggesting that these two groups may be indicators of bad settlement conditions of sludge. As identification of the microfauna species is di cult and time-consuming, we recommend using microfauna functional groups to evaluate the performance of the activated sludge system. ER -